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Full-Text Articles in Life Sciences

Fish Biodiversity Patterns Of A Mesophotic-To-Subphotic Artificial Reef Complex And Comparisons With Natural Substrates, St Jones, Jm Asher, Rc Boland, Bk Kanenaka, Kevin C. Weng Apr 2020

Fish Biodiversity Patterns Of A Mesophotic-To-Subphotic Artificial Reef Complex And Comparisons With Natural Substrates, St Jones, Jm Asher, Rc Boland, Bk Kanenaka, Kevin C. Weng

VIMS Articles

Artificial reefs act as high-rugosity habitats and are often deployed to enhance fishing; however, the effects of man-made features on fish communities can be unpredictable and are poorly understood in deeper waters. In this study, we used a submersible to describe a deep-water artificial reef complex (93-245 m) off of Ewa Beach, Oahu, Hawaii, USA, and evaluated possible conservation and/or fisheries-related contributions. Sixty-eight species were recorded, with larger features supporting greater diversity of species. Species composition changed strongly with depth and a faunal break was detected from 113-137 m. While the features supported diverse fish communities, they were not ...


Bycatch In A Commercial Lobster Fishery: Effects On Two Benthic Predators, Sea Raven And Longhorn Sculpin, Brooke N. Anderson, Amelia M. Weissman, Brett Sweezey, John Mandelman, David Rudders, James A. Sulikowski Apr 2020

Bycatch In A Commercial Lobster Fishery: Effects On Two Benthic Predators, Sea Raven And Longhorn Sculpin, Brooke N. Anderson, Amelia M. Weissman, Brett Sweezey, John Mandelman, David Rudders, James A. Sulikowski

VIMS Articles

Studying the species‐specific responses to fishing capture is critical for effective management and conservation of bycatch species given that acute stress incurred from capture and handling may ultimately lead to mortality. While species of low commercial value are often overlooked, having accurate information on the effects of capture on all species is necessary for ecosystem‐based management. Sea Raven (SR) Hemitripterus americanus and Longhorn Sculpin (LHS) Myoxocephalus octodecemspinosus are routinely captured in the commercial American lobster Homarus americanus fishery in the Gulf of Maine, and they are discarded due to low commercial value. Despite a lack of economic value ...


In The Face Of Climate Change And Exhaustive Exercise: The Physiological Response Of An Important Recreational Fish Species, Daniel P. Crear, Richard Brill, Lauren M.L. Averilla, Sara C. Meakem, Kevin C. Weng Mar 2020

In The Face Of Climate Change And Exhaustive Exercise: The Physiological Response Of An Important Recreational Fish Species, Daniel P. Crear, Richard Brill, Lauren M.L. Averilla, Sara C. Meakem, Kevin C. Weng

VIMS Articles

Cobia (Rachycentron canadum) support recreational fisheries along the US mid- and south-Atlantic states and have been recently subjected to increased fishing effort, primarily during their spawning season in coastal habitats where increasing temperatures and expanding hypoxic zones are occurring due to climate change. We therefore undertook a study to quantify the physiological abilities of cobia to withstand increases in temperature and hypoxia, including their ability to recover from exhaustive exercise. Respirometry was conducted on cobia from Chesapeake Bay to determine aerobic scope, critical oxygen saturation, ventilation volume and the time to recover from exhaustive exercise under temperature and oxygen conditions ...


Barriers To Eastern Oyster Aquaculture Expansion In Virginia, Jennifer Beckensteiner, David M. Kaplan, Andrew M. Scheld Mar 2020

Barriers To Eastern Oyster Aquaculture Expansion In Virginia, Jennifer Beckensteiner, David M. Kaplan, Andrew M. Scheld

VIMS Articles

The eastern oyster once provided major societal and ecosystem benefits, but these benefits have been threatened in recent decades by large declines in oyster harvests. In many areas, recovery of oyster aquaculture faces significant societal opposition and spatial constraints limiting its ability to meet expectations regarding future food needs and provision of ecosystem services. In Virginia, oyster aquaculture has begun to expand, concurrent with an increase in subaqueous leased areas (over 130,000 acres of grounds are currently leased). Though private leases must in theory be used for oyster production, in practice, they can be held for other reasons, such ...


