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Animal Sciences

Series

2018

Fisheries Science Peer-Reviewed Articles

Articles 1 - 26 of 26

Full-Text Articles in Life Sciences

Impacts Of A Multi-Trap Line On Benthic Habitat Containing Emergent Epifauna Within The Mid-Atlantic Bight, Cara C. Schweitzer, Rom Lipcius, Bradley G. Stevens Dec 2018

Impacts Of A Multi-Trap Line On Benthic Habitat Containing Emergent Epifauna Within The Mid-Atlantic Bight, Cara C. Schweitzer, Rom Lipcius, Bradley G. Stevens

VIMS Articles

Alteration and degradation of benthic structure by fishing gear can impede efforts to manage fish stock sustainably. Although the impacts of mobile gear are well known, effects of passive gear (e.g. fish traps) upon structure have been little studied. We modified commercial traps for American lobster Homarus americanus and black sea bass Centropristis striata by attaching GoPro (R) cameras to ascertain the degree and nature of impacts to seafloor habitats. Customized traps were included within a line of 20 traps, deployed and retrieved according to standard commercial fishing practice. Less than 5% of traps landed directly on bedforms when deployed. …


Assessment Of The Relationship Of Stock And Recruitment In The Atlantic Surfclam Spisula Solidissima In The Northwestern Atlantic Ocean, Jeremy R. Timbs, Eric N. Powell, Roger L. Mann Dec 2018

Assessment Of The Relationship Of Stock And Recruitment In The Atlantic Surfclam Spisula Solidissima In The Northwestern Atlantic Ocean, Jeremy R. Timbs, Eric N. Powell, Roger L. Mann

VIMS Articles

Atlantic surfclams support a major commercial fishery in the western North Atlantic Ocean with landings consistently between 15,000 and 25,000 metric tons since 1982. The stock is not and historically has not been overfished nor has overfishing occurred; however, in recent years landings per unit effort have declined. Surfclams are a biomass dominant on the continental shelf and a bellwether of climate change in the northwestern Atlantic. This study investigated the relationship of broodstock and recruitment during a period when Mid-Atlantic warming initiated a shelf-wide shift in the surfclams range. A species distribution function model was used to assess the …


Rising Temperatures, Molting Phenology, And Epizootic Shell Disease In The American Lobster, Maya Groner, Jeffrey D. Shields, Df Landers, J Swenarton, Jm Hoenig Nov 2018

Rising Temperatures, Molting Phenology, And Epizootic Shell Disease In The American Lobster, Maya Groner, Jeffrey D. Shields, Df Landers, J Swenarton, Jm Hoenig

VIMS Articles

Phenological mismatchmaladaptive changes in phenology resulting from altered timing of environmental cuesis an increasing concern in many ecological systems, yet its effects on disease are poorly characterized. American lobster (Homarus americanus) is declining at its southern geographic limit. Rising seawater temperatures are associated with seasonal outbreaks of epizootic shell disease (ESD), which peaks in prevalence in the fall. We used a 34-year mark-recapture data set to investigate relationships between temperature, molting phenology, and ESD in Long Island Sound, where temperatures are increasing at 0.4 degrees C per decade. Our analyses support the hypothesis that phenological mismatch is linked to the …


The Effect Of Capture And Handling Stress In Lophius Americanus In The Scallop Dredge Fishery, Amelia M. Weissman, John W. Mandelman, David Rudders, James A. Sulikowski, Oct 2018

The Effect Of Capture And Handling Stress In Lophius Americanus In The Scallop Dredge Fishery, Amelia M. Weissman, John W. Mandelman, David Rudders, James A. Sulikowski,

VIMS Articles

Capture and handling stress 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, a commercially valuable finfish in New England, constitutes the second highest bycatch species within the sea scallop dredge fishery. Despite its commercial importance, no data exists on the capture and handling stress of monkfish for any gear type. Given these shortcomings, our goals were to evaluate the stress response of monkfish captured in scallop dredge gear by evaluating physical, behavioural and physiological responses to scallop fishing practices. While …


