Marine Biology Commons^™

Habitat Requirements For The Softshell Clam, Mya Arenaria In The Chesapeake Bay, Patrick Baker, Roger L. Mann

Reports

Large populations of softshell clams persist only in relatively shallow, sandy. mesohaline portions of Chesapeake Bay. These areas are mostly in Maryland, but can also occur in the Rappahannock River. Virginia. In some other portions of the bay, especially polyhaline portions. sparse populations of soft shell clams persist subtidally. Restricted populations exist intertidally.

Softshell clams grow rapidly in Chesapeake Bay, reaching commercial size in two years or less. They reproduce twice per year, in spring and fall, but probably only fall spawnings are important in maintaining population levels. Major recruitment events do not occur in most years. despite heavy annual …

The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White

OES Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and benzo[a]pyrene (B[a]P) are common in the water column and sediments of estuarine and coastal areas. The mud crab Rhithropanopeus harrisii was exposed to varying concentrations of Nap or B[a]P to determine the effects on reproductive success, embryological development, larval physiology and mortality. Nap and B[a]P decreased hatching success and prolonged embryological development. Both pollutants produced high abnormality frequencies for egg exposed larvae. Molt frequency and respiratory rates of larvae from non-exposed eggs were more chronically affected by these pollutants than were egg exposed larvae. The EC₅₀ concentrations were determined for …

Estimation Of Standing Crop Of Oysters In The James River, Virginia, Using Commercial Fishing Records : Final Report, Bruce J. Barber, Roger L. Mann

Reports

Virginia was the leading producer of oysters, Crassostrea virginica, as recently as the late 1950's, when landings of market oysters from the 243,000 acres of public grounds was about 700,000 bushels (Hargis and Haven, 1988). Beginning about 1960, a major decline in market oyster production occurred, principally the result of two oyster pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus ( Dermo) . These pathogens have essentially decimated productive oyster grounds in the main stem of Chesapeake Bay as well as the lower portions of all the major rivers. Market oyster landings from public grounds had declined to 328,338 bushels in …

Early Life-History Implications Of Selected Carcharhinoid And Lamnoid Sharks Of The Northwest Atlantic, Steven Branstetter

VIMS Books and Book Chapters

The size of most newborn sharks makes them susceptible to predation from their own kind and other large fishes. In the northwestern Atlantic, juvenile nursery grounds can be generally classified according to whether or not the young are exposed to such predatory risk. Several related factors-breeding frequency, litter size, size at birth, early growth rate-may help offset early natural mortality. These factors are counterbalanced by the different species in several different ways, producing numerous early life history strategies. In general, slow growing species are either born at relatively large sizes or use protected nursery grounds, whereas faster growing species tend …

Western North Atlantic Shark-Fishery Management Problems And Informational Requirements, Thomas B. Hoff, John A. Musick

VIMS Books and Book Chapters

The Mid-Atlantic Fishery Management Council (Council) has primary responsibility for the development ofihe Western North Atlantic Shark Fishery Management Plan (FMP). Currently, there is a consensus among the five East Coast Councils that an FMP for sharks should be prepared. The current concerns focus on many of the same issues that were germane a decade ago when a shark FMP was initiated and then halted mainly because of inadequate information. These issues include 1) an expanded, nondiscriminant, commercial longline fishery ; (2) an existing and rapidly expanding recreational fishery; (3) concern for the extensive waste which occurs from both recreational …

Naphthalenes Associated With Treated Wastewater Effluents In An Urban National Wildlife Refuge, John T. Tanacredi Ph.D.

Faculty Works: CERCOM

Our coastal enviornments have become the invariable recipient of petroleum and petroleum wastes. Demands for petroleum products coupled with a lack of economic incentive to recycle waste oil, will increase the probability of greater concentrations of petroleum derived hyrdrocarbons entering our estuaries (CEQ Report, 1983).