Timing Of The Reproductive Cycle Of Waved Whelk, Buccinum Undatum, On The Us Mid-Atlantic Bight, Sarah Borsetti, Daphne Munroe, David Rudders, Jul-Han Chang Feb 2020

Timing Of The Reproductive Cycle Of Waved Whelk, Buccinum Undatum, On The Us Mid-Atlantic Bight, Sarah Borsetti, Daphne Munroe, David Rudders, Jul-Han Chang

VIMS Articles

Development of the unmanaged waved whelk (Buccinum undatum) fishery on the Mid-Atlantic continental shelf of the United States has initiated investigation into fisheries-related biological and population attributes of the species in this region. Maturation and reproduction timing vary by location for this species and are likely linked to bottom water temperature. This study examined the seasonal fluctuations in relevant body metrics and gonadosomatic index in relation to bottom temperature to assess the timing of the reproductive cycle of the B. undatum population in the southern-most extent of this species' range in the Atlantic. To characterize variation over the maturation schedule ...


Density-Dependence Mediates The Effects Of Temperature On Growth Of Juvenile Blue Catfish In Nonnative Habitats, Vaskar Nepal, Mary C. Fabrizio Jan 2020

Density-Dependence Mediates The Effects Of Temperature On Growth Of Juvenile Blue Catfish In Nonnative Habitats, Vaskar Nepal, Mary C. Fabrizio

VIMS Articles

The combined effects of conspecific density and climate warming on the vital rates of invasive fish species have not been well studied, but may be important in predicting how successful they will be in the future. We evaluated the effects of temperature and population density on monthly time series of sizes of age-0 Blue Catfish Ictalurus furcatus in the James, York, and Rappahannock River subestuaries (defined here as tidally influenced bodies of water that feed into the Chesapeake Bay) from 1996 to 2017, using growing degree-days (GDDs, °C day) as a measure of thermal time. Our pre- dictive linear mixed-effects ...


Drivers And Trends In Catch Of Benthic Resources In Chilean Turfs And Surrounding Open Access Areas, Jennifer Beckensteiner, Andrew M. Scheld, Miriam Fernandez, David M. Kaplan Jan 2020

Drivers And Trends In Catch Of Benthic Resources In Chilean Turfs And Surrounding Open Access Areas, Jennifer Beckensteiner, Andrew M. Scheld, Miriam Fernandez, David M. Kaplan

VIMS Articles

Beginning in the 1990’s, Chile implemented an extensive Territorial User Rights for Fisheries (TURFs) network that now comprises nearly 1,000 TURFs. This network provides a rare opportunity to examine spatial and temporal trends in TURF use and impacts on surrounding open access areas (OAAs). In this analysis, landings of keyhole limpet (Fissurella spp.), kelp (Lessonia spp.) and red sea urchin (Loxechinus albus) were used to estimate catch-per-unit effort (CPUEs) and catch-per-unit area (CPUAs) indices inside and outside TURFs by fishing cove. For these species, CPUEs and CPUAs in 2015 were significantly higher inside TURFs. However, temporal trends analyzed ...


Quantifying The Behavioral And Economic Effects Of Regulatory Change In A Recreational Cobia Fishery, Andrew M. Scheld, William M. Goldsmith, Shelby White, Hamish J. Small, Susanna Musick Jan 2020

Quantifying The Behavioral And Economic Effects Of Regulatory Change In A Recreational Cobia Fishery, Andrew M. Scheld, William M. Goldsmith, Shelby White, Hamish J. Small, Susanna Musick

VIMS Articles

Fisheries economists typically assume recreational anglers make decisions that maximize individual angler utility, which may depend on fishery and regulatory conditions. Under this framework, changes in regulations can lead to target species substitution by anglers in response to shifts in expectations of trip utility. A stated preference survey was developed and distributed to recreational cobia (Rachycentron canadum) anglers in Virginia to explore the effects of regulatory change on angler decision-making, species targeting, and resulting economic outcomes. The survey included a series of hypothetical choice scenarios, where respondents were asked to select their most preferred alternative after being presented with different ...


