Life Sciences Commons^™

Transmission Of Withering Syndrome In Black Abalone, Haliotis Cracherodii Leach, Cs Friedman, W Biggs, Jeffrey D. Shields, Rp Hedrick

VIMS Articles

Withering syndrome (WS) has been associated with catastrophic declines in black abalone populations in southern and central California. In an effort to identify the etiological agent of WS and to characterize the progression of this disease, we initiated a transmission study in which abalone from Ano Nuevo Island, a location free of WS, shared aquaria with animals from Vandenberg Airforce Base, a location where WS is epizootic. The mean incubation period of WS (time to develop overt signs of the disease) was 245 days with a mean time to death after development of clinical signs of 42 days. Median time …

Haplosporidium Costale (Seaside Organism), A Parasite Of The Eastern Oyster, Is Present In Long Island Sound, I Sunila, Na Stokes, R Smolowitz, Rc Karney, E. M. Burreson

VIMS Articles

A haplosporidian parasite, Haplosporidium costale (seaside organism or SSO), is associated with high mortalities of eastern oysters (Crassostrea virginica) in seaside bays of Virginia and Maryland. Its presence in Long Island Sound has been tentatively suggested in several publications for the last 50 y. Positive identification of H. costale and differentiation from another haplosporidian parasite, Haplosporidium nelsoni (MSX), from histological sections is difficult and requires the presence of spores. We detected H. costale spores in 4 out of 5010 (0.08%) oysters collected from Long Island Sound in 1997-1999. In situ hybridization using an oligonucleotide DNA probe designed to detect small …

Hybridization Of Tetraploid And Diploid Crassostrea Gigas (Thunberg) With Diploid C-Ariakensis (Fujita), H Que, Standish K. Allen Jr.

VIMS Articles

Three replicates of hybrid crosses of tetraploid and diploid C gigas (Thunberg) with diploid C ariakensis (Fujita) were produced with controls. Larval survival and growth were documented. Cytological events were also monitored in oocytes from hybrid crosses following insemination. Among the four types of hybrid crosses, diploid C. gigas (female) x diploid C. ariakensis (male) (GA) was the most successful. Survival of GA was about the same as that of controls in two of three replications, although its growth rate was 25-30% lower. Crosses of tetraploid C. gigas (female) and diploid C. ariakensis (male) (GGA) had poor yield at day …

Examination Of Diffusion Versus Advection Dominated Sediment Suspension On The Inner Shelf Under Storm And Swell Conditions, Duck, North Carolina, Guan-Hong Lee, Carl T. Friedrichs, Chris E. Vincent

VIMS Articles

[1] A benthic boundary layer tripod supporting six current meters and three profiling acoustic backscatter sensors (ABS) documented storm and swell conditions during the fall of 1996 at a depth of 13 m on the inner shelf off Duck, North Carolina. Sediment concentration was higher in the wave boundary layer (WBL) during storm conditions but higher similar to40 cm above the bed (cm ab) during swell conditions. To test the applicability of a diffusive balance during storm versus swell, ABS data were used to invert the vertical diffusion equation and solve for eddy diffusivity from 1 to 50 cm ab. …

Across-Shelf Sediment Transport: Interactions Between Suspended Sediment And Bed Sediment, Courtney K. Harris, Patricia Wiberg

VIMS Articles

[1] We use a two-dimensional, time-dependent sediment-transport model to quantify across-shelf transport, deposition, and sorting during wave-driven resuspension events characteristic of those that dominate sediment transport on many continental shelves. Decreases in wave-orbital velocities as water depth increases, and the resulting cross-shelf gradient in bed shear stress favor a net offshore transport of sediment. On wide, flat shelves (slopes similar to0.1%), these gradients are low, and the depth to which the seabed is reworked depends mainly on bottom shear stress and local sediment availability. On narrow, steep shelves (slopes similar to0.5%), however, the gradient in bottom stress generates significant cross-shelf …

