Check out the most recent updates from our members on the AFS SNEC Facebook Page! https://www.facebook.com/SNECAFS/
The 2020 Two Day meeting was a success! The next SNEC meeting will take place in January 2021 but a location has not yet been determined. Want to help organize it or host it? Please email President Alex Haro.
*Bittner, Steven1,2, Allison H. Roy1,2,3, Matthew T. Devine1,2, Habibollah Mohammadi2,4, Adrian Jordaan2. Dietary preferences among juvenile and adult River Herring in freshwater lakes.
1Massachusetts Cooperative Fish and Wildlife Research Unit, 2Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA, 3US Geological Survey, 4Department of Fisheries, University of Kurdistan, Sanandaj, Iran
Each Spring, anadromous River Herring (Alosa pseudoharengus & Alosa aestivalis) migrate from the ocean to freshwater lakes to spawn and then return to the ocean after 2-6 weeks. While in lakes, these fish deposit marine-derives nutrients, provide forage for many species (e.g., predatory fish, waterbirds, and mammals), and prey heavily on zooplankton. Studies have shown that River Herring dietary preference is system-specific, but have not compared juvenile and adult diets among lakes to assess dietary overlap. We sampled River Herring from two lakes (Whitman’s Pond and Upper Mystic Lake) in Massachusetts using a beach seine at dusk and a pelagic purse seine at night. For each lake, 20 individuals from each life stage (adult and juvenile) were immediately frozen on dry ice. In the lab, fish were thawed and sagittal otoliths were extracted, mounted and aged; stomachs were removed and dissected with food items identified, enumerated, and measured. We describe differences in dietary preferences among juvenile and adult River Herring and use an electivity index to assess preference for certain prey items. If juveniles and adults are consuming the same resources, there is potential for intraspecific competition while adults reside in the lakes that may impact juvenile growth rates. This work will help fill knowledge gaps about trophic dynamics of River Herring in these lakes. Fully understanding River Herring dietary preferences allows us to assess potential for alteration of trophic dynamics during and after their spawning migration and evaluate density-dependent interactions.
Boucher, Jason M.1, Richard McBride2. A reconsideration of testing within-gonad homogeneity of oocyte density as a precursor to estimating fecundity: what is the goal?
1Integrated Statistics, Woods Hole, MA, 2Northeast Fisheries Science Center, Woods Hole, MA
Due to the high fecundity of many fish species, measurement is regarded as complicated and time consuming. Less attention has been paid to testing a basic assumption: are subsamples of oocyte density within the gonad homogeneous? There are two ramifications of heterogeneity: 1) does it bias or affect precision of the estimate? 2) what is the pattern among taxa? In our review of fecundity studies, most have been focused on the first question, because this affects the reliability of the reported estimates. Nonetheless, we note that the rigor of methods varies considerably between studies, and some studies do not test for homogeneity. Standardized methodology was established in the 1980s to address whether bias exists, and if so, how many samples are needed to obtain accurate, precise estimates. Herein, we also introduce an alternative procedure that measures heterogeneity within the gonad of individuals. Regarding the second question, we find no pattern among a review of 24 fish species from 15 families. Most studies found no location effect, but the majority also did not follow the standard procedure. Five studies identified a location effect, four of which followed the standard procedure. Testing for homogeneity of oocyte density is a necessary step of quality assurance that is unlikely to be publishable on its own. We recommend that a standard effort is still needed to demonstrate that estimates are reliable, and point out that more of such studies should eventually lead to understanding the pattern among taxa, and separate its statistical and biological significance.
Bronger, Kristen1. International year of Salmon, 2019: research for the future.
1Integrated Statistics in support of NOAA Fisheries, Gloucester, MA
The North Atlantic Salmon Conservation Organization (NASCO) and the North Pacific Anadromous Fish Commission (NPAFC) are collaborating to celebrate salmon restoration and recovery with an International Year of the Salmon in 2019. The overall theme is Salmon and people in a changing world. During the International Year of the Salmon, our outreach efforts will raise awareness of what humans can do to better to ensure salmon and their varied habitats are conserved and restored in light of increasing environmental variability. The International Year of the Salmon will also stimulate an investment in research and leave a legacy of knowledge, data/information systems, tools and a generation of scientists better equipped to provide timely advice to inform rational management of salmon. The countries who are participating include the U.S., Canada, Norway, EU, Russia, Japan and Korea. Planning, promotion and outreach has begun and will continue through 2018. An international science symposium will launch the International Year of the Salmon in the fall of 2018. Over 2018 – 2022, research will be conducted, analyzed, results published and then findings disseminated through an international dénouement symposium. The proposed research themes for the International Year of the Salmon include the Status of Salmon, Salmon in a changing “salmosphere”, New Frontiers, Human Dimensions and Information Systems. We will provide more information on how the International Year of Salmon is an opportunity to connect with others, share the research that scientists are doing to a wider audience and contribute to the collective international research effort.
*Calandrino, Mila1, Andrea Bogomolni2, Michelle Staudinger3. Spatio-temporal movement of individual Gray Seals (Halichoerus grypus) hauled-out on Duck Island, ME.
1University of Massachusetts Amherst, Amherst, MA, 2Woods Hole Oceanographic Institute, Woods Hole, MA, 3Northeast Climate Science Center, Amherst, MA
Gray Seals (Halichoerus grypus) are increasing in numbers on Duck Island, a unique, mixed-species haul-out ite that serves as a potential stop-over between large populations in Canada and on Cape Cod. Individual seal sighting data has been collected on photographic mark-recapture surveys of seal abundance in the summers of 2011-2016. The specific ledges on which the seals were seen, as well as the date they were seen were recorded, and every new individual was added to a growing identification catalogue. This study aims to understand the movement and land use of individually identified Gray Seals over the course of the six-year study period. Factors of importance include whether the animals are displaying inter-annual site fidelity, and if certain individuals are arriving and departing around the same date each year. The results of this study will provide insight into the movements and land use of Gray Seals in the entire Gulf of Maine, and help improve the understanding of Gray Seals & relationship to seasonal changes.
*Comb, Dylan1, William Helt2, Jon Grabowski1, Randall Hughes1, Eric Schneider2. Comparing three growth conditions of Crassostrea virginica in Southern New England to better inform restoration science.
1Northeastern Marine Science Center, Nahant, MA, 2RIDEM, Jamestown, RI
Due to anthropogenic influence, a serious decline in populations of the Eastern Oyster Crassostrea virginica has occurred over the last few centuries. The loss of oyster reefs from direct harvesting and habitat alteration is exceptionally evident in New England, where today wild stocks are a fraction of historic abundance. Understanding the critical importance of this foundation species has recently shifted public perception and awareness, resulting in many efforts to restore oyster reefs to recover the ecological functioning and ecosystem services lost. Although several existing studies assess the successes of past restoration projects, few studies compare restored reefs to other growing conditions, and fewer have examined this within New England. This study compares Rhode Island Oysters growing on restored reefs to those on natural reefs as well as individuals grown in aquaculture. To better inform future restoration efforts in the North Atlantic region, we investigated how oysters in these different settings influence growth, condition, and sex ratio. Restored reefs appeared to be severely lacking recruitment, and adult oysters were significantly less dense than on naturally occurring reefs. These findings are interesting when compared to natural reef recruitment, given the proximity of constructed reefs. Further examination assessing this lack of recruitment on restored reefs is needed to ensure restoration success.
*Dangora, Anthony1, Matthew Devine1,2, Allison Roy1,2,3, Adrian Jordaan1, Joseph Zydlewski3,4,5. Evaluating DIDSON as a tool to monitor juvenile River Herring in coastal freshwater lakes.
1Department of Environmental Conservation, University of Massachusetts, Amherst, MA, 2Massachusetts Cooperative Fish and Wildlife Research Unit, 3U.S. Geological Survey, 4Maine Cooperative Fish and Wildlife Research Unit, 5Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, ME
Anadromous Alewives (Alosa pseudoharengus) are an important forage fish distributed throughout coastal northeastern United States. Alewife are consumed by freshwater and marine predator species and transport nutrients between the ecosystems. Large knowledge gaps exist about the species, particularly for juvenile out-migration densities from freshwater lakes. Currently, monitoring techniques are limited due to financial and logistical constraints, and rarely explore juvenile recruitment. Purse seining in freshwater lakes is a novel approach to pelagic juvenile sampling but this method may be size selective. DIDSON (Dual Frequency Identification Sonar) is an alternative non-invasive method that may overcome this potential bias. This study conducted a comparison between pelagic purse seine and DIDSON measured juvenile Alewives to study potential impacts of gear bias and alternatives. We deployed a DIDSON for one hour intervals at the outlet of two lakes, Upper Mystic Lake (MA) and Winnisquam Lake (NH) in August of 2015. Concurrent with DIDSON, a purse seine was deployed during the same night. Fish length was estimated using DIDSON software (Mark and Measure Tool) and compared with the purse seine lengths. A one-way analysis of variance was used to test for differences in length between methods. Our results indicate that incorporating DIDSON technology into fisheries surveys may help inform our knowledge about stock recruitment dynamics on anadromous Alewives.
*Davis, Amanda1, Michelle Staudinger1,2, Emily Powell3, Steven Mattocks4, Melissa Ocana1, Scott Jackson1. The Massachusetts Wildlife Climate Action Tool.
University of Massachusetts, Amherst, MA, 2DOI Northeast Climate Science Center, 3North Atlantic Landscape Conservation Cooperative, 4MA Division of Fisheries and Wildlife
The Massachusetts Wildlife Climate Action Tool (climateactiontool.org) is designed to inspire local action to protect natural resources in a changing climate. This informative tool provides approachable and current data for a range of local decision-makers, including conservation practitioners, landowners, municipal agencies, and community leaders, who seek to conduct on-the-ground climate change adaptation efforts. The interactive tool uses public-friendly scientific research results with effective visuals to show users how they can: 1) access information on climate change impacts and vulnerabilities of fish and wildlife species and associated habitats; 2) explore adaptation strategies and actions to help maintain healthy, resilient natural communities based on location and area of interest; and 3) find additional resources to help guide decision-making and actions. Content within the tool focuses on fish and wildlife species, aquatic, terrestrial and marine connectivity, land protection, and conservation planning. Although this tool was designed for decision-making in the state of Massachusetts, it provides broadly relevant climate and adaptation information, and can serve as a model for related efforts across the Northeast region. For example, the strategies, actions, and current research that the tool showcases in regard to coastal fish and wildlife conservation, nutrient pollution and coastal resiliency in a changing climate can be implemented across Atlantic coastal socio-ecological communities. This tool has been developed by a diverse team of experts from the Massachusetts Division of Fisheries & Wildlife, the University of Massachusetts-Amherst, the Department of Interior’s Northeast Climate Science Center, and the USGS Massachusetts Cooperative Fish and Wildlife Research Unit.
Davis, Justin1. The rise of the catch-and-release era in Connecticut’s inland fisheries.
1Connecticut Department of Energy and Environmental Protection, Marine Fisheries Division – Old Lyme, CT
Much of traditional fisheries management has focused on managing harvest mortality to achieve a desired outcome. As catch-and-release fishing becomes more prevalent and harvest becomes increasingly insignificant, many traditional management measures may be rendered ineffective. In Connecticut, angler surveys conducted by CT DEEP Inland Fisheries Division (IFD) over the last three decades demonstrate a substantial shift in freshwater angler practices and attitudes related to harvest. Voluntary release rates for most freshwater fish species have increased substantially since the 1980s, and for some species now approach 100 percent. Responses to opinion questions in recent surveys indicate many anglers have low motivation to harvest fish, and commonly self-identify as “catch-and-release only” anglers. This phenomenon reflects changes in angler demographics (e.g. reductions in generalist and/or subsistence fishing), a trend towards specialization (e.g. increased participation in catch & release tournaments), and a pervasive perception amongst anglers that a strict catch-and-release ethic represents a “one size fits all” best practice. Here we illustrate the challenges of managing inland sportfish populations in the face of high angler release rates by describing the CT DEEP Bass Management Lake program, which was initiated in the 1980s, experienced early successes, but then ultimately failed to substantially alter bass sizes structure in management lakes – primarily because of shifts in angler harvest practices.
*Evanilla, Johnathan1 and Stephen Winters-Hilt1. Characterization of fish diversity via EST analysis.
