Life Sciences Commons^™

Interannual Decline, Compensatory Exploitation, And Conservation Of The Chesapeake Bay Blue Crab Population In Winter, Rom Lipcius, Marcel M. Montane

Reports

No abstract provided.

Sorbitol-Fermenting Bifidobacteria As Indicators Of Diffuse Human Faecal Pollution In Estuarine Waters, Mw Rhodes, H Kator

VIMS Articles

Sorbitol fermenting bifidobacteria were evaluated as indicators of non-point source human faecal pollution to three sub-estuaries with elevated faecal coliform densities. Human-specific bifidobacteria correlated with identifiable human sanitary deficiencies in feeder streams to estuarine creeks in two of three watersheds examined, one rural and one moderately developed. Sorbitol-fermenting bifidobacteria were recovered at densities ranging from 1 to 90 colony-forming-units 100 ml(-1) in 11 of 258 water samples but were undetected in sediment (n = 68) and scat from resident wildlife (deer, muskrat and raccoon, n = 20). Failure to detect sorbitol-fermenting bifidobacteria in water samples during the summer months was …

Development Of An Expert System Based On A Tidal Prism Water Quality Model For Small Coastal Basins In Virginia, Albert Y. Kuo, Sung-Chan Kim, Kyeong Park, M. Dale Phillips

Reports

No abstract provided.

Perkinsus Marinus Extracellular Protease Modulates Survival Of Vibrio Vulnificus In Eastern Oyster (Crassostrea Virginica) Hemocytes, Bd Tall, Jf La Peyre, Et Al, M Faisal

VIMS Articles

The in vitro effects of the Perkinsus marinus serine protease on the intracellular survival of Vibrio vulnificus in oyster hemocytes were examined by using a time-course gentamicin internalization assay. Results showed that protease-treated hemocytes were initially slower to internalize V. vulnificus than untreated hemocytes. After 1 h, the elimination of V. vulnificus by treated hemocytes was significantly suppressed compared with hemocytes infected with invasive and noninvasive controls. Our data suggest that the serine protease produced by P. marinas suppresses the vibriocidal activity of oyster hemocytes to effectively eliminate V. vulnificus, potentially leading to conditions favoring higher numbers of vibrios in …

What Does It Take To Become A Marine Scientist?, Virginia Institute Of Marine Science

Reports

Note: This material may not meet current educational standards and is presented as part of the Institute's historical publications.

The Crest, Summer 1999, Virginia Institute Of Marine Science

Reports

Table of Contents:

• New Research Aquarium System
• Finfish Aquaculture at VIMS
• Virginia Creates State Research Reserve System
• Pollution-Laden Sediments In Constant Flux
• Survey of Mid-Atlantic Sea Scallop Closed Areas
• Pfiesteria Update
• New Computer Program Helps Planners Balance Growth, Protection
• Virginia Sea Grant to Administer Commercial Fishery Resource Program
• VIMS Stranded Sea Turtle Project Underway Coastal Sediments Offer Clues to Climate Change, Pollution
• Seemingly Barren Habitat Proves Vital for Economically Important Virginia Fish (juvenile flounder)

Fish Species Richness In Relation To Restored Oyster Reefs, Piankatank River, Virginia, Jm Harding, Roger L. Mann

VIMS Articles

Fish assemblages in relation to “reef” structures in marine habitats have been and continue to be topics for research addressing ecological and management questions. Much effort has been spent describing and defining fish assemblages, or groups of species, associated with tropical coral reefs (e.g., Sale 1991 and chapters therein), temperate hard bottom or rocky reefs (e.g., Sedberry and Van Dolah, 1984; Ambrose and Swarbrick, 1989), tropical lava flows (e.g., Godwin and Kosaki, 1989), and artificial “fishing” reefs (e.g., Chandler et al., 1985; Hueckel and Buckley, 1987; Bohnsack, 1989; Feigenbaum et al., 1989; Rountree, 1989; Stephan and Lindquist, 1989). Temperate oyster …

