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Full-Text Articles in Life Sciences

The Case Of The ‘Missing’ Arctic Bivalves And The Walrus: The Biggest [Overlooked] Clam Fishery On The Planet, Roger L. Mann, Eric N. Powell, Daphne M. Munroe Dec 2020

The Case Of The ‘Missing’ Arctic Bivalves And The Walrus: The Biggest [Overlooked] Clam Fishery On The Planet, Roger L. Mann, Eric N. Powell, Daphne M. Munroe

VIMS Articles

Bivalve molluscs represent a significant proportion of the diet of both Atlantic and Pacific walrus (Odobenus rosmarus rosmarus and Odobenus rosmarus divergens, respectively) and are pivotal to benthic–pelagic coupling and carbonate cycling in the Arctic oceans. The latter is of particular relevance in a period of seasonal ice retreat, freshwater release into associated surface waters, decreasing water pH, and possible undersaturation of Arctic waters with respect to aragonite. Using population estimates and predation rates for the walruses on bivalve molluscs, a conservative estimate of bivalve consumption in the regions of active walruses foraging is 2.0–3.0 3 106 tonnes y–1—a tonnage …


Estimating Shifts In Phenology And Habitat Use Of Cobia In Chesapeake Bay Under Climate Change, Daniel P. Crear, Brian E. Watkins, Marjorie A.M. Friedrichs, Pierre St-Laurent, Kevin C. Weng Nov 2020

Estimating Shifts In Phenology And Habitat Use Of Cobia In Chesapeake Bay Under Climate Change, Daniel P. Crear, Brian E. Watkins, Marjorie A.M. Friedrichs, Pierre St-Laurent, Kevin C. Weng

VIMS Articles

Cobia (Rachycentron canadum) is a large coastal pelagic fish species that represents an important fishery in many coastal Atlantic states of the U.S. They are heavily fished in Virginia when they migrate into Chesapeake Bay during the summer to spawn and feed. These coastal habitats have been subjected to warming and increased hypoxia which in turn could impact the timing of migration and the habitat suitability of Chesapeake Bay. With conditions expected to worsen, we project current and future habitat suitability of Chesapeake Bay for cobia and predict changes in their arrival and departure times as conditions shift. To do …


The Power Struggle: Assessing Interacting Global Change Stressors Via Experimental Studies On Sharks, Ian A. Bouyoucos, Sue-Ann Watson, Serge Planes, Colin A. Simpfendorfer, Gail D. Schwieterman, Et Al Oct 2020

The Power Struggle: Assessing Interacting Global Change Stressors Via Experimental Studies On Sharks, Ian A. Bouyoucos, Sue-Ann Watson, Serge Planes, Colin A. Simpfendorfer, Gail D. Schwieterman, Et Al

VIMS Articles

Ocean warming and acidification act concurrently on marine ectotherms with the potential for detrimental, synergistic effects; yet, effects of these stressors remain understudied in large predatory fishes, including sharks. We tested for behavioural and physiological responses of blacktip reef shark (Carcharhinus melanopterus) neonates to climate change relevant changes in temperature (28 and 31 °C) and carbon dioxide partial pressures (pCO2; 650 and 1050 µatm) using a fully factorial design. Behavioural assays (lateralisation, activity level) were conducted upon 7–13 days of acclimation, and physiological assays (hypoxia tolerance, oxygen uptake rates, acid–base and haematological status) were …


Identifying Important Juvenile Dusky Shark Habitat In The Northwest Atlantic Ocean Using Acoustic Telemetry And Spatial Modeling, Charles W. Bangley, Tobey H. Curtis, David H. Secor, Robert J. Latour, Matthew B. Ogburn Oct 2020

Identifying Important Juvenile Dusky Shark Habitat In The Northwest Atlantic Ocean Using Acoustic Telemetry And Spatial Modeling, Charles W. Bangley, Tobey H. Curtis, David H. Secor, Robert J. Latour, Matthew B. Ogburn