1Connecticut College, New London, CT
While many current fishery stock assessment methods rely on the fish that are brought back to the dock by fisherman, it is important to also have models that represent a fish stock with respect to the total population of that species, not what is being caught. This study focused on the correlation between transcriptome level diversity and the phenotype expression ability of commercially targeted fish. By analyzing the complexity of miRNA/RNAi 7mer-based regulatory capabilities, it is hypothesized that certain assumptions can be made about the current health and abundance of a stock of fish. These assumptions have to do with a less varied group of phenotypes available to use in response to environmental change. Preliminary results have indicated Atlantic Cod (Gadus Morhua) to be lacking this complexity, which appears to be a result of the collapse of the Cod fishery in the Northeast.
Gonzalez, Susan1, Shannon Nardi1. Shifts in demersal fish and macroinvertebrate communities detected by long-term (1976-2015) trawl monitoring in eastern Long Island Sound.
1Dominion Resources Services, Millstone Environmental Lab
Biweekly trawl monitoring conducted in the vicinity of Millstone Power Station has recorded catches of demersal fish and macroinvertebrates since 1976. Multivariate analyses used to examine temporal differences in the integrated fish and macroinvertebrate dataset identified three distinct periods for the assemblages: 1976-1979, 1980-2001, and 2002-2015. The current community structure is characterized by higher abundances of fish with southern affinities like Scup and Black Sea Bass and lower abundances of northern species such as Winter Flounder and American Lobster. Overall, this analysis of four decades of trawl data provides valuable information on fish and macroinvertebrate populations in eastern Long Island Sound and is consistent with results of regional studies documenting shifts in species distribution as a response to a natural rise in seawater temperatures.
*Grasso, Kyle D.1,2, Matthew Devine1,2, Allison Roy1,2,3, Andrew Whiteley4, Julianne Rosset1,2,5, Meghna Marjardi1,2,6, Adrian Jordaan1. Testing for differences in juvenile growth rates of anadromous Alewife and Blueback Herring.
1Department of Environmental Conservation, University of Massachusetts-Amherst, Amherst, MA, 2Massachusetts Cooperative Fish and Wildlife Research Unit, 3U.S. Geological Survey, 4Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT, 5New England Field Office, U.S. Fish and Wildlife Service, Concord, NH, 6Ohio State University, Columbus, OH
Alewife (Alosa pseudoharengus) and Blueback Herring (Alosa aestivalis), collectively known as River Herring, are important anadromous forage fish distributed along the northeast coast of the United States. Currently, both species are managed together due to geographic overlap in range and difficulty in identification to species level. Until now, most species level divergence is equated to small differences in preferred temperature and migration timing, although there is substantial overlap in these characteristics and both species co-occur during the period of freshwater habitat use. Little is known about differences in growth rates of juvenile Alewife and Blueback Herring. This study aims to fill these data gaps by investigating individual growth rates for the two species. Fish were collected from four coastal lakes (Great Herrin, Upper Mill/Walkers, Santuit, and Coonamessett) in Massachusetts. Individual fish of approximately the same length were genetically identified to species and their sagittal otoliths were imaged and aged using ImagePro Software. Age and total length were used to calculate growth rates. Although we do not expect to see differences in growth rates between species, species-specific assessments of growth are critical for developing appropriate management targets for mortality and understanding the variation in responses to environmental conditions. The results of this study will contribute to our understanding of life history traits that are selected for through evolution, may help predict early life history responses to climate change, and facilitate development of restoration strategies.
*Greene, Danielle1, Lucas Nathan1, Jason Vokoun1. Landscape correlates of hybridization between hatchery and wild Brook Trout (Salvelinus fontinalis).
1University of Connecticut
Brook Trout (Salvelinus fontinalis) is one of the few native salmonid species in Eastern North America. Once widely distributed throughout the region, sensitivity to land use changes and habitat degradation now restrict many Brook Trout populations to small, isolated headwater streams where conditions remain suitable. Their popularity among anglers as a sport fish has led to the raising and stocking of hatchery fish to provide enhanced recreational fishing opportunities in ponds and streams across Southern New England. The practice of stocking hatchery fish, however, can have unintended consequences when stocked individuals survive and reproduce with wild individuals creating hybrids and the potential for population genetic introgression. Although a conservation concern for wild Brook Trout, little is known about the prevalence and spatial distribution of introgression at the landscape scale. The objective of this study was to identify where hybridization and introgression had recently occurred in Connecticut populations of Brook Trout as well as identification of predictive correlates for introgressed streams. We collected tissue samples from over 100 headwater locations and hatchery individuals and then used a series of individual based analyses to identify evidence of hybridization and introgression. Locations with and without hybrids were modeled against a suite of watershed variables to identify those characteristics most commonly associated with hatchery introgression. This assessment will be used to aid in decision making processes of best management practices for future stocking efforts to reduce alterations to the genetic composition of wild trout populations.
Haas-Castro, Ruth1, Molly McCarthy2, Mark Renkawitz1. Effects of Inter-analyst and Intra-fish Scale Feature Measurement Variation on Back-calculations of Atlantic Salmon Smolt Lengths-at-First-Annulus Formation
1Northeast Fisheries Science Center, Woods Hole, MA, 2University of Alaska Anchorage, Anchorage, AK
Scale pattern analysis (SPA) and estimates of back-calculated lengths-at-age events provide important information to better understand Atlantic Salmon ecology. Sources of variation that may influence back-calculation results have been identified but have not been fully evaluated. In this study, two sources of potential variation were examined: intra-fish scale feature variation, and inter-analyst transect selection/scale measurement variation. Two analysts conducted SPA on 5 scales from 10 age 2 smolts (n = 50, size range 151 to 225 mm) to examine the degree of intra-fish variability in circulus number, inter-circulus width, focus-radius distance, and focus-freshwater annulus distance. Analysts were then compared to examine inter-analyst variability. The magnitude of influence that variation in SPA measurements exerted on back-calculated length-at-life-stage was then evaluated. While intra-fish scale feature variation was low (all p > 0.072), intra-fish back-calculated lengths varied significantly (F9, 49 = 40.07, p <0.001), were in some cases up to 16 mm different. SPA measurement variability between analysts was also significant for 2 variables; inter-circulus width (p = 0.010) and focus-freshwater annulus distance (p < 0.001). Measurement variability was insignificant for circulus number (p = 0.697) and focus-radius distance (p = 0.428). These differences also had a significant influence on back-calculated lengths (F1, 73 = 30.14, p <0.001) resulting in greater back-calculated length by one analyst in 33 of 37 cases. Inter-analyst differences were the most influential sources of variation in this study indicating that uniformly trained analysts are important for the consistency of SPA measurements, data quality, and accurate back-calculated length-at-age estimates.
*Izzo, Lisa K.1,2, Donna L. Parrish1,2, Gayle B. Zydlewski3, Chet MacKenzie4. Feasibility of estimating Lake Sturgeon abundance using side-scan SONAR on a river delta in Lake Champlain.
1Vermont Cooperative Fish & Wildlife Research Unit, 2Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT, 3School of Marine Sciences, University of Maine, Orono, ME, 4Vermont Fish & Wildlife Department, Rutland, VT
While Lake Champlain once supported a small commercial fishery for Lake Sturgeon, Acipenser fulvescens, the species was listed as endangered in Vermont in 1972. Spawning has been confirmed in three of the four historic spawning tributaries to the lake, but information on the abundance of Lake Sturgeon in Lake Champlain is currently lacking. Low numbers and sampling conditions have made gillnet-based mark-recapture surveys challenging in spawning tributaries. A potential alternative is the use of hydroacoustic methods, which can allow for sampling of endangered populations without physical handling of individuals. Recent acoustic telemetry of Lake Sturgeon that spawned in the Winooski River indicate that they may aggregate on the adjacent Winooski River delta during the winter months. In the winter of 2016 – 2017, we initiated side-scan SONAR surveys in an attempt to visualize wintering Lake Sturgeon on the river delta. These surveys will be used to develop sampling protocols to estimate Lake Sturgeon abundance in the area. Information gained from this work will aid managers in tracking population recovery over time in Lake Champlain.
*Liu, Chang1, Geoffrey Cowles1. Developing and validating a GPU-accelerated geolocation method for groundfish using particle filter.
1School for Marine Science and Technology, UMass Dartmouth, New Bedford, MA
Geolocation methods have been applied to electronic tagging data to estimate locations of groundfish species. Such information can improve stock assessments and fishery management plans that account for population structure, including movements across stock boundaries. Many popular geolocation methods have limitations including low horizontal resolution, flawed land boundary treatment, and long computational time. The particle filter is a state-space approach that has been applied to localization problems and addresses the aforementioned problems. We present a geolocation method based on the particle filter that is accelerated with the graphics processing unit (GPU). The geolocation method involves the comparison of the tag-recorded depth and temperature to the same variables from an unstructured grid oceanographic model. The geolocation output of each tagged fish include the most probable track and associated uncertainty distribution. The speedup for geolocation computation using the GPU implementation is compared with the CPU (central processing unit) implementation. Validation of the geolocation estimates was performed using stationary tags and through double-electronic-tagging (archival and acoustic tags) studies of Atlantic Cod. This work is expected to provide a geolocation method of deriving reliable movement information from electronic tagging data in a time-efficient manner.
*Markowitz, Emily1, Michael Frisk1, Skyler Sagarese2, Janet Nye1. Distribution shifts associated with changing environmental parameters in two demersal species Summer Flounder (Paralichthys dentatus) and Black Sea Bass (Centropristis striata).
1School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, 2NOAA NEFSC SWFSC, 75 Virginia Beach Drive, Miami, FL
Shifts in fish population distributions are a growing concern for fishermen and fisheries management scientists. Temperature has been implicated as the main driver of poleward distributional shifts in many marine fishery stocks, including two abundant and commercially valuable fish along the Northeast US coastline: Summer Flounder (Paralichthys dentatus; SF) and Black Sea Bass (Centropristis striata; BSB). Other environmental drivers may also influence their abundance and distribution in the Northeast US. These drivers may be different for different age and size classes within a species. Juvenile SF and BSB may be expected to select for different aspects of their environments and may be found at a wider and warmer range of temperatures than have been experimentally found to support positive growth in adult conspecifics. This study will use fishery-independent Northeast Fisheries Science Center bottom trawl survey data to develop cumulative distribution functions, generalized additive models, and habitat suitability models to determine what parameters (surface and bottom temperature, surface and bottom salinity, bottom depth, rugosity, and distance from nearest bay) are selected for by SF and BSB and influence their distribution in different length classes in winter, spring, and fall. We will also assess whether these factors change the availability of SF and BSB to the Northeast Fisheries Science Center bottom trawl survey in such a way that impacts estimates of stratified-mean biomass and abundance.
McBride, Richard S1. Binomial model selection for estimating fish age and size at maturity: an application with different stocks of Winter Flounder (Pseudopleuronectes americanus).
1Northeast Fisheries Science Center, Woods Hole, MA
Logistic regression is most commonly used to fit maturity data in fisheries research, but there are other binomial link functions, notably the probit, Cauchit, and complementary log-log. This poster addresses how these different link functions compare in terms of model uncertainty and parameter estimation using data for a regional flatfish species. The logit and probit links were indistinguishable between each other, in terms of fitting the certainty of the data (i.e., AIC < 1), and they predicted realistic maturity estimates across their respective ogives. In my experience, the logit is most commonly used, and these results suggest this is well deserved. The probit link may fit a particular dataset better than the logit, but if historic (or future) modeling efforts use the logit, then differences in median or other estimates of maturity could be confounded by model choice alone. The other two link functions (Cauchit, log-log), which are not commonly used to fit maturity data, were not suited to these data nor have they done well with some other data simulations (see https://rpubs.com/fishmcbride).
Pavey, Scott A.1. New ecological genomic tools in Atlantic Canada.
1Canadian Rivers Institute
Recent rapid technological advances in genetic tools have ushered in a new era of genomics. Genomics is different from genetics because entire genomes in multiple individuals and populations to assess genetic diversity, delineate population structure, or identify genes important to local adaptation. Though these topics represent the main thrust of Ecological Genomics, there are a number of other smaller cost effective tools that may be of high interest to managers. These include using genetic barcodes to identify species, mixed stock analysis, parentage analysis to determine the success of fisheries supplementation. Part of the Canadian Rivers Institute, CRI Genomics is a new lab at University of New Brunswick Saint John. It has state-of-the-art genomics infrastructure. We are very interested in new collaborative projects with regional fisheries biologists. We offer at-cost fee-for-service pricing.
