Life Sciences 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 …

An Evaluation Of At-Sea Handling Practices: Effects On Sea Scallop Meat Quality, Volume And Integrity, William D. Dupaul, Robert A. Fisher, James E. Kirkley

Reports

No abstract provided.

On-Board Quality Control Preparing Mid-Atlantic Fisheries For The Future, Robert A. Fisher

Reports

The U.S. population is eating more seafood than at any time in the nation's history. Strong national and local marketing and consumer education programs have encouraged this increased consumption. AF, consumers become more knowledgeable about seafood products, and as sales respond to competition, high quality products will be the 1ule rather than the exception. This guide focuses on the very beginning of quality assurance, on-board handling.

Areas of focus for on-board quality control measures include vessel sanitation, icing-temperature control, harvesting techniques, on-deck handling, and storage. These procedures, outlined on the following pages, are in line with preliminary requirements being set …

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 …

Marine Pollution Impacts On Living Marine Resources, Herbert M. Austin

Reports

No abstract provided.

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 …

A Fisherman's Guide: Getting The Most Out Of Monkfish, Robert A. Fisher, Bill Dupaul

Reports

No abstract provided.

Short-Run Situation Outlook: Mid-Atlantic Sea Scallops, James Kirkley, William Dupaul

Reports

No abstract provided.

Heating Soft Crab Shedding Systems, Mike Oesterling

Reports

The molting of blue crabs, and ultimately soft shell crab production, is regulated by water temperature. A certain threshold or minimum water temperature must be reached before blue crabs begin to molt (shed). Although crabs begin shedding at temperatures in the mid-60'sF (18-19°C), water temperatures near 70°F (21°C) are optimum for active shedding. As the water temperature increases, the time required for a crab to progress through the stages leading to molting decreases (the time needed to go from a white-line, to a pink-line and finally red-line crab). The time needed for a complete molt--for a soft crab to exit …

Status Of The Major Oyster Diseases In Virginia 1989 A Summary Of The Annual Monitoring Program, Eugene M. Burreson

Reports

No abstract provided.

Marine Resource Bulletin Vol. 22, No. 1, Virginia Sea Grant, Virginia Institute Of Marine Science

Virginia Marine Resource Bulletin

Contents

Introduction

Beaches: Dynamic and Transformed Daily

An Inhospitable Environment

Over 5,000 Miles of Tidal Shoreline

Waterfront Redevelopment Mazimizing the Use of Urban Coastline

Behind the Dunes

Shifting Sand

Educating Future Decision Makers

Replenishing the Shoreline

Hurricanes

People to People

Marine Notes

Eastern Atlantic Tonguefishes (Symphurus: Cynoglossidae, Pleuronectiformes), With Descriptions Of Two New Species, Thomas A. Monroe

VIMS Articles

Six species of symphurine tonguefishes, including two previously undescribed, from the Mediterranean Sea and eastern Atlantic Ocean (including the Azores, Madeira, Ascension, and St. Helena) are described and illustrated.

Effect Of Decreasing Oxygen Tension Of Swimming Rate Of Crassostrea Virginica (Gmelin, 1791) Larvae, Roger L. Mann, Julia S. Rainer

VIMS Articles

Four sizes of Crassostrea virginica Gmelin larvae (mean lengths 76.8, 118.1, 139.7 and 290.2 [Lm) were exposed to ·stepwise decreases in oxygen concentration from I 00% saturation (5 .38 mill at 22°C and 22 ppt salinity) to as low as 10% saturation and their swimming rates (net vertical movement per unit time) were recorded at each oxygen concentration. No cessation of swimming was observed and in only two conditions, that of 76.8 [Lm larvae at 10% saturation and 290.2 j.Lm larvae at 21% saturation, was swimming rate significantly lower than that of the same size larvae at full saturation.

