Life Sciences Commons^™

Evaluation Of Automated Threshold Selection Methods For Accurately Sizing Microscopic Fluorescent Cells By Image-Analysis, Me Sieracki, Se Reichenbach, Kl Webb

VIMS Articles

The accurate measurement of bacterial and protistan cell biomass is necessary for understanding their population and trophic dynamics in nature. Direct measurement of fluorescently stained cells is often the method of choice. The tedium of making such measurements visually on the large numbers of cells required has prompted the use of automatic image analysis for this purpose. Accurate measurements by image analysis require an accurate, reliable method of segmenting the image, that is, distinguishing the brightly fluorescing cells from a dark background. This is commonly done by visually choosing a threshold intensity value which most closely coincides with the outline …

Natural And Disturbance-Induced Demographic Variation In An Infaunal Polychaete, Nephtys Incisa, Roman Zajac, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Demography of the infaunal polychaete Nephtys incisa was investigated for periods of 1 yr prior to and following disturbance (dredge material disposal) at a site in central Long Island Sound, USA. Infaunal grab samples were taken at 5 stations 200 m to 3 km apart. The demography of populations at each station was based on age-classes spanning juveniles to adults 4 + yr of age. Age-specific survivorship and fecundity were based on changes in mean density of each cohort and a positive correlation between female size and egg production, respectively. Analyses of population matrix models indicated pre-disposal populations had positive …

Tidal Flat Ecology: An Experimental Approach To Species Interactions By K. Riess, John T. Tanacredi Ph.D.

Faculty Works: CERCOM

A periodic pause to intensely observe a singularly unique ecosystem sharpens one's awareness of this diverse world of ours, especially, as the author notes, if one observes a transitional ecosystem whose ecological treasures are hidden or maybe obscured by a tidal sediment's resemblance to a large, rotten cheese! "It smells, is slimy and sticky, is punched with holes and crowded with various worms." Sounds good to me! Reise's "pause" encompasses 10 years in which he investigated the Wadden Sea mudflats near the border between West Germany and Denmark. He uses this site to discuss the biotic and abiotic interactions within …

Phase I - Preconstruction Progress Report For Biological Monitoring Of The John U. Lloyd Beach Renourishment, Richard E. Dodge, Steven C. Hess, Charles G. Messing, Glenda Kelley

Marine & Environmental Sciences Faculty Reports

In 1987, Nova University (Contractor) with ERM South (Subcontractor) was awarded a contract to provide biological monitoring services for the John U. Lloyd State Recreation Area Beach Renourishment Project. A notice to proceed for the initial biological monitoring (phase I - Preconstruction) was issued in February, 1989. Field monitoring took place in February and March, 1989. Laboratory work has continued from March, 1989 to present. The renourishment dredging took place from May 16, 1989 to July 14, 1989. Approximately 603,000 cu yds of sediment were removed and subsequently emplaced on 1.6 miles of shoreline. Within the next 6 months, Broward …

Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman

Biology and Environmental Science Faculty Publications

Using a laboratory model system comprised of newly settled oysters Crassostrea virginica and established fouling species (Botrylloides sp. initially, and others including Styela clava and Ciona intestinalis as the experiment progressed), we tested how differences in food supply and competitor density may affect post-settlement surivorship and growth of sessile marine invertebrates over a 44 d period. After 15 d, results were mixed but indicated that both food and density conditions affected growth and survivorship significantly, with some suggestion of high food levels ameliorating high density effects However, 44 d after settlement, oysters had reduced survivorship and growth when competitors …

Distribution And Marketing Of Western Australia Rock Lobster., P. J. Monaghan

Fisheries management papers

This report describes the marketing and distribution of Western Australian rock lobster products in the major consuming countries namely, USA, Japan and Taiwan. It is based on a study which was commissioned by the Fisheries Department of Western Australia who sought, for the benefit of industry generally, an understanding of the world lobster markets.

Effects Of Hypoxia And Anoxia On Survival, Energy Metabolism, And Feeding Of Oyster Larvae (Crassostrea Virginica, Gmelin), J Widdows, Rie Newell, Roger L. Mann

VIMS Articles

The tolerance of Crassostrea virginica larvae to anoxia increases with developmental stage and body size. Median mortality times range from 11 h for prodissoconch larvae of 82 micro m (shell length) to 51 h for pediveliger larvae of 3 12 micro m, and 150 h for juvenile oysters. Simultaneous calorimetry and respirometry showed that in response to declining oxygen tension (P02), the rates of heat dissipation and oxygen uptake by oyster larvae are maintained independent of PO2 down to low Pc values (2 kPa for prodissoconch larvae and 8 kPa for pediveliger and juveniles). Therefore, total energy metabolism is sustained …

A Mark-Recapture Study Of Striped Bass In The James River, Virginia : Annual Report 1988, Joseph G. Loesch, Bruce W. Hill

Reports

EXECUTIVE SUMMARY

1. In the Spring 1988, 2,145 striped bass were tagged in the James River.

2. The mean size of striped bass tagged in 1988 (351.6 mm) was 117.9 mm smaller than mean size in 1987. The difference may be due to different locations and times of tagging.