*Rich, Tiffany1, Elizabeth A. Fairchild1. Using otolith microchemistry to identify natal origins of Winter Flounder (Pseudopleuronectes americanus).
1Department of Biological Science, University of New Hampshire, Durham, NH
Chemical signatures of Winter Flounder (Psuedopleuronectes americanus) are being utilized to identify the natal areas of adult fish caught from offshore locations. Pilot studies indicate there are discernable differences in young-of-the-year otolith trace metal compositions between estuaries. These signatures are site specific, in a range of 5-10 km. As otoliths are biologically inert, the otolith core signatures of adult fish could be compared to signatures of a known nursery to identify an individual’s origin. For this study, both young-of-the-year specimens from 15 estuaries ranging from New Jersey to Maine and adults of an unknown natal origin caught in multiple offshore locations in the GOM and SNE/MA management areas prior to spawning seasons are being examined. Right sagittal otoliths are being analyzed for elemental composition. Left sagittal otoliths are being analyzed for age verification and stable isotope analysis of 13C and 18O. Using the signatures from Bailey et al.’s 2012 study, annual variability of natal estuarine signatures will be checked. After assessing the annual variability from the pilot study signatures to newly collected samples, temporal variation and trends may be identified in some estuaries and used to identify the sources of adults. If successful, the natural, lifelong available natal signature can be used to identify which estuaries yield better recruitment and from which specific year classes. This information can in turn be used for a variety of stock management methods such as protecting successful estuaries or providing mitigation and recovery efforts to less successful estuaries.
*Valenti, Jessica L.1, Thomas Grothues1, Kenneth W. Able1. Fishes of a temperate estuary: temporal and sub-habitat influences on species composition and abundance.
1Rutgers University Marine Field Station, Tuckerton, NJ
An inventory of the fishes inhabiting Barnegat Bay, a lagoonal estuary in New Jersey, was based on a survey of the fish community within the bay using otter trawl sampling which occurred yearly (2012-2014) in April, June, August, and October. We sampled at 49 stations encompassing four different habitats: open bay, submerged aquatic vegetation (SAV), upper marsh creek, and marsh creek mouth. Throughout the sampling duration, 1,731 tows were performed and 33,993 fish comprising 72 species were collected. The fish fauna consisted of both resident (e.g. Oyster Toadfish, Opsanus tau) and transient (e.g. Summer Flounder, Paralichthys dentatus) species. Composition and abundance of the fish fauna varied seasonally with certain species only collected in a particular month (e.g. Pollock, Pollachius virens in April), whereas others were present within the estuary during all months sampled (e.g. Lined Seahorse, Hippocampus erectus). For many of the species collected, a majority (50% or greater) of their catch was collected in a single habitat (e.g. Fourspine Stickleback, Apeltes quadracus in SAV), whereas others were ubiquitous (e.g. Bay Anchovy). This data set provides a baseline from which long-term stability, improvement, or decline in the Barnegat Bay fish community can be assessed.
*Weston, Ashley1, Gavin Fay1, Carey McGilliard2. Identifying robust model selection tools for including environmental links to recruitment in North Pacific groundfish stock assessments.
1School for Marine Science and Technology, University of Massachusetts Dartmouth, Fairhaven, MA, 2Alaska Fisheries Science Center, NOAA Fisheries, Seattle, WA
Environmental and climate drivers have been linked to the recruitment success of groundfish in the Gulf of Alaska. Stock assessment models for these species have the ability to include recruitment linkages to environmental processes, but the robustness of model selection tools and harvest policies for these types of relationships are not definitive. We simulation tested the ability of Akaike’s Information Criterion (AIC) and Mohn’s retrospective statistic for choosing among models that correctly and incorrectly include a recruitment-environmental linkage. Uncertainty also surrounds the current and future implications of mis-specified recruitment-environmental linkages on population parameters. Using Stock Synthesis we tested operating models that differ in their inclusion of a single recruitment-environmental linkage on unfished recruitment within the Gulf of Alaska flathead sole assessment. Results showed neither AIC or Mohn’s retrospective statistic were able to consistently choose the correctly specified model. Mis-specified models led to greater bias in estimates of catch at maximum sustainable yield, but not for current spawning stock biomass. Model selection tools that incorrectly choose amongst models may misguide stock assessment development and application. Further research will evaluate the implications of including alternative recruitment-environmental linkages in population forecasts with respect to uncertainty associated with climate change, and compare the expected
Alexander, Ricky1, Farrell Davis1, Chris Parkins2, and Ron Smolowitz1. A modified flounder sweep for flatfish bycatch reduction in the LAGC scallop fishery.
1Coonamesset Farm, Falmouth, MA, 2Rhode Island Department of Environmental Management, Jamestown, RI
Limited-Access General Category (LAGC) scallop vessels in Northeast region are generally small (< 60 feet), and therefore more spatially and temporally restricted than the Limited-Access fleet. Due to this limitation, the LAGC fishing season is typically a function of fishing conditions, rather than management restrictions. Further, there may be an increase in bycatch due to temporal and spatial overlap of nearshore fish migrations. Interactions by the LAGC fleet with managed flatfish species could result in the implementation of Accountability Measures (AM), potentially jeopardizing the fleet’s profitability. One approach to avoid exceeding Annual Catch Limits (ACL) and triggering an AM is to develop gear based solutions for mitigating bycatch. To that end, a cookie sweep was attached to the outer bale bars of a scallop dredge forward of the cutting bar to drag the bottom, creating a sand cloud that initiates a herding (escape) response from flatfish, which, in turn, should result in a lower catch rate of flatfish. If effective, the flounder sweep could prevent the need for seasonal closures of nearshore fishing grounds that could have severe impacts for the LAGC fleet. In the fall 2016, testing of the flounder sweep began aboard an active LAGC scallop vessel. Preliminary results are promising with an 11.35% decrease in total bycatch of all finfish species and a 14.66% decrease in flatfish bycatch. These results indicate that the flounder sweep may be effective in reducing finfish bycatch, without impacting gear handling or target species catch, sea scallop (Placopecten magellanicus).
Apell, Bryan1. Field methods for evaluating passage of adult American Shad at the Turners Falls and Northfield Mountain Projects.
The Turners Falls Hydroelectric and Northfield Mountain Pump Storage Projects (NMPS) are currently undergoing relicensing. The projects are on the Connecticut River in Massachusetts and located within the diadromous fish migratory corridor. The American shad is a species of particular interest to resource agencies and stakeholders and represents the largest diadromous migration in the Connecticut River drainage. In 2015, FirstLight conducted a telemetry-based study to investigate the behavior, routes of passage, passage success, survival, and delay of American shad as they encounter the Projects during both upstream and downstream migration. Radio and Passive Integrated Transponder (PIT) telemetry methods were employed to track nearly 800 shad as they migrated through the projects. A total of 29 fixed radio telemetry monitoring stations and 13 PIT monitoring stations were deployed to track the tagged shad migration throughout the 43 river mile study area extending from Holyoke to Northfield, MA. Additional data were collected during 33 mobile surveys. This presentation will concentrate on the technologies and field methods employed. Data analysis methods and results will be presented during a later presentation.
Bell, Richard1, Anthony Wood2, Jonathan Hare2, David Richardson2, John Manderson2, and Timothy Miller2. Rebuilding in the face of climate change.
1The Nature Conservancy, 2Northeast Fisheries Science Center
Rebuilding plans provide a legally binding time-line to reduce overfishing. For many species along the Northeast US Shelf, heavy fishing pressure severely depleted populations and was the major driver controlling stock status. As fishing pressure declined, the potential increased for the physical environment to influence intrinsic rates such as growth, mortality, and fecundity. Decadal-scale climate variability and climate change can cause trends in oceanographic conditions over the course of rebuilding plans, and thus rebuilding projections developed assuming constant intrinsic rates may not be realistic. Winter Flounder is an important commercial and recreational species that has declined in the southern portion of its range despite reduced fishing pressure. Laboratory and mesocosm studies suggest that stock productivity is reduced under warmer conditions and that rebuilding to historical levels may not be possible. Our goal was to examine the rebuilding potential of Winter Flounder in the face of regional warming. We integrated winter temperature into a population model to estimate environmentally driven stock-recruit parameters and then used the parameters to project the stock into the future under different climate and fishing scenarios. The inclusion of winter temperature had very little impact on the estimates of abundance, but provided greater understanding of the drivers of recruitment. Future projections suggest that rebuilding the stock to historical levels is unlikely, but specific biomass projections depend heavily on model assumption. The integration of both fishing and the environment has the potential to provide more realistic expectations of future stock status.
*Calabrese, Nicholas1 and Kevin D.E. Stokesbury1. A video trawl survey for Atlantic Cod (Gadus morhua) in New England.
1Department of Fisheries Oceanography, School for Marine Science and Technology, University of Massachusetts Dartmouth.
Researchers at the School for Marine Science and Technology (SMAST), in collaboration with members of the fishing industry, have developed a survey system that utilizes a live feed video camera mounted in the codend of a demersal trawl. This system can be towed with an open codend allowing fish to be recorded, identified, and quantified as they pass through, or with a closed codend periodically to collect biological information and verify video observations. Seven field trials have been conducted on Georges Bank with the intent of identifying flatfish. In January 2016 a pilot study in the Gulf of Maine applied these same methods to survey Atlantic cod (Gadus morhua). With the 19 hours of video collected we plan to test the following hypotheses: (1) there is no difference between the number of cod counted from the video and in the catch; (2) there is no difference between the number of cod counted by sampling the entire video and subsampling the video; and (3) the distribution of Atlantic cod along the path of each tow is uniform. Preliminary results show no significant difference (P>0.05) between the catch and video counts of cod. This approach could provide a non-invasive method of surveying aggregations of Atlantic cod in the Gulf of Maine and in conjunction with the existing fisheries independent surveys could strengthen the assessment of this stock.
*Davis, Farrell1, Liese Siemman1, David Rudders2, and Ronald Smolowitz1. The impact of increasing the inter-ring spacing on scallop dredge efficiency.
1Coonamessett Farm Foundation, East Falmouth, MA, 2Virginia Institute of Marine Science, Gloucester Point, VA.
Large sea scallop (Placopecten magellanicus) recruitment events in scallop rotational access areas can create a situation where high densities of pre-recruit scallops are found amongst commercially viable densities of harvestable scallops. Under these circumstances there is a real likelihood that recruitment overfishing could occur as a result of high discard mortality associated with thermal shock and desiccation. Modifications to the scallop dredge bag configuration to increase the selectivity could reduce the impact of fishing effort on pre-recruit scallops while allowing for the harvest of commercial sized scallops. By using two links rather than a single link to connect the rings of the apron together, the inter-ring spacing can be increased both vertically and horizontally altering the selective properties of the dredge bag. Preliminary analysis of the data collected during four research trips, one of which utilized a non-selective dredge bag, indicates that this configuration has the potential to reduce the bycatch of pre-recruit scallops as well as elasmobranchs and finfish.
Davis, Justin1 and Eric Schultz2. Simulation models of the predator-prey interaction between Striped Bass and Blueback Herring in the Connecticut River.
1Connecticut Department of Energy and Environmental Protection, Marine Fisheries Division, Old Lyme, CT. 2 University of Connecticut, Storrs, CT.
Case studies of the ramifications of predator management for prey population dynamics can play a valuable role in developing ecosystem fisheries management approaches. Atlantic coastal populations of Striped Bass (Morone saxatilis), a large predatory finfish of significant fisheries value, have been rebuilt to high levels of abundance in recent decades. The spawning run of Blueback Herring (Alosa aestivalis) to the Holyoke Dam on the Connecticut River in southern New England has collapsed coincident with Striped Bass recovery; our previous study of this predator-prey interaction in the Connecticut River suggested that annual Striped Bass in-river consumption of herring was substantial, and that increased in-river Striped Bass harvests might modestly improve herring survival. Here we incorporate our measurements of predation rates into a herring population model to test whether increased Striped Bass predatory demand can account for the collapse of the Holyoke Dam run, and whether alternative management of the in-river recreational Striped Bass fishery can substantially improve prospects for run recovery. Over half of our simulations incorporating estimates of Striped Bass predation during the 1980-2000s predicted the observed collapse of the Holyoke run; further, current rates of Striped Bass predation in the river stretch below Holyoke Dam appear sufficient to prevent run recovery. Implementation of alternative regulations that encourage increased Striped Bass harvests by recreational anglers offer only limited potential to aid herring recovery; the levels of additional harvest required to substantially improve predicted future herring returns are unlikely to be achieved at observed levels of fishing intensity. Our model illustrates potential trade-offs between predator and prey management initiatives, provides estimates of uncertainty associated with those trade-offs, and highlights important areas for further research into this important predator-prey interaction.
