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 …

Changes In Caloric Content As A Result Of Sub-Lethal Stress In Neanthes Virens (Sars), Phyllis J. Friello

Biological Sciences Theses & Dissertations

Neanthes virens were subjected to a toxicity test with 1.8, 3.4, 6.7 and 11.0 mg/1 Cd²⁺. Worms were withdrawn on Days 1, 4, 7, 10 and 14 from each of five replicate tanks and their caloric content determined by bomb calorimetry. Analyses of variance and covariance showed no significant differences in worm caloric content with withdrawal day or cadmium concentration.

In a second experimental series, a sediment toxicity test with Neanthes virens was conducted in contaminated sediments from two sites, as well as reference sediments from a control site. Caloric content of the worms was measured by bomb …

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 …

Number 20 (August 1989), Southern Fishes Council

Southeastern Fishes Council Proceedings

(August 1989) - Distribution and Conservation Status of the Northern Studfish, Fundulus catenatus, in Indiana. By J.E. Thomerson and L.N. Smith, 6pp.

New Records and Comments on the Distribution of Blair's Starhead Topminnow, Fundulus blairae (Fundulidae). By M.G. Warren and P.E. Denette, 3 pp.

The Chestnut Lamprey, Ichthyomyzon castaneus Girard, in the Mobile Basin. By R.L. Mayden, et al., 3 pp.

Diet of Juvenile Bowfm, Amia calva Linnaeus, in the Sipsey River, Alabama. By K.S. Frazer et al., 3 pp.

Distribution And Conservation Status Of The Northern Studfish, Fundulus Catenatus, In Indiana, Jamie E. Thomerson, Lana M. Smith

Southeastern Fishes Council Proceedings

No abstract provided.

Sfc Region And Subregions, Southeastern Fishes Council

Southeastern Fishes Council Proceedings

No abstract provided.

Diet Of Juvenile Bowfin Amia Calva Linnaeus, In The Sipsey River, Alabama, Kenneth S. Frazer, Herbert T. Boschung, Richard L. Mayden

Southeastern Fishes Council Proceedings

No abstract provided.

New Records And Comments On The Distribution Of Blair's Starhead Topminnow, Fundulus Blairae (Fundulidae), Mark A. Warren, Philias E. Denette

Southeastern Fishes Council Proceedings

No abstract provided.

The Chestnut Lamprey, Ichthyomyzon Castaneus Girard, In The Mobil Basin, Richard L. Mayden, Ronald H. Matson, Bernard R. Kuhajda, J. Malcom Pierson, Maurice F. Mettee, Kenneth S. Frazer

Southeastern Fishes Council Proceedings

No abstract provided.

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 …

The Temporal And Spatial Distribution Of Blue Crab Larvae On The Mid-Atlantic Bight Adjacent To The Chesapeake Bay, 1982-1983, Lyle Michael Varnell

OES Theses and Dissertations

Recruitment processes are important information for the management of commercially and recreationally exploited marine species. Recruitment processes of the Chesapeake Bay's most important commercial and recreational species, the blue crab, are unknown, due in part to the lack of knowledge of the processes directly preceeding recruitment.

The present study was undertaken to investigate and explain the movement and developmental patterns of blue crab larvae while offshore. Interannual and intraseasonal variations of these patterns were also examined.

Sampling occurred from May to November during 1982 and 1983. Larvae were collected at three depths (neuston layer (upper 10 cm), one meter and …

Picoplankton/Phytoplankton Dynamics In Hampton Roads, Virginia, Leslie E. Dorworth

OES Theses and Dissertations

The biomass distribution of the three main size components of the phytoplankton (net, nano, and picoplankton) was examined in the lower Chesapeake Bay. Work was done at two stations during the spring and neap tidal cycles when freshwater flow into the bay was at its seasonal minimum and maximum. Emphasis was placed on how the picoplankton ( < 2.0 μm, > 0.2 μm) reacted during the sampling period.

Picoplankton made up approximately 13% of the total biomass, during the observed time period, at the more oceanic station. The picoplankton fraction contributed up to 16% of the total biomass at the estuarine station. From this …

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 …

Number 19 (July 1989), Southern Fishes Council

Southeastern Fishes Council Proceedings

(July 1989) - Atlas of Fishes of the Upper Tombigbee River Drainage, Alabama-Mississippi. By H.T. Boschung, 104 pp.

Atlas Of Fishes In The Upper Tombigbee River Drainage, Alabama-Mississippi, Herbert Boschung

Southeastern Fishes Council Proceedings

No abstract provided.

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 …

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.

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

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.

Behavioral Determination Of A Geomagnetic Senstivity In The Atlantic Bottlenose Dolphin, Tursiops Truncatus (Cetacea, Onotoceti), Alene A. Minchew

Master's Theses

No abstract provided.

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 …

Population Variation In The Mitochondrial-Dna Of Two Marine Organisms: The Hard Shell Clam Mercenaria Spp. And The Killifish, Fundulus Heteroclitus, Bonnie Lynn Brown

OES Theses and Dissertations

The two major topics are covered in this dissertation: the integration of molecular genetic tools with applied aquacultural research and short-term evolutionary dynamics. The first study investigated the extent of geographic differentiation of native clam stocks along the U.S. east and Gulf coasts. Clam mitochondrial DNA (mtDNA) demonstrated size polymorphism (16.5-19.0 kb) and restriction site heteroplasmy. Size heteroplasmic individuals occurred at a frequencies of 0-89% in clam populations. Restriction site heteroplasmy occurred in 12% of the 317 individuals assayed. Results of the study indicated that although harbouring a wealth of genetic variation, clams from northern regions were similar and lacked …