Contemporary And Future Distributions Of Cobia, Rachycentron Canadum, Dp Crear, Be Watkins, Vs Saba, Je Graves, Dr Jensen, Aj Hobday, Kevin C. Weng Jan 2020

Contemporary And Future Distributions Of Cobia, Rachycentron Canadum, Dp Crear, Be Watkins, Vs Saba, Je Graves, Dr Jensen, Aj Hobday, Kevin C. Weng

VIMS Articles

Climate change has influenced the distribution and phenology of marine species, globally. However, knowledge of the impacts of climate change is lacking for many species that support valuable recreational fisheries. Cobia (Rachycentron canadum) are the target of an important recreational fishery along the U.S. east coast that is currently the subject of a management controversy regarding allocation and stock structure. Further, the current and probable future distributions of this migratory species are unclear, further complicating decision-making. The objectives of this study are to better define the contemporary distribution of cobia along the U.S. east coast and to project ...


Bony-Tongue Fishes (Teleostei: Osteoglossomorpha) From The Eocene Nanjemoy Formation, Virginia, Eric J. Hilton, Jeffrey Carpenter Jan 2020

Bony-Tongue Fishes (Teleostei: Osteoglossomorpha) From The Eocene Nanjemoy Formation, Virginia, Eric J. Hilton, Jeffrey Carpenter

VIMS Articles

Bony-tongue fishes, Osteoglossomorpha, are distributed in North and South America, Africa, Asia, and Australia and are found on all continents except Antarctica in the fossil record. The group includes fishes such as the mooneyes (Hiodontidae), freshwater knifefishes (Notopteridae), elephantfishes (Mormyridae), and the arowanas and pirarucu (Osteoglossidae). Remains identified as belonging to the family Osteoglossidae are known from the Nanjemoy Formation of Maryland and northern Virginia and comprise isolated teeth and fragmentary jaw bones assigned to the now extinct †Brychaetus muelleri. The second author discovereda partial toothed parasphenoid among other isolated and frag-mentary vertebrate microfossils from the Fisher–Sullivan Site of ...


Multidisciplinary Observing In The World Ocean's Oxygen Minimum Zone Regions: From Climate To Fish - The Voice Initiative, V Garcon, J Karstensen, A Palacz, Et Al, Kevin C. Weng Dec 2019

Multidisciplinary Observing In The World Ocean's Oxygen Minimum Zone Regions: From Climate To Fish - The Voice Initiative, V Garcon, J Karstensen, A Palacz, Et Al, Kevin C. Weng

VIMS Articles

Multidisciplinary ocean observing activities provide critical ocean information to satisfy ever-changing socioeconomic needs and require coordinated implementation. The upper oxycline (transition between high and low oxygen waters) is fundamentally important for the ecosystem structure and can be a useful proxy for multiple observing objectives connected to eastern boundary systems (EBSs) that neighbor oxygen minimum zones (OMZs). The variability of the oxycline and its impact on the ecosystem (VOICE) initiative demonstrates how societal benefits drive the need for integration and optimization of biological, biogeochemical, and physical components of regional ocean observing related to EBS. In liaison with the Global Ocean Oxygen ...


