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VIMS Articles

1998

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Articles 1 - 23 of 23

Full-Text Articles in Life Sciences

Organic Carbon Partitioning During Spring Phytoplankton Blooms In The Ross Sea Polynya And The Sargasso Sea, C.A. Carlson, Hugh Ducklow, Da Hansell, Walker O. Smith Jr. Dec 1998

Organic Carbon Partitioning During Spring Phytoplankton Blooms In The Ross Sea Polynya And The Sargasso Sea, C.A. Carlson, Hugh Ducklow, Da Hansell, Walker O. Smith Jr.

VIMS Articles

In this study we evaluate the partitioning of organic carbon between the particulate and dissolved pools during spring phytoplankton blooms in the Ross Sea, Antarctica, and the Sargasso Sea. As part of a multidisciplinary project in the Ross Sea polynya we investigated the dynamics of the dissolved organic carbon (DOC) pool and the role it played in the carbon cycle during the 1994 spring phytoplankton bloom. Phytoplankton biomass during the bloom was dominated by an Antarctic Phaeocystis sp. We determined primary productivity (PP; via H14CO3, incubations), particulate organic carbon (POC), bacterial productivity (BP; via [3H]thymidine incorporation), and DOC during ...


Molecular Insights Into The Population Structures Of Cosmopolitan Marine Fishes, John Graves Sep 1998

Molecular Insights Into The Population Structures Of Cosmopolitan Marine Fishes, John Graves

VIMS Articles

Many marine fishes are cosmopolitan, occurring in continuous (e.g., circumtropical) or discontinuous (e.g., antitropical) distributions. Little is known of the genetic basis of population structure of these species, even though several support extensive fisheries. To develop a database that would facilitate comparison of the population structures among cosmopolitan fishes we consistently included restriction fragment length polymorphism (RFLP) analysis of mitochondrial DNA (mtDNA) as a common approach to our investigations of these species. This article presents a review of those analyses. Considerable intra`specific genetic variation was revealed within all cosmopolitan marine species. Continuously distributed species displayed population structures ...


On The Frequency Of Eusociality In Snapping Shrimps (Decapoda : Alpheidae), With Description Of A Second Eusocial Species, Je Duffy Sep 1998

On The Frequency Of Eusociality In Snapping Shrimps (Decapoda : Alpheidae), With Description Of A Second Eusocial Species, Je Duffy

VIMS Articles

Recently, the Caribbean snapping shrimp Synalpheus regalis was shown to be eusocial by the criteria historically used for honeybees, ants, and termites, i.e., colonies contain a single reproducing female and a large number of non-breeding "workers." This finding prompted a reexamination of several previously puzzling reports of unusual population structures in other Synalpheus species. New collections, and observations made by students of this genus over the last century, suggest that several sponge-dwelling Synalpheus species similarly exhibit overlapping generations and monopolization of reproduction by a few individuals, and thus that these species may also be eusocial according to classical entomological ...


Perkinsus Marinus Tissue Distribution And Seasonal Variation In Oysters Crassostrea Virginica From Florida, Virginia And New York, Lm Oliver, Ws Fisher, Se Ford, Lm Ragone Calvo, Em Burreson, Et Al Sep 1998

Perkinsus Marinus Tissue Distribution And Seasonal Variation In Oysters Crassostrea Virginica From Florida, Virginia And New York, Lm Oliver, Ws Fisher, Se Ford, Lm Ragone Calvo, Em Burreson, Et Al

VIMS Articles

Perkinsus marinus infection intensity was measured in eastern oysters Crassostrea virginica collected in October and December 1993, and March, May, and July 1994 from 3 U.S. sites: Apalachicola Bay (FL), Chesapeake Bay (VA), and Oyster Bay (Mr'). Gill, mantle, digestive gland. adductor muscle, hemolymph, and remaining tissue (including gonadal material and rectum) were dissected from 20 oysters from each site at each collection time. Samples were separately diagnosed for P. marin us infections by incubation in Ray's Fluid Thioglycollate Medium (RFTM) and subsequent microscopic quantification of purified enlarged hypnospores. At all sampling times and sites, average P. marinus ...