Systematics Of The Pearlfishes (Pisces, Carapidae), Df Markle, Je Olney

VIMS Articles

A review of taxonomy, anatomy, ontogeny, ecology, and phylogeny of the ophidiiform family Carapidae was conducted using over 2,300 larval, juvenile and adult specimens. A cladistic classification based on swimbladder morphology, developmental and osteological characters of the vertebral column, fins, pectoral and pelvic girdles, gill arches, ethmoid, jaws, and habitat is presented. A total of 31 species (6 new names and one unnamed larval form) in seven genera are recognized in two subfamilies. A species previously assigned to Echiodon is made the type of a new monotypic genus. Species of the tribe Carapini are rearranged in the genera Carapus and …

Utilization Of Marsh And Seagrass Habitats By Early Stages Of Callinectes-Aapidus - A Latitudinal Perspective, R J. Orth, J Van Montfrans

VIMS Articles

Seagrass beds and marshes have been identified as important nurseries for the blue crab, Callinectes sapidus. This nursery paradigm is based on blue crab abundance data from trawl, seine and drop-net sampling that has revealed greater abundances in these habitats than in adjacent unvegetated areas. Recently, more quantitative and intensive sampling in seagrass beds and marshes over broad latitudinal scales, combined with manipulative experiments, indicate that the same habitat may vary in utilization on regional scales. Mechanisms accounting for enhanced abundances in these nursery habitats have not been elucidated from a latitudinal perspective. Regional comparisons of blue crab catch data …

Estimates Of Spawning Stock Size Of Blue Crab, Callinectes Sapidus, In Chesapeake Bay, 1986-1987, Cynthia M. Jones, John R. Mcconaugha, Patrick J. Geer, Michael H. Prager

OES Faculty Publications

The 1986 spawning stock exhibited a single abundance peak, increasing from 1.0×105 individuals in early July to 9.3×106 in late July, maintaining high levels throughout the summer, and declining in the fall to 7.4×105 individuals. The 1987 spawning stock showed 2 peaks of abundance. The population reached the lesser peak, 1.0×106 individuals, in late July; the greater peak, 1.5×106, in late August. By late September, the population had declined to 6.5×105 individuals. The peak abundance of the 1987 female spawning stock was only 16% as great as the peak abundance in 1986; the 1987 spawning stock size in 1986. Variability …

Seasonal Composition Of Finfish In Waters Behind The Virginia Barrier Islands, Brenda L. Norcross, David Hata

VIMS Articles

Semi-monthly sampling of finfish was conducted in the lagoons and marshes behind Parramore and Cedar Islands at Wachapreague Inlet, Cobb and Wreck Islands at Sand Shoal Inlet, and on the northwest side of Fisherman Island from September 1986 through September 1987. Although all lifestages were collected, the study was designed to focus on utilization of this area by juvenile finfish. Sixty-nine species offinfish were collected. Species diversity and abundance fluctuated widely among seasons. Both were highest in the fall and lowest in the winter. The most abundant species over all seasons and locations were silversides (Menidia menidia) and bay anchovy …

Blue-Crab Population-Dynamics In Chesapeake Bay - Variation In Abundance (York River, 1972-1988) And Stock-Recruit Functions, Rom Lipcius, Wa Van Engel

VIMS Articles

Blue crab abundance in the York River, Virginia was analyzed for interannual, monthly and spatial variation at two stations sampled by bottom trawl from 1972-1988. Various stock-recruitment and recruit-stock functions were derived from trawl abundance and commercial fishery landings statistics. The key component of variation was due to interannual fluctuations in abundance, which remained consistently high or low for two or more years before changing, suggesting internal population feedback mechanisms, such as cannibalism, or long-term climatic control. In addition, significant cyclic patterns in residuals from stockrecruitment functions further indicated the existence of long-term variability in abundance. Peak seasonal abundance and …