*Devine, Matthew T1, Allison H Roy1,2,3, Andrew R Whiteley4, Benjamin I Gahagan5, Michael P Armstrong5, Michael M Bailey6, and Adrian Jordaan1. The lake effect: identifying optimal growth conditions for juvenile anadromous Alewife.
1Department of Environmental Conservation, University of Massachusetts-Amherst, Amherst, MA 01003, 2Massachusetts Cooperative Fish and Wildlife Research Unit, 3U.S. Geological Survey
4Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT 59812, 5Massachusetts Division of Marine Fisheries, Annisquam River Marine Fisheries Station, Gloucester, MA 01930, 6U.S. Fish and Wildlife Service, Central New England Fishery Resources Office, Nashua, NH 03063
Anadromous alewives (Alosa pseudoharengus) have experienced substantial population declines over the past five decades due in part to habitat degradation and overfishing. Current management objectives include restoring alewives to historic spawning habitats, yet favorable conditions are not well described. Without understanding what constitutes ideal conditions, restoration strategies and locations are limited. We used generalized linear mixed models to explain the variation in growth rates in 10 coastal New England lakes (natural n=7; stocked n=3) sampled monthly from June-August of 2015. Juveniles were sampled by purse seine, and preserved in 95% ethanol. Physical (e.g. size, depth, temperature) and chemical (e.g. phosphorous, dissolved organic carbon) lake properties were also measured or collected during fish sampling. In the lab, total fish length was measured and otoliths from 50 fish per month for each lake were extracted, mounted in resin, and double-aged. Length-based growth was calculated for individuals and averaged across lakes and months. Monthly alewife densities were calculated and used in models. Individual growth rates varied wildly (0.53±1.61 mm/d) among lakes, and low density stocked systems exhibited higher growth rates (mean SE = 1.04 ±0.020) than natural systems (0.891 ±0.017), suggesting density dependent growth as a key mechanism. These results are consistent with others, and suggest management based solely on run size may impact juvenile productivity. This and future exploration of size-selective mortality and size at age events (e.g. egress, diet shifts) will eventually aid site selection for restoration projects, such as dam removal and stocking events, and produce effective management strategies.
Dey, William1, Brooks Fost2, and John Young2. Can fish eggs and larvae survive a trip through the cooling system: What have we learned since 1972?
1ASA Analysis & Communication, Washingtonville, NY 2ASA Analysis & Communication, Lemont, PA
316(b) of the CWA Amendments of 1972 initiated a tremendous amount of research on the impacts of fish being trapped on power plant water intake screens (impingement), and passage of fish eggs and larvae through the cooling system (entrainment). At that time, conventional wisdom held that passage through the cooling system was always fatal, a result of the combined effects of physical damage, high temperatures, and biocides. Actual measurement of the probability of surviving entrainment presents unique sampling challenges, and required intensive research, most of it performed at estuarine facilities within the boundaries of the NED, to develop specialized sampling equipment and protocols. By 1980, the reality of entrainment survival was an accepted part of 316(b) knowledge. However, at that point most power plants had obtained permits for their water discharges, and interest in 316(b) research, particularly entrainment survival, waned. When USEPA published its new regulations for 316(b) in 2004, it reverted back to the original premise of 100% mortality. This retrogression was reversed in 2011 when revised regulations allowed for entrainment survival to be demonstrated. This has led to a resurgence of entrainment survival studies at several coastal facilities in NED states. The new studies have concentrated on fish eggs, and have, as before, required further development of techniques and equipment. Also, as before, the studies demonstrated that passage through the cooling system is survivable by a large proportion of the entrained organisms.
*Ellis, Laura1, Walt Golet2,3, and James Suljkowski1. Using skeletal muscle tissue to determine the sex specific ratios of Atlantic Bluefin Tuna (Thunnus thynnus) in the New England Fishery.
1University of New England, 2University of Maine, 3Gulf of Maine Research Institute, Portland, ME
The Atlantic Bluefin Tuna (Thunnus thynnus) is a large, highly migratory and highly prized commercial fish species. Historical overexploitation led to a 20-year rebuilding plan initiated in 1998, and current assessments still lack fundamental biological inputs. Routine biological sampling has been problematic given the nature of the fishery (evisceration at sea). As a result, gross examination of specific tissues (e.g. gonads) to determine reproductive characteristics of the fished population has not been possible. To overcome these challenges, an alternative technique for assessing reproductive biology must be utilized. Previous studies have quantified sex hormones reliably to determine the reproductive characteristics of various fish species. Building off this premise, radioimmunoassay was used to quantify estradiol (E2) and testosterone (T) concentrations from the muscle tissue of 22 females and 34 males landed in the New England fishery from June-December 2014-2015. These results suggest the hormone profiles between males and females are different, with females having a higher concentration of E2 (422+148pg/g) compared to males (213+87pg/g), while males’ T concentration is higher (1283+211pg/g) than females (539+127pg/g). Based on these results, the levels of reproductive hormone were used to develop a method for sex determination by comparing the ratio of T:E2. When applying the method to 111 samples of unknown sex collected from 2014-2015, a sex ratio of 1.5:1 males to females was established, which showed seasonal hormone fluctuation between the sexes. The present investigation demonstrates that skeletal muscle tissue is an effective substrate for determining the reproductive characteristics of Atlantic Bluefin Tuna.
Gahagan, Benjamin1 and Michael Bailey2. Impediments to restoration of American Shad (Alosa sapidissima) in the Charles River.
1Massachusetts Division of Marine Fisheries, 2United States Fish and Wildlife Service Central New England Fish and Wildlife Conservation Office
Since 2006, Massachusetts Division of Marine Fisheries and the United States Fish and Wildlife Service have worked cooperatively to restore American shad to the Charles River in Boston, MA USA. Surveys for spawning adults in the years 2012-2014 indicated low returns related to larval stocking numbers. To better understand restoration issues we conducted an acoustic telemetry study. Adult shad were collected using a boat electrofisher and acoustic tags were surgically implanted in the springs of 2015 (n=46) and 2016 (n=52). We observed limited mortality and a degree of fallback as a result of tagging. In both years tagged shad displayed pronounced diel movements as they attempted to navigate upstream passage barriers. No tagged fish were detected above the Watertown Dam (rkm 17), the first fishway on the river. Tagged shad attempted to pass this fishway for 2 to 46 days (mean = 16.9) before expiring or attempting to emigrate from the Charles River. Downstream transit was rapid, followed by delays of 1 to 15 days (mean = 5.02) at the locks associated with New Boston Dam in Boston Harbor. These two structures appear to cause delays and perhaps increase mortality for American shad attempting to spawn in the Charles River and are likely impediments to population restoration. In both years a significant percentage (2015=41%, 2016=59%) of tagged fish successfully exited the river and a subset of these shad were detected making northwards post-spawning movements, although no shad tagged in 2015 were detected in the Charles River in the spring of 2016.
Gardner, Lynette1. Evaluation of upstream passage of American Eel at the Turners Falls Project.
1 Kleinschmidt Associates, Essex, CT
To determine the best place to install upstream eel passage facilities, Kleinschmidt Associates conducted a two-year study (2014-2015) to investigate the route of upstream eel migration at the Turners Falls Project located on the Connecticut River in Massachusetts. In 2014, study objectives were to identify areas where eel congregated and to determine whether there are suitable sites to construct permanent eel passage structures. During this initial study year, 13 sites were surveyed on eleven nights each between June 11 and October 9, 2014. The approximate number of eels, the date and time of survey, eel behavior, and environmental conditions (e.g., weather, leakage, discharge) were recorded. The results of the surveys were clear as 94% of the 6,263 total eels recorded during the study period were observed at the Turners Falls Spillway Fish Ladder. Based on the results of the 2014 study, three temporary eel ramp traps were deployed in 2015 to investigate passage potential and eel abundance. The ramp traps were operated continuously between July 9 and November 2, 2015. The majority of the eels (88%) were collected at the Spillway Fish Ladder, a result that was consistent with the 2014 results. The study results were explicit in identifying that the most viable location for permanent upstream eel passage is at the Turners Falls Spillway Fish Ladder.
Goclowski, Matthew1, Tracy Maynard1, and Kevin Nebiolo1. American Shad spawning and spawning habitat in the Massachusetts portion of the Connecticut River.
1 Kleinschmidt Associates, Essex, CT
American shad (Alosa sapidissima) is an anadromous species that spawns in rivers along the Atlantic Coast from Florida, USA up to Newfoundland, Canada. Historic records indicate that American shad may have spawned as far North as Bellows Falls, Vermont on the mainstem Connecticut River. As part of a relicensing study, we used night-time visual and aural surveys to identify shad spawning locations and to assess spawning activity from the Vernon Dam tailwater (at river kilometer 228.4) to the Route 116 Bridge (river kilometer 176.1) in Sunderland, Massachusetts between May 13th and June 22nd, 2015. When groups of spawning shad were encountered, observers delineated the approximate extent of spawning habitat utilized by shad, recorded a suite of environmental variables to describe each habitat, and recorded the number of splashes that occurred within a 15-minute interval as an index of spawning activity. Spawning was observed at temperatures between 15.6 to 20.2°C and generally occurred in run and riffle habitats over gravel and cobble substrates. The effects of water temperature, flow, photoperiod, and time-after-sunset were assessed with multiple regression. Photoperiod appeared to be the biggest driver influencing spawning activity.
*Hammer, Lars1 and James Sulikowski1. The importance of the Saco River Estuary to Winter Flounder (Pseudopleuronectes americanus) life stages.
1University of New England, Biddeford, ME
Due to the effects of overfishing and habitat loss, Winter Flounder stocks have drastically declined since the 1980s. Although strict fishing regulations have stabilized populations, they are still below sustainable harvesting levels. In order to better manage and further promote the rebuilding of Winter Flounder stocks, essential fish habitat (EFH), such as nursery grounds and spawning areas, need to be identified. While previous EFH have been documented in the southern most US range of the species, very little information has been gathered in their northern most US range. Previous studies have suggested the Saco River Estuary System (SRES), in southern Maine, has the potential to serve as a nursery ground for Winter Flounder based on the presence of YOY and juvenile individuals. However, the extent to which Winter Flounder utilize the SRES needs to be addressed. In order to assess the importance of this northern estuary to Winter Flounder, a multifaceted study was initiated in 2016. Thus far, a total of 61 beach seines and 17 otter trawls have been conducted between May and August. Fish captured ranged in size from 25mm-400mm TL. Flounder captured in seine nets had an average total length of 53.3mm+-25mm, while flounder captured by otter trawling averaged 156.8mm+-80mm. These methods yielded CPUE’s of 0.31 (fish/seine) and 0.15 (fish/minute towed) respectively. Based on the wide size distribution range of sampled specimens, it would appear that this estuary not only has value as a nursery ground, but for other life history stages as well.
Harnish, Ryan1, Alison Colotelo1, Gary Johnson2, Zhiqun Deng1, and Marshall Richmond1. Biologically-based design and evaluation of hydro-turbines.
1Pacific Northwest National Laboratory, Richland, WA, 2Pacific Northwest National Laboratory, Portland, OR
The US Department of Energy’s Biologically-Based Design and Evaluation (BioDE) Initiative is providing advanced technologies for biologically-based design, operation, and evaluation of hydro-turbines to optimize the biological performance of hydropower. The technical approach for BioDE involves integration of experimentally-derived dose-response relationships, design tools for predicting biological performance, and evaluation tools for empirical measurements. Lab experiments are conducted to establish statistically rigorous relationships between physical stressors and responses of priority fish species, such as species listed under the Endangered Species Act. Sensor Fish, an autonomous multi-sensor device that measures certain physical conditions fish experience during turbine passage, are used along with computational fluid dynamics models and hydraulic measurements from laboratory tests to estimate the location, frequency of occurrence, and magnitude of stressors in the turbine environment. These data are integrated with dose-response relationships obtained from the laboratory studies to index the biological performance of the turbine. The resulting biological performance measures are used by the hydropower community (plant owner/operators, turbine manufacturers, regulators, and resource agencies) to select designs and operations that meet both power generation and fish passage criteria. Novel acoustic telemetry systems and dam passage survival models provide empirical measures of turbine passage survival that can be used to validate biological performance indices from BioDE. This presentation will provide a review of the approach, methods, and technologies used to evaluate the biological performance of hydro-turbines, including examples of their implementation.
