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Full-Text Articles in Aquaculture and Fisheries
Detection Of Toxins And Harmful Algal Bloom Cells In Shellfish Hatcheries And Efforts Toward Removal, Marta P. Sanderson, Karen Hudson, Lauren Gregg, Amanda Chesler-Poole, Ja M. Small, Kimberly S. Reece, Ryan Carnegie, Juliette L. Smith
Detection Of Toxins And Harmful Algal Bloom Cells In Shellfish Hatcheries And Efforts Toward Removal, Marta P. Sanderson, Karen Hudson, Lauren Gregg, Amanda Chesler-Poole, Ja M. Small, Kimberly S. Reece, Ryan Carnegie, Juliette L. Smith
VIMS Articles
As the start of the supply chain for the aquaculture industry, hatcheries are a crucial component in the success of oyster and northern quahog (hard clam) aquaculture on the East Coast of the US. Intermittent failures in hatchery production slow industry growth and reduce profits. To begin investigations into the possible role of algal toxins in hatchery production failure, post-treatment hatchery water from one research and four commercial hatcheries in lower Chesapeake Bay, USA, was sampled for (1) toxin presence and (2) harmful algal bloom (HAB) cell enumeration. Overall, seven toxin classes, likely produced by six different HAB species, were …
Climate Drives Long-Term Change In Antarctic Silverfish Along The Western Antarctic Peninsula, Andrew D. Corso, Deborah K. Steinberg, Sharon E. Stammerjohn, Eric J. Hilton
Climate Drives Long-Term Change In Antarctic Silverfish Along The Western Antarctic Peninsula, Andrew D. Corso, Deborah K. Steinberg, Sharon E. Stammerjohn, Eric J. Hilton
VIMS Articles
Over the last half of the 20th century, the western Antarctic Peninsula has been one of the most rapidly warming regions on Earth, leading to substantial reductions in regional sea ice coverage. These changes are modulated by atmospheric forcing, including the Amundsen Sea Low (ASL) pressure system. We utilized a novel 25-year (1993–2017) time series to model the effects of environmental variability on larvae of a keystone species, the Antarctic Silverfish (Pleuragramma antarctica). Antarctic Silverfish use sea ice as spawning habitat and are important prey for penguins and other predators. We show that warmer sea surface temperature and …
Biological Responses Of The Predatory Blue Crab And Its Hard Clam Prey To Ocean Acidification And Low Salinity, Katherine S. Longmire, Rochelle D. Seitz, Michael S. Seebo, Richard Brill, Rom Lipcius
Biological Responses Of The Predatory Blue Crab And Its Hard Clam Prey To Ocean Acidification And Low Salinity, Katherine S. Longmire, Rochelle D. Seitz, Michael S. Seebo, Richard Brill, Rom Lipcius
VIMS Articles
How ocean acidification (OA) interacts with other stressors is understudied, particularly for predators and prey. We assessed long-term exposure to decreased pH and low salinity on (1) juvenile blue crab Callinectes sapidus claw pinch force, (2) juvenile hard clam Mercenaria mercenaria survival, growth, and shell structure, and (3) blue crab and hard clam interactions in filmed mesocosm trials. In 2018 and 2019, we held crabs and clams from the Chesapeake Bay, USA, in crossed pH (low: 7.0, high: 8.0) and salinity (low: 15, high: 30) treatments for 11 and 10 wk, respectively. Afterwards, we assessed crab claw pinch force and …
Saved By The Shell: Oyster Reefs Can Shield Juvenile Blue Crabs Callinectes Sapidus, Katherine S. Longmire, Rochelle D. Seitz, Alison Smith, Romuald N. Lipcius
Saved By The Shell: Oyster Reefs Can Shield Juvenile Blue Crabs Callinectes Sapidus, Katherine S. Longmire, Rochelle D. Seitz, Alison Smith, Romuald N. Lipcius
VIMS Articles
Juvenile blue crabs Callinectes sapidus use seagrass and other structured habitats as refuges from predation. Oyster reef habitats provide structural complexity that may offer refuge, but the value of these habitats for juvenile blue crabs has not been examined. We quantified survival of juvenile C. sapidus in structured oyster reef habitat versus unstructured soft-bottom habitat. In a field tethering experiment in the York River, lower Chesapeake Bay (USA), juvenile C.sapidus (10−50 mm carapace width [CW]) were tethered in sand (n = 40) or oyster reef (n = 39)habitats at subtidal sites 1−2 m deep. An underwater camera system was used …
Effect Of Environmental History On The Physiology And Acute Stress Response Of The Eastern Oyster Crassostrea Virginica, Jill Ashey, Emily B. Rivest
Effect Of Environmental History On The Physiology And Acute Stress Response Of The Eastern Oyster Crassostrea Virginica, Jill Ashey, Emily B. Rivest
VIMS Articles