VIMS Articles

Highly mobile species can be challenging for fisheries management and conservation due to large home ranges combined with dependence on discrete habitat areas where they can be easily targeted or vulnerable to anthropogenic disturbances. Management of the Dusky Shark Carcharhinus obscurus in the northwest Atlantic Ocean has been particularly challenging due to the species' inherent vulnerability to overfishing and poorly understood habitat associations. To better understand habitat associations and seasonal distributions, we combined telemetry and remotely sensed environmental data to spatially model juvenile Dusky Shark presence probability in the northwest Atlantic Ocean. To accomplish this, 22 juvenile Dusky Sharks (107-220 …


Spillover Of Sea Scallops From Rotational Closures In The Mid-Atlantic Bight (United States), Deborah R. Hart, Daphne M. Munroe, Joseph C. Caracappa, Dale Haidvogel, Burton V. Shank, David Rudders, Et Al Sep 2020

Spillover Of Sea Scallops From Rotational Closures In The Mid-Atlantic Bight (United States), Deborah R. Hart, Daphne M. Munroe, Joseph C. Caracappa, Dale Haidvogel, Burton V. Shank, David Rudders, Et Al

VIMS Articles

We examined evidence for larval spillover (increased recruitment outside the closures) of Atlantic sea scallops (Placopecten magellanicus) due to rotational closures in the Mid-Atlantic Bight using a 40-year fisheries survey time series and a larval transport model. Since the first closure of the Hudson Canyon South (HCS) area in 1998, mean recruitment in the two areas directly down-current from this closure, Elephant Trunk (ET) and Delmarva (DMV), increased significantly by factors of about 7 and 2, respectively. Stock–recruit plots indicate that low biomasses in HCS were associated with reduced mean recruitment in ET and DMV. Simulations indicate that …


Improving Production Of The Eastern Oyster Crassostrea Virginica Through Coordination Of Genetic Improvement Programs, Research, And Technology Transfer Activities, Standish K. Allen Jr., Caird Rexroad Iii, Robert Rheault Aug 2020

Improving Production Of The Eastern Oyster Crassostrea Virginica Through Coordination Of Genetic Improvement Programs, Research, And Technology Transfer Activities, Standish K. Allen Jr., Caird Rexroad Iii, Robert Rheault

VIMS Articles

The East Coast Shellfish Growers Association has been actively advocating for continued improvement of breeding infrastructure to support a vibrant and ecologically crucial industry. This white paper acknowledges these efforts and is meant to serve as a paradigm for oyster breeding on the East Coast. The vision is relatively straightforward; however, its execution—like most things—will be fraught with detail and inertia. Yet describing simply the idea without articulating some detail and potential roadblocks would be misleading. Instead, we present a picture of a breeding paradigm as it might play out across the entire range of a species. At this particular …


Are Predator−Prey Model Predictions Supported By Empirical Data? Evidence For A Storm-Driven Shift Toan Alternative Stable State In A Crab−Clam System, Cassandra N. Glaspie, Rochelle D. Seitz, Romuald N. Lipcius Jun 2020

Are Predator−Prey Model Predictions Supported By Empirical Data? Evidence For A Storm-Driven Shift Toan Alternative Stable State In A Crab−Clam System, Cassandra N. Glaspie, Rochelle D. Seitz, Romuald N. Lipcius

VIMS Articles

A dynamic systems approach can predict steady states in predator−prey interactions,but there are very few examples of predictions from predator−prey models conforming to empirical data. Here, we examined the evidence for the low-density steady state predicted by a Lotka-Volterra model of a crab−clam predator−prey system using data from long-term monitoring, and data from a previously published field survey and field predation experiment. Changepoint analysis of time series data indicate that a shift to low density occurred for the soft-shell clam Mya arenaria in 1972, the year of Tropical Storm Agnes. A possible mechanism for the shift is that Agnes altered …