Selectivity Of Two Commercial Dredges Fished In The Northwest Atlantic Sea Scallop Fishery, Sally Roman, David Rudders Dec 2019

Selectivity Of Two Commercial Dredges Fished In The Northwest Atlantic Sea Scallop Fishery, Sally Roman, David Rudders

VIMS Articles

Size selectivity curves were estimated for two commercial dredge configurations used in the United States Atlantic sea scallop (Placopecten magellanicus) fishery. Traditionally, the New Bedford Style dredge (New Bedford dredge) has been used by the commercial fleet; however, since 2013, the Coonamessett Farm Turtle Deflector Dredge (turtle dredge) has been required seasonally in the Mid-Atlantic region to minimize the capture of sea turtles. This analysis provides estimates of selectivity and relative efficiency for the turtle dredge and the New Bedford dredge. Selectivity information for the turtle dredge is currently unknown, and selectivity for the New Bedford dredge was originally assessed ...


A Conservation Palaeobiological Perspective On Chesapeake Bay Oysters, Rowan Lockwood, Roger L. Mann Dec 2019

A Conservation Palaeobiological Perspective On Chesapeake Bay Oysters, Rowan Lockwood, Roger L. Mann

VIMS Articles

The eastern oyster plays a vital role in estuarine habitats, acting as an ecosystem engineer and improving water quality. Populations of Chesapeake Bay oysters have declined precipitously in recent decades. The fossil record, which preserves 500 000 years of once-thriving reefs, provides a unique opportunity to study pristine reefs to establish a possible baseline for mitigation. For this study, over 900 fossil oysters were examined from three Pleistocene localities in the Chesapeake region. Data on oyster shell lengths, lifespans and population density were assessed. Comparisons to modern Crassostrea virginica, sampled from monitoring surveys of similar environments, reveal that fossil oysters ...


Analysing Tropical Elasmobranch Blood Samples In The Field: Blood Stability During Storage And Validation Of The Hemocue® Haemoglobin Analyser, Gail D. Schwieterman, Ian A. Bouyoucos, Kristy Potgieter, Colin A. Simpfendorfer, Richard Brill, Jody L. Rummer Nov 2019

Analysing Tropical Elasmobranch Blood Samples In The Field: Blood Stability During Storage And Validation Of The Hemocue® Haemoglobin Analyser, Gail D. Schwieterman, Ian A. Bouyoucos, Kristy Potgieter, Colin A. Simpfendorfer, Richard Brill, Jody L. Rummer

VIMS Articles

Blood samples collected from wild-caught fishes can provide important information regarding the effects of capture (and thus post-release survival) as well as other stressors. Unfortunately, blood samples often cannot be analysed immediately upon sampling, and blood parameters (e.g. blood oxygen levels and acid–base parameters) are known to change with storage duration due to the metabolic activity of the red blood cells. We obtained blood samples from both untreated and stressed individuals of both blacktip reef shark (Carcharhinus melanopterus) and sicklefin lemon shark (Negaprion acutidens) to determine the effects of storage duration on blood pH, haematocrit and haemoglobin concentration ...


High Salinity Tolerance Of Invasive Blue Catfish Suggests Potential For Further Range Expansion In The Chesapeake Bay Region, Vaskar Nepal, Mary C. Fabrizio Nov 2019

High Salinity Tolerance Of Invasive Blue Catfish Suggests Potential For Further Range Expansion In The Chesapeake Bay Region, Vaskar Nepal, Mary C. Fabrizio

VIMS Articles

In estuaries, salinity is believed to limit the colonization of brackish water habitats by freshwater species. Blue catfish Ictalurus furcatus, recognized as a freshwater species, is an invasive species in tidal rivers of the Chesapeake Bay. Salinity tolerance of this species, though likely to determine its potential range expansion and dispersal in estuarine habitats, is not well-known. To address this issue, we subjected blue catfish to a short-term salinity tolerance experiment and found that this species tolerates salinities higher than most freshwater fishes and that larger blue catfish tolerate elevated salinities for longer periods compared with smaller individuals. Our results ...


Temporal, Spatial, And Biological Variation Of Nematode Epidemiology In American Eels, Zt Warshafsky, Troy D. Tuckey, Wk Vogelbein, Rj Latour, Ar Wargo Oct 2019

Temporal, Spatial, And Biological Variation Of Nematode Epidemiology In American Eels, Zt Warshafsky, Troy D. Tuckey, Wk Vogelbein, Rj Latour, Ar Wargo

VIMS Articles

This is the accepted manuscript version of the article.