Environmental history (regimes of water quality to which an organism has been exposed in the past) may influence how the physiology of eastern oysters Crassostrea virginica responds to future environmental conditions caused by climate change. Previous research has examined environmental history in a 1-dimensional framework, failing to capture environmental history complexity through space and time. In this study, we examined environmental history as a multi-faceted parameter, incorporating abiotic water quality components, such as temperature, pH, and salinity, that differ among locations. We also assessed how different lengths of environmental histories, defined as proximal and distal, affected oyster physiology and stress …
An Ecosystem Is Not A Monument, And Other Challenges To Fishing In The 21st Century, Roger Mann
An Ecosystem Is Not A Monument, And Other Challenges To Fishing In The 21st Century, Roger Mann
VIMS Articles
The continental shelf of the United States was once the preserve of commercial fishermen. This is no longer the case. The exclusive economic zone is increasingly becoming the focus of other economically powerful, sometimes incompatible uses, including green energy, shipping, communications, mining, military exclusion zones, and conservation regions. These other uses generally have fixed boundaries. The distribution of fished species moves in relation to warming of shelf waters, presenting challenges to both federal regional fishery management councils and industry alike. There is need for continued engagement between user groups with respectful use of guiding science and legal structure to ensure …
Environmentally-Determined Production Frontiers And Lease Utilization In Virginia's Eastern Oyster Aquaculture Industry, Jennifer Beckensteiner, Andrew M. Scheld, Pierre St-Laurent, Marjorie A.M. Friedrichs, David M. Kaplan
Environmentally-Determined Production Frontiers And Lease Utilization In Virginia's Eastern Oyster Aquaculture Industry, Jennifer Beckensteiner, Andrew M. Scheld, Pierre St-Laurent, Marjorie A.M. Friedrichs, David M. Kaplan
VIMS Articles
During the last decade, oyster aquaculture has rebounded in Virginia and has been associated with an increase in subaqueous leased area. Production levels remain historically low, however, and many leases are thought to be underutilized. This study uses a novel approach leveraging high-resolution environmental data to evaluate lease utilization and identify constraints on aquaculture development. Stochastic Frontier Analysis (SFA) and Data Envelopment Analysis (DEA) were used to define environmentally-determined production frontiers, i.e. production possibilities based on empirical observations of aquaculture production, available space, and environmental conditions. Both methods estimated Lease Capacity Utilization (LCU, from 0 to 1) for leases producing …
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
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 …
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
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 …
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
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
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 …
Minimal Effects Of Oyster Aquaculture On Local Water Quality: Examples From Southern Chesapeake Bay, Jessica Turner, M. Lisa Kellogg, Grace M. Massey, Carl Friedrichs
Minimal Effects Of Oyster Aquaculture On Local Water Quality: Examples From Southern Chesapeake Bay, Jessica Turner, M. Lisa Kellogg, Grace M. Massey, Carl Friedrichs
VIMS Articles
As the oyster aquaculture industry grows and becomes incorporated into management practices, it is important to understand its effects on local environments. This study investigated how water quality and hydrodynamics varied among farms as well as inside versus outside the extent of caged grow-out areas located in southern Chesapeake Bay. Current speed and water quality variables (chlorophyll-a fluorescence, turbidity, and dissolved oxygen) were measured along multiple transects within and adjacent to four oyster farms during two seasons. At the scale of individual aquaculture sites, we were able to detect statistically significant differences in current speed and water quality variables between …
Ecosystem Services Of Restored Oyster Reefs In A Chesapeake Bay Tributary: Abundance And Foraging Of Estuarine Fishes, Bruce Pfirrmann, Rochelle D. Seitz
Ecosystem Services Of Restored Oyster Reefs In A Chesapeake Bay Tributary: Abundance And Foraging Of Estuarine Fishes, Bruce Pfirrmann, Rochelle D. Seitz
VIMS Articles
Restoration of oyster reefs in coastal ecosystems may enhance fish and fisheries by providing valuable refuge and foraging habitat, but understanding the effects of restoration requires an improved understanding of fish habitat use and trophic dynamics, coupled with long-term (>5 yr) monitoring of restored habitats. We evaluated the relationship between large (3-5 ha) restored subtidal oyster reefs and mobile estuarine fishes in the Lynnhaven River System (LRS), Virginia, more than 8 yr following reef construction. We compared the (1) diversity, (2) abundance, (3) size, (4) stomach fullness, (5) diet composition, and (6) daily consumption rate of fishes collected from …