Haro, Alex1,2. Past, present, and future of eel passage in the Northeast: A 35-year perspective
1S.O. Conte Anadromous Fish Research Laboratory, 2U.S. Geological Survey
Prior to 2000, upstream and downstream passage of American Eels in North America received relatively little attention. Although advances in upstream passage were being made in Europe, management and protection of eels in the US was a low priority. Successful State and grass-roots efforts to provide upstream passage at small dams, coupled with documented declines in eel populations and two Endangered Species listing petitions motivated new interest in provision of passage for eels, and development of management plans that identified passage and access to habitat as critical areas of restoration effort. Presently, upstream passage technologies have been refined and can be implemented with some effectiveness at most sites; downstream passage remains technically problematic. This presentation will review the progression of passage technology development and remaining issues and problems of eel restoration programs over one researcher’s 35-year span of experiences with one of the Northeast’s most enigmatic yet poorly understood fishes.
He, Pingguo1. Research on fish behavior and conservation engineering related to marine capture fisheries: Past, present, and future
1University of Massachusetts Dartmouth, North Dartmouth, MA
World marine capture fisheries are at a critical juncture. On the one hand, many of the world’s fish stocks are overfished, resulting in decreased quota and landing. On the other hand, conservation of protected species and sensitive ecosystems requires that fishing gears and their operation cause minimal collateral impact. How to reconcile conservation and sustainable exploitation requires better understanding of fish capture processes, especially behavior of fish during fish capture. This presentation will review research on fish behavior and conservation engineering related to marine capture fisheries in the North Atlantic during the past fifty years, discuss current issues facing the capture fisheries, and future challenges related to management and sustainable utilization of marine fisheries resources and sustainability of ecosystem. The talk will include notable scholars in fish behavior research and their contributions, major technological advances, conservation issues, and trends in behavioral and conservation research. The presentation will provide examples on how advances in our understanding of fish behavior and development of fishing technology may contribute to sustainable exploitation of fisheries resources with minimal collateral impacts to the ecosystem.
*Hodgdon, Cameron1, James Sulikowski1, Woon Yuen Koh1, Jeri Fox1, and Craig Tennenhouse1. Shortnose Sturgeon in the Saco River Estuary: An assessment of critical habitat
1University of New England, Biddeford, ME
The Shortnose Sturgeon (SNS) (Acipenser brevirostrum) is an endangered fish species that migrates between large river systems along the U.S. east coast. Despite its endangered status, our understanding of the species’ ecology is limited, especially in regards to the importance of smaller river systems to their recovery. The Saco River watershed represents a smaller system and is a midpoint between larger rivers of New England known to serve as essential fish habitat for SNS. However, prior to 2010, SNS were undocumented within the Saco River. Since then, 90 SNS have been captured, of which 27 were fitted with acoustic tags and monitored. Preliminary data suggests that 77 percent of tagged SNS appear to aggregate in the western-most portion of the tidal reach, closest to the dam. In 2016, the collection of abiotic data was coupled with the acoustic tagging study in an effort to establish which environmental parameters are most influential to the observed aggregations. Temporal and spatial variances of temperature, salinity, dissolved oxygen, acidity, substrate type, and water depth were monitored within the river from June to December with HOBO conductivity loggers and YSI instruments. These 6 parameters were ranked by significance they have influencing Shortnose Sturgeon movements within the river by way of multivariable regression analyses. Preliminary results suggest that salinity is the most influential abiotic factor of the 6. Further rankings and trends are being identified and will be presented at the AFS SNEC Conference.
Kahn, Desmond1. Management of a top inshore predator: Differing goals of recreational and commercial fishers of Atlantic Striped Bass and the unforeseen impacts on other fisheries.
1Desmond M. Kahn- Fisheries Investigation, 916 Rahway Drive, Newark, DE 19711
Striped Bass are produced in Mid-Atlantic estuaries, then migrate into New England waters in summer. They are the only inshore teleost in the Northeast that attains a fabled big game status for the recreational fishery; they also serve an economically important commercial fishery. After a crash in the 1980s attributed variously to acid rain/water quality and overfishing, striped bass recovered by the mid-1990s. Conservative management driven by recreational interests seeking high catch rates and large sizes brought the stocks to unprecedented abundance by the 2000s. High bass predation has been linked to severe declines in fisheries for weakfish, American shad and river herring. The Chesapeake Bay resident male stock, at a high density, has suffered starvation and an epidemic of Mycobacteriosis. Despite high spawning stock biomass, the Chesapeake Bay stock also failed for seven years to produce a dominant year class until 2011, leading to a slow coast wide decline in abundance. Due to their political dominance of the management process, recreational anglers have driven a 25% cut in commercial quotas, despite the dominant 2011 year class now beginning to recruit to the coastal fishery. Having lost the fisheries for weakfish and American shad, commercial baymen have few alternative finfish targets.
*Kasper, Jacob M.C.1, Amanda Caskenette2, Jason Vokoun1, and Eric T. Schultz1. Sound fisheries management: A regional stock assessment for Tautog.
1University of Connecticut, 2Fisheries and Oceans Canada
The Atlantic States Marine Fisheries Commission (ASMFC) Tautog management board approved a regionalized stock assessment for Tautog, a chronically overfished coastal species. Under this assessment, Long Island Sound (LIS) is a separate region. In a collaboration between the ASMFC, state agencies, and the University of Connecticut, three decades of data on regional demography and fishing activity were assimilated from state and federal databases into a statistical catch-at-age stock assessment. The assessment has been approved and accepted by the Tautog Management Board. Results indicate that Tautog in LIS have been overfished and overfishing is occurring. We are now developing regulatory scenarios designed to reduce harvest with the goal of achieving target levels of fishing mortality and spawning stock biomass by 2020.
*Langan, Joe A.1, Gavino Puggioni2, and Jeremy S Collie1. Evidence of spatiotemporal skew in the observed sex ratio of Winter Flounder in Narragansett Bay, Rhode Island.
1University of Rhode Island Graduate School of Oceanography, Narragansett, RI, 2University of Rhode Island, Kingston, RI
Sex-specific life history characteristics and spatial distributions are viewed as important considerations for the understanding of fish population dynamics. Although the sex ratio for many populations is expected to be relatively invariant, recent evidence suggests that this assumption is not always accurate. Winter Flounder (Pseudopleuronectes americanus) in southern New England and the Gulf of Maine, for example, have been observed to exhibit strongly female-skewed sex ratios around spawning that are thought not to be present during other seasons. However, data from the University of Rhode Island Graduate School of Oceanography weekly fish trawl survey in Narragansett Bay, Rhode Island (1985-Present) indicate further variability in the recorded sex ratio of this species over spatial, seasonal, and inter-annual scales that have not been previously described. This study used time series analysis methods to investigate these patterns and gain insight into the causes influencing the observed sex ratio of Winter Flounder in Narragansett Bay. The results of this modeling suggest that winter water temperature influences both apparent sex-specific movement patterns and time-delayed sex ratio variability through its known impacts on recruitment. While more in-depth data collection will be required to fully characterize such dynamics, these findings represent a step toward a more nuanced understanding of how Winter Flounder utilize habitats and interact with their environment around which targeted management measures may be developed to promote population recovery.
*Long, Michael1, Theodore Castro-Santos2, Adrian Jordaan1, and Chris Sutherland1. Dynamic detection range and efficiency of acoustic receivers based on transmitter distance and environmental conditions.
1University of Massachusetts, Amherst, MA, 2USGS S.O. Conte Anadromous Fish Research Center, Turners Falls, MA
Acoustic telemetry is widely used to monitor occupancy and movements of aquatic animals. However, detection ranges and efficiencies can vary as a function of environmental parameters, leading to potentially biased interpretations of data. An existing acoustic telemetry study on horseshoe crab movements in Wellfleet Harbor, Massachusetts provided an opportunity to examine detection ranges and efficiencies of acoustic receivers. 15 Vemco V13 acoustic transmitters were deployed within an array of 20 Vemco VR2W acoustic receivers over 3 test sessions. 5 transmitters were deployed per session at varying distances away from a reference receiver; duration of transmitter deployments ranged from 2-9 days. We used linear regression models to quantify the effects of transmitter distance from receiver, wind speed, wave height, water temperature, tidal height, and water depth on detection efficiencies in all sessions. Detection ranges varied from 50-1,500 meters and efficiencies varied from 0-100%. These results have potential to provide insight for future acoustic telemetry studies to advance telemetry analyses beyond presence and absence only data. Modeling detection ranges and efficiencies in future acoustic telemetry studies can improve estimates of animal occupancy and movement by reducing bias in analyses.
Lucey, Sean M.1 and Sarah K. Gaichas1. An Ecopath model of the Georges Bank Ecological Production Unit.
1Northeast Fisheries Science Center, Woods Hole, MA
Ecosystem based fisheries management is inherently place-based. The Northeast Fisheries Science Center has developed four ecological production units (EPU) that will serve as a spatial footprint for ecosystem-based management actions. The first EPU to undergo management strategy testing is the Georges Bank EPU located just off the coast of New England. In order to test various management strategies there will need to be a robust operating model of the area. One candidate model is a mass balance representation of the ecosystem commonly parameterized using the Ecopath with Ecosim modelling software. There is an existing Ecopath model of the region that contains highly aggregated species groups. This study updates that work with a more disaggregated box structure. It was also implemented using the Rpath package which is an R implementation of the classic EwE software. This model will be used as an operating model for testing various ecosystem strategies in an MSE framework.
Malvezzi, Alex1. Assessment of adult Sea Lamprey spawning in the Connecticut River.
1Kleinschmidt Associates, Essex, CT
The life cycle, habitat preferences and behavior of the adult oceanic stage of the Sea Lamprey, Petromyzon marinus, are not well understood. As an anadromous species, their spawning behavior and habitats in the Connecticut River are vastly understudied. In support of hydroelectric relicensing efforts, the aim of this study was to evaluate spawning of Sea Lamprey in the Connecticut River. Forty lamprey were radio tagged and released in two locations during the early and mid-portion of their spawning run to identify spawning locations via mobile tracking. Twenty-nine lamprey nests (redds) were selected in five regions within the Project area to be monitored throughout the 2015 spawning season. Several parameters (water velocity, water depth, substrate characterization, presence/absence, and water quality) were measured weekly at each lamprey redd from June 12 to July 31, 2015. Five redds were capped after visual confirmation of spawning/nesting activity to characterize spawning success by collecting any emerging larval lamprey, or ammocoetes. Using depth, velocity and substrate data, composite suitability index maps of the project area were produced by way of existing habitat suitability index (HSI) criteria for spawning Sea Lamprey developed as part of an Instream Flow study conducted in the early 1980s. Our findings indicate that Sea Lamprey utilize spawning habitats with greater depths and coarser substrates than those in the referenced HSI criteria.
McDermott, Sean1, Christine Lipsky2, and Tim Sheehan3. Diadromous fish and their predators in coastal Maine: Past, present, and future.
1Greater Atlantic Regional Fisheries Office, Gloucester, MA, 2Northeast Fisheries Science Center, Orono, ME, 3Northeast Fisheries Science Center, Woods Hole, MA
Diadromous fish species, including River Herring (Alosa pseudoharengus; A. aestivalis) and American Shad (A. sapidissima), are known to have been historically important prey items for Atlantic Cod (Gadus morhua) and other groundfish species in coastal Maine. Anthropogenic factors (e.g. harvest, dams, water quality degradation) have resulted in a major decline in diadromous fish populations. Researchers have hypothesized that this decline has exacerbated similar declines in groundfish stocks over the past 200 years. Recent large-scale restoration efforts in Maine have enhanced the abundance of diadromous fish species in nearshore waters, increasing their numbers by several orders of magnitude. Several assessment surveys have been conducted to evaluate diadromous species responses to large-scale river restoration projects, and to evaluate the effect that changing prey resource availability may have on groundfish species distribution and abundance. Restoring a healthy diadromous prey species assemblage in coastal Maine may assist in rebuilding depleted groundfish populations regionally, given the close historical predator-prey relationship between the two groups of fish.
McDowell, Christopher1, Gerald Leonard2, Brian Eltz2, Justin Davis3, Eileen O’Donnell1, Robert Jacobs1, Timothy Barry2. The Past, present and future of Walleye management in Connecticut.