Histopathological Alterations Associated With Perkinsus Spp. Infection In The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal Sep 1998

Histopathological Alterations Associated With Perkinsus Spp. Infection In The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal

VIMS Articles

Softshell clams (Mya arenaria) collected from the Chester River in the upper Chesapeake Bay showed the presence of Perkinsus spp, in similar to 12 % (28/240) Of clams examined. The infection seems to run a mild course with the host prevailing in encapsulating invading parasites. The gills appear to be the major site of infection, however, the parasite was also found in the digestive gland, gonads, and kidneys and occasionally in the tissue and sinuses of adductor muscles. Typically, clusters of protozoal cells were embedded in on amorphous PAS-positive substrate and were surrounded by one or more layers of granulocytes ...


Prevalence And Distribution Of Qpx, Quahog Parasite Unknown, In Hard Clams Mercenaria Mercenaria In Virginia, Usa, Lm Ragone Calvo, Jg Walker, Em Burreson Jul 1998

Prevalence And Distribution Of Qpx, Quahog Parasite Unknown, In Hard Clams Mercenaria Mercenaria In Virginia, Usa, Lm Ragone Calvo, Jg Walker, Em Burreson

VIMS Articles

In July 1996, the Virginia Institute of Marine Science initiated a sampling program to examine wild and cultured hard clams Mercenaria mercenaria for QPX, Quahog Parasite Unknown, a protistan parasite associated with severe mortalities of hard clams in localized areas in maritime Canada and Massachusetts, USA. The sampling program set out to seasonally monitor wild clams from one site, James River, Virginia, and cultured clams from 2 sites, Chincoteague Bay and Mattawoman Creek, Virginia. Histological examination of initial samples revealed 8% prevalence of the parasite in 1-2 yr old cultured clams in Chincoteague Bay. This is the first documentation of ...


Ontogenetic Diet Shifts In Nassau Grouper: Trophic Linkages And Predatory Impact, Db Eggleson, Jj Grover, Rom Lipcius Jun 1998

Ontogenetic Diet Shifts In Nassau Grouper: Trophic Linkages And Predatory Impact, Db Eggleson, Jj Grover, Rom Lipcius

VIMS Articles

Understanding which fauna and flora from seagrass beds serve as primary food for reef-based commuters is critical in defining trophic linkages between shallow-water habitats of tropical oceanic regions. Although numerous studies have documented the relative importance of crustaceans in the diet of reef fishes associated with tropical seagrass meadows, it is unknown if trophic importance corresponds to a significant effect on prey distribution and abundance patterns. We quantified size-specific diet of juvenile Nassau grouper (Epinephelus striatus) inhabiting natural and artificial patch reefs, and manipulated the density of artificial patch reefs (0, 8, and 16 patch reefs per ha) to examine ...


Effects Of Wind Speed And Particulate Matter Source On Surface Microlayer Characteristics And Enrichment Of Organic Matter In Southern Chesapeake Bay, Kewen Liu, Rebecca M. Dickhut May 1998

Effects Of Wind Speed And Particulate Matter Source On Surface Microlayer Characteristics And Enrichment Of Organic Matter In Southern Chesapeake Bay, Kewen Liu, Rebecca M. Dickhut

VIMS Articles

Surface microlayer (SM) samples were collected with a rotating cylinder sampler from the York and Elizabeth River estuaries of lower Chesapeake Bay bimonthly from May 1994 through June 1995. Two intensive samplings were also conducted in the York River during different seasons: one in December 1994 and another during June 1995. Four SM samples were collected during each intensive sampling within 4 days. All the samples were analyzed for total suspended particulates (TSP), particulate nitrogen (PN), particulate organic carbon (POC) and dissolved organic carbon(DOC). The thickness of the SM was observed to decrease linearly with increased wind speed. TSP ...


Oyster Reef Broodstock Enhancement In The Great Wicomico River, Virginia, Melissa Southworth, Roger L. Mann Jan 1998

Oyster Reef Broodstock Enhancement In The Great Wicomico River, Virginia, Melissa Southworth, Roger L. Mann

VIMS Articles

The Great Wicomico River is a small, trap-type estuary on the western shore of the Chesapeake Bay that once supported substantial oyster populations. These populations were essentially eliminated by the combined effects of Tropical Storm Agnes in 1972, and subsequent disease mortalities related to Perkinsus marinus and Haplosporidium nelsoni. Oyster broodstock enhancement was initiated in June 1996 by the construction of a three-dimensional intertidal reef with oyster shell, followed by the "seeding," in December 1996, of that reef with high densities of large oysters from disease-challenged populations in Pocomoke and Tangier Sound. Calculations of estimated fecundity of the reef population ...