It’S About Time: A Synthesis Of Changing Phenology In The Gulf Of Maine Ecosystem, Md Staudinger, Ke Mills, Et Al, David S. Johnson, Et Al
It’S About Time: A Synthesis Of Changing Phenology In The Gulf Of Maine Ecosystem, Md Staudinger, Ke Mills, Et Al, David S. Johnson, Et Al
VIMS Articles
The timing of recurring biological and seasonal environmental events is changing on a global scale relative to temperature and other climate drivers. This study considers the Gulf of Maine ecosystem, a region of high social and ecological importance in the Northwest Atlantic Ocean and synthesizes current knowledge of (a) key seasonal processes, patterns, and events; (b) direct evidence for shifts in timing; (c) implications of phenological responses for linked ecological-human systems; and (d) potential phenology-focused adaptation strategies and actions. Twenty studies demonstrated shifts in timing of regional marine organisms and seasonal environmental events. The most common response was earlier timing, …
Comparison Of Methods For Determining Biogeochemical Fluxes From A Restored Oyster Reef, Melanie Jackson, Michael S. Owens, Jeffrey C. Cornwell, M. Lisa Kellogg
Comparison Of Methods For Determining Biogeochemical Fluxes From A Restored Oyster Reef, Melanie Jackson, Michael S. Owens, Jeffrey C. Cornwell, M. Lisa Kellogg
VIMS Articles
Oyster reef restoration can significantly increase benthic denitrification rates. Methods applied to measure nutrient fluxes and denitrification from oyster reefs in previous studies include incubations of sediment cores collected adjacent to oyster clumps, benthic chambers filled with intact reef segments that have undergone in situ equilibration and ex situ incubation, and cores with single oysters. However, fluxes of nutrients vary by orders of magnitude among oyster reefs and methods. This study compares two methods of measuring nutrient and metabolic fluxes on restored oyster reefs: incubations including intact segments of oyster reef and incubations containing oyster clumps without underlying sediments. Fluxes …
Restoring The Eastern Oyster: How Much Progress Has Been Made In 53 Years?, Ab Hernandez, Rochelle Brumbaugh, P Fredrick, R Grizzle, Mark Luckenbach, Ch Peterson, C Angelini
Restoring The Eastern Oyster: How Much Progress Has Been Made In 53 Years?, Ab Hernandez, Rochelle Brumbaugh, P Fredrick, R Grizzle, Mark Luckenbach, Ch Peterson, C Angelini
VIMS Articles
Coastal ecosystem restoration is accelerating globally as a means of enhancing shoreline protection, carbon storage, water quality, fisheries, and biodiversity. Among the most substantial of these efforts have been those focused on re-establishing oyster reefs across the US Atlantic and Gulf coasts. Despite considerable investment, it is unclear how the scale of and approaches toward oyster restoration have evolved. A synthesis of 1768 projects undertaken since 1964 reveals that oyster substrate restoration efforts have primarily been concentrated in the Chesapeake Bay and the Gulf Coast, have been heavily reliant on oyster shell, and have re-established 4.5% of the reef area …
Fish Assemblage Change Following The Structural Restoration Of A Degraded Stream, Carl A. Favata, Anabela Maia, Manisha Pant, Vaskar Nepal
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. …
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
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 …
Human Influence At The Coast: Upland And Shoreline Stressors Affect Coastal Macrofauna And Are Mediated By Salinity, Rochelle D. Seitz, Kathleen E. Knick, Theresa M. Davenport, Gabrielle G. Saluta
Human Influence At The Coast: Upland And Shoreline Stressors Affect Coastal Macrofauna And Are Mediated By Salinity, Rochelle D. Seitz, Kathleen E. Knick, Theresa M. Davenport, Gabrielle G. Saluta
VIMS Articles
Anthropogenic stressors can affect subtidal communities within the land-water interface. Increasing anthropogenic activities, including upland and shoreline development, threaten ecologically important species in these habitats. In this study, we examined the consequences of anthropogenic stressors on benthic macrofaunal communities in 14 subestuaries of Chesapeake Bay. We investigated how subestuary upland use (forested, agricultural, developed land) and shoreline development (riprap and bulkhead compared to marsh and beach) affected density, biomass, and diversity of benthic infauna. Upland and shoreline development were parameters included in the most plausible models among a candidate set compared using corrected Akaike's Information Criterion. For benthic macrofauna, density …