American eels (Anguilla rostrata) are infected by the non-native parasitic nematode Anguillicoloides crassus, which can cause severe swim bladder damage. We investigated epidemiology of A. crassus to better understand its population-level effects on American eels. Nematode prevalence, abundance, and intensity and swim bladder damage were quantified in glass eels, elvers, and yellow eels from the lower Chesapeake Bay and related to season of capture, river system, and total length. Age-variant force-of-infection and disease-associated mortality were estimated using a three-state irreversible disease model, which assumes recovery is not possible. Results showed glass ...


Evaluation Of The Stock Structure Of Cobia (Rachycentron Canadum) In The Southeastern United States By Using Dart-Tag And Genetics Data, M Perkinson, T Darden, M Jamison, Mj Walker, Mr Denson, J Franks, R Hendon, Susanna Musick, Es Orbesen Aug 2019

Evaluation Of The Stock Structure Of Cobia (Rachycentron Canadum) In The Southeastern United States By Using Dart-Tag And Genetics Data, M Perkinson, T Darden, M Jamison, Mj Walker, Mr Denson, J Franks, R Hendon, Susanna Musick, Es Orbesen

VIMS Articles

Available tag-recapture and population genetics data for cobia (Rachycentron canadum) in the south-eastern United States were evaluated to provide information on population structure and determine the geographic boundary between stocks in the Gulf of Mexico and the Atlantic Ocean. The movements of 1750 cobia were evaluated on the basis of assigned tagging and recapture zones. Genetic samples from an additional 2796 cobia collected during the presumed spawning season were genotyped at 10 microsatellite loci, and standard population genetic statistical analyses were applied to the resulting sample data set. Tag- recapture results indicate that cobia tagged south of Cape Canaveral, Florida ...


Combined Effects Of Acute Temperature Change And Elevated Pco2 On The Metabolic Rates And Hypoxia Tolerances Of Clearnose Skate (Rostaraja Eglanteria), Summer Flounder (Paralichthys Dentatus), And Thorny Skate (Amblyraja Radiata), Gail D. Schwieterman, Daniel P. Crear, Brooke N. Anderson, Danielle R. Lavoie, James A. Sulikowski, Peter G. Bushnell, Richard Brill Jul 2019

Combined Effects Of Acute Temperature Change And Elevated Pco2 On The Metabolic Rates And Hypoxia Tolerances Of Clearnose Skate (Rostaraja Eglanteria), Summer Flounder (Paralichthys Dentatus), And Thorny Skate (Amblyraja Radiata), Gail D. Schwieterman, Daniel P. Crear, Brooke N. Anderson, Danielle R. Lavoie, James A. Sulikowski, Peter G. Bushnell, Richard Brill

VIMS Articles

Understanding how rising temperatures, ocean acidification, and hypoxia affect the performance of coastal fishes is essential to predicting species-specific responses to climate change. Although a population’s habitat influences physiological performance, little work has explicitly examined the multi-stressor responses of species from habitats differing in natural variability. Here, clearnose skate (Rostaraja eglanteria) and summer flounder (Paralichthys dentatus) from mid-Atlantic estuaries, and thorny skate (Amblyraja radiata) from the Gulf of Maine, were acutely exposed to current and projected temperatures (20, 24, or 28 °C; 22 or 30 °C; and 9, 13, or 15 °C, respectively) and acidification conditions (pH 7.8 ...


