SNEC held the Summer meeting via Zoom with 9 talks and a keynote speaker. Check out the program here. We look forward to an in-person meeting in 2022.
Ambrose Jearld Jr. will be the SNEC Summer 2021 keynote speaker and will present a talk titled, “You Can Be the Future Now: How Will History View You?” Dr. Jearld worked at the National Oceanic and Atmospheric Administration Northeast Fisheries Science Center from 1978 until his retirement in 2016.
SNEC is offering a $500.00 travel award to a student giving a presentation at the 2021 AFS Annual Meeting in Baltimore. Applications are due on August 20. Check out the Student Travel Award page for all the details!
Thank you to everyone who planned for and participated in the Winter 2021 virtual meeting on January 11th. We had 96 registrants and over 70 people participating during the sessions. It was nice to see familiar faces, meet new people in breakout sessions, and learn together. The Program with the abstracts can now be found in the Meeting Archives. Check the website and your listserv email for news about the Summer 2021 meeting. If you have ideas for it, please contact me or the Program Committee Chair, Sara Turner.
AFS SNEC President
Student presentations made as part of the Winter Virtual meeting will be eligible for the Saul B. Saila Best Student Oral Presentation and Grace Klein-MacPhee Best Student Poster Awards. We will also have a special prize for the most unique/engaging virtual presentation!
*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.