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
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 …
Habitat Complexity And Benthic Predator-Prey Interactions In Chesapeake Bay, Cn Glaspie, Rochelle D. Seitz
Habitat Complexity And Benthic Predator-Prey Interactions In Chesapeake Bay, Cn Glaspie, Rochelle D. Seitz
VIMS Articles
In Chesapeake Bay, the soft-shell clam Mya arenaria (thin-shelled, deep-burrowing) exhibits population declines when predators are active, and it persists at low densities. In contrast, the hard clam Mercenaria mercenaria (thick-shelled, shallow-burrowing) has a stable population and age distribution. We examined the potential for habitat and predators to control densities and distributions of bivalves in a field caging experiment (Mya only) and laboratory mesocosm experiments (both species). In the field, clams exposed to predators experienced 76.3% greater mortality as compared to caged individuals, and blue crabs were likely responsible for most of the mortality of juvenile Mya. In mesocosm experiments, …
Biotime: A Database Of Biodiversity Time Series For The Anthropocene, M Dornelas, Lh Antao, F Moyes, Ae Bates, Ae Magurran, Et Al., Jonathan S. Lefcheck
Biotime: A Database Of Biodiversity Time Series For The Anthropocene, M Dornelas, Lh Antao, F Moyes, Ae Bates, Ae Magurran, Et Al., Jonathan S. Lefcheck
VIMS Articles
Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains …
Wetlands In A Changing Climate: Science, Policy And Management, Wr Moomaw, Gl Chmura, Gt Davies, Cm Finlayson, Ba Middleton, Sm Natali, Je Perry, N Roulet, Ar Sutton-Grier
Wetlands In A Changing Climate: Science, Policy And Management, Wr Moomaw, Gl Chmura, Gt Davies, Cm Finlayson, Ba Middleton, Sm Natali, Je Perry, N Roulet, Ar Sutton-Grier
VIMS Articles
Part 1 of this review synthesizes recent research on status and climate vulnerability of freshwater and saltwater wetlands, and their contribution to addressing climate change (carbon cycle, adaptation, resilience). Peatlands and vegetated coastal wetlands are among the most carbon rich sinks on the planet sequestering approximately as much carbon as do global forest ecosystems. Estimates of the consequences of rising temperature on current wetland carbon storage and future carbon sequestration potential are summarized. We also demonstrate the need to prevent drying of wetlands and thawing of permafrost by disturbances and rising temperatures to protect wetland carbon stores and climate adaptation/resiliency …
Long-Term Nutrient Reductions Lead To The Unprecedented Recovery Of A Temperate Coastal Region, Js Lefcheck, R J. Orth, Wc Dennison, D. J. Wilcox, Rr Murphy, K. Moore, Et Al.
Long-Term Nutrient Reductions Lead To The Unprecedented Recovery Of A Temperate Coastal Region, Js Lefcheck, R J. Orth, Wc Dennison, D. J. Wilcox, Rr Murphy, K. Moore, Et Al.
VIMS Articles
Humans strongly impact the dynamics of coastal systems, yet surprisingly few studies mechanistically link management of anthropogenic stressors and successful restoration of nearshore habitats over large spatial and temporal scales. Such examples are sorely needed to ensure the success of ecosystem restoration efforts worldwide. Here, we unite 30 consecutive years of watershed modeling, biogeochemical data, and comprehensive aerial surveys of Chesapeake Bay, United States to quantify the cascading effects of anthropogenic impacts on submersed aquatic vegetation (SAV), an ecologically and economically valuable habitat. We employ structural equation models to link land use change to higher nutrient loads, which in turn …
Antibiotic Effects On Microbial Communities Responsible For Denitrification And N2o Production In Grassland Soils, M Semedo, Bk Song, T Sparrer, Rl Phillips
Antibiotic Effects On Microbial Communities Responsible For Denitrification And N2o Production In Grassland Soils, M Semedo, Bk Song, T Sparrer, Rl Phillips
VIMS Articles
Antibiotics in soils may affect the structure and function of microbial communities. In this study, we investigated the acute effects of tetracycline on soil microbial community composition and production of nitrous oxide (N2O) and dinitrogen (N-2) as the end-products of denitrification. Grassland soils were pre-incubated with and without tetracycline for 1-week prior to measurements of N2O and N-2 production in soil slurries along with the analysis of prokaryotic and fungal communities by quantitative polymerase chain reaction (qPCR) and next-generation sequencing. Abundance and taxonomic composition of bacteria carrying two genotypes of N2O reductase genes (nosZ-I and nosZ-II) were evaluated through qPCR …
Estimating Fishing And Natural Mortality Rates, And Catchability Coefficient, From A Series Of Observations On Mean Length And Fishing Effort, Ay Then, Jm Hoenig, Qc Huynh
