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Full-Text Articles in Life Sciences

Differential Effects Of Bivalves On Sediment Nitrogen Cycling In A Shallow Coastal Bay, Ashley Smyth, Anna E. Murphy, Iris C. Anderson, Bk Song Jan 2017

Differential Effects Of Bivalves On Sediment Nitrogen Cycling In A Shallow Coastal Bay, Ashley Smyth, Anna E. Murphy, Iris C. Anderson, Bk Song

VIMS Articles

In coastal ecosystems, suspension-feeding bivalves can remove nitrogen though uptake and assimilation or enhanced denitrification. Bivalves may also retain nitrogen through increased mineralization and dissimilatory nitrate reduction to ammonium (DNRA). This study investigated the effects of oyster reefs and clam aquaculture on denitrification, DNRA, and nutrient fluxes (NOx, NH4 6 +, O2). Core incubations were conducted seasonally on sediments adjacent to restored oyster reefs (Crassostrea virginica), clam aquaculture beds (Mercenaria mercenaria) which contained live clams, and bare sediments from Smith Island Bay, Virginia, USA. Denitrification was significantly higher at oyster reef sediments and clam aquaculture site than bare sediment in the ...


Innervation Of Gill Lateral Cells In The Bivalve Mollusc Crassostrea Virginica Affects Cellular Membrane Potential And Cilia Activity, Edward J. Catapane, Michael Nelson, Trevon Adams, Margaret A. Carroll May 2016

Innervation Of Gill Lateral Cells In The Bivalve Mollusc Crassostrea Virginica Affects Cellular Membrane Potential And Cilia Activity, Edward J. Catapane, Michael Nelson, Trevon Adams, Margaret A. Carroll

Publications and Research

Gill lateral cells of Crassostrea virginica are innervated by the branchial nerve, which contains serotonergic and dopaminergic fibers that regulate cilia beating rate. Terminal release of serotonin or dopamine results in an increase or decrease, respectively, of cilia beating rate in lateral gill cells. In this study we used the voltage sensitive fluorescent probe DiBAC4(3) to quantify changes in gill lateral cell membrane potential in response to electrical stimulation of the branchial nerve or to applications of serotonin and dopamine, and correlate these changes to cilia beating rates. Application of serotonin to gill lateral cells caused prolonged membrane depolarization ...


Quantifying The Effects Of Boat Wakes On Intertidal Oyster Reefs In A Shallow Estuary, Donna Campbell Jan 2015

Quantifying The Effects Of Boat Wakes On Intertidal Oyster Reefs In A Shallow Estuary, Donna Campbell

Electronic Theses and Dissertations, 2004-2019

There have long been concerns about the negative impacts of recreational boating activity in the Indian River Lagoon system (IRL), especially in Mosquito Lagoon (ML), the northernmost part of the IRL. My research is focused on the impacts of boat wakes on intertidal reefs formed by the eastern oyster, Crassostrea virginica. There has been a 24% loss of oyster habitat in ML since 1943, where natural oyster reefs have been replaced by dead oyster reefs which do not serve the same ecological function. While there is anecdotal and correlative evidence that this loss is a result of boat wakes, no ...


Understanding The Role Of Stylochus Ellipticus As A Predator Of Crassostrea Virginica In Chesapeake Bay Tributaries, Marion Kensey Barker May 2014

Understanding The Role Of Stylochus Ellipticus As A Predator Of Crassostrea Virginica In Chesapeake Bay Tributaries, Marion Kensey Barker

Theses and Dissertations

Predation may be a key component of the unsuccessful restoration of the Eastern Oyster (Crassostrea virginica), a former keystone species in Chesapeake Bay. Here, I examine the polyclad flatworm Stylochus ellipticus and its potential role as an important predator of C. virginica. Using small-fragment size C. virginica specific DNA primers, oyster DNA was successfully detected in whole organisms homogenates of wild-caught S. ellipticus individuals. Of the 1,575 individuals tested, 68.1% tested positive, thus predation occurred. Predation did not appear to be affected by salinity or temperature; however, season did appear to have an effect on both predation and ...


Predation On The Eastern Oyster Crassostrea Virginica On Intertidal Reefs Affected By Recreational Boating, Jennifer Stiner Jan 2006

Predation On The Eastern Oyster Crassostrea Virginica On Intertidal Reefs Affected By Recreational Boating, Jennifer Stiner

Electronic Theses and Dissertations, 2004-2019

Widely regarded as a keystone species and ecosystem engineer, the eastern oyster Crassostrea virginica plays a vital role in estuarine environments. Complex, three-dimensional oyster reefs act as havens for biodiversity and contribute to ecological processes. Recently, concern for this resource has arisen in Mosquito Lagoon, Florida, the southernmost limit along the Atlantic coast for undisturbed, intertidal reefs of C. virginica. Since the 1990s, intense recreational boating activity has caused atypical dead margins (mounds of disarticulated shells) to emerge on the seaward edges of oyster reefs located along major navigational channels. Once dead margins are formed, little is known about their ...


Native And Invasive Competitors Of The Eastern Oyster Crassostrea Virginica In Mosquito Lagoon, Florida, Michelle Boudreaux Jan 2005

Native And Invasive Competitors Of The Eastern Oyster Crassostrea Virginica In Mosquito Lagoon, Florida, Michelle Boudreaux

Electronic Theses and Dissertations, 2004-2019

Populations of Crassostrea virginica within Mosquito Lagoon, Florida have recently undergone significant die-offs, which are a subject of major concern. Restoration efforts within Mosquito Lagoon are focusing on reconstructing the three-dimensional reef habitats. Before effective protocols can be established, however, important questions about the sources of juvenile and adult oyster mortality must be answered. Potential causes of Crassostrea virginica mortality in the Indian River Lagoon system include sediment loads, competition, predation, and disease. My research focused on the interactions between oysters and the competitors that may affect the settlement, growth, and survival of Crassostrea virginica. The four objectives of my ...


Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman Aug 1989

Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman

Biology and Environmental Science Faculty Publications

Using a laboratory model system comprised of newly settled oysters Crassostrea virginica and established fouling species (Botrylloides sp. initially, and others including Styela clava and Ciona intestinalis as the experiment progressed), we tested how differences in food supply and competitor density may affect post-settlement surivorship and growth of sessile marine invertebrates over a 44 d period. After 15 d, results were mixed but indicated that both food and density conditions affected growth and survivorship significantly, with some suggestion of high food levels ameliorating high density effects However, 44 d after settlement, oysters had reduced survivorship and growth when competitors were ...


Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch Jun 1989

Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Laboratory and field experiments revealed that a variety of species of common, sessile invertebrates, including barnacles, ascidians, and bryozoans, affected the settlement and post-settlement abundance of the oyster Crassostrea virginica (Gmelin). While the nature of the effects varied, most species both reduced oyster settlement by covering and removing substrate available for attachment, and increased settlement on adjacent surfaces. The solitary ascidians Ciona intestinalis (L.) and Styela clava (Herdman), were found to be predators of oyster larvae. Post-settlement survivorship and growth were also strongly affected by the presence of sessile species. In most cases the effects were negative and correlated with ...