Successful Recruitment, Survival And Long-Term Persistence Of Eastern Oyster And Hooked Mussel On A Subtidal, Artificial Restoration Reef System In Chesapeake Bay, Rom Lipcius, Russell P. Burke Oct 2018

Successful Recruitment, Survival And Long-Term Persistence Of Eastern Oyster And Hooked Mussel On A Subtidal, Artificial Restoration Reef System In Chesapeake Bay, Rom Lipcius, Russell P. Burke

VIMS Articles

Restoration efforts with native eastern oyster, Crassostrea virginica, in Chesapeake Bay and elsewhere have been limited by shell availability, necessitating the use of alternative structures as subtidal reefs, yet these have rarely been evaluated quantitatively. We quantified population structure, density, abundance and biomass of eastern oyster and hooked mussel, Ischadium recurvum, on a concrete modular reef (75 m(2) surface area over 5 m(2) of river bottom) deployed subtidally at 7 m depth in the Rappahannock River, Virginia during October, 2000. After nearly 5 y (May 2005), we took 120 stratified random samples over the reef. The reef was heavily …


An Overview Of Factors Affecting Distribution Of The Atlantic Surfclam (Spisula Solidissima), A Continental Shelf Biomass Dominant, During A Period Of Climate Change, Ee Hofmann, En Powell, Jm Klinck, Dm Munroe, Roger L. Mann, Et Al Oct 2018

An Overview Of Factors Affecting Distribution Of The Atlantic Surfclam (Spisula Solidissima), A Continental Shelf Biomass Dominant, During A Period Of Climate Change, Ee Hofmann, En Powell, Jm Klinck, Dm Munroe, Roger L. Mann, Et Al

VIMS Articles

The Atlantic surfclam (Spisula solidissitna) is a dominant member of the biological community of the Middle Atlantic Bight continental shelf and a commercially harvested species. Climate warming is affecting the biology and distribution of this species, which provides an opportunity to investigate the processes and conditions that are restructuring this fishery and the implications for ecological and socioeconomic systems. A Management Strategy Evaluation (MSE) developed for the surfclam fishery provides a mechanistic description of the surfclam's response to climate change and understanding of the cascade of effects initiated by changes in oceanographic conditions that ultimately appear as social …


Short-Term Pain And Long-Term Gain: Using Phased-In Minimum Size Limits To Rebuild Stocks-The Pacific Bluefin Tuna Example, Lisa E. Ailloud, Todd Gedamke, John M. Hoenig Oct 2018

Short-Term Pain And Long-Term Gain: Using Phased-In Minimum Size Limits To Rebuild Stocks-The Pacific Bluefin Tuna Example, Lisa E. Ailloud, Todd Gedamke, John M. Hoenig

VIMS Articles

Like many stocks, the Pacific Bluefin Tuna Thunnus orientalis has been considerably depleted. High exploitation rates on very young fish have reduced the spawning stock biomass (SSB) to 2.6% of the unexploited level. We provide a framework for exploring potential benefits of minimum size regulations as a mechanism for rebuilding stocks, and we illustrate the approach using simulations patterned after Pacific Bluefin Tuna dynamics. We attempt to mitigate short-term losses in yield by considering a phased-in management strategy. With this approach, the minimum size limit (MSL) is gradually increased as biomass rebuilds, giving fishing communities time to adjust to new …


Fish Assemblage Change Following The Structural Restoration Of A Degraded Stream, Carl A. Favata, Anabela Maia, Manisha Pant, Vaskar Nepal Oct 2018

Fish Assemblage Change Following The Structural Restoration Of A Degraded Stream, Carl A. Favata, Anabela Maia, Manisha Pant, Vaskar Nepal