Application Of Molecular Genetic Markers To Conservation Of Freshwater Bivalves, Margaret Mulvey, Hsiu-Ping Liu, Karen Kandl Jan 1998

Application Of Molecular Genetic Markers To Conservation Of Freshwater Bivalves, Margaret Mulvey, Hsiu-Ping Liu, Karen Kandl

VIMS Articles

Freshwater bivalves (Unionacea) are among the most endangered faunal elements in North America. Molecular genetic studies have much to offer conservation efforts directed to this declining fauna. Molecular genetic data can provide information needed to identify evolutionarily significant units, resolve taxonomic ambiguities, describe population structure, evaluate impacts of habitat fragmentation and reduced gene flow among populations, reconstruct phylogenetic relationships, clarify fish host-glochidia relationships, and provide evidence in legal actions. Molecular genetic techniques and their application to freshwater bivalves are reviewed.


Microencapsulation As A Potential Control Technique Against Sabellid Worms In Abalone Culture, Jeffrey D. Shields, Ma Buchal, Cs Friedman Jan 1998

Microencapsulation As A Potential Control Technique Against Sabellid Worms In Abalone Culture, Jeffrey D. Shields, Ma Buchal, Cs Friedman

VIMS Articles

We have developed a novel application for lipid-walled microcapsules (LWMs) in the potential control of sabellid infestations in abalone aquaculture. The use of LWMs takes advantage of the filter-feeding nature of the worms, versus the herbivory of the host abalone. Initial observations indicated that the pest was capable of feeding on particles ranging from 3-30 mu m in size. Lipid-walled microcapsules were prepared using different combinations of lipids (tristearin, tripalmitin, and fish oil) to encapsulate water-based solutions. Feeding experiments using worm-infested shells indicated that in a relatively short time (30-60 min) most of the worms (80-95%) fed on the LWMs ...


Growth Dynamics Of Phaeocystis Antarctica-Dominated Plankton Assemblages From The Ross Sea, Walker O. Smith Jr., Ca Carlson, Hw Ducklow, Da Hansell Jan 1998

Growth Dynamics Of Phaeocystis Antarctica-Dominated Plankton Assemblages From The Ross Sea, Walker O. Smith Jr., Ca Carlson, Hw Ducklow, Da Hansell

VIMS Articles

Large-volume experiments were conducted using natural seawater assemblages collected in the southern Ross Sea during austral spring 1994 and summer 1995 to assess the carbon and nitrogen exchanges among phytoplankton, bacteria and dissolved organic carbon pools, and to compare the elemental partitioning in these experimental enclosures with those observed in situ. Large concentrations of particulate matter were produced in these enclosures, which were at all times dominated by the colonial haptophyte Phaeocystis antarctica. Particulate organic carbon concentrations exceeded 200 mu mol l(-1) at the end of the experiment. Bacterial carbon comprised only a small (%) fraction of the particulate carbon ...


Using Metal-Ligand Binding Characteristics To Predict Metal Toxicity: Quantitative Ion Character-Activity Relationships (Qicars), Michael C. Newman, John T. Mccloskey, Christopher Tatara Jan 1998

Using Metal-Ligand Binding Characteristics To Predict Metal Toxicity: Quantitative Ion Character-Activity Relationships (Qicars), Michael C. Newman, John T. Mccloskey, Christopher Tatara

VIMS Articles

Ecological risk assessment can be enhanced with predictive models for metal toxicity. Modelings of published data were done under the simplifying assumption that intermetal trends in toxicity reflect relative metal-ligand complex stabilities. This idea has been invoked successfully since 1904 but has yet to be applied widely in quantitative ecotoxicology. Intermetal vends in toxicity were successfully modeled with ion characteristics reflecting metal binding to ligands for a wide range of effects. Most models were useful for predictive purposes based on an F-ratio criterion and cross-validation, but anomalous predictions did occur in speciation was ignored in general, models for metals with ...


In Vitro Propagation Of Two Perkinsus Species From The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal Jan 1998

In Vitro Propagation Of Two Perkinsus Species From The Softshell Clam Mya Arenaria, Sm Mclaughlin, M Faisal

VIMS Articles

Two continuous, axenic cultures of Perkinsus spp. (H49 and G117)were obtained from the softshell clam Mya arenaria collected from Swan Point in the Chester River, Chesapeake Bay (Maryland).