A Preliminary Study Of Predation On Blue Crabs By Three Fish Predators In A Seagrass Bed, R J. Orth, Jacques Van Montfrans, James Fishman

Reports

This report serves as a preliminary assessment of potential feeding impacts on blue crab prey inhabiting a seagrass bed in the York River by three species of recreationally and commercially important fish (striped bass, croaker, and red drum). We also provide an historic perspective indicating possible changes in relative abundance of these predatory fish between the period 1978-1980 and 1998. In no way do we intend for this report to reflect an accurate, bay-wide assessment of these relationships; the extremely limited temporal and spatial scope of this effort precludes such conclusions. However, this report supports the contention that habitat-specific predation …

Analysis Of Historical Distribution Of Submerged Aquatic Vegetation (Sav) In The James River, Ken Moore, David J. Wilcox, R J. Orth, Eva Bailey

Reports

Analyses of historical photography and ground surveys dating from the 1930s indicate that approximately 1645 hectares of SAV have been historically present in shallow water regions throughout the James River. This compares to 77 hectares of vegetation reported in 1997 and a James River Tier I SAV restoration goal of 107 hectares (areas mappped with SAV from 1971- 1991). Overall, the temporal and spatial patterns of loss of SAV populations in the James River suggest declines occurred first in the tidal freshwater regions of the upper James beginning approximately 50 years ago, and then subsequently in the lower James beginning …

Non-Redfield Carbon And Nitrogen Cycling In The Arctic: Effects Of Ecosystem Structure And Dynamics, Kendra L. Daly, Douglas W.R. Wallace, Walker O. Smith Jr., Annelie Skoog, Ruben Lara, Michel Gosselin, Eva Falck, Patricia L. Yager

VIMS Articles

The C:N ratio is a critical parameter used in both global ocean carbon models and field studies to understand carbon and nutrient cycling as well as to estimate exported carbon from the euphotic zone. The so-called Redfield ratio (C:N = 6.6 by atoms) [Redfield et nl., 1963] is widely used for such calculations. Here we present data from the NE Greenland continental shelf that show that most of the C:N ratios for particulate (autotrophic and heterotrophic) and dissolved pools and rates of transformation among them exceed Redfield proportions from June to August, owing to species composition, size, and biological interactions. …

Gloucester County Shoreline And Tidal Marsh Inventory, Marcia Berman, Harry Berquist, Sharon Dewing, George Thomas, Rose Laird

Reports

This inventory is intended to serve as a useful planning tool for managers, planners, regulators, and environmentalists with an interest in Gloucester County. This report documents conditions measured in the County of Gloucester using remote sensing techniques. Two separate activities have occurred in tandem to develop this inventory of tidal marsh, and shoreline features. First, a delineation of tidal marshes within the county used high end image processing software along with color infra-red imagery to delineate the boundaries oftidal marshes'within 33 georeferenced scenes. The process calculates the amount of tidal marsh measured within each river segment in acres. Second, the …

Selective Feeding Behavior Of Larval Naked Gobies Gobiosoma Bosc And Blennies Chasmodes Bosquianus And Hypsoblennius Hentzi: Preferences For Bivalve Veligers, Jm Harding

VIMS Articles

Naked gobies Gobiosoma bose, striped blennies Chasmodes bosquianus, and feather blennies Hypsoblennius hentzi provide important intermediate links within the trophic structure of estuarine oyster reef communities. Predator-prey interactions between planktonic larvae of these fishes and larval eastern oysters Crassostrea virginica may influence recruitment success within oyster reef communities. These 3 species of oyster reef fish larvae were cultured from wild nests and used in multifactorial laboratory feeding experiments with larval oysters or hard clams Mercenaria mercenaria as well as wild plankton as prey items to determine the effects of predator age, predator concentration, and prey type on feeding selectivity of …

1998 Annual Awards, Virginia Institute Of Marine Science

Miscellaneous

The Annual Awards ceremony is an occasion in which new employees and volunteers are introduced, employee service is recognized and student and faculty awards are presented.