Predation On Seeds Of The Seagrass Posidonia Australis In Western Australia, R J. Orth, Kl Heck, Dj Tunbridge

VIMS Articles

Despite much evidence that predation governs seed abundance, and ultimately seedling and adult plant distribution and abundance in terrestrial ecosystems, there is a dearth of information from seagrass dominated ecosystems. We report here on the first study to examine predation rates from seeds of Posidonia australis measured during field tethering experiments at 5 locations in Western Australia. Seeds that were recently dehisced from ripe fruits and at a similar stage of development were tethered in seagrass and adjacent unvegetated sand for 24 h and then assessed for damage. Seed predation was noted at all sites and ranged from partially to …

Evidence Of Countergradient Variation In The Growth Of An Intertidal Snail In Response To Water Velocity, Gc Trussell

VIMS Articles

Growth rates in rocky intertidal snails can vary considerably across wave exposure gradients, and have both plastic and genetic bases. However, little is known regarding whether genetic and environmental influences on variation in growth act in the same (cogradient) or in an opposing (countergradient) direction. Determining how genetic and environmental influences on growth covary with one another may improve our understanding of how habitat-specific variation in growth emerges. This study utilized laboratory flumes to examine the effects of high and low water velocities on the growth of intertidal snails Littorina obtusata from a wave-exposed and a sheltered shore. Both flow …

Active Transport Of Particulate Organic Carbon And Nitrogen By Vertically Migrating Zooplankton In The Sargasso Sea, A Schnetzer, Deborah K. Steinberg

VIMS Articles

Diel vertically migrating zooplankton can contribute significantly to dissolved carbon and nutrient export by respiring and excreting surface-ingested particulate organic matter below the mixed layer. Active export of particulate organic carbon (POC) and particulate organic nitrogen (PON) due to defecation at depth has rarely been considered in export budgets. We measured the gut passage time (GPT) of common migrant species at the Bermuda Atlantic Time-series Study (BATS) site, using the gut fluorescence method, to determine whether GPT is slow enough to allow active export of POC and PON to depth. Mean GPT for the copepods Pleuromamma xiphias and Euchirella messinensis …

Habitat Quality And Prey Size As Determinants Of Survival In Post-Larval And Early Juvenile Instars Of The Blue Crab Callinectes Sapidus, R J. Orth, J Van Montfrans

VIMS Articles

Habitat structure and prey size are important determinants in the outcome of predator-prey interactions. We investigated the role of simulated habitat type and density (simulated Zostera marina [hereafter referred to as 'Zostera']: 500 and 1500 shoots m(-2), and simulated Spartina alterniflora [hereafter referred to as 'Spartina']: 97 and 291 shoots m(-2)) in mediating predator-prey interactions. Proportional survival during predation by the piscene predator Fundulus heteroclitus on 2 successive life-history stages (post-larvae and first juvenile instars) of the blue crab Callinectes sapidus (Rathbun), was quantified under laboratory conditions that closely approximated field conditions. We also examined the effects of juvenile crab …

Ecosystem Modeling Analysis Of Size-Structured Phytoplankton Dynamics In The York River Estuary, Virginia (Usa). I. Development Of A Plankton Ecosystem Model With Explicit Feedback Controls And Hydrodynamics, Y Sin, Rl Wetzel

VIMS Articles

An ecosystem simulation model was developed to investigate potential mechanisms controlling the size-structured phytoplankton and nutrient dynamics in the mesohaline zone of the York River estuary. The model included 12 state variables in a unit volume (m(3)) describing the distribution of carbon and nutrients (nitrogen, phosphorus) in the surface mixed layer. General size-scale relationships and density-dependent feedback control terms were used in the ecosystem model. Forcing functions included incident solar radiation, water temperature, wind stress, river flow and tide, which include advective transport and turbulent mixing. Advective transport and turbulent mixing were incorporated into the model explicitly without coupling to …