Effects Of Dietary Taurine Level On Visual Function In European Sea Bass (Dicentrarchus Labrax), Richard Brill, Andrij Z. Horodysky, Allen R. Place, Mary E. Larkin, Renate Reimschuessel Jun 2019

Effects Of Dietary Taurine Level On Visual Function In European Sea Bass (Dicentrarchus Labrax), Richard Brill, Andrij Z. Horodysky, Allen R. Place, Mary E. Larkin, Renate Reimschuessel

VIMS Articles

Dietary insufficiencies have been well documented to decrease growth rates and survival (and therefore overall production) in fish aquaculture. By contrast, the effects of dietary insufficiencies on the sensory biology of cultured fish remains largely unstudied. Diets based solely on plant protein sources could have advantages over fish-based diets because of the cost and ecological effects of the latter, but plant proteins lack the amino acid taurine. Adequate levels of taurine are, however, necessary for the development of a fully functional visual system in mammals. As part of ongoing studies to determine the suitability of plant-based diets, we investigated the ...


Plasticity In Standard And Maximum Aerobic Metabolic Rates In Two Populations Of An Estuarine Dependent Teleost, Spotted Seatrout (Cynoscion Nebulosus), Jingwei Song, Richard Brill, Jan Mcdowell Jun 2019

Plasticity In Standard And Maximum Aerobic Metabolic Rates In Two Populations Of An Estuarine Dependent Teleost, Spotted Seatrout (Cynoscion Nebulosus), Jingwei Song, Richard Brill, Jan Mcdowell

VIMS Articles

We studied the effects of metabolic cold adaptation (MCA) in two populations of a eurythermal species, spotted seatrout (Cynoscion nebulosus) along the U.S. East Coast. Fish were captured from their natural environment and acclimated at control temperatures 15 °C or 20 °C. Their oxygen consumption rates, a proxy for metabolic rates, were measured using intermittent flow respirometry during acute temperature decrease or increase (2.5 °C per hour). Mass-specific standard metabolic rates (SMR) were higher in fish from the northern population across an ecologically relevant temperature gradient (5 °C to 30 °C). SMR were up to 37% higher in ...


Multiple Drivers Of Interannual Oyster Settlement And Recruitment In The Lower Chesapeake Bay, Brendan Turley, Kimberly S. Reece, Jian Shen, Jeong-Ho Lee, Ximing Guo, Jan Mcdowell May 2019

Multiple Drivers Of Interannual Oyster Settlement And Recruitment In The Lower Chesapeake Bay, Brendan Turley, Kimberly S. Reece, Jian Shen, Jeong-Ho Lee, Ximing Guo, Jan Mcdowell

VIMS Articles

Despite global investment in shellfish restoration activities, relatively little attention has been given to predicting optimal restoration sites and testing these expectations. We used a coupled biological-physical connectivity model as a guide to plant two distinct hatchery-spawned strains of the eastern oyster, Crassostrea virginica, in the Lafayette River, Virginia during the summer of 2013 at two locations corresponding to virtual spawning locations within the connectivity model. We utilized single nucleotide polymorphism markers to test the model predictions by genotyping oysters recruited after planting two hatchery-spawned strains and examining interannual recruitment variability for two successive years. Two spat were identified as ...


Modeling Quantitative Value Of Habitats For Marine And Estuarine Populations, Romauld N. Lipcius, David B. Eggleston, F.J. Fodrie, Et Al May 2019

Modeling Quantitative Value Of Habitats For Marine And Estuarine Populations, Romauld N. Lipcius, David B. Eggleston, F.J. Fodrie, Et Al

VIMS Articles

Coastal habitats (e.g., seagrass beds, shallow mud and sand flats) strongly influence survival, growth, and reproduction of exploited marine fish and invertebrate species. Many of these species have declined over the past decades, coincident with widespread degradation of coastal habitats, such that an urgent need exists to model the quantitative value of coastal habitats to their population dynamics. Demand for habitat considerations will increase as fisheries management contends with habitat issues in stock assessments and management in general moves towards a more ecosystem-based approach. The modeling of habitat function to support fishery species has, to date, been done on ...