Environmental Stress In Hard Coral: Evaluating Lipid As An Indicator Of Sublethal Stress On Short Time Scales, David Harold Niebuhr

Dissertations, Theses, and Masters Projects

Lipid quality was evaluated in Montastrea spp. under sediment- and heat-stressed conditions to evaluate lipid ratio as an indicator of sub-lethal stress on short time scales. The ratio of storage lipid (wax ester + triacylglyceride) to structural lipid (sterol esters + phospholipid) decreased significantly (0.25 to 0.14, p < 0.01) after experimental sedimentation. FAME analysis of colonies exposed to experimental sedimentation showed a reduction of the algal, 18:3(n-6) and 18:4(n-3), polyunsaturated fatty acid (PUFA) in the polar lipid fraction. This loss of PUFA suggests a loss of algal membrane in sediment-stressed colonies. Lipid quality was similarly measured in M. faveolata over a 10-day period. Mean (n = 20) ratio of storage to structural lipid in M. faveolata dropped from 2.43 to a level of 0.98 immediately following a natural sedimentation event before recovering to levels of 1.4 and 2.9 on post-storm days 2 and 4, respectively. Colonies of M. annularis subject to heat-stress (35??C) exhibited no significant change in storage lipid ratio, while levels of Free Fatty Acids increased significantly from 0.012 (n = 22) to 0.156 mg lipid/g dry tissue (n = 22)(p < 0.05). FAME analysis of tissue lipids extracted from the heat-stressed colonies showed changes in the polar fraction, with significant decreases in the 18:3(n-6), 18:3(n-3), 18:4(n-3), 20:4(n-6) and 20:5(n-3) (p < 0.05) PUFA and subsequent significant increases in the saturated fatty acids, 16:0 and 18:0 (p < 0.05). These changes in lipid quantity and quality indicate possible oxidation and preferential digestion of zooxanthellar membranes. Stress experiments were repeated in M. annularis using VacutainerRTM blood collection tubes to collect micro-tissue samples without destroying skeleton of the sample colonies. A significant decrease in storage: structural lipid ratio after sedimentation was also detected using the micro-tissue technique. This study indicates that the relative abundance of lipid subclass components can indicate sub-lethal environmental stress, on short time scales, in M. annularis and M. faveolata. Furthermore, micro-tissue collection techniques permit repeated monitoring coral colonies to assess the manifestation of stress from first detection of impact at the cellular level to changes in community to changes in community structure detectable over longer time scales.

Mortality And Pathophysiology Studies Of Blue Crabs Infected With The Parasitic Dinoflagellate Hematodinium Perezi, Jeffrey D. Shields

Reports

On the eastern seaboard of the USA, populations of the blue crab, Callinectes sapidus, experience recurring epizootics of a parasitic dinoflagellate. The parasite, H ematodinium perezi, fulminates in the summer and autumn causing mortalities in high salinity embayments and estuaries. In laboratory studies, we experimentally investigated host mortality due to the disease, assessed differential hematological changes in infected crabs, and examined proliferation of the parasite. Mature, overwintering, non-ovigerous, female crabs were injected with 103 or 105 cells of H. perezi. Mortalities began 14 dafter infection, with a median time to death of30.3 ± 1.5 d (se). Subsequent mortality rates were …

Ontogenetic Changes In Habitat Use By Postlarvae And Young Juveniles Of The Blue Crab, Ra Pardieck, R J. Orth, R. J. Diaz, Rom Lipcius

VIMS Articles

Changing habitat requirements are evident during the developmental cycles of many species. In this field investigation, we attempted to distinguish between depth (shallow vs deep), habitat structure (seagrass species), and study site as factors influencing the distribution and abundance of postlarvae and juvenile blue crabs Callinectes sapidus in the Chesapeake Bay. Deep (greater than or equal to 70 cm mean low water [MLW]) and shallow (less than or equal to 50 cm MLW) suction samples in monospecific Zostera marina and Ruppia maritima beds were taken in the York River, a tributary of the Chesapeake Bay. Our studies revealed ontogenetic changes …

The Effect Of Seagrass Habitat Fragmentation On Juvenile Blue Crab Survival, Kevin Hovel