1CT DEEP IFD, Marlborough, CT, 2CT DEEP IFD, Harwinton, CT, 3CT DEEP IFD, Old Lyme, CT
Walleye (Sander vitreus) stocking in Connecticut dates back to the early 1900s. During a 47-year period (1911-58), approximately 77 million Walleye fry were stocked into 16 Connecticut lakes and the Connecticut River by the State Board of Fish and Game. These efforts produced fishable Walleye populations; however, the program was deemed unsuccessful and was discontinued because no self-sustaining populations were created. In 1993 the Connecticut Department of Environmental Protection initiated a put-grow-and-take Walleye Management program by annually releasing 4-6 inch fingerlings into select Walleye Management Lakes (WMLs) purchased from vendors located in the Midwest. Presently, Connecticut’s Walleye fisheries are regulated by a statewide 18-inch minimum length, two-fish-per-day limit. Though there are still no documented self-sustaining populations in the WMLs that would allow for the discontinuation of stocking to create a fishery, the program is deemed successful. Within surveyed WMLs, anglers are consistently in favor (52-89%) of this program and regularly submit proof of catching qualifying (23-inches or five pounds) Walleye for a Trophy Fish Award (151 awards distributed between 1997-2015). Overall, better Walleye fisheries are found in the Western portion (West of the Connecticut River) of the State. This may be linked to the fact that these lakes lie in a different geological strata and therefore have different water chemistry, water temperatures and forage species. Because Connecticut’s Walleye fisheries are important, investigations into how to maintain, as well as enhance, this program will continue. Currently, adjustments to fingerling stocking rates and sizes is being investigated at our struggling WMLs.
McGuire, Christopher1, Douglas Zemeckis2, Micah Dean3, William Hoffman3, Annamaria Izzi4, Sofie Van Parijs4, Mark Baumgartner5, Leila Hatch6, and Steven Cadrin1. Identifying the distribution of Atlantic Cod spawning activity to inform fishery management in the western Gulf of Maine.
1The Nature Conservancy, Boston, MA, 2U. Mass Dartmouth SMAST, 3MA Division of Marine Fisheries, 4Northeast Fisheries Science Center, 5Woods Hole Oceanographic Institution, 6Stellwagen Bank National Marine Sanctuary
Rebuilding the Gulf of Maine stock of Atlantic Cod (Gadus morhua) has been much slower than anticipated. Many historical spawning components have been depleted, which has reduced stock productivity and stability. In response, fishery managers have implemented closures to protect cod spawning aggregations. The objective of this project was to identify the spatial and temporal distribution of cod spawning activity during the winter to inform future fishery management decisions in the western Gulf of Maine. Through effective collaboration among state, academic, federal, and NGO scientists, and commercial fishermen, this study successfully utilized multiple acoustic technologies to identify Cod spawning distribution during three consecutive winter spawning seasons, from October 2013 through March 2016, in Massachusetts Bay. Based on a combined synthesis of the acoustic telemetry and passive acoustic monitoring data, from both fixed station and mobile autonomous glider deployments, the temporal distribution of Cod spawning activity was shown to have some inter-annual variability, with spawning activity primarily occurring during early November through January with a peak in mid-December. The spatial distribution of spawning activity was generally consistent among years and concentrated in areas deeper than 50 meters. Our scale of observation annually increased and permitted documentation of multiple hotspots of spawning activity centered in an area in the northern section of the Bay, west of Stellwagen Bank. The findings, when published, will be shared with fishery managers to inform future management actions to protect spawning Cod while enabling harvest of other target stocks.
Mrakovcich, Karina L1 and Lucy Vlietstra1. Fishes of the Thames River Estuary, Connecticut: Long-term trends in relation to sea surface temperature.
1U.S. Coast Guard Academy, New London, CT
The Thames River, Connecticut, is a salt wedge estuary located on Long Island Sound. It supports a diverse assemblage of commercially and recreationally important fish species and is subject to a variety of human impacts. To study long-term shifts in the fish community concurrent with environmental change in the region, U.S. Coast Guard Academy instructors and their students have been collecting bottom trawl data on a weekly basis from August to October for >20 years. Field methods have been remarkably consistent over time, yielding a valuable long-term data set unique to the region. In this study, we focus on observed trends in finfish relative abundance across four decades: 1970s, 1990s, 2000s, and 2010s. Overall, we found an overall shift of dominant communities from cold-adapted temperate species to warm-adapted temperate species in the estuary. For example, the relative abundance of species changed over time from Winter Flounder (Pseudopleuronectes americanus), dominant in the 1970s and 1990s, to Scup (Stenotomus crysops), dominant in the 2000s and 2010s. In addition, surveys conducted between 2003 and 2016 detected an increase in the proportion of fish species typically found in subtropical waters. Other studies conducted in nearby estuaries have observed a warming trend in surface waters, and our results suggest a shift in finfish abundance in the Thames River estuary consistent with this trend. Understanding the fluctuation of finfishes and possible links to climatic factors and other sources of environmental variability is important for the effective management of fisheries.
Munroe, Daphne1, Jason Morson1, and Ryan Harner1. Sex ratios of Summer Flounder discards in the recreational fishery.
1Haskin Shellfish Research Laboratory, Rutgers University
The most recent peer review of the Summer Flounder stock assessment offered support for the application of a sex-based population model. To implement a fully sex-disaggregated model however the sex composition of the catch must be known or assumptions must be made about the sex-specific selectivity curves of the fisheries and their stability in space and time. Recreational landings are 95% female, but no information is available on the sex composition of discards for this fishery. To address this gap in available data, the sex composition of the entire Summer Flounder catch (landings and discards) was evaluated during the recreational season aboard fishing vessels (49 trips total) in New Jersey, New York, and Rhode Island. While fish above the minimum landing size (46cm) were predominantly female as has been reported previously, fish caught below the minimum landings size were predominantly male. Fish under the legal-size limit made up 84% of the total catch. Given 10% of these discards are assumed to die, we estimated that 74% of the recreational fishing mortality (landings plus dead discards) is directed at the female portion of the stock. In addition, male fish were more common at a given size in deeper water and at higher latitudes. This information should prove useful in both the continued development of a sex-structured assessment model for this species and in evaluating alternative management strategies and their influence on sex-specific fishing mortality.
Murphy, Brian D1, Stephen R Gephard2, and Mindy M Barnett1. Engineering and design features of a culvert sliplining project in Connecticut to facilitate Brook Trout passage.
1Department of Energy and Environmental Protection (CTDEEP), Inland Fisheries Division, Marlborough, CT 06447, 2CTDEEP Inland Fisheries Division, Old Lyme, CT 06371
Many aging culverts that convey streams under Connecticut highways are being rehabilitated with “sliplining”, a technique that involves placement of a smaller diameter culvert within the larger failing culvert. In 2015, Inland Fisheries worked with the Department of Transportation to design and implement fish passage solutions at several slipline projects. One project located on a Tributary to Lyman Brook (TLB) will serve as a demonstration site to evaluate design features and passage performance for a native Brook Trout population via passive integrated transponder (PIT) tag monitoring. The TLB project involved sliplining twin 5 ft. diameter culverts that were: 262 ft. in length, slope of 4.5% and outlet perch of 1.5 ft. A concrete pool/weir fishway was constructed at the outlet for fish to ascend the perched culvert. The fishway culvert was retrofitted with an angled corner baffle system. Mean daily flows are directed into the baffled culvert by an inlet diversion wall. Brook Trout movement will be studied by stationary PIT tag antenna systems installed below/above the culvert pre-, during and post-fall spawning from 2016-2018. Mobile tag searches will also be conducted. Preliminary results of PIT tag monitoring in 2016 will be discussed that include passage transit times, efficiency and daily movement patterns. Information and lessons learned from this sliplining project will help guide the development and design of fish passage features at future projects. If culvert modifications cannot successfully pass fish, future projects may require offsite mitigation.
*Nathan, Lucas R1, Amy B Welsh2, and Jason C Vokoun1. A tale of two watersheds: exploring riverscape drivers of Brook Trout genetic structuring.
1University of Connecticut, Storrs, CT, 2West Virginia University, Morgantown, WV
The dispersal of fish and other aquatic organisms is influenced by a diverse array of natural and anthropogenic factors. Although species like Brook Trout are commonly assumed to be predominately residential, infrequent dispersal at larger scales can play substantial roles in promoting long term population viability by maintaining genetic diversity. Identifying features on the landscape that limit connectivity, therefore, is an important and necessary step towards designing effective conservation actions. To evaluate the potential influence of riverscape variables on Brook Trout population structuring, we collected genetic samples from over 2,000 individuals across two Connecticut watersheds each spanning approximately 1000 km2. The two watersheds were selected based on contrasting network architectures, with one having a more classic dendritic pattern while the other was a network of parallel, linear subwatersheds. Using a suite of genetic techniques, we documented genetic relatedness and quantified dispersal among headwater stream populations. We then used landscape genetic analyses to identify the combination of anthropogenic and natural variables potentially driving genetic structuring. Results indicated metrics of genetic differentiation (Fst) between neighboring streams ranged ten-fold over comparable stream distances and a combination of anthropogenic barriers and natural features influenced such relationships. The results of this study will be used to identify features limiting connectivity across broad spatial extents which can be targeted for conservation actions. This type of empirically-informed approach will allow for more biologically relevant upstream/downstream and among stream restoration prioritization strategies, moving beyond simply attempting to maximize miles upstream of a barrier recommended for removal.
Nebiolo, Kevin1. Analysis methods for evaluating passage of adult American Shad at the Turners Falls and Northfield Mountain Projects.
1Kleinschmidt Associates, Essex, CT
An analysis on the migration and emigration of adult shad throughout the Connecticut River was conducted as part of a FERC relicensing study. In 2015, FirstLight conducted a combined radio and PIT telemetry-based study to investigate the behavior, routes of passage, passage success, survival, and delay of American Shad as they encounter the project infrastructure during both upstream and downstream migration. Radio and Passive Integrated Transponder (PIT) telemetry methods were employed to track nearly 800 shad as they migrated through the projects. We first created a telemetry network consisting of receivers as nodes, and possible passage pathways of edges. Then, a mix of methods assessed each objective, including the classic Cormack-Jolly-Seber open population mark recapture model to assess ladder passage and identify bottlenecks, Cox Proportional Hazards regression modelling to assess project induced delay, and Multi-State Markov models to assess route of passage and attraction. A subset of the analyses is presented herein.
Nelson, Gary A1. Bias in catch curve analysis of age-frequency data from fisheries-independent surveys.
1Massachusetts Division of Marine Fisheries
Catch curve analysis is a common way to estimate total mortality (Z) from a single sample of age-frequency data taken from a fish population. In cases where catch age compositions are not available for exploited stocks, researchers often use age data collected from fisheries-independent surveys. A basic requirement of all estimators (e.g., Chapman-Robson, Heincke, linear regression etc.) is that individuals are collected via simple random sampling to meet the independence assumption of the underlying probability models. In reality, fish are not collected by simple random sampling during fisheries surveys, but rather by random cluster sampling because individuals are captured in groups or cluster by the survey gear. Cluster sampling creates non-independence of observations. If the common methods are applied to age frequencies from cluster sampling, estimates of total mortality and associated variance will likely be biased. In addition, fish for ageing are often subsampled from a tow or haul and this adds extra-variation to estimated age frequencies which is not accounted for by the common estimators.
In this study, I explored the impacts of clustering and subsampling on the performance of catch curve estimators through simulation. I found that the least biased estimates of Z were produced by the Chapman-Robson and Poisson regression methods, and that the newly-introduced random-intercept Poisson mixed model, which usually performs better than the other methods when assumptions are violated, performed very poorly when subsampling occurred.
Nieland, Julie1 and Timothy Sheehan1. Assessing the effects of dams, marine and freshwater survival, and hatchery supplementation on Atlantic Salmon recovery in the Penobscot River, Maine.