Foraging Behavior Of The Blue-Crab, Callinectes-Sapidus, On Juvenile Oysters, Crassostrea-Virginica - Effects Of Prey Density And Size, Db Eggleson

VIMS Articles

Blue crabs (Callinectes sapidus) are major predators of juvenile oysters (Crassostrea virginica) in Chesapeake Bay, yet little information exists on the foraging behavior and predatorprey dynamics for this predator-prey system. Laboratory experiments assessed functional responses of blue crabs to six densities of three size-classes of juvenile American oysters. Behavioral subcomponents of the crabs' functional response were quantified: total and successful encounter rates, proportional attack success, persistence time in unsuccessful encounters, and breaking, eating and handling times in successful encounters. Specific opening techniques were used by crabs for the three oyster size-classes. Blue crabs exhibited a hyperbolic type II functional response …

Molting In The Mature Female Blue-Crab, Callinectes-Sapidus Rathbun, Kirk J. Havens, Jr Mcconaugha

VIMS Articles

The present study examined the hypothesis that mature female blue crabs, Callinectes sapidus, do not enter a terminal anecdysis. Induced molting via eyestalk ablation, size frequency distributions, gonad development and limb regeneration indices from field collected animals are used as indicators of potential post maturity molts. Eyestalk ablation of 15mature females resulted in ecdysis in II individuals approximately 51 days (standard error = 0.64) after ablation, indicating a physiological ability of mature females to complete ecdysis. Analysis of size frequency distributions from catch data indicated two distinct shifts from smaller to larger females, one in early spring and a second …

Settlement Patterns Of Crassostrea Virginica (Gmelin, 1791) Larvae In Relation To Tidal Zonation, G. Curtis Roegner, Roger L. Mann

VIMS Articles

Experiments were conducted to determine the settlement distribution of the oyster Crassostrea virginica (Gmelin) in relation to tidal zonation in an area where adult populations are largely confined to the intertidal zone. Hatchery-reared pediveliger larvae were interned in PVC tubes positioned at known tidal heights. The influence of non-tidal factors was limited: mesh covering the ends of the tubes prevented loss of larvae to dispersal or predation, the settling substrate was not colonized by competitors, and the effects of light and horizontal currents were minimized. Settlement was found to occur throughout the intertidal zone but predominated at the bottom of …

Variation In Planktonic Availability And Settlement Of Blue-Crab Megalopae In The York River, Virginia, Ej Olmi, J Van Montfrans, Rn Lipcius, R J. Orth, Pw Sadler

VIMS Articles

Blue crab, Callinectes sapidus, megalopae and juveniles were sampled in the plankton and on natural (grassbeds) and artificial settlement substrates (collectors) at two sites in each of two areas of a lower Chesapeake Bay tributary (York River, Virginia) to examine spatial variability in blue crab recruitment. Spatial patterns of abundance were not consistent across habitats (plankton, artificial collectors and grassbeds) or time. Densities of planktonic megalopae were homogeneous at 1-2 m (within site) but varied at spatial scales of hundreds of meters (between sites) and kilometers (between areas). Settled megalopae were distributed unevenly within and between sites, but their abundance …

Public Oyster Shoal Survey - Spring 1990, Bruce Barber

Reports

This report summarizes data collected during 1990 in the Virginia portion of the Chesapeake Bay. The report focuses on the spring public oyster shoal survey in Virginia.

Striped Bass Research, Virginia : Estimation Of Juvenile Striped Bass Relative Abundance, Annual Report 1989, James A. Colvocoresses

Reports

The Virginia Institute of Marine Science (VIMS) has conducted a juvenile striped bass seine survey during the years from 1967 through 1973 and from 1980 through the present, with the primary objective of monitoring the relative annual recruitment success of juvenile striped bass in the spawning and nursery areas of Lower Chesapeake Bay. The survey was funded during it's initial period by the U.S. Fish and Wildlife Service and then reinstated in 1980 with funding from the National Marine Fisheries Service under the Emergency Striped Bass Study program. Commencing with the 1988 annual survey reported herein, support of the program …

Status Of The Virginia Public Oyster Fishery - Fall 1990, Bruce Barber

Reports

This report summarizes data collected during 1990 in the Virginia portion of the Chesapeake Bay. The report focuses on the fall oyster survey in Virginia.