Dissertations, Theses, and Masters Projects

Habitat fragmentation leads to small, isolated habitat patches in which ecological processes may differ substantially from those in larger, continuous habitats. Seagrass is a structurally complex but fragmented subtidal habitat that serves as a refuge from predation for juveniles of the blue crab, Callinectes sapidus Rathbun. I compared the effects of eelgrass ( Zostera marina L.) patch size and shoot density on juvenile blue crab survival both before (June) and after (September) shoot defoliation and cownose ray disturbance changed eelgrass habitat, and used artificial seagrass to determine the influence of eelgrass patch size on juvenile blue crab survival in the …

Sensory Development In Settlement-Stage Larvae Of Caribbean Labrids And Scarids: A Comparative Study With Implications For Ecomorphology And Life History Strategies, Monica R. Lara

Dissertations, Theses, and Masters Projects

The sensory capabilities of settlement-stage fishes are unknown but this information is necessary to studies of larval settlement and recruitment. The morphology of the cephalic lateral line, eye and external olfactory organ of thirteen species of settlement-stage Caribbean labroids was described. Scanning electron images of the cephalic lateral line neuromasts, lateral line canals and olfactory epithelia and histological studies of the retinae and morphological measurements of visual acuity were used to assess the level of sensory development attained at settlement. The sensory capabilities of settlement-stage fishes are discussed in relation to the possible cues settlement-stage fishes may be using to …

Distribution, Swimming Physiology, And Swimming Mechanics Of Brief Squid Lolliguncula Brevis, Ian K. Bartol

Dissertations, Theses, and Masters Projects

Squids are thought to have physiological and locomotive deficiencies that put them at a competitive disadvantage to fishes and exclude them from inshore, highly variable environments that are rich in nektonic fauna. However, brief squid Lolliguncula brevis may be a notable exception. Trawl surveys revealed that L. brevis, particularly juveniles <6 cm dorsal mantle length (DML), are abundant in the Chesapeake Bay, especially when salinity and water temperature are high, and tolerate a wide range of physical conditions relative to other cephalopods. L. brevis is also different from other cephalopods examined previously because its pattern of oxygen consumption as a function of velocity was found to be parabolic and thus similar to aerial flight, and its swimming costs were competitive with ecologically equivalent fishes. Power-speed curves derived from video footage of swimming squid and hydrodynamic force calculations also were parabolic in shape, with high costs both at low and high speeds because of power requirements for lift generation and overcoming drag, respectively. L. brevis employed various behaviors to increase swimming efficiency and compensate for negative buoyancy, such as swimming in various orientations (e.g., arms-first and tail-first), altering angles of attack of the mantle, arms, and funnel, and using fin activity. Fin motion, which could not be characterized exclusively as drag- or lift-based propulsion, was used over 50--95% of the sustained speed range and provided as much as 78% of the vertical and 55% of the horizontal thrust. Small squid (<3.0 cm DML) used different swimming strategies than larger squid possibly to maximize the benefits of toroidal induction, and aerobic efficiency curves indicated that squid 3--5 cm. DML are most efficient. Brief squid also may take advantage of unsteady phenomena, such as attached vortices, for added lift and thrust. Furthermore, an electromyographic study revealed that L. brevis uses different circular muscle layers for various speeds and like fish has muscular "gears", suggesting that there is specialization and efficient use of locomotive muscle in some cephalopods. Therefore, the presumption that squids are inescapably constrained by a second-rate propulsive system and physiological deficiencies is not applicable to L. brevis.