Quantifying Habitat Selection And Variability In Habitat Suitability For Juvenile White Sharks, Cf White, K Lyons, Sj Jorgensen, J O'Sullivan, C Winkler, Kevin C. Weng, Cg Lowe May 2019

Quantifying Habitat Selection And Variability In Habitat Suitability For Juvenile White Sharks, Cf White, K Lyons, Sj Jorgensen, J O'Sullivan, C Winkler, Kevin C. Weng, Cg Lowe

VIMS Articles

While adult white sharks (Carcharodon carcharias) are apex predators with a circumglobal distribution, juvenile white sharks (JWS) feed primarily on bottom dwelling fishes and tend to be coastally associated. Despite the assumedly easier access to juveniles compared to large, migratory adults, limited information is available on the movements, environments, and distributions of individuals during this life stage. To quantify movement and understand their distribution in the southern California Bight, JWS were captured and fitted with dorsal fin-mounted satellite transmitters (SPOT tags; n = 18). Nine individuals crossed the U.S. border into Baja California, Mexico. Individuals used shallow habitats (134.96 ...


Bridging Disciplines To Advance Elasmobranch Conservation: Applications Of Physiological Ecology, K Lyons, Js Bigman, Et Al, Kevin C. Weng, Et Al, Richard Brill, Cn Bedore May 2019

Bridging Disciplines To Advance Elasmobranch Conservation: Applications Of Physiological Ecology, K Lyons, Js Bigman, Et Al, Kevin C. Weng, Et Al, Richard Brill, Cn Bedore

VIMS Articles

A strength of physiological ecology is its incorporation of aspects of both species' ecology and physiology; this holistic approach is needed to address current and future anthropogenic stressors affecting elasmobranch fishes that range from overexploitation to the effects of climate change. For example, physiology is one of several key determinants of an organism's ecological niche (along with evolutionary constraints and ecological interactions). The fundamental role of physiology in niche determination led to the development of the field of physiological ecology. This approach considers physiological mechanisms in the context of the environment to understand mechanistic variations that beget ecological trends ...


A General Theory Of Age-Length Keys: Combining The Forward And Inverse Keys To Estimate Age Composition From Incomplete Data, Lisa E. Ailloud, John M. Hoenig Apr 2019

A General Theory Of Age-Length Keys: Combining The Forward And Inverse Keys To Estimate Age Composition From Incomplete Data, Lisa E. Ailloud, John M. Hoenig

VIMS Articles

There are two approaches to estimating age composition from a large number of length observations and a limited number of age determinations: the forward and the inverse age-length keys. The forward key looks at the distribution of age within each length bin while the inverse key looks at the distribution of length at each age. The former is more precise but has stringent requirements for the way data are collected. The latter approach is more widely applicable. We review the theory of the two keys with particular attention to necessary assumptions and the restrictions on when the methods are applicable ...


Estimating Age Composition For Multiple Years When There Are Gaps In The Ageing Data: The Case Of Western Atlantic Bluefin Tuna, Lisa E. Ailloud, Matthew V. Lauretta, John F. Walter Iii, John M. Hoenig Apr 2019

Estimating Age Composition For Multiple Years When There Are Gaps In The Ageing Data: The Case Of Western Atlantic Bluefin Tuna, Lisa E. Ailloud, Matthew V. Lauretta, John F. Walter Iii, John M. Hoenig

VIMS Articles

Age–length key (ALK) methods generally perform well when length samples and age samples are representative of the underlying population. It is unclear how well these methods perform when lengths are representative but age samples are sparse (i.e. age samples are small or missing in many years, and some length groups do not have any age observations). With western Atlantic bluefin tuna, the available age data are sparse and have been, for the most part, collected opportunistically. We evaluated two methods capable of accommodating sparse age data: a novel hybrid ALK (combining forward ALKs and cohort slicing) and the ...