Fecundity Of Blue Crab, Callinectes Sapidus, In Chesapeake Bay: Biological, Statistical And Management Considerations, Michael H. Prager, John R. Mcconaugha, Cynthia M. Jones, Patrick J. Geer

OES Faculty Publications

Ovigerous blue crabs were collected from the mouth of Chesapeake Bay during the 1986 and 1987 spawning seasons. Mean carapace width was 14.7 cm; mean fecundity was 3.2×106 eggs. Fecundity was significantly related to carapace width, and did not vary significantly with developmental stage of the eggs. Mean fecundities were 2.6×106 eggs in 1986, and 4.0×106 eggs in 1987. An additive model with year and size effects described the observed fecundities reasonably well, was compact, and was easier to interpret than a multiplicative model. To fit a more general model without year effects, the authors took the mean of 1986 …

A Mark-Recapture Study Of Striped Bass In The James River, Virginia : Annual Report 1989, Joseph G. Loesch, Bruce W. Hill

Reports

No abstract provided.

Habitat Requirements For The Hard Clam, Mercenaria Mercenaria, In Chesapeake Bay, G.Curtis Roegner, Roger L. Mann

Reports

The hard clam, Mercenaria mercenaria, is found along the eastern coast of North America from the Gulf of St. Lawrence to Texas. In Chesapeake Bay the hard clam is restricted to salinities above approximately 12 ppt. The abundances and distribution patterns of hard clams in Chesapeake Bay are based on studies performed nearly 20 years ago - a more extensive survey of hard clam resources is due. Statements concerning long term trends in populations are not feasible.

The basic anatomy of hard clams conform to that of venerid bivalves. Hard clams grow to a maximum shell length (anterior-posterior dimension) of …

Striped Bass Research, Virginia: Characterization Of Virginia's Striped Bass Commercial Fisheries Annual Report 1989-90, Virginia Institute Of Marine Science

Reports

The research reported herein (and in the 1982 through 1989 annual reports) is directly related to Priority III stated in the "Action Plan" (p. 15) of the Emergency Striped Bass Study (Anadromous Fish Conservation Act Amendment, Public Law 96-118). The amendment was the result of a decline in striped bass (Marone saxatilis) landings from Maine to North Carolina since the mid-1970's. This report summarizes the results of the fall 1989 and spring 1990 sampling period and compares these results with the previous work.

Cataract Occurrence In Micropogonia Furnieri (Desmarest, 1822) In The Area Between Capes Frio And Torres (23° S And 29° S), Brazil : Investigation Of Causes And Electrophoretic Studies Of Total Proteins Of The Eye Lenses, Anna Emila A. De M. Vazzoler, Van Ngan Phan

Reports

The frequency and distribution of these specimens were analysed and the electrophoretic patterns of soluble eye-lens proteins were determined. This cataract is not of parasitic origin and was rare in specimens from the coastal area. In the lagunar region it occurs mainly in specimens of the River Baguacu from April to November.

A Mark-Recapture Study Of Striped Bass In The Rappahannock River, Virginia Annual Report 1989-1990, Joseph G. Loesch, Bruce W. Hill, Philip W. Sadler

Reports

A total of 6,203 striped bass were tagged in fall 1989 and 2,033 in spring 1990 on the Rappahannock River.

In fall 1989, 63.5% of the tagged striped bass were less than 400 mm fork length (FL). In comparison, 86% of the fish were greater than 400 mm FL in spring 1990.

Pound nets in the Rappahannock River account for 75% of the recaptures, while out of state recaptures account for only 0. 008% of the total returns.