Current And Future Remote Sensing Of Harmful Algal Blooms In The Chesapeake Bay To Support The Shellfish Industry, Jl Wolny, Mc Tomlinson, S Schollaert Uz, Ta Egerton, Jr Mckay, A Meredith, Ks Reece, Gp Scott, Rp Stumpf May 2020

Current And Future Remote Sensing Of Harmful Algal Blooms In The Chesapeake Bay To Support The Shellfish Industry, Jl Wolny, Mc Tomlinson, S Schollaert Uz, Ta Egerton, Jr Mckay, A Meredith, Ks Reece, Gp Scott, Rp Stumpf

VIMS Articles

Harmful algal bloom (HAB) species in the Chesapeake Bay can negatively impact fish, shellfish, and human health via the production of toxins and the degradation of water quality. Due to the deleterious effects of HAB species on economically and environmentally important resources, such as oyster reef systems, Bay area resource managers are seeking ways to monitor HABs and water quality at large spatial and fine temporal scales. The use of satellite ocean color imagery has proven to be a beneficial tool for resource management in other locations around the world where high-biomass, nearly monospecific HABs occur. However, remotely monitoring HABs …


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, these predatory …


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 …


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 as …


Acute And Long-Term Manganese Exposure And Subsequent Accumulation In Relation To Idiopathic Blindness In The American Lobster, Homarus Americanus, Addison T. Ochs, Jeffrey D. Shields, Gary W. Rice, Michael A. Unger Feb 2020

Acute And Long-Term Manganese Exposure And Subsequent Accumulation In Relation To Idiopathic Blindness In The American Lobster, Homarus Americanus, Addison T. Ochs, Jeffrey D. Shields, Gary W. Rice, Michael A. Unger

VIMS Articles

Manganese (Mn) is a hypoxic reactive metal commonly found in marine sediments. Under hypoxic conditions the metal becomes fully reduced to Mn2+ and is biologically available to the benthic community for uptake. Mn is also a potent neurotoxin and it may play a role in the etiology of idiopathic blindness that has been observed in American lobsters. An acute exposure study was designed to expose American lobster, Homarus americanus, to 0, 20, 80, 150, and 300 mg L−1 (ppm) for 96 hs to explore disparities in Mn accumulation among several tissues: optic nerve, brain, hepatopancreas, muscle, hemolymph, …


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 …


Movements, Habitat Utilization, And Post-Release Survival Of Cobia (Rachycentron Canadum) That Summer In Virginia Waters Assessed Using Pop-Up Satellite Archival Tags, Douglas R. Jensen, John Graves Jan 2020

Movements, Habitat Utilization, And Post-Release Survival Of Cobia (Rachycentron Canadum) That Summer In Virginia Waters Assessed Using Pop-Up Satellite Archival Tags, Douglas R. Jensen, John Graves

VIMS Articles

Cobia (Rachycentron canadum) is a cosmopolitan marine fish that inhabits tropical, sub-tropical, and temperate marine and estuarine waters and supports a major recreational fishery along the U.S. Atlantic and Gulf of Mexico coasts. Recent changes in U.S. cobia management have sparked controversy and highlighted limitations in our understanding of the species’ biology. This study utilized pop-up satellite archival tags (PSATs) to assess the movements, habitat utilization, and post-release survival of cobia that summer in Virginia waters


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 potential shifts …


Sublethal Effects Of Salinity And Temperature On Non-Native Blue Catfish: Implications For Establishment In Atlantic Slope Drainages, Vaskar Nepal, Mary C. Fabrizio Jan 2020

Sublethal Effects Of Salinity And Temperature On Non-Native Blue Catfish: Implications For Establishment In Atlantic Slope Drainages, Vaskar Nepal, Mary C. Fabrizio

VIMS Articles

The distribution and further range expansion of non-native blue catfish Ictalurus furcatus in coastal waters throughout the United States Atlantic slope depend, in part, on the salinity tolerance of the fish. However, temperature-mediated sublethal effects of increased salinities on blue catfish biology are not yet known. We assessed the effects of salinity and temperature on growth, body condition, body composition and food consumption of juvenile blue catfish in a controlled laboratory experiment. Temperature and salinity had an interactive effect on blue catfish biology, although most fish survived 112 days in salinities up to 10 psu. At salinities 9 psu) likely …