Environmental Factors And The Infectious Disease Caused By The Protozoan Parasite, Perkinsus Marinus, In Eastern Oysters (Crassostrea Virginica), Fle Chu

VIMS Articles

Temperature and salinity are two important factors limiting the distribution and abundance of Perkinsus marinus, a protozoan parasite of Eastern oysters (Crassostrea virginica). Results of laboratory studies ale consistent with field observations and clearly demonstrate that P. marinus susceptibility and disease advancement are positively correlated with temperature, salinity and in situ number of infective cells. Laboratory findings also suggest that environmental degradation may enhance the epizootic, although disease caused by P. marinus in oysters is known to be predominantly exacerbated by elevated temperature and salinity. Oysters cellular defence mechanisms appear ineffective in defence against P. marinus. Also, pollutant esposure caused …

Correspondence Between Environmental Gradients And Summer Littoral Fish Assemblages In Low Salinity Reaches Of The Chesapeake Bay, Usa, Cm Wagner, Hm Austin

VIMS Articles

Patterns in the assemblage structure of littoral fishes occupying the gradient between riverine and estuarine ecosystems were revealed through multivariate analysis of 5 annual summer seine surveys in 4 tributary systems of the lower Chesapeake Bay. Catch per unit effort of fishes was quantified and environmental variables measured to characterize assemblage structure and population responses along large-scale (km) environmental gradients. Results of two-way indicator species analysis (TWINSPAN), detrended correspondence analysis (DCA) and detrended canonical correspondence analysis (DCCA) suggested the presence of 4 intergrading assemblages of littoral beach fishes: permanent tidal freshwater, lower tidal freshwater, oligohaline estuary and mesohaline estuary. Littoral …

Flow Convergence And Stability At A Tidal Estuarine Front: Acoustic Doppler Current Observations, John M. Brubaker, John H. Simpson

VIMS Articles

Characteristics of the flow field in an estuarine frontal zone have been investigated in a field study in the lower James River estuary. Underway sampling with an acoustic Doppler current profiler (ADCP) on repeated transects across the front provided information on the structure of the flow field near the front and its evolution in time. As this tidal intrusion front advanced up the estuary during the flooding tide, prominent and consistent features in the velocity field included a localized zone of convergent flow beneath the visible surface line and a stratified shear layer just upriver of the front. Within the …

Teleost Antibody Structure: Simple Prototype Or Elegant Alternative?, Sl Kaattari, Jv Klemer, Da Evans

VIMS Articles

Teleosts possess mechanism(s) by which they can generate considerable structural diversity within their tetrameric antibody molecules. In salmonids, this diversity is generated through a process of random polymerisation of the constituent monomeric subunits rather than dependency upon isotypic gene diversity. Thus, one gene product can give rise to as many as six different structural forms of immunoglobulin. In contrast to mammals, evidence suggests that this polymerisation process occurs late in the secretory process and not within the endoplasmic reticulum. This assembly process is likely to be important in the generation of teleost antibody functional diversity, thereby potentially simulating isotypy.

Isolation Of Aphanomyces Sp(P). Associated With Skin Lesions And Mortalities In The Striped (Mugil Cephalus) And The Thin Lip (Liza Ramada) Grey Mullets, Aa Shaheen, E Elsayed, M Faisal

VIMS Articles

Aphanomyces spp. were isolated from skin erosions and ulcers of cultured Striped and thin lip grey mullets. Fungi with non-septated hyphae were found in wet mount preparations of skin. Samples inoculated on glucose peptone liquid medium for three successive steps then mycelial growths were transferred into glucose peptone yeast extract agar medium. Aphanomyces spp. were successfully isolated, in axenic cultures, from seven out of 35 fish samples. The cultures were maintained on glucose peptone yeast extract liquid media. Formation of sporangia in tap water that contained hemp seeds confirmed that the grey mullet isolates are members of tlx genus Aphanomyces. …

Estimation Of Bacterial Respiration And Growth Efficiency In The Ross Sea, Antarctica, C. A. Carlson, N. R. Bates, H. W. Ducklow, D. A. Hansell

VIMS Articles

Seawater cultures were conducted in large volume (36 l) gas impermeable tri-laminate bags for the purpose of empirically deriving bacterial growth efficiency (BGE) and carbon conversion factors (CCF) in the south central Ross Sea. This experimental design allowed for concomitant measurements of metabolic reactants (loss of total and dissolved organic carbon [TOC and DOG]) and products (gain of total carbon dioxide [TCO2] and bacterial biomass) to be made from a single incubation vessel. Some previous studies have relied on proxy measurements (e.g. O-2, H-3-thymidine incorporation and cell abundance) to determine BGE and CCF rather than direct carbon measurements. Our experimental …

Bacterial Growth In Experimental Plankton Assemblages And Seawater Cultures From The Phaeocystis Antarctica Bloom In The Ross Sea, Antarctica, H. W. Ducklow, C. Carlson, Walker O. Smith Jr.