1NOAA Fisheries, Northeast Fisheries Science Center, Woods Hole, Ma
Atlantic salmon populations in Maine are listed as endangered under the Endangered Species Act. Marine survival and dams are considered to be two of the biggest impediments to increasing these populations, but freshwater survival and hatchery supplementation will also affect their recovery potential. We used a population viability analysis of Atlantic salmon in the Penobscot River, Maine, to assess the effects of dams, marine and freshwater survival, and hatchery supplementation on the demographics of this population. We ran various scenarios to evaluate the influence of these four factors on recovery of Atlantic salmon in the Penobscot River watershed. Increased marine survival led to greater increases in abundance than increased freshwater survival, and, as expected, hatchery supplementation and fewer dams in the watershed helped the population reach recovery when marine and freshwater survival rates were low. Although increases in marine and freshwater survival will both be necessary for this Atlantic salmon population to recover, new management options for increasing marine survival appear limited. Therefore, restoration efforts should focus on increasing the number of salmon coming from the freshwater environment, which means increasing survival during juvenile life stages, minimizing dam impacts, and continuing hatchery supplementation to increase the recovery potential of the population. Quantifying the impacts of these factors on the recovery potential of Atlantic salmon in the Penobscot River can help inform management strategies and frame expected outcomes for potential management options across the species’ U.S. range to facilitate recovery.
Nye, Janet A1, Emily Markowitz1, Adam F Younes1, and Maxwell Silverstein2. Does overwintering survival determine recruitment of black sea bass on the New England US continental shelf?
1School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, 2Duke University, Durham, NC
As climate change induces the large-scale redistribution of fishes, it is critical to understand the mechanisms that cause these shifts to allow us to predict their future abundance and distribution. In the Northeast US, the northward expansion of black sea bass has been documented and it will likely become an important fishery in the Gulf of Maine in the near future. One mechanism that has been proposed to explain the northward expansion of black sea bass has been that overwintering mortality has decreased in recent years because of warmer water temperatures. We tested this hypothesis by first developing a winter survivorship model as a function of temperature, salinity and fish size for black sea bass in the laboratory. We then applied this model to the Northeast US shelf using bottom temperature and salinity hindcasts from a Regional Ocean Modelling Systems (ROMS) for 1967-2007. We found that recruitment only in some state surveys was correlated to a simple measure of the coastwide winter suitable habitat. Furthermore, each year there was a consistent region of suitable winter habitat to which black sea bass could migrate to overwinter and survive. Even in some places in the Gulf of Maine, conditions would allow survivorship of black sea bass in most years. We discuss several reasons for the weak relationship between recruitment and our index of total suitable winter habitat and hypothesize that the increase in the length of the summer-fall growing season has improved survival of juvenile black sea bass in the northern US.
Rillahan, Chris1 and Pingguo He1. Reducing flounder bycatch in the Georges Bank Haddock Fishery: Application of a modified European grid system.
1SMAST University of Massachusetts Dartmouth
Georges Bank (GB) haddock is one of the few robust groundfish stocks in New England. GB haddock is a fully rebuilt stock which is not overfished and is not experiencing overfishing. However, the exploitation of the haddock resource is dependent on the status and quota allocations of bycatch species. Currently the populations of flatfish species, including yellowtail and windowpane flounder, are significantly depressed, making them quota-limiting species. To reduce the catch of these fish, a grid system with horizontal slots placed in the extension of a commercial demersal trawl was evaluated to exploit the morphological differences between groundfish (including Atlantic cod and haddock) and flatfish. The grid system was designed to allow selective escape of flatfish and juvenile groundfish. To evaluate their performance, comparative fishing trials were conducted on Georges Bank with the commercial fishing vessel F/V Hera. Alternating tows were conducted with and without the grid system. The result of twenty six tow pairs showed a 51.3% reduction in the catch rate of flounder, primarily winter flounder, and 29.4% reduction in skates, a major discard species. There was no significant reduction for Atlantic cod, the major round fish captured during sea trials. While the overall catch rate of haddock was reduced by 36.9%, the reduction was mainly associated with small fish below 47 cm fork length (19”). Overall the use of this modular grid system may be a tool which will allow fishermen to quickly alter species and size selection properties on their nets to match their species quote and to reduce undersize fish.
Savoy, Tom1. Sturgeon in Connecticut waters: an update.
1CT Department of Energy and Environmental Protection
From 1984 through 2016, Connecticut Department of Energy and Environmental Protection staff collected 4,985 Shortnose and Atlantic Sturgeon. All sturgeon were identified, examined, most were tagged and many selected for additional procedures (lavage, ageing and telemetry), roughly 15% of fish were recaptures. Shortnose Sturgeon accounted for 52% of the catch. Shortnose Sturgeon recaptures ranged up to 24 years between collections and many fish have been collected multiple times. Mark recapture data document growth (length and weight) and systematic increases in the numbers of Shortnose Sturgeon in the lower Connecticut River. Atlantic Sturgeon recaptures include many tagged out of State with coastal migrants recaptured from all 5 NOAA designated DPS’. Atlantic Sturgeon tagged and recaptured in Connecticut waters document highly variable growth but averaged 0.31 mm FL/day for sub-adult fish. Over 350 sturgeon were surgically implanted with ultrasonic transmitters for determining seasonal movement patterns and important habitats. Passive acoustic receivers were deployed to document fish presence and movements. Array size and configuration varied widely among years but over 10,000,000 detections have been collected. Telemetry and recapture efforts documented high fidelity of Atlantic Sturgeon to and seasonal presence in Connecticut waters, some fish returning up to four years in a row. Atlantic Sturgeon also annually entered the Connecticut River and traveled well above the salt wedge (rkm 26), some to river kilometer 84. Genetic testing of 47 small Atlantic Sturgeon collected in 2014 documented a unique genotype suggesting a successful spawning in the Connecticut River.
Savoy, Tom1, Jacqueline Benway1. Connecticut River American Shad.
A brief life history of the fish and the Connecticut River basin will be presented for background. Restoring shad to river areas denied them were thought to enhance stock size by providing access to additional spawning and rearing habitat. A CT River restoration target was 2,000,000 shad to the mouth and 50% over each dam. A significant distinction of the Connecticut River population from many other Rivers was that from 1849 (first main stem dam completion at river kilometer 140) to 1975, the population persisted, sustained moderate sport and commercial fisheries and had a robust age structure. Upstream fish passage of 20 to 60% of the annual run above the first dam since 1976 has resulted in no discernable large increases in population size. In contrast, management efforts had significant negative effects by reducing both the percentage of repeat spawning shad and thus the number of age classes in the annual spawning run. The stock is now primarily composed of virgin fish and is at greater risk of recruitment failure given dependency on few virgin year classes in the spawning population (currently 3 versus 5-7 historically). Older year classes of repeat spawners had both higher fecundities and larger more viable eggs. One or more poor consecutive year classes will reduce population size to levels well below the long term average and raises concern over long term population stability. Year class failure is more likely with the truncated age structure and long term viability of the population is threatened.
*Snyder, Jacob1, Christopher Murray1, and Hannes Baumann1. Maternal effects on offspring CO2 sensitivity in a coastal marine fish.
1UCONN Avery Point Department of Marine Sciences
Many marine fish employ maternal provisioning as a strategy to better prepare offspring for changing environmental conditions. Whether maternal provisioning influences the sensitivity of fish early life stages to elevated CO2 conditions has yet to be determined. We reared offspring batches derived from five female Atlantic silversides (Menidia menidia) under contrasting CO2 conditions from fertilization to 16 days post hatch and quantified six response traits, including growth and survival. For most traits, we found strongly divergent responses (expressed as log-transformed response ratios, lnRR) between batches, and subsequently used fatty acid (FA) profiles of the unfertilized eggs to test for associations with the observed lnRR’s. Multiple FA’s were positively correlated (20:1n9, 22:5n3, 15:0) with survival lnRR’s while others were negatively correlated (18:3n3, 18:4n3, 22:6n3) with length lnRR’s. Maternal investment has been shown to be highly important to offspring survival, and this study shows that variable egg provisioning by mothers with certain FAs may influence offspring sensitivity to high CO2 environments. Our study also suggested that ocean acidification experiments on fish early life stages need to be based on a large number of spawners in order to avoid biases resulting from individual maternal effects.
Staudinger, Michelle D1, Kathy Mills2, Nathan Rebuck3, Christy Hudak4, Adrian Jordaan5, Karen Stamieszkin6, Dan Pendleton7, Kevin Friedland3, Rubao Ji8, Andrew Allyn2, Mila Calandrino5, Tony Diamond9, Zhixuan Feng8, Christine Feurt10, Walt Golet2, Meaghan Henderson11, Chrissy Hernandez8, Tom Huntington12, Catherine Johnson13, Dave Johnson14, John Kocik3, Yun Li8, Matt Liebman15, Ivy Misna15, Owen Nichols4, Nick Record16, Anne Richards3, Tom Robben17, Jen Seavey18, Josh Stoll6, Jenny Sun2, Andy Thomas6, Harvey Walsh3, and Keenan Yakola5. It’s about time: A synthesis of changing phenology in the Gulf of Maine Ecosystem.
1Northeast Climate Science Center, Amherst, MA, 2Gulf of Maine Research Institute, 3NOAA Northeast Fisheries Science Center, 4Center for Coastal Studies, 5University of Massachusetts Amherst, 6University of Maine, 7New England Aquarium, 8Woods Hole Oceanographic Institution, 9University of New Brunswick, 10Univeristy of New England, 11Stony Brook University, 12United States Geological Survey, 13Fisheries and Oceans Canada, 14Virginia Institute of Marine Science, 15United States Environmental Protection Agency, 16Bigelow Lab for Ocean Sciences, 17Connecticut Ornithological Association, 18University of New Hampshire
Climate change is causing species to shift their phenology, or the timing of recurring life events, in variable and complex ways. If phenological shifts differ among species, the result would be mismatches or asynchronies in food and habitat resources that impact individual fitness, population dynamics, and ecosystem function. While climate change induced shifts in phenology have been well documented in terrestrial ecosystems, particularly relative to flowering plants and migratory song birds, studies of marine organisms have been limited to date. This presentation will provide an overview of the current understanding of changes in timing of recurring seasonal environmental and ecological events, as well as the implications of those shifts on regional management, conservation, and climate change adaptation strategies in the Gulf of Maine Ecosystem. Results highlight where we have sufficient evidence and observations to detect regional phenological shifts and where gaps remain. While climate change is a likely factor influencing observed or inferred shifts in phenology, other direct and indirect mechanisms that can confound our detection of regional signals will also be discussed. A set of phenology-relevant recommendations that address bias and gaps in monitoring protocols will help identify where additional effort is needed to improve spatial and temporal resolution for specific variables and species of high conservation and management concern. We anticipate this comprehensive examination of shifting phenology will be useful to inform climate change adaptation strategies seeking to reduce uncertainty and sustain important natural resources in the Gulf of Maine region.
Sweanarton, John T1 and Donald F Landers Jr1. Long-term (1984-2015) trends in catches of incidental species from an experimental lobster trap survey in eastern Long Island Sound.
1Dominion Resources Services, Millstone Environmental Laboratory, PO Box 128, Rope Ferry Rd, Waterford, CT 06385
Since 1984, catches of incidental fishes and invertebrates in 60 experimental lobster traps deployed from May to October around Millstone Power Station were recorded as part of a comprehensive ecological monitoring study. While lobster catches have declined locally (and throughout southern New England), catches of other crustaceans increased during the study period (blue crabs, hermit crabs) or have fluctuated without any apparent trend (Jonah crabs). Catches of fishes commonly found in traps (Cunner, Tautog, Scup) have also fluctuated without any obvious trend as have whelk catches. Spider crab and rock crab catches have generally declined since peaks in the 1990s, similar to the trend in lobsters. Incidental catch data provide another perspective on significant ecosystem changes observed in other aspects of this monitoring study (e.g., adult finfish and ichthyoplankton) as well as other studies in the region.
*Sweezey, Brett1, Micah Dean2, Benoit Hugues3, John Mandelman1, and James Sulikowski1. Determining post-release mortality for Atlantic Cod discarded in the Gulf of Maine lobster fishery.
1University of New England, 2Massachusetts Division of Marine Fisheries, 3University of New Brunswick
Atlantic cod, Gadus morhua, has experienced heightened fishing-induced mortality since the 1990s leading to the lowest population abundances in recorded history. Although rigorous commercial and recreational limitations have been established in an attempt to restore this species, population levels remain at all-time lows. A potential issue affecting the recovery of cod populations is the unaccounted discard mortality experienced within Northwest Atlantic fisheries. With over 4 million fished traps, the lobster industry represents Maine’s largest fishery and has recently been suggested as a major contributor towards the increased mortality rates of cod within this region. For example, preliminary data suggests that discard rates as high as 1.32 cod/trip may exist. Additionally, recent evidence suggests individuals that experience multiple capture events may have elevated rates of mortality due to chronic stress. To evaluate the post release mortality of cod within commercial lobster gear, an acoustic array measuring 36 km2 was established off of Cape Porpoise. Data was collected from June to October 2016, resulting in 55 cod captured over 54 fishing trips (consisting of approximately 10,000 individual trap hauls). Acoustic transmitters were placed on 30 individuals, 28 of these cod were detected throughout the array, and three of which were later recaptured within lobster gear. Preliminary results indicate injury conditions upon capture ranging from absent (68%), to minor (20%), or deceased upon haul (12%). Discard mortality will be assessed by correlating vitality condition upon capture with the observed or absence of movement throughout the acoustic array.