VIMS Articles

Decades of anthropogenic pressure have harmed riverscapes throughout North America by degrading habitats and water quality and can result in the extirpation of sensitive aquatic taxa. Local stream restoration projects have increased in frequency, but monitoring is still infrequent. In 2010, Kickapoo Creek in East Central Illinois was subjected to a stream restoration project that included implementation of artificial riffles, riprap, scouring keys, and riparian vegetation. We monitored the restoration efforts for 6years after the restoration through annual sampling efforts at restored and reference sites to determine changes in habitat and fish assemblage using standard habitat sampling and electrofishing techniques. …


A Hierarchical Bayesian Modeling Approach For The Habitat Distribution Of Smooth Dogfish By Sex And Season In Inshore Coastal Waters Of The Us Northwest Atlantic, Andrea Dell'apa, Maria Grazia Pennino, Charles W Bangley, Christopher F. Bonzek Oct 2018

A Hierarchical Bayesian Modeling Approach For The Habitat Distribution Of Smooth Dogfish By Sex And Season In Inshore Coastal Waters Of The Us Northwest Atlantic, Andrea Dell'apa, Maria Grazia Pennino, Charles W Bangley, Christopher F. Bonzek

VIMS Articles

The Smooth Dogfish Mustelus canis is an abundant, small coastal shark occurring along the U.S. Atlantic coast. Despite being targeted by a directed fishery and having recently undergone a stock assessment that found the population neither overfished nor experiencing overfishing, little is known about the spatial and temporal distribution of this species. Here, we used catch data from the spring and fall Northeast Area Monitoring and Assessment Program's fishery-independent trawl surveys conducted between 2007 and 2016 and various environmental factors to perform hierarchical Bayesian modeling as a first attempt to spatially predict adult Smooth Dogfish CPUE in U.S. northwest Atlantic …


Dermal Mycobacteriosis And Warming Sea Surface Temperatures Are Associated With Elevated Mortality Of Striped Bass In Chesapeake Bay, Maya L. Groner, John M. Hoenig, Roger Pradel, Remi Choquet, Wolfgang K. Vogelbein, David T. Gauthier, Marjorie A.M. Friedrichs Sep 2018

Dermal Mycobacteriosis And Warming Sea Surface Temperatures Are Associated With Elevated Mortality Of Striped Bass In Chesapeake Bay, Maya L. Groner, John M. Hoenig, Roger Pradel, Remi Choquet, Wolfgang K. Vogelbein, David T. Gauthier, Marjorie A.M. Friedrichs

VIMS Articles

Temperature is hypothesized to alter disease dynamics, particularly when species are living at or near their thermal limits. When disease occurs in marine systems, this can go undetected, particularly if the disease is chronic and progresses slowly. As a result, population-level impacts of diseases can be grossly underestimated. Complex migratory patterns, stochasticity in recruitment, and data and knowledge gaps can hinder collection and analysis of data on marine diseases. New tools enabling quantification of disease impacts in marine environments include coupled biogeochemical hydrodynamic models (to hindcast key environmental data), and multievent, multistate mark-recapture (MMSMR) (to quantify the effects of environmental …


Abundance Trends Of Highly Migratory Species In The Atlantic Ocean: Accounting For Water Temperature Profiles, Patrick D. Lynch, Kyle W. Shertzer, Enric Cortes, Robert J. Latour Jul 2018

Abundance Trends Of Highly Migratory Species In The Atlantic Ocean: Accounting For Water Temperature Profiles, Patrick D. Lynch, Kyle W. Shertzer, Enric Cortes, Robert J. Latour

VIMS Articles

Relative abundance trends of highly migratory species (HMS) have played a central role in debates over the health of global fisheries. However, such trends have mostly been inferred from fishery catch rates, which can provide misleading signals of relative abundance. While many biases are accounted for through traditional catch rate standardization, pelagic habitat fished is rarely directly considered. Using a method that explicitly accounts for temperature regimes, we analysed data from the US pelagic longline fishery to estimate relative abundance trends for 34 HMS in the Atlantic Ocean from 1987 through 2013. This represents one of the largest studies of …