Ecosystem Modeling Analysis Of Size-Structured Phytoplankton Dynamics In The York River Estuary, Virginia (Usa). Ii. Use Of A Plankton Ecosystem Model For Investigating Controlling Factors On Phytoplankton And Nutrient Dynamics, Y Sin, Rl Wetzel

VIMS Articles

An ecosystem simulation model was used to investigate potential mechanisms controlling the size-structured phytoplankton and nutrient dynamics in the mesohaline zone of the York River estuary, The York River ecosystem model (Sin & Wetzel 2001, Mar Ecol Prog Ser 228:75-90)was calibrated and validated based on field observations and laboratory measurements prior to the exercises reported here. Analyses of model sensitivity to state variable changes and parameter variations were performed to examine hypotheses proposed from previous studies regarding controls on phytoplankton and nutrient dynamics in the York River estuary. The model results supported the general view that phytoplankton dynamics may be …

Total Cover And Cover Quality: Predicted And Actual Effects On A Predator's Foraging Success, A Bartholomew

VIMS Articles

I tested the importance of both total cover and cover quality to the foraging ability of large Fundulus heteroclitus fish in tanks. Total cover was measured as the combined areas of all the individual structures, viewed as shadows. I divided total cover by the bottom area of the tank to form C-t/A(t), an index that measures the total amount of structure available in a given area for prey to hide behind. Cover quality was measured as the width of each individual structure divided by the width of the individual prey organism (C-w/P-w). This index measures how visible a prey organism …

Concurrent Decline Of The Spawning Stock, Recruitment, Larval Abundance, And Size Of The Blue Crab Callinectes Sapidus In Chesapeake Bay, Rom Lipcius, Wt Stockhausen

VIMS Articles

Conservation of exploited marine populations requires knowledge of interannual variation in the characteristics of and relationships between the spawning stock and recruitment, which determine Population resilience and persistence. We examined relationships between spawning stock abundance, postlarval recruitment, larval abundance, and female size of the blue crab in Chesapeake Bay, both within the Spawning grounds over a 13 yr interval (1988 to 2000) and within lower-bay tributaries over 20 yr (1979 to 1998). Our findings establish that there has been a concurrent, persistent and substantial reduction in the spawning stock, recruitment, larval abundance, and female size, Specifically, in 1992 to 2000: …

Photo Synthesis/Irradiance Relationships In The Ross Sea, Antarctica, And Their Control By Phytoplankton Assemblage Composition And Environmental Factors, C. M. Van Hilst, Walker O. Smith Jr.

VIMS Articles

The photosynthetic parameters of natural phytoplankton assemblages from the Ross Sea, Antarctica, as well as unialgal cultures of the diatom Pseudonitzschia sp. and the colonial haptophyte Phaeocystis antarctica were investigated to determine if differential responses to irradiance could explain the distribution of phytoplankton in the Ross Sea. Field assemblages had photosynthetic responses that suggested acclimation to low irradiance levels, and the initial rate of photosynthesis per unit chlorophyll (a) and the theoretical maximum rate of production (p(max)(B)) averaged 0,083 mg C (mg chl a)(-1) h(-1) (mumol m(-2) s(-1))(-1) and 2,40 mg C (mg chl a)(-1) h(-1), respectively. An increase in …

The Status Of Virginia's Public Oyster Resource 2001, Melissa Southworth, Juliana Harding, Roger L. Mann

Reports

This report summarizes data collected during 2001 in the Virginia portion of the Chesapeake Bay. The report is comprised of two parts, part one, oyster recruitment (shell string) in Virginia and part two, dredge survey of selected oyster bars in Virginia.

Annual Report Of The Virginia Institute Of Marine Science Eastern Shore Laboratory 2002, Eastern Shore Laboratory

Reports

No abstract provided.