Tableau, Adrien1, Jeremy Collie1, and Richard Bell2. Understanding climate-induced changes in fish productivity to inform sustainable management.
1Rhode Island University – Graduate School of Oceanography, Narragansett, RI, 2The Nature Conservancy, Narragansett, RI
Evidence is accumulating that climate change and variability are affecting the distribution, recruitment and production of marine fish species. Even so, it is difficult to distinguish climate signals from other processes, including mortality from fishing and predation. At the same time, annual catch limits must be specified without full understanding of these production processes. This study identifies changes in stock productivity for 20 managed fish species on the Northeast Shelf Large Marine Ecosystem with a Kalman filter approach. For each stock, biological reference points are used to define harvest control rules. Thus, time-varying biological reference points are calculated for stocks exhibiting changes in productivity. They are compared to constant reference points to determine their relevance for use in management. A second step consists of improving the prediction of productivity for each stock. For data-poor stocks, the approach of using the covariance with other stocks will be introduced. For stocks exhibiting a trended and/or climate-driven productivity, we offer a method to account for this shared information in the Kalman filter framework. For both approaches, we assess the performance of the productivity prediction to conclude on their respective value for management.
*Teffer, Amy1, Kristi Miller2, Steven Cooke3, Ken Jeffries4, Francis Juanes1, Scott Hinch5. Incorporating infectious disease processes into our understanding of the impacts of multiple stressors on wild Pacific salmon.
1Department of Biology, University of Victoria, Victoria, BC, 2Fisheries and Oceans Canada, Molecular Genetics Section, Pacific Biological Station, Nanaimo, BC, 3Fish Ecology and Conservation Physiology Laboratory, Carleton University, Ottawa, ON, 4Department of Biological Sciences, University of Manitoba, Winnipeg, MB, 5Pacific Salmon Ecology and Conservation Laboratory, Department of Forest Sciences, University of British Columbia, Vancouver, Canada
Like many migratory species, adult Pacific salmon encounter multiple stressors en route to spawning grounds, simultaneously carrying a diversity of infectious agents. Productivity of Pacific salmon in recent decades has declined concurrently with rising river temperatures and intense fisheries effort. Fisheries bycatch, a generally stressful and injurious event, and climate-induced high river temperatures likely influence the mechanisms of en route mortality by interacting with or enhancing infectious disease processes. To test this hypothesis, we collected adult Coho salmon from the Fraser River watershed, British Columbia and exposed them to gillnet entanglement at cool or warm temperatures. We non-lethally sampled gill tissue at the onset and periodically throughout a holding period of two weeks, and used high-throughput qPCR to characterize infectious agent intensity concurrently with host genomic immune responses. Survival was decreased at high temperature and following entanglement. Infectious agents showed variable responses to high temperature and entanglement, but infection intensity was generally enhanced in fish that died prematurely. Gene expression biomarkers of iron metabolism, osmotic stress, and wound healing in gill positively associated with entanglement, high temperature, mortality, and females. Our results demonstrate the importance of temperature, fisheries, and sex in understanding the disease processes of wild fish and the fitness consequences for semelparous species like Pacific salmon as river temperatures and fisheries demand continue to rise.
Tomicheck, Chris1 and Rich Murray2. Overview of development and construction of Shortnose Sturgeon passage protection at the Holyoke Dam.
1Kleinschmidt Associates, Essex, CT, 2Holyoke Gas & Electric, Holyoke, MA
Holyoke Dam is the first dam fish encounter during their annual migration up the Connecticut River. The owners of the Holyoke Dam, Holyoke Gas & Electric (HG&E) conducted over 10 years of research in cooperation with the Resource Agencies to address a permanent solution for downstream fish passage including, specifically, Shortnose Sturgeon. The first challenge for this project was gaining an understanding of the swimming behaviors of the Shortnose Sturgeon. Until this project, little was known about passing Shortnose Sturgeon upstream and downstream of hydroelectric facilities. First through flume studies, we were able to gain knowledge of swimming behaviors at varying intake rack velocities and attraction to bypass devices. Once an understanding of the flow dynamics needed to attract and move Shortnose Sturgeon was developed, a series of computational fluid dynamic (CFD) models were created to model the desired flow fields at the Holyoke Dam. Based on the results of the research, in 2015, HG&E installed a multi-million-dollar downstream fish passage system. Field evaluations of passage effectiveness are being conducted with Shortnose Sturgeon, juvenile and adult American shad and American eels. Interestingly after the Project was completed there was a surge in the number of Shortnose Sturgeon entering the upstream fish lift. In 2016, 93 sturgeon entered and were successfully lifted which is a significant increase from the previous average of 3 Shortnose Sturgeon per year.
Turner, Sara M1, Bradford C Chase1, and Michael S Bednarski2. Evaluating the effect of dam removal on yellow-phase American eel abundance in a Northeast U.S. watershed.
1Massachusetts Division of Marine Fisheries, 2Virginia Department of Game and Inland Fisheries
The negative effects of dams and the benefits of dam removal for anadromous populations have been well documented. The effects of dams on catadromous Anguillidae may be less drastic, although documentation of the response of catadromous species to dam removal is limited. We developed a mark-recapture study design to estimate the abundance of catadromous American eel (Anguilla rostrata) within a small coastal watershed and to compare estimates of abundance before and after barrier removal. In the Mill River, Taunton, MA, two dams were removed, juvenile eel passage installed at another, and removal of the final is scheduled. Mark-recapture sampling and modeling methods were developed and applied in Lake Sabbatia, the source of the Mill River, over a four-year period from the initiation of restoration. Rectangular eel traps were found to have higher catch per unit effort than double-funnel traps used in previous studies, and a tag retention study found relatively high retention rates (97% overall). Abundances of yellow-phase American eels have increased with improved passage and recruitment to sampling gear during the study period. Dam removal could have substantial benefits to the coastwide stock of American eel, and methods to evaluate changes in abundances are important for management as well as restoration ecology and project selection.
Walsh, Harvey J1, Jon Hare2, Ken Able3, Thomas Grothues3, Jason Goldstein4, and Jeremy Miller4. A comparison of long-term oceanic and estuarine larval fish abundance between the Gulf of Maine and Mid-Atlantic Bight.
1NOAA, Northeast Fisheries Science Center, Narragansett, RI, 2NOAA, Northeast Fisheries Science Center, Woods Hole, MA, 3Rutgers University Marine Field Station, Tuckerton, NJ, 4Wells National Estuarine Research Reserve, Wells, ME
Changes in climate and ocean conditions are topics of increasing importance because of the current and future implications of its effects, especially in marine ecosystems that support commercially important fisheries. Distributional shifts have been documented for a number of species, for both adults and larvae, along the Northeast U.S. Shelf Ecosystem. Many of the species that have shifted distributions use oceanic, shallow coastal, and estuarine environments for at least part of their life cycle. Thus, the trends in long-term abundance among multiple locations along the Northeast Shelf can inform changes in distribution, including range expansions or contractions. The Northeast Fisheries Science Center (NEFSC) has been collecting shelf-wide concurrent ichthyoplankton and hydrographic data on the Northeast U.S. Shelf Ecosystem since the 1970s. The Rutgers University Marine Field Station (RUMFS) has been collecting larval fish ingressing into the Mullica River, Great Bay Little Egg Inlet (Mid-Atlantic Bight) since 1989. Finally, ingress sampling of larval fishes of the Webhannet River Estuary (Gulf of Maine) by the Wells National Estuarine Research Reserve (WNERR) started in 2008. Relationships between mean larval abundance from the shelf collections and larval abundance from estuarine collections were assessed using cross-correlation analyses for three species: Black Sea Bass (Centropristis striata), Windowpane (Scophthalmus aquosus), and Summer Flounder (Paralichthys dentatus). Patterns from cross-correlation analyses will be used to describe range shifts for the three species.
*Weissman, Amelia1, John Mandelman2, Dave Rudders3, and James Sulikowski1. Stress and discard mortality of Lophius americanus in the scallop dredge fishery.
1University of New England, Biddeford, ME, 2New England Aquarium, Boston, MA, 3Virginia Institute of Marine Science
Post-release mortality (PRM) studies are considered a primary research priority, particularly for species and fisheries where discard rates are high, and/or for overfished stocks and species of concern. Lophius americanus, the most lucrative finfish in New England, constitutes the second highest bycatch species within the scallop dredge fishery. Despite its commercial importance, no data exists on the mortality rates of monkfish for any gear type. Given these shortcomings, our goals were to evaluate the stress and PRM of monkfish captured in scallop dredge gear. This was accomplished by assessing various physical and physiological conditions. To quantify stress levels, blood samples were taken to measure cortisol, lactate, hemoglobin, and hematocrit concentrations. In addition, a series of reflex responses were tested and injury codes, ranging from 1 (uninjured) to 4 (dead), were assigned to each monkfish in order to develop vitality indices. To correlate the aforementioned parameters to discard mortality, monkfish were held in onboard flow-through seawater tanks and all stress indicators were reassessed after a 72-hour holding period. Preliminary results suggest that number of reflex responses decreased significantly as exposure time (p<0.0001), tow duration (p = 0.007), and air temperature (p = 0.002) increased. In addition, average cortisol levels significantly increased as exposure time (mean change: 2.5 to 12.0 ng/ml; p = 0.003) and tow duration (mean change: 0.9 to 2.4 ng/ml; p = 0.0001) increased. Analysis of the tank study indicates that 80% of monkfish placed in holding tanks died after 72 hours, regardless of initial vitality index.
*Winton, Megan1, Gavin Fay1, Heather Haas2, Michael Arendt3, Susan Barco4, Michael James5, Christopher Sasso6, and Ronald Smolowitz7. Estimating loggerhead sea turtle densities from satellite telemetry data using geostatistical mixed models.
1Department of Fisheries Oceanography, School for Marine Science and Technology, University of Massachusetts Dartmouth, 200 Mill Road, Suite 325, Fairhaven, MA 02719, 2NOAA Fisheries, Protected Species Branch, Northeast Fisheries Science Center, 166 Water Street, Woods Hole, MA 02543, 3South Carolina Department of Natural Resources, 217 Fort Johnson Road, Charleston, SC 29412, 4Virginia Aquarium and Marine Science Center, 717 General Booth Blvd, Virginia Beach, VA 23451, 5Fisheries and Oceans Canada, 531 Brandy Cove Road, St. Andrews, New Brunswick ESB 2L9, 6NOAA Fisheries, Southeast Fisheries Science Center, 75 Virginia Beach Drive, Miami, FL, 7Coonamessett Farm Foundation, 277 Hatchville Road, East Falmouth, MA 02536
Data collected via satellite telemetry devices are often used to inform spatial conservation measures for threatened sea turtle populations. Most applied telemetry studies aim to reconstruct the continuous utilization distribution underlying reported locations to characterize the relative intensity of space use. However, commonly applied space use estimators do not directly estimate the underlying distribution of interest and, perhaps more importantly, ignore correlations in space and time that may bias estimates. Here we describe how geostatistical mixed models, which explicitly account for spatial and/or temporal correlation using Gaussian random fields, can be applied to directly approximate densities from satellite telemetry data. We illustrate this approach via application to satellite telemetry location observations collected from two hundred and seventy-one large juvenile and adult loggerhead sea turtles in the western North Atlantic from 2004-2016. We demonstrate how such models can be used to predict the overall spatial distribution of tagged individuals, as well as seasonal shifts in densities at smaller time scales. For tagged loggerheads, overall predicted densities were greatest in the shelf waters along the US Atlantic from Florida to North Carolina, but monthly predictions highlight the importance of summer foraging habitat in the mid-Atlantic Bight.
Introducing the new 50th SNEC edition t-shirt. Available in two styles on the back with the SNEC 50th logo on the front. Get yours today on the SNEC 50th registration page!
Help us design a new t-shirt for SNEC’s 50th Anniversary! Please contact Dr. Eric Schultz with ideas.