Comparative Performance Of Three Length-Based Mortality Estimators, Quang C. Huynh, Jennifer Beckensteiner, Liese M. Carleton, Benjamin J. Marcek, Vaskar Nepal Kc, Cassidy D. Peterson, Megan A. Wood, John M. Hoenig May 2018

Comparative Performance Of Three Length-Based Mortality Estimators, Quang C. Huynh, Jennifer Beckensteiner, Liese M. Carleton, Benjamin J. Marcek, Vaskar Nepal Kc, Cassidy D. Peterson, Megan A. Wood, John M. Hoenig

VIMS Articles

Length‐based methods provide alternatives for estimating the instantaneous total mortality rate (Z) in exploited marine populations when data are not available for age‐based methods. We compared the performance of three equilibrium length‐based methods: the length‐converted catch curve (LCCC), the Beverton–Holt equation (BHE), and the length‐based spawning potential ratio (LB‐SPR) method. The LCCC and BHE are two historically common procedures that use length as a proxy for age. From a truncated length‐frequency distribution of fully selected animals, the LCCC estimates Z with a regression of the logarithm of catch at length by the midpoint of the length‐bins, while the …


Gear And Survey Efficiency Of Patent Tongs For Oyster Populations On Restoration Reefs, David M. Schulte, Rom Lipcius, Rp Burke May 2018

Gear And Survey Efficiency Of Patent Tongs For Oyster Populations On Restoration Reefs, David M. Schulte, Rom Lipcius, Rp Burke

VIMS Articles

Surveys of restored oyster reefs need to produce accurate population estimates to assess the efficacy of restoration. Due to the complex structure of subtidal oyster reefs, one effective and efficient means to sample is by patent tongs, rather than SCUBA, dredges, or bottom cores. Restored reefs vary in relief and oyster density, either of which could affect survey efficiency. This study is the first to evaluate gear (the first full grab) and survey (which includes selecting a specific half portion of the first grab for further processing) efficiencies of hand-operated patent tongs as a function of reef height and oyster …


Debating The Effectiveness Of Marine Protected Areas, Linwood H. Pendleton, Gabby N. Ahmadia, Howard I. Browman, Ruth Thurstan, David M. Kaplan, Valerio Bartolino May 2018

Debating The Effectiveness Of Marine Protected Areas, Linwood H. Pendleton, Gabby N. Ahmadia, Howard I. Browman, Ruth Thurstan, David M. Kaplan, Valerio Bartolino

VIMS Articles

Increasing the size and number of marine protected areas (MPAs) is widely seen as a way to meet ambitious biodiversity and sustainable development goals. Yet, debate still exists on the effectiveness of MPAs in achieving ecological and societal objectives. Although the literature provides significant evidence of the ecological effects of MPAs within their boundaries, much remains to be learned about the ecological and social effects of MPAs on regional and seascape scales. Key to improving the effectiveness of MPAs, and ensuring that they achieve desired outcomes, will be better monitoring that includes ecological and social data collected inside and outside …


Tidal Habitats Support Large Numbers Of Invasive Blue Catfish In A Chesapeake Bay Subestuary, Mary C. Fabrizio, Troy D. Tuckey, Robert J. Latour, Gary C. White, Alicia J. Norris May 2018

Tidal Habitats Support Large Numbers Of Invasive Blue Catfish In A Chesapeake Bay Subestuary, Mary C. Fabrizio, Troy D. Tuckey, Robert J. Latour, Gary C. White, Alicia J. Norris

VIMS Articles

The introduction of a non-native freshwater fish, blue catfish Ictalurus furcatus, in tributaries of Chesapeake Bay resulted in the establishment of fisheries and in the expansion of the population into brackish habitats. Blue catfish are an invasive species in the Chesapeake Bay region, and efforts are underway to limit their impacts on native communities. Key characteristics of the population (population size, survival rates) are unknown, but such knowledge is useful in understanding the impact of blue catfish in estuarine systems. We estimated population size and survival rates of blue catfish in tidal habitats of the James River subestuary. We tagged …