Isolate H49 was obtained from the hemolymph of a heavily infected clam. Except for their larger size, H49 trophozoites and schizonts exhibited the characteristic morphology of Perkinsus marinus and divided by schizogony. Isolate G117 was obtained from a combined gill/palp sample of a moderately infected clam. Unlike H49, vegetative forms (trophozoites and schizonts) of G117 were present along with prezoosporulation stages in the same culture. In culture, G117 cells multiplied ...


Novel Optical Remote Sensing And Ground-Truthing Of Benthic Habitat Using The Burrow-Cutter-Diaz Plowing Sediment Profile Camera System (Bcd Sled), Gr Cutter Jr., Robert J. Diaz Jan 1998

Novel Optical Remote Sensing And Ground-Truthing Of Benthic Habitat Using The Burrow-Cutter-Diaz Plowing Sediment Profile Camera System (Bcd Sled), Gr Cutter Jr., Robert J. Diaz

VIMS Articles

The Jefferson Benthic Sled provides video sediment profile imagery of continuous cross-sectional data. Subsurface imaging is achieved by attaching a profile camera prism behind an agricultural plow that extends beneath the plane of the sled skids, slicing through the top 10 to 20 cm of sediment. The plowing video profile provides a high-resolution, real-time: remotely controlled view of the flat side of the plow furrow. Successful continuous profiles of up to 100 m have been collected. The equipment allows immediate characterization of benthic habitats, transition zones, sediment types, sediment oxidation layering, biological resources, and fisheries impact.


Blue Crab Resources In Other Countries: Implications For The Us Industry, Michael J. Oesterling Jan 1998

Blue Crab Resources In Other Countries: Implications For The Us Industry, Michael J. Oesterling

VIMS Articles

The blue crab, Callinectes sapidus, supports a major fishery in the United States. In recent years, domestic crab meat processors have been besieged by imports into their traditional national marketplace. The direct substitutability of the meat from other Callinectes species or other portunid crabs for domestically produced product has contributed to this influx. "Blue" crabs occur worldwide. Within the genus Callinectes, there are 14 different species, with distributions on both sides of the Atlantic Ocean and along the Pacific coast of the Americas. Other species of portunid crabs that can be exploited for crab meat production occur throughout tropical regions ...


Spatiotemporal Variation In Postlarval Recruitment Of The Caribbean Spiny Lobster In The Central Bahamas: Lunar And Seasonal Periodicity, Spatial Coherence, And Wind Forcing, Db Eggleston, Rom Lipcius, Ls Marshall, Sg Ratchford Jan 1998

Spatiotemporal Variation In Postlarval Recruitment Of The Caribbean Spiny Lobster In The Central Bahamas: Lunar And Seasonal Periodicity, Spatial Coherence, And Wind Forcing, Db Eggleston, Rom Lipcius, Ls Marshall, Sg Ratchford

VIMS Articles

A large-scale recruitment study of the Caribbean spiny lobster Panulirus argus in the central Bahamas identified (1) strong spatial coherence in settlement to inshore nursery habitats, (2) temporal variability due in part to stochastic wind forcing, and (3) lunar and seasonal periodicity in settlement. First, we quantified lunar variation in settlement on standardized artificial substrates to determine whether or not intra- and inter-annual variability in recruitment could be adequately described by measuring influx of postlarvae during the first quarter of each new moon, as suggested by previous studies. Next, we compared settlement data obtained from artificial surface substrates to concentrations ...


Predation On Postlarvae And Juveniles Of The Shore Crab Carcinus Maenas: Importance Of Shelter, Size And Cannibalism, Po Moksnes, L Pihl, J Van Montfrans Jan 1998

Predation On Postlarvae And Juveniles Of The Shore Crab Carcinus Maenas: Importance Of Shelter, Size And Cannibalism, Po Moksnes, L Pihl, J Van Montfrans

VIMS Articles

Settlement and early juvenile stages are considered a bottleneck in the Life history of many epibenthic organisms because of high predation mortality. Nursery habitats may play an important role in mitigating settlement and post-settlement mortality by providing refuge from predation. We examined these relationships in postlarvae and early juvenile stages of the shore crab Carcinus maenas L. in laboratory and field tethering experiments. We studied habitat and size related habitat mortality using postlarvae and young juvenile crabs as prey, and various predators, including juvenile conspecifics, in several habitats common in shallow (0 to 1 m) soft bottom nursery areas on ...