VIMS Articles

A series of seawater culture experiments was carried out during the Phaeocystis antarctica bloom in the Ross Sea polynya (76.5 degrees S, 180 degrees W; November to December 1994 and December 1995 to January 1996) to examine bacterioplankton growth and derive empirical factors for estimating bacterial production rates. Bacterial growth was exponential over 3 to 10 d in all experiments, at rates of ca 0.1 to 0.7 d(-1), even in persistently cold waters (-2 to + 1 degrees C). Growth rates were lower in the early part of the bloom (early to mid-November) and highest during the period of peak …

Phytoplankton Growth Rates In The Ross Sea, Antarctica, Determined By Independent Methods: Temporal Variations, Walker O. Smith Jr., D. M. Nelson, S. Mathot

VIMS Articles

The development of the seasonal phytoplankton bloom in the Ross Sea was studied during two cruises. The first, conducted in November-December 1994, investigated the initiation and rapid growth of the bloom, whereas the second (December 1995-January 1996) concentrated on the bloom's maximum biomass period and the subsequent decline in biomass. Central to the understanding of the controls of growth and the summer decline of the bloom is a quantitative assessment of the growth rate of phytoplankton. Growth rates were estimated over two time scales with different methods. The first estimated daily growth rates from isotopic incorporation under simulated in situ …

Observations On The Biology Of The Veined Rapa Whelk, Rapana Venosa (Valenciennes, 1846) In The Chesapeake Bay, Juliana Harding, Roger L. Mann

VIMS Articles

The recent discovery of the Veined Rapa whelk (Rapana venosa, Valenciennes, 1846) in the lower Chesapeake Bay provides an opportunity to observe the initial biological and ecological consequences of a novel bioinvasion. These large predatory gastropods occur in subtidal, hard bottom habitats in the lower Bay and are capable of feeding, mating, and moving while completely burrowed. Hard clams (Mercenaria mercenaria) are consumed preferentially in the laboratory when offered concurrently with oysters (Crassostrea virginica), soft clams (Mya arenaria), and mussels (Mytilus edulis). Chesapeake Bay R. venosa readily open and consume large hard clams (30 to 85 mm SH) leaving no …

The Bacterial Component Of The Oceanic Euphotic Zone, H. W. Ducklow

VIMS Articles

Bacteria in the open sea remote from land are sustained strictly on local sources of organic production which should make understanding their nutrition and growth regulation easier than in nearshore systems, estuaries and lakes. Until now, a paucity of data from geographically isolated oceanic sites prevented ready :interpretation. In the past decade investigation of bacterial properties in oceanic systems has increased rapidly, stimulated in part by large oceanographic programs like the Joint Global Ocean Flux Study. Here I review comprehensive investigations of bacterial biomass and production dynamics in the subarctic north Atlantic and north Pacific, oligotrophic gyres in both oceans, …

Phylogenetic Analysis Of Cytochrome C Oxidase I Sequences To Determine Higher-Level Relationships Within The Coleoid Cephalopods, Db Carlin, John Graves

VIMS Articles

Until recently, the higher-level phylogenetic relationships of coleoid cephalopods have remained unclear. A thorough knowledge of the higher-level phylogeny of the group has been limited by the paucity of paleontological data for this poorly-fossilized group and the lack of cladistic analyses of developmental, morphological, and molecular data applied to the coleoids. In this study we analyzed a 657 base pair portion of the mitochondrial cytochrome c oxidase I (COI) gene from 48 cephalopod species representing a broad spectrum of coleoid diversity to examine higher-level phylogenetic relationships within the group. The COI gene exhibited a high degree of nucleotide sequence variability, …