Population Structure Of The Blue Crab Callinectes Sapidus In The Maryland Coastal Bays, Kristen A. Lycett, Jeffrey D. Shields, J. Sook Chung, Joseph S. Pitula Jan 2020

Population Structure Of The Blue Crab Callinectes Sapidus In The Maryland Coastal Bays, Kristen A. Lycett, Jeffrey D. Shields, J. Sook Chung, Joseph S. Pitula

VIMS Articles

The population structure of the blue crab Callinectes sapidus was examined in the Maryland Coastal Bays (MCB) from 2014 to 2016. Crabs were sampled from April to December of each year. Size–frequency distributions showed a strong seasonal cycle, with small crabs being abundant in April, increasing in size through September, with adult crabs observed in the highest proportions from August through October of each year. A subsample of crabs was assayed for hemolymph ecdysone concentrations to examine molting patterns in field-collected blue crabs. Molting was observed throughout the sampling season, peaking in April for immature crabs, with lows in all …


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 …


Water Temperature During Winter May Control Striped Bass Recruitment During Spring By Affecting The Development Time Of Copepod Nauplii, Nicole C. Millette, J. J. Pierson, E. W. North Jan 2020

Water Temperature During Winter May Control Striped Bass Recruitment During Spring By Affecting The Development Time Of Copepod Nauplii, Nicole C. Millette, J. J. Pierson, E. W. North

VIMS Articles

Striped bass (Morone saxatilis) are anadromous fish that support an important fishery along the east coast of North America. In Chesapeake Bay, strong juvenile recruitment of striped bass can occur when larvae overlap with high concentrations of their zooplankton prey, but the mechanisms fostering the temporal overlap are unknown. Here, the influence of winter temperature on the peak abundances of a key prey, Eurytemora carolleeae, was estimated with a temperature-dependent developmental model. The role of these peaks in regulating striped bass recruitment was explored in three nursery areas: upper Chesapeake Bay, Choptank River, and Patuxent River. Model results indicated that …


Alternative Substrates Used For Oyster Reef Restoration: A Review, Taylor Goelz, Bruce Vogt, Troy W. Hartley Jan 2020

Alternative Substrates Used For Oyster Reef Restoration: A Review, Taylor Goelz, Bruce Vogt, Troy W. Hartley

VIMS Articles

Oyster populations and reef habitats have notably declined in the last century around the world. The ecological, economic, and cultural values of oysters have led to a variety of restoration efforts seeking to recover these lost benefits. Limitations of the native oyster shell substrate and the large-scale nature of many restoration projects have resulted in the increased use of a variety of alternative, or artificial, substrates to create reef structures. A text mining package was used to conduct a review of alternative substrates used for oyster restoration. Specifically, the review (1) assessed commonly used alternative substrates, (2) locations where alternative …


Invasive Blue Catfish In The Chesapeake Bay Region: A Case Study Of Competing Management Objectives, Mary C. Fabrizio, Vaskar Nepal, Troy D. Tuckey Jan 2020

Invasive Blue Catfish In The Chesapeake Bay Region: A Case Study Of Competing Management Objectives, Mary C. Fabrizio, Vaskar Nepal, Troy D. Tuckey

VIMS Articles

Freshwater fishes have been introduced outside their native range to establish recreational fisheries, but management conflicts arise when such introductions also result in potentially harmful effects on native species. In this case study, we focus on Blue Catfish Ictalurus furcatus, which were introduced in the Chesapeake Bay region and are now considered invasive. In many tidal tributaries, Blue Catfish have increased dramatically in abundance, expanded into high-salinity habitats (up to 21.8 psu), and negatively affected native species, prompting calls for the development of an effective management plan. However, management of this conflict species is complicated by multiple competing objectives, including …


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 with a …