Activity Seascapes Highlight Central Place Foraging Strategies In Marine Predators That Never Stop Swimming, Yannis P. Papastamatiou, Yuuki Y. Watanabe, Urska Demšar, Vianey Leos-Barajas, Darcy Bradley, Roland Langrock, Kevin C. Weng, Christopher Lowe, Alan M. Friedlander, Jennifer E. Caselle May 2018

Activity Seascapes Highlight Central Place Foraging Strategies In Marine Predators That Never Stop Swimming, Yannis P. Papastamatiou, Yuuki Y. Watanabe, Urska Demšar, Vianey Leos-Barajas, Darcy Bradley, Roland Langrock, Kevin C. Weng, Christopher Lowe, Alan M. Friedlander, Jennifer E. Caselle

VIMS Articles

Background: Central place foragers (CPF) rest within a central place, and theory predicts that distance of patches from this central place sets the outer limits of the foraging arena. Many marine ectothermic predators behave like CPF animals, but never stop swimming, suggesting that predators will incur ‘travelling’ costs while resting. Currently, it is unknown how these CPF predators behave or how modulation of behavior contributes to daily energy budgets. We combine acoustic telemetry, multi-sensor loggers, and hidden Markov models (HMMs) to generate ‘activity seascapes’, which combine space use with patterns of activity, for reef sharks (blacktip reef and grey reef …


Genetic Evaluation Of Population Structure In White Marlin (Kajikia Albida): The Importance Of Statistical Power, Nadya Mamoozadeh, Jan Mcdowell, Jay R. Rooker, John E. Graves Mar 2018

Genetic Evaluation Of Population Structure In White Marlin (Kajikia Albida): The Importance Of Statistical Power, Nadya Mamoozadeh, Jan Mcdowell, Jay R. Rooker, John E. Graves

VIMS Articles

The genetic basis of population structure in white marlin (Kajikia albida) is not well understood. Previous evaluation of genetic population structure in this species utilized a small number of molecular markers to survey genetic variation across opportunistically collected samples of adults, resulting in statistically significant levels of genetic differentiation for some pairwise comparisons and global levels of genetic differentiation that approached statistical significance. This study increased statistical power to improve resolution of genetic population structure in white marlin by surveying a larger number of molecular markers across sample collections of increased size, including collections from additional geographic locations …


Mitotic Instability In Triploid And Tetraploid One-Year-Old Eastern Oyster, Crassostrea Virginica, Assessed By Cytogenetic And Flow Cytometry Techniques, Jt De Sousa, Standish K. Allen Jr., Bm Wolfe, Ja Moss Feb 2018

Mitotic Instability In Triploid And Tetraploid One-Year-Old Eastern Oyster, Crassostrea Virginica, Assessed By Cytogenetic And Flow Cytometry Techniques, Jt De Sousa, Standish K. Allen Jr., Bm Wolfe, Ja Moss

VIMS Articles

For commercial oyster aquaculture, triploidy has significant advantages. To produce triploids, the principal technology uses diploid x tetraploid crosses. The development of tetraploid brood stock for this purpose has been successful, but as more is understood about tetraploids, it seems clear that chromosome instability is a principal feature in oysters. This paper is a continuation of work to investigate chromosome instability in polyploid Crassostrea virginica. We established families between tetraploids-apparently stable (non-mosaic) and unstable (mosaic)-and normal reference diploids, creating triploid groups, as well as tetraploids between mosaic and non-mosaic tetraploids. Chromosome loss was about the same for triploid juveniles produced …


Phylogenetic Analysis Of Apicomplexan Parasites Infecting Commercially Valuable Species From The North-East Atlantic Reveals High Levels Of Diversity And Insights Into The Evolution Of The Group, R. Xavier, R. Severino, M. Pérez-Losada, C. Gestal, R. Freitas, D. James Harris, Ana Verissimo, D. Rosado, J. Cable Jan 2018