Examining Derelict Pot Impacts On Harvest In A Commercial Blue Crab Callinectes Sapidus Fishery, James A. Delbene, Donna M. Bilkovic, Andrew M. Scheld Feb 2019

Examining Derelict Pot Impacts On Harvest In A Commercial Blue Crab Callinectes Sapidus Fishery, James A. Delbene, Donna M. Bilkovic, Andrew M. Scheld

VIMS Articles

Pot fisheries occur worldwide with a significant proportion of the gear becoming derelict. Derelict pots induce detrimental ecological and economic impacts, and more recently were found to reduce blue crab harvests in the Chesapeake Bay commercial fishery. We simulated the presence of derelict pots near actively fished pots in seasonal field experiments to quantify the effect derelict pots have on blue crab harvest. Derelict pots reduced harvests by 30% during the summer, but not during the fall. Female blue crab capture rates were consistently lower when derelict pots were present; while capture rates of the less abundant males were not ...


Genome-Wide Snps Resolve Spatiotemporal Patterns Of Connectivity Within Striped Marlin (Kajikia Audax), A Broadly Distributed And Highly Migratory Pelagic Species, Nadya Mamoozadeh, John Graves, Jan Mcdowell Jan 2019

Genome-Wide Snps Resolve Spatiotemporal Patterns Of Connectivity Within Striped Marlin (Kajikia Audax), A Broadly Distributed And Highly Migratory Pelagic Species, Nadya Mamoozadeh, John Graves, Jan Mcdowell

VIMS Articles

Genomic methodologies offer unprecedented opportunities for statistically robust studies of species broadly distributed in environments conducive to high gene flow, providing valuable information for wildlife conservation and management. Here, we sequence restriction site‐associated DNA to characterize genome‐wide single nucleotide polymorphisms (SNPs) in a broadly distributed and highly migratory large pelagic fish, striped marlin (Kajikia audax). Assessment of over 4,000 SNPs resolved spatiotemporal patterns of genetic connectivity throughout the species range in the Pacific and, for the first time, Indian oceans. Individual‐based cluster analyses identified six genetically distinct populations corresponding with the western Indian, eastern Indian, western ...


Evaluating Summer Flounder Spatial Sex-Segregation In A Southern New England Estuary, Joseph A. Langan, M. Conor Mcmanus, Adena J. Schonfeld, Corinne L. Truesdale, Jeremy S. Collie Jan 2019

Evaluating Summer Flounder Spatial Sex-Segregation In A Southern New England Estuary, Joseph A. Langan, M. Conor Mcmanus, Adena J. Schonfeld, Corinne L. Truesdale, Jeremy S. Collie

VIMS Articles

Marine fish species can exhibit sex-specific differences in their biological traits. Not accounting for these characteristics in the stock assessment or management of a species can lead to misunderstanding its population dynamics and result in ineffective regulatory strategies. Summer Flounder Paralichthys dentatus, a flatfish that supports significant commercial and recreational fisheries along the northeastern U.S. shelf, expresses variation in several traits between the sexes, including growth and habitat preference. To further understand these patterns, 1,302 Summer Flounder were collected and sexed in 2016 and 2017 from fisheries-independent surveys conducted in Rhode Island state waters. Female flounder were more ...


Nursery Habitat Quality Assessed By The Condition Of Juvenile Fishes: Not All Estuarine Areas Are Equal, Ryan W. Schloesser, Mary C. Fabrizio Jan 2019

Nursery Habitat Quality Assessed By The Condition Of Juvenile Fishes: Not All Estuarine Areas Are Equal, Ryan W. Schloesser, Mary C. Fabrizio

VIMS Articles

High-quality nursery habitats support greater numbers of juveniles that survive to adulthood, but characteristics underlying high-quality habitats remain elusive because their productivity varies spatially and temporally and may be species-specific. Fish condition is an energy-integrative measure of ecological interactions, stress, and activity within a habitat, such that juvenile fish condition is representative of the quality of nursery habitats. We apply spatially explicit models to examine patterns in nursery habitat quality of Virginia estuaries based on nutritional condition for Atlantic croaker Micropogonias undulatus, summer flounder Paralichthys dentatus, and striped bass Morone saxatilis. Environmental factors (water temperature, dissolved oxygen, salinity, and depth ...