3. The dominant age group in 1987 was the 1982 year class but in 1988 the dominant age group was the 1984 year class. This difference may also be accounted for by different locations and times of tagging.

4. The exodus of the mature fish out of the river after spawning …

Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Laboratory and field experiments revealed that a variety of species of common, sessile invertebrates, including barnacles, ascidians, and bryozoans, affected the settlement and post-settlement abundance of the oyster Crassostrea virginica (Gmelin). While the nature of the effects varied, most species both reduced oyster settlement by covering and removing substrate available for attachment, and increased settlement on adjacent surfaces. The solitary ascidians Ciona intestinalis (L.) and Styela clava (Herdman), were found to be predators of oyster larvae. Post-settlement survivorship and growth were also strongly affected by the presence of sessile species. In most cases the effects were negative and correlated with …

Southern Demersal Gillnet And Longline Fishery., Management Advisory Committee

Fisheries management papers

In its report to the Ministier for Fisheries in November 1986, the Southern Western Australian Shark Working Group recommended the establishment of an Industry/Government Mangement Advisory Committee to provide managememt advice on the fishery to the Minister for Fisheries. The Advisory Committee held its first meeting in Albany on 23 February 1989. After being briefed on the state of shark stocks, the Committee's deliberations fell into three broad categories. In the first category there was sufficient time and information available to make a recommendation to the Minister for Fisheries. In the second category, discussion commenced, but was held over to …

Sediment Processes Monitoring Annual Report For Calendar Year 1988, Richard Wetzel, Bruce Neilson

Reports

No abstract provided.

Hypoxia In The Lower Rappahannock Estuary, Albert Y. Kuo, Mohamed Z. Moustafa

Reports

There are several objectives to this study. The immediate objective is to collect a comprehensive and consistent set of field observations to better describe the hypoxic condition in the Rappahannock River. Other objectives can be classified as short and long term goals.

Long term: (1) Identify and quantify the processes contributing to the dissolved oxygen budget in deep waters, and explain the variabilities among the three Virginia major tributary estuaries. (2) Provide information for resource management so that the James River can be protected from hypoxic problems and, perhaps, the problems in the York and Rappahannock Rivers can be alleviated. …

Virginia's Recreational Marlin And Tuna Fishery 1983 -1988 : A Report To The Fishermen, Eleanor A. Bochenek, Nancy J. Chartier, Jon A. Lucy

Reports

No abstract provided.

Occurrence Of Indicators Of Fecal Pollution In Water And Sediment Of A Subestuary Impacted By Non-Point Pollution, Howard I. Kator, Martha Rhodes

Reports

No abstract provided.

Management Of The Perth Metropolitan Purse-Seine Fishery., N. Moore

Fisheries management papers

This report outlines the management plan for the limited entry purse-seine fishery for small pelagic fish in coastal waters between Lancelin and Cape Bouvard and seaward to the 200 mile limit of the Australian Fishing Zone. The plan includes Cockburn Sound.

Determination Of Marina Buffer Zones Using Simple Mixing And Transport Models : A Report To The Virginia State Dept. Of Health, Bureau Of Shellfish Sanitation As Part Of The Chesapeake Bay Initiatives Marine Pollution Abatement Initiative, John M. Hamrick, Bruce J. Neilson

Reports

This report describes the rationale, development and application of simple mixing and transport models for the determination of marina buffer zones and buffer zones for other point source discharges. Included in the report are two computer programs for implementation of the most general two dimensional transport model.

A Review Of The Shark Bay Pearling Industry., D. A. Hancock

Fisheries management papers

While there are currently only two pearl culture leases in Shark Bay, two new applications for leases have already been received by the W.A. Fisheries Department. Increased interest is being generated about pearl culture in Shark Bay, which will need to be considered against the background of management plans designed to restrict further entry into other areas, notably the pearly industry of W.A from Exmouth Gulf northwards, and the pearling industry of the Northern Territory. Recent successes with pearl culture in both those areas, and the greatly increased revenues and high lease transfer values realised, must inevitably focus interest on …

Geotechnical And Benthic Evaluation Of Sand Resources In The Lower Chesapeake Bay - Report 1: Thimble Shoal, Suzette M. Kimball, Linda C. Schaffner, Carl H. Hobbs Iii

Reports

This report details the results of an exploration program to delineate reserves containing quantities of beach quality sand suitable for emplacement on public recreational beaches in the City of Hampton.

A Report On Marron Fishing In Western Australia., Doug Wenn

Fisheries management papers

The marroning experience is one enjoyed by many Western Australians. A rapid increase in fishing effort evidenced by the increase in number of recreational fishing licences issued, combined with low rainfall in the last few years resulted in a dramatic reduction of marron catch rates during 1986/87. In view of the state of marron stocks, the Minister for Fisheries considered it appropriate to close the 1987/88 marron season.

