Life Sciences Commons^™

Phytoplankton Dynamics In The Very Low Salinity Region Of The James River Estuary, Virginia, U.S.A., Changho Moon

OES Theses and Dissertations

During summer and autumn discharge from the James River estuary, Virginia, was less than 120 _m³sec^-1. There was a peak phytoplankton biomass in the very low salinity region (defined as the location where surface salinity measured less than 0.5$ 0/00) and this peak represented five to ten times greater biomass than adjacent waters. The peak biomass occurred independent of the tidal state and the location of nutrient inputs. It disappeared during winter and spring, and nutrient limitation was not responsible for the low phytoplankton biomass, indicating there were physical, not chemical controlling factors.

The peak biomass …

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

OES Theses and Dissertations

The present study examines the hypothesis that mature female blue crabs, Callinectes sapidus, do not have a terminal anecdysis. Induced molting via eyestalk ablation, size frequency distributions and gonad and limb regeneration indices from field collected animals are used as indicators of potential post maturity molts.

Eyestalk ablation of mature females resulted in ecdysis approximately 51 days after ablation, indicating a physiological ability if mature females to complete ecdysis. Analysis of size frequency distributions indicates two distinct shifts from smaller to larger females, one in early spring and a second in early fall. While migration of larger females into …

Growth Potential Of Young Black Sea Bass, Centropristis Striata, In Artificial Environments, Joung Won Kim

OES Theses and Dissertations

The growth potential of the commercially important marine finfish, black sea bass (Centropristis striata), was examined for aquaculture under controlled conditions. The effect of food and body weight on growth was evaluated using juveniles and young black sea bass cultured with a natural diet and a commercial diet at various feeding levels.

Growth was affected by type of food, food consumption rate, and fish body weight. For fish having positive weight gain, absolute growth rate (gram/day) increased exponentially as food consumption rate (percent of body weight per day) and/or body weight increased. Instantaneous growth rate (percent of body weight per …

A Comparison Of Potential Fishing Methods Associated With Fish Aggregating Devices Off The Northeast Coast Of Puerto Rico, Alan M. Friedlander

OES Theses and Dissertations

Six fish aggregating devices (FADs) were deployed in June and monitored through December 1986. Emphasis was placed on trolling, live-bait handlining and longlining.

There was a significant difference (x2 = 7.815, pCoryphaena hippurus) which made up 64.2% of the catch.

Handlining at night around inshore buoys for one boat yielded 82.7 kg per trip. Pelagic fish comprised 83.9% of the catch, with the majority (81.4%) being kingfish (Scomberomorous cavalla). Catch rates were 50% higher and the species diversity much greater on the FADs versus control during experimental nightfishing, but the difference was not significant.

Longlining resulted in 3.4 …

Acceleration Of Nutrient Uptake By Phytoplankton In A Coastal Upwelling Ecosystem: A Modeling Analysis, Richard C. Zimmerman, James N. Kremer, Richard C. Dugdale

OES Faculty Publications

Studies of upwelling centers in the eastern Pacific suggest that maximum rates of nitrate uptake (light and nutrient saturated) increase, or shift-up, as newly upwelled water moves downstream. The rate of shift-up appears to be related to irradiance and the ambient concentration of limiting nutrient at the time of upwelling. A mathematical model was developed to evaluate effects of irradiance and initial nitrate concentration on temporal patterns of shift-up and subsequent time scales of nutrient utilization over a range of simulated upwelling conditions. When rates consistent with field studies were used, complete shift-up was possible only under certain conditions, and …

The Respiratory Response Of Busycon Canaliculatum (L) To Seasonal Variation Of Water Temperature, Salinity, And Oxygen, Harry Gregory Polites

Dissertations, Theses, and Masters Projects

No abstract provided.

Identification And Distribution Of Urophycis (Gill) And Phycis (Artedi) Larvae And Pelagic Juveniles In The Middle Atlantic Bight, Bruce Henry Comyns

Dissertations, Theses, and Masters Projects

No abstract provided.

Population Structure Of The White Perch, Morone Americana, In Lower Chesapeake Bay As Inferred From Mitochondrial Dna Restriction Analysis, Brian W. Bowen

Dissertations, Theses, and Masters Projects

No abstract provided.

A Trophic Resource Analysis Of Dominant Benthic Microfauna Of The Lower Chesapeake Bay, Douglas Vernon Huggett

Dissertations, Theses, and Masters Projects

No abstract provided.