Global Phylogeography Of Mackerels Of The Genus Scomber, Daniel Scoles, Bruce B. Collette, John Graves Jan 1998

Global Phylogeography Of Mackerels Of The Genus Scomber, Daniel Scoles, Bruce B. Collette, John Graves

VIMS Articles

Inter- and intraspecific genetic relationships among and within three species of mackerels of the genus Scomber were investigated by restriction site analysis of the whole mitochondrial (mt) DNA genome and direct sequence analysis of the mitochondrial cytochrome b gene. A total of 15 samples, averaging 19 individuals each, were collected from geographically isolated populations throughout the ranges of S. scombrus (two samples), S, australasicus (five samples), and S. japonicus (eight samples). Restriction site analysis with 12 restriction enzymes revealed substantial genetic variation within each species. Sample haplotype diversities ranged from 0.28 to 0.95, and nucleotide sequence diversities from ...


Evaluation Of Toxicity Of Oxytetracycline On Growth Of Captive Nurse Sharks, Ginglymostoma Cirratum, James Gelsleichter, Enric Cortes, Charles A. Manire, R. Hueter, John Musick Jan 1998

Evaluation Of Toxicity Of Oxytetracycline On Growth Of Captive Nurse Sharks, Ginglymostoma Cirratum, James Gelsleichter, Enric Cortes, Charles A. Manire, R. Hueter, John Musick

VIMS Articles

No abstract provided.


Response Of Settling Oyster Larvae, Crassostrea Virginica, To Specific Portions Of The Visible Light Spectrum, Patrick Baker, Roger L. Mann Jan 1998

Response Of Settling Oyster Larvae, Crassostrea Virginica, To Specific Portions Of The Visible Light Spectrum, Patrick Baker, Roger L. Mann

VIMS Articles

Settlement site choice was used to rest the ability of competent-to-settle oyster (Crassostrea virginica) larvae to detect specific portions of the visible light spectrum. Larvae were permitted to settle on illuminated or shaded sides of vertically oriented settlement substrates. Five light treatments were used, including white light (400-700 nm), three fractions of white light; red light (600-700 nm), green light (450-575 nm, peak at 525 nm), blue light (400-500 nm, peal; at 425 nm); and total darkness. In total darkness, no settlement preference for either side of the substrates was detected. In all light treatments, larvae settled in significantly higher ...


Estimation Of Oyster, Crassostrea Virginica, Standing Stock, Larval Production And Advective Loss In Relation To Observed Recruitment In The James River, Virginia, Roger L. Mann, David A. Evans Jan 1998

Estimation Of Oyster, Crassostrea Virginica, Standing Stock, Larval Production And Advective Loss In Relation To Observed Recruitment In The James River, Virginia, Roger L. Mann, David A. Evans

VIMS Articles

Standing stock and demographic data for oysters, Crassostrea virginica, in the James River, Virginia are used to generate spatial estimates of egg production on a reef-specific basis. Subsequent estimates are made of losses related to density-dependent fertilization, natural mortality in the plankton, advective loss related to estuarine circulation, availability of substrate (both absolute amounts and after occlusion by fouling organisms), limited competency of pediveligers to metamorphose, and post settlement mortality to an age of 4 wk post metamorphosis. Reef-specific egg production is highly variable on a per unit basis within the James. In all reef systems fertilization losses approach two ...


Effects Of Periodic Environmental Hypoxia On Predation Of A Tethered Polychaete, Glycera Americana: Implications For Trophic Dynamics, Ja Nestlerode, Rj Diaz Jan 1998

Effects Of Periodic Environmental Hypoxia On Predation Of A Tethered Polychaete, Glycera Americana: Implications For Trophic Dynamics, Ja Nestlerode, Rj Diaz

VIMS Articles

Hypoxia and anoxia have significant deleterious ecological effects on living resources throughout many estuarine and marine ecosystems worldwide. Brief periods of low oxygen have the potential to facilitate transfer of benthic production to higher trophic levels as many benthic infaunal species have shallower sediment depth distributions during hypoxic events. In August-September 1994, a time-lapse camera equipped with a water quality datalogger was used to document in situ exploitation of a tethered prey organism (Glycera americana Leidy) by mobile fish and crustacean predators during alternating normoxia-hypoxia cycles in the York River, Virginia, USA. Based on photographic and diver observations, this hypoxia-induced ...