Phylogenetic Analysis Of Apicomplexan Parasites Infecting Commercially Valuable Species From The North-East Atlantic Reveals High Levels Of Diversity And Insights Into The Evolution Of The Group, R. Xavier, R. Severino, M. Pérez-Losada, C. Gestal, R. Freitas, D. James Harris, Ana Verissimo, D. Rosado, J. Cable

VIMS Articles

Background: The Apicomplexa from aquatic environments are understudied relative to their terrestrial counterparts, and the seminal work assessing the phylogenetic relations of fish-infecting lineages is mostly based on freshwater hosts. The taxonomic uncertainty of some apicomplexan groups, such as the coccidia, is high and many genera were recently shown to be paraphyletic, questioning the value of strict morphological and ecological traits for parasite classification. Here, we surveyed the genetic diversity of the Apicomplexa in several commercially valuable vertebrates from the NorthEast Atlantic, including farmed fish. Results: Most of the sequences retrieved were closely related to common fish coccidia of Eimeria, …


Depth- And Range-Dependent Variation In The Performance Of Aquatic Telemetry Systems: Understanding And Predicting The Susceptibility Of Acoustic Tag-Receiver Pairs To Close Proximity Detection Interference, S R. Scherrer, B P. Rideout, G. Giorli, E M. Nosal, Kevin C. Weng Jan 2018

Depth- And Range-Dependent Variation In The Performance Of Aquatic Telemetry Systems: Understanding And Predicting The Susceptibility Of Acoustic Tag-Receiver Pairs To Close Proximity Detection Interference, S R. Scherrer, B P. Rideout, G. Giorli, E M. Nosal, Kevin C. Weng

VIMS Articles

BACKGROUND:

Passive acoustic telemetry using coded transmitter tags and stationary receivers is a popular method for tracking movements of aquatic animals. Understanding the performance of these systems is important in array design and in analysis. Close proximity detection interference (CPDI) is a condition where receivers fail to reliably detect tag transmissions. CPDI generally occurs when the tag and receiver are near one another in acoustically reverberant settings. Here we confirm transmission multipaths reflected off the environment arriving at a receiver with sufficient delay relative to the direct signal cause CPDI. We propose a ray-propagation based model to estimate the arrival …


Characterizing The Preferences And Values Of Us Recreational Atlantic Bluefin Tuna Anglers, William Morris Goldsmith, Andrew M. Scheld, John Graves Jan 2018

Characterizing The Preferences And Values Of Us Recreational Atlantic Bluefin Tuna Anglers, William Morris Goldsmith, Andrew M. Scheld, John Graves

VIMS Articles

The Atlantic Bluefin Tuna Thunnus thynnus is the target of a recreational fishery along the U.S. East Coast that is thought to be of considerable economic value. In some years, recreational landings have exceeded the sector’s annual subquota due to changes in fish availability, limited predictability of angler effort, and difficulties in realtime monitoring of catch. Understanding the drivers of angler behavior is critical for predicting how effort and harvest may vary as a function of changing fish availability, regulations, or costs. To investigate angler decision making, preferences, and values, we surveyed private recreational anglers from Maine to North Carolina …


Biological Reference Points For Atlantic Surfclam (Spisula Solidissima) In Warming Seas, Dr Hennen, Roger Mann, Dm Munroe, En Powell Jan 2018

Biological Reference Points For Atlantic Surfclam (Spisula Solidissima) In Warming Seas, Dr Hennen, Roger Mann, Dm Munroe, En Powell

VIMS Articles

Atlantic surfclam (Spisula solidissima) are a large, commercially important shellfish in the United States faced with several important management challenges. Compared to many harvested fish and shellfish, their life history is relatively unknown. They are undergoing contraction in the southern and inshore parts of their range, as well as expansion into deeper water. Atlantic surfclam are thermally sensitive, and the changes in their distribution track changes in maximum bottom temperature. Sessile species cannot emigrate and are limited to recruitment and mortality as mechanisms for redistribution in response to changing climate. Management of Atlantic surf clam should account for these challenges. …