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 …

Settlement Of Oysters, Crassostrea Virginica (Gmelin, 1791), On Oyster Shell, Expanded Shale And Tire Chips In The James River, Virginia, Roger L. Mann, Bruce J. Barber, James P. Whitcomb, Kenneth S. Walker

VIMS Articles

The effectiveness of oyster shell, expanded shale, and tire chips as substrates for settlement of oysters, Crassostrea virgi11ica (Gmelin), was compared at four locations in the James River, Virginia, over three two-week time intervals in August and September, 1988. Only differences between substrate were significant (P < 0.001). Over all locations and time intervals, a significantly higher (P < 0.001) proportion of total oyster settlement occurred on oyster shell (63.8%) than on either tire chips (22.1 %) or expanded shale (14.2%).

Recruitment And Growth Of Oysters On Shell Planted At Four Monthly Intervals In The Lower Potomac River, Maryland, Reinaldo Morales-Alamo, Roger L. Mann

VIMS Articles

Oyster shells were planted on four successive months (May to August 1986) in contiguous plots at Jones Shore Bar in the Potomac River, Maryland, to study the effect of differences in time of cultch planting on settlement and survival of oyster spat. The plots were usually sampled at two-week intervals from time of planting through November, 1986, and once in June, 1987. A massive concentration of the tunicate Molgula manhattensis covered the bottom in all plots within four to six or eight weeks following shell planting. A commercially acceptable number of spat per shell, between 1.8 and 2.2 (approximately equivalent …

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 …

Development Of The Reproductively Functional Form In The Male Blue-Crab, Callinectes-Sapidus, Wa Van Engel

VIMS Articles

The progression of the morphological features of the male blue crab reproductive system that culminate in puberty involves one change in the gonad, four combinations of the method and degree of adherence of the abdomen to the sternum, four variations in the positions of the penes, and four variations in the positions of the pleopods. The sequence of development appears to be established: (I) spennatophores must be present in the anterior vasa deferentia; (2) the abdomen must be completely free of the sternum, or, in addition, may be locked by the sternal tubercles; (3) and the penes and second pleopods …

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 …

Biochemical Genetics Of Southern California Basses Of The Genus Paralabrax - Specific Identification Of Fresh And Ethanol-Preserved Individual Eggs And Early Larvae, John Graves, Michelle J. Curtis, Paul A. Oeth, Robin S. Waples

VIMS Articles

No abstract provided.

Oceanic Dispersion Of Larval Fish And Its Implication For Mortality Estimates - Case-Study Of Walleye Pollock Larvae In Shelikof Strait, Alaska, Suam Kim, Bohyun Bang

VIMS Articles

No abstract provided.

Stomach Contents And Parasite Infestation Of School Bluefin Tuna Thunnus-Thynnus Collected From The Middle Atlantic Bight, Virginia, David B. Eggleston, Eleanor A. Bochenek

VIMS Articles

No abstract provided.

Differential Growth Among Cohorts Of Age-0 Weakfish Cynoscion-Regalis In Chesapeake Bay, Stephen T. Szedimayer, Mp Weinstein, John A. Musick

VIMS Articles

Age-0 weakfish Cynoscion regalis, were sampled from the Chesapeake Bay-York River estuary in 1983 and 1984 to test for the existence of multiple cohorts and compare growth rates. In both years juveniles were first collected in the estuary in late July, were significantly more abundant from August to mid-October, but were uncommon by the end of October. Significantly more weakfish were collected in 1983 than in 1984. Daily ages were determined based on scale circuli. Cohorts were separated by local minima in birthdate distributions: cohort 1 hatched before 16 July 1983, cohort 2 (16 July-15 August 1983), cohort 3 (15 …

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 …

The Assessment Of Commercial Fishing Effort In Virginia Annual Report 1990, Joice S. Davis, James C. Owens, Joseph G. Loesch

Reports

The Virginia Institute of Marine Science (VIMS), through funding by the Virginia Marine Resources Commission (VMRC), has conducted an assessment of commercial fishing effort in Virginia's major rivers and Chesapeake Bay beginning in late 1985 to the present, except for brief intervals when funding was unavailable.

This report primarily summarizes the final year of assessment, from 1 October 1989 through 30 September 1990. Objectives of the study were: -1) to assess pound net fishing effort in Chesapeake Bay, in the James, York, Rappahannock, and Potomac rivers, and the Virginia tributaries to the Potomac River; and, 2) to assess stake, anchor …