Virginia Game Fish Tagging Program Annual Report 2001, John A. Lucy, C.M. Bain Iii

Reports

The Virginia Game Fish Tagging Program (VGFTP), in its seventh year during 2001, systematically trains and assists anglers in tagging a select number of species important to Virginia's marine recreational fishery and maintains the resulting tagging database. A cooperative project of the Virginia Marine Resources Commission and the Virginia Institute of Marine Science (VIMS), the program is primarily funded with revenues from Virginia's saltwater recreational fishing license funds (Recreational Fishing Development Fund). In addition, support for the program is provided by Virginia's Sea Grant Marine Advisory Program at VIMS.

Estimation Of Juvenile Striped Bass Relative Abundance In The Virginia Portion Of Chesapeake Bay, January 2001-December 2001 : Annual Progress Report, Herbert M. Austin, A. Dean Estes, Donald M. Seaver

Reports

The Virginia Institute of Marine Science (VIMS) has conducted a juvenile striped bass seine survey from 1967 through 1973 and from 1980 through the present. The primary objective has been the monitoring of the relative annual recruitment success of juvenile striped bass in the spawning and nursery areas of Lower Chesapeake Bay. Initially (1967-1973), the survey was funded by the U.S. Fish and Wildlife Service and when reinstated in 1980 with funding from the National Marine Fisheries Service under the Emergency ~trfped Bass Study program. Commencing with the 1988 annual survey, support of the program has been jointly made through …

Rundown On The Rapa, Juliana M. Harding, Vicki P. Clark, Roger L. Mann

Reports

Explains what rapa whelks are, where they came from, and why they are of concern in the Chesapeake Bay ecosystem. The booklet describes ways to identify rapa whelks in relation to local whelks, compares rapa whelk egg masses with those laid by local whelks, and examines life history traits of the rapa whelk that make it a successful invader.

An Evaluation Of Sea Turtle Abundances, Mortalities And Fisheries Interactions In The Chesapeake Bay, Virginia, 2001, Katherine L. Mansfield, Erin E. Seney, John A. Musick

Reports

Since 1979, the Virginia Institute of Marine Science (VIMS) Sea Turtle Research Program has served as the Commonwealth's center for sea turtle research and conservation. The primary goal of this program is to assess and monitor sea turtle mortalities and population trends within the Chesapeake Bay and coastal waters of Virginia This has been accomplished through the management of a statewide sea turtle stranding network, aerial population research, behavioral studies using radio and satellite telemetry, arid age and growth research.

A major migratory pathway for loggerhead (Carella caretta), Kemp's ridley (Lepidochelys kempi) and leatherback (Dermochelys coriacea) sea turtles exists between …

Comparisons Of Community Structure Between Seep And Vent Mussel-Beds, Mary Parker Turnipseed

Dissertations, Theses, and Masters Projects

No abstract provided.

Temporal And Spatial Variation In Reproductive Output Of The Veined Rapa Whelk (Rapana Venosa) In The Chesapeake Bay, Catherine C. Ware

Dissertations, Theses, and Masters Projects

No abstract provided.

Effects Of Urbanization And Land Use On Pah Accumulation In Wetland Sediments, Kimani L. Kimbrough

Dissertations, Theses, and Masters Projects

The relationship between wetland polycyclic aromatic hydrocarbon (PAH) concentrations and adjacent land use was assessed using surface sediments, sediment cores and global information systems (GIS) in the Elizabeth River, Virginia, an urbanized subestuary of the Chesapeake Bay. Wetlands adjacent to parking lots and petroleum industrial sites exhibited the highest PAH concentrations of all land uses in surfaces sediment and historically. Automobile and coal are the dominant sources of PAHs in wetland sediments historically as determined by relative concentration, fingerprinting and source specific compounds. An analysis of variance (ANOVA) test used to compare sixteen surface sediment sites based on land use …

Distribution, Fluxes, And Bacterial Utilization Of Different Molecular Weight Fractions Of Dissolved Organic Matter In The York River Estuary, Carol J. Pollard

Dissertations, Theses, and Masters Projects

No abstract provided.