Potential Fish Egg Production By Mnemiopsis Leidyi Determined By Hydrography At The Chesapeake Bay Mouth, Harry D. Johnson

Dissertations, Theses, and Masters Projects

No abstract provided.

Studies Of Pipefish Foraging In Simulated Seagrass Habitats, Clifford H. Ryer

Dissertations, Theses, and Masters Projects

Laboratory experiments determined the effects of two levels of habitat complexity upon pipefish (Syngnathus fuscus) foraging for amphipods. Habitats were composed of equal densities of either narrow (low complexity) or wide (high complexity) leafed artificial seagrass. The response to habitat, as measured by rate of encounter with amphipods, probability of attack after encounter, probability of success after attack, and overall rate of amphipod consumption, was determined for combinations of two fish size classes and three amphipod size classes. Small fish did not experience visually inhibitive effects in either habitat, while large fish had their visual fields impinged upon in the …

Primary Production And Temporal Variation In The Macrophytic Community Of A Tidal Freshwater Swamp, Bryan Keith Fowler

Dissertations, Theses, and Masters Projects

No abstract provided.

Monogenetic Trematodes From The Southern Pacific Ocean Polyopisthocotyleids From The Australian Fishes, The Subfamily Polylabrinae And Microcotylinae, W. A. Dillon, William J. Hargis Jr., Antonio E. Harrises

Reports

This eighth of a series of monogenetic trematodes from the Southern Pacific Ocean discusses two species of Monogenea from Australian waters. Polylabroides mylionis n. sp., from the gills of Mylio butcheri, is described. Neobivagina agonostomi (Sandars, 1945} Dillon and Hargis, 1965, from the gills of Aldrichett~ forsteri, is redescribed; a new locality record is reported for Neobivagina agonostomi.

Is Growth Of Eelgrass Nitrogen Limited? A Numerical Simulation Of The Effects Of Light And Nitrogen On The Growth Dynamics Of Zostera Marina, Richard C. Zimmerman, Robert D. Smith, Randall S. Alberte

OES Faculty Publications

A numerical model of nitrogen uptake and growth was developed for the temperate seagrass Zostera marina L. Goals were to evaluate the relative effects of light and nitrogen availability on nitrogen uptake and partitioning between leaf and root tissue, and to estimate nitrogen concentrations in the sedment and water column required to saturate growth. Steady-state predictions are quite robust with respect to a range of parameter values justified by available data The calculations indicated that roots are probably more important in overall nitrogen acquisition in most light and nitrogen environments encountered in situ, but may contribute less than 50 …

The Relationship Of Upwelling To Mussel Production In The Rias On The Western Coast Of Spain, Jack O. Blanton, Kenneth R. Tenore, F. Castillejo, Larry P. Atkinson, Franklin B. Schwing, Amy Lavin

CCPO Publications

We have calculated an upwelling index for each month over a 17-year period (1969-1985) for a point off the western coast of Spain. We interpret April through September values of the index to indicate the flux of nitrate-rich water in the Spanish Rias. The index representing the 6-month upwelling series has been correlated with an index representing the conditions of mussels grown during that season on rafts in Ria de Arosa. Two seasons represent extreme upwelling conditions over the 17-year sampling period: 1977 when the upwelling index was the highest, and 1983 when it was the lowest. A comparison of …

Validation Of The Otolith Increment Aging Technique For Striped Bass, Morone Saxatilis, Larvae Reared Under Suboptimal Feeding Conditions, Cynthia Jones, Edward B. Brothers

OES Faculty Publications

Striped bass, Morone saxatilis, larvae were reared in the laboratory for 97 days to validate the otolith increment aging technique for this species. Otolith-increment deposition rates were determined under optimal laboratory conditions for growth and under three conditions of restricted feeding and using both light and scanning electron microscopy (SEM). Under optimal laboratory conditions. increments were deposited daily from the fourth day after hatching through the first 2 months of life and were discernible with the light microscope. For larvae reared under restricted feeding regimes and readings done with the light microscope, counts did not reflect true age. Counts …

System Response Of A Nourished Beach In A Low-Energy Estuarine Environment, Gloucester Point, Virginia, Tracy Eanes Skrabal

Dissertations, Theses, and Masters Projects

No abstract provided.

Life History Of The Goosefish, Lophius Americanus, Michael P. Armstrong

Dissertations, Theses, and Masters Projects

No abstract provided.