Management Of The South-West Inshore Trawl Fishery., N. Moore

Fisheries management papers

This report outlines the management plan for the south west inshore trawl fishery which already operates in coastal waters less than 200 metres deep between Guilderton and Cape Leeuwin. This management plan takes into account these important concerns and has specifically set aside a strip of coastal area from Cape Bouvard to Cape Leeuwin for recreational usage and for protection of the benthic community, and closed the management zone north of Burns Beach to trawling.

Feasibility Of Crab Meal Processing In The Chesapeake Bay Region Ii: An Integrated Economic Analysis For Hampton/Newport News, Virginia, Phillip R. Grulich, William D. Dupaul

Reports

The crab waste problem in Virginia and Maryland has been well documented by past research efforts, (Hatem, 1980) (Murray and DuPaul 1981) (Cathcart et, al.1984). Murray and DuPaul (1981) documented both the magnitude and location of the problem in Maryland and Virginia. Their analysis provided a description of the total waste disposal problem in the Bay and pinpointed specific trouble spots. The report provided enterprise budgets for three locations; Hampton, Virginia, Crisfield, Maryland, and Cambridge, Maryland. These locations were chosen because of their proximity to crab processors and their ability to produce sufficient quantities of crab waste to make a …

A Flow Cytometric Approach To Assessing The Environmental And Physiological Status Of Phytoplankton, Serge Demers, Kimberly Davis, Terry L. Cucci

CCPO Publications

No abstract provided.

Rock Lobster Industry Advisory Committee Reported To The Minister For Fisheries., Rock Lobster Industry Advisory Committee

Fisheries management papers

The total catch of about 12.1 million kilograms for the 1987/88 season, based on processor returns, was an increase of 44% on the 1986/87 season. This very high catch, the third highest on record, resulted from an above average perulus settlement in 1983/84 and a "flow-on" of fast growing animals stemming from the expected high recruitment in 1988/990 caught as "reds" in 1987/88. The Committee has identified five major elements related to the state of the rock lobster fishery upon which management advice is considered. a) The undersize fraction of the population. b) The "whites" which provide a significant proportion …

Fact Sheet: Aviation Services, College Of William And Mary, Virginia Institute Of Marine Science

Miscellaneous

Brochure describing the features and specifications of the 1954 DeHavilland Beaver aircraft, acquired on loan from the U.S. Navy in late1975, used for aerial photography, reconnaissance, observation and transport in support of the Institute's research mission.

The brochure is undated, 1989 is estimated.

Additional background information on the airplane available p.1 : https://scholarworks.wm.edu/miscellaneous/19/

The College Of William And Mary, School Of Marine Science, 1989-90 Program, College Of William And Mary, School Of Marine Science

Miscellaneous

Catalog for the Graduate program from the School of Marine Science at the College of William and Mary for the listed academic year.

Ingestion Of Gametes By Protists: Fate Of Surplus Reproductive Energy In The Sea, Hm Galvao, At Fritz, R Schmaljohann

VIMS Articles

No abstract provided.

Biological Control Of Crab Predation On Hard Clams Mercenaria Mercenaria (Linnaeus, 1758) By The Toadfish Opsanus Tau (Linnaeus) In Tray Cultures, Robert Bisker, Michael Castagna

VIMS Articles

Oyster toadfish Opsanus tau (Linne) were tested as biological controls of crab predation on juvenile hard clams Mercenaria mercenaria (Linne) in trays with crushed stone aggregate. Clam survival after 34 weeks was 69.5% in the presence of toadfish and 2.3% in trays without toadfish. Toadfish reduced the total number of crabs (mud crabs and blue crabs). Crabs in trays with toadfish present had smaller carapace widths.

Predation By The Oyster Toadfish Opsanus Tau (Linnaeus) On Blue Crabs And Mud Crabs, Predators Of The Hard Clam Mercenaria Mercenaria (Linnaeus, 1758), Robert Bisker, Mary Gibbons, Michael Castagna

VIMS Articles

The oyster toadfish, Opsanus tau (Linne), reduces predation by xanthid and portunid crabs on juvenile hard clams, Mercenaria mercenaria (Linne), in field cultures. This study examined the influence of size and species on the predator-prey relationship between toadfish and crabs. The mud crabs Eurypanopeus depressus (Smith), Neopanope sayi (Smith), and Panopeus herbstii Milne Edwards of 5-40 mm carapace width and blue crabs Callinectes sapidus Rathbun of 77-105 mm carapace width were offered to toadfish of 70-322 mm total length. Toadfish predation rates on mud crabs were higher with increasing toadfish size and lower with increasing crab size. Toadfish injured or …

Autotrophic Picoplankton Dynamics In A Chesapeake Bay Sub-Estuary, Rt Ray, Lw Hass, Me Sieracki

VIMS Articles

No abstract provided.

Striped Bass Research, Virginia - Annual Report 1988-89, Virginia Institute Of Marine Science

Reports

The research reported herein (and in the 1982 through 1987 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 (Morone saxatilis) landings from Maine to North Carolina since the mid-1970's. This report summarizes the results of the Fall 1988 and Spring 1989 sampling periods and compares these results with the previous work.