A Review Of The Systematic Biology Of Fossil And Living Bony-Tongue Fishes, Osteoglossomorpha (Actinopterygii: Teleostei), Eric J. Hilton, Sebastien Lavoue Jan 2018

A Review Of The Systematic Biology Of Fossil And Living Bony-Tongue Fishes, Osteoglossomorpha (Actinopterygii: Teleostei), Eric J. Hilton, Sebastien Lavoue

VIMS Articles

The bony-tongue fishes, Osteoglossomorpha, have been the focus of a great deal of morphological, systematic, and evolutionary study, due in part to their basal position among extant teleostean fishes. This group includes the mooneyes (Hiodontidae), knifefishes (Notopteridae), the abu (Gymnarchidae), elephantfishes (Mormyridae), arawanas and pirarucu (Osteoglossidae), and the African butterfly fish (Pantodontidae). This morphologically heterogeneous group also has a long and diverse fossil record, including taxa from all continents and both freshwater and marine deposits. The phylogenetic relationships among most extant osteoglossomorph families are widely agreed upon. However, there is still much to discover about the systematic biology of these …


Intensified Environmental And Density-Dependent Regulation Of White Perch Recruitment After An Ecosystem Shift In The Hudson River Estuary, Bk Gallagher, Dh Secor Jan 2018

Intensified Environmental And Density-Dependent Regulation Of White Perch Recruitment After An Ecosystem Shift In The Hudson River Estuary, Bk Gallagher, Dh Secor

VIMS Articles

Long-term monitoring data were used to test whether the invasion of zebra mussels (Dreissena polymorpha) in the Hudson River Estuary in 1991 altered the influence of density dependence and environmental conditions on life-stage transitions, growth, and partial migration in white perch (Morone americana). During the post-invasion period (1992-2013), we estimated standing stocks of white perch eggs, yolk-sac larvae (YSL), post-yolk-sac larvae (PYSL), young-of-the-year (YOY), and adults as well as indices of YOY growth and spatial distribution. A series of linear and nonlinear functions were employed to model life-stage transitions, while the effects of six environmental and density-dependent variables on YOY …


An Analysis Of Fishing Selectivity For Northeast Us Multispecies Bottom Trawlers, Andrew M. Scheld, John Walden Jan 2018

An Analysis Of Fishing Selectivity For Northeast Us Multispecies Bottom Trawlers, Andrew M. Scheld, John Walden

VIMS Articles

Observed production sets in multispecies fisheries are affected by regulatory incentives influencing spatiotemporal fishing decisions. Rights-based output controls can promote selective fishing; however, this ability may be limited and insufficient in achieving full utilization of catch quotas. We measure fishing selectivity for bottom trawlers catching federally regulated groundfish in the Gulf of Maine and Georges Bank before and after the introduction of rights-based output controls. Directional distance functions are applied to tow-level catch data collected by fishery observers to construct a measure of selectivity equal to the difference between strong and weak output disposal efficient production frontiers. Quantile regressions are …


Consequences Of Drift And Carcass Decomposition For Estimating Sea Turtle Mortality Hotspots, Bianca Santos, David M. Kaplan, Marjorie A.M. Friedrichs, Susan G. Barco, Katherine L. Mansfield, James P. Manning Jan 2018

Consequences Of Drift And Carcass Decomposition For Estimating Sea Turtle Mortality Hotspots, Bianca Santos, David M. Kaplan, Marjorie A.M. Friedrichs, Susan G. Barco, Katherine L. Mansfield, James P. Manning

VIMS Articles

Sea turtle strandings provide important mortality information, yet knowledge of turtle carcass at-sea drift and decomposition characteristics are needed to better understand and manage where these mortalities occur. We used empirical sea turtle carcass decomposition and drift experiments in the Chesapeake Bay, Virginia, USA to estimate probable carcass oceanic drift times and quantify the impact of direct wind forcing on carcass drift. Based on the time period during which free-floating turtle carcasses tethered nearshore were buoyant, we determined that oceanic drift duration of turtle carcasses was highly dependent on water temperature and varied from 2 to 15 days during typical …