Estimating Fishing And Natural Mortality Rates, And Catchability Coefficient, From A Series Of Observations On Mean Length And Fishing Effort, Ay Then, Jm Hoenig, Qc Huynh
VIMS Articles
Gedamke and Hoenig (2006) (Transactions of the American Fisheries Society, 135: 476-487) developed a non-equilibrium version of the Beverton and Holt estimator of total mortality rate, Z, based on mean length and thereby increased the usefulness of length-based methods. In this study, we extend their model by replacing period-specific Z parameters with the year-specific parameterization Z(y) = qf(y) + M where q is the catchability coefficient, f(y) is the fishing effort in year y, F (= qf) is the fishing mortality rate, and M is the natural mortality rate. Thus, the problem reduces to estimating just three parameters: q, M …
Saltmarsh Plants, But Not Fertilizer, Facilitate Invertebrate Recolonization After An Oil Spill, David S. Johnson, Jw Fleeger, Mr Riggio, Ia Mendelssohn, Qx Lin, Dr Deis, A Hou
Saltmarsh Plants, But Not Fertilizer, Facilitate Invertebrate Recolonization After An Oil Spill, David S. Johnson, Jw Fleeger, Mr Riggio, Ia Mendelssohn, Qx Lin, Dr Deis, A Hou
VIMS Articles
Foundation species contribute to the recovery of animal communities from disturbance by engineering, by improving habitat quality, and by regulating food availability. In a salt marsh impacted by the Deepwater Horizon oil spill, we tested the hypothesis that nutrient subsidies would enhance the positive effects of the foundation species Spartina alterniflora on the initial recolonization of benthic invertebrate communities (e.g., copepods, annelids, nematodes) by augmenting food (i.e., microalgae) availability. After two months, plantings of S.alterniflora significantly elevated the densities of the polychaete Capitella capitata, meiofauna-sized annelids, and total macroinfauna over unplanted plots. After 7months, the significant effect of plantings persisted …
Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard
Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard
VIMS Articles
Parasitism is a fundamental ecological interaction. Yet we understand relatively little about the ecological role of parasites compared to the role of free-living organisms. Bottom-up theory predicts that resource enhancement will increase the abundance and biomass of free-living organisms. Similarly, parasite abundance and biomass should increase in an ecosystem with resource enhancement. We tested this hypothesis in a landscape-level experiment in which salt marshes (60,000 m2 each) received elevated nutrient concentrations via flooding tidal waters for 11 yr to mimic eutrophication. Nutrient enrichment elevated the densities of the talitrid amphipod, Orchestia grillus, and the density and biomass of its …
Sea Level Rise May Increase Extinction Risk Of A Saltmarsh Ontogenetic Habitat Specialist, David S. Johnson, Bethany L. Williams
Sea Level Rise May Increase Extinction Risk Of A Saltmarsh Ontogenetic Habitat Specialist, David S. Johnson, Bethany L. Williams
VIMS Articles
Specialist species are more vulnerable to environmental change than generalist species. For species with ontogenetic niche shifts, specialization may occur at a particular life stage making those stages more susceptible to environmental change. In the salt marshes in the northeast U.S., accelerated sea level rise is shifting vegetation patterns from flood-intolerant species such as Spartina patens to the flood-tolerant Spartina alterniflora. We tested the potential impact of this change on the coffee bean snail, Melampus bidentatus, a numerically dominant benthic invertebrate with an ontogenetic niche shift. From a survey of eight marshes throughout the northeast U.S., small snails …
Ghost Of Invasion Past: Legacy Effects On Community Disassembly Following Eradication Of An Invasive Ecosystem Engineer, Pl Reynolds, J Glanz, S Yang, C Hann, J Couture, E Grosholz
Ghost Of Invasion Past: Legacy Effects On Community Disassembly Following Eradication Of An Invasive Ecosystem Engineer, Pl Reynolds, J Glanz, S Yang, C Hann, J Couture, E Grosholz
VIMS Articles
By changing ecosystem processes and altering the physical landscape, invasive ecosystem engineers can have substantial impacts on ecosystem functions and human economies and may facilitate other non-native species. Eradication programs in terrestrial and aquatic systems aim to reverse the impacts of invasive species and return the system to its pre-invasion conditions. Despite an extensive focus on the impacts of both native and non-native ecosystem engineers, the consequences of removing invasive ecosystem engineers, particularly in coastal ecosystems, are largely unknown. In this study, we quantified changes in a benthic community following the eradication of the invasive ecosystem engineer, hybrid cordgrass Spartina, …