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Articles 3151 - 3180 of 3959

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Plankton Transport Patterns And Residence Times Around A Tall Seamount: Simulation Results, Dorlisa Louise Hommel Oct 1992

Plankton Transport Patterns And Residence Times Around A Tall Seamount: Simulation Results, Dorlisa Louise Hommel

OES Theses and Dissertations

A semi-spectral primitive equation circulation model was used to simulate flow over an isolated gaussian seamount. Model configuration was such that a Taylor Cap was generated in the flow over the seamount. Arrays of 100 drifters were released in the simulated flow fields at several depths (50, 100, 200, and 400 m) both upstream and over the seamount. For several experiments vertical behaviors were imposed on the drifters to simulate zooplankton migration patterns. The drifter simulations extended for three months. Drifter transport patterns were determined by the initial release position of the drifter relative to the Taylor Cap as well …


The Gulf Stream Front, Its Role In Larval Fish Survival And Recruitment In Florida: Hydrographic Station And Plankton Data, Denis William Frazel, M. Elizabeth Clarke, G. S. Kleppel, Peter B. Ortner, John M. Braker, Carol A. Burkart, Gayle Louise Stone Sep 1992

The Gulf Stream Front, Its Role In Larval Fish Survival And Recruitment In Florida: Hydrographic Station And Plankton Data, Denis William Frazel, M. Elizabeth Clarke, G. S. Kleppel, Peter B. Ortner, John M. Braker, Carol A. Burkart, Gayle Louise Stone

Technical Reports

The goal of this project was to develop a clearer understanding of the role that the Gulf Stream system plays in larval fish survival and recruitment in Florida waters. The specific objectives of this study were to:

  1. Determine whether the biomass of fish larva, other zooplankton, microzooplankton and phytoplankton is higher at the shoreward front of the Gulf Stream than on either side of it.
  2. Characterize the assemblages of fish larvae predators and prey both at the front and on either side of it.
  3. Determine if the composition, abundance and size frequency distribution of larval and juvenile fishes in the …


Mat Movement In Coastal Louisiana Marshes: Effect Of Salinity And Inundation On Vegetation And Nutrient Levels, Christopher Martin Swarzenski Jul 1992

Mat Movement In Coastal Louisiana Marshes: Effect Of Salinity And Inundation On Vegetation And Nutrient Levels, Christopher Martin Swarzenski

Biological Sciences Theses & Dissertations

The present research compared and contrasted the physical structure of floating and rooted marshes, their differing responses to open-water salinities and inundation, as well as the nutrient distribution in the porewaters and sediment. The effects of the physical differences in the two marsh types on the ocurrence of the dominant emergent vegetation was discussed.

The main difference in physical structure of the two marsh types was the presence of a mineral, non-buoyant layer at 25-45 cm depth in the rooted marsh, which could serve as an anchor for the overlying highly organic mat layer found in both marsh types. Porewater …


Post-Shearing Losses Of Sheep Following Cyclonic Rains, M. Holm Glass, R. Jacob May 1992

Post-Shearing Losses Of Sheep Following Cyclonic Rains, M. Holm Glass, R. Jacob

Animal production and livestock published reports

Sudden unpredicted rainfall during summer has caused high mortality rates in newly shorn sheep on at least two previous occasions. These occurred at Darkan, Western Australia, in 1982 (Buckman 1982) and at Kybylolite in the south-east of South Australia in 1960 (Geytenbeek 1982).

Geytenbeek (1982) reported an average mortality of 8.3%, which was highest for sheep within five days of shearing. The mortality declined for animals shorn more than seven days before the rain.

Buckman (1982) reported an average mortality of 27.9% which was highest within 12 days of shearing. The losses related directly to the amount of rain received. …


Factors Affecting The Kinetics Of Light Intensity Adaptation In Marine Phytoplankton, Chunzhi Guo Apr 1992

Factors Affecting The Kinetics Of Light Intensity Adaptation In Marine Phytoplankton, Chunzhi Guo

OES Theses and Dissertations

It has been suggested that the recent light history of phytoplankton and the kinetics of photoadaptation can be used to provide information about the vertical mixing processes in the upper mixed layer. To be useful as a parameter in a model of photoadaptation and vertical mixing, the response of a photoadaptive variable to changes in growth irradiance must be monotonic, significant, and comparable in time rate scale to mixing processes. Previous studies of photoadaptation kinetics have focused on the response of phytoplankton to changes in light intensity under continuous illumination. This dissertation attempts to elucidate the effects of light:dark cycle, …


The Growth And Bioenergetics Of Callinectes Sapidus Larvae And The Effects Of Diet Quality On Larval Physiology, James J. Pletl Apr 1992

The Growth And Bioenergetics Of Callinectes Sapidus Larvae And The Effects Of Diet Quality On Larval Physiology, James J. Pletl

OES Theses and Dissertations

Food quality, especially ω3 polyunsaturated fatty acids (PUFA), can affect the physiology and metabolic efficiency of larvae of the blue crab, Callinectes sapidus. These affects may correlate with success in development and juvenile recruitment.

Larvae were exposed to two diets differing quantitatively in ω3 PUFA and respiration, excretion, growth, and feeding rates were measured for each larval stage and the megalopal stage. The energy partitioned to molts and specific dynamic action was also measured. T

he ω3 PUFA enriched diet resulted in a lower respiration rate when compared to the unsupplemented diet, but there was little differences in excretion …


The Helioporacean Octocoral Epiphaxum, Recent And Fossil: A Monographic Iconography, Frederick M. Bayer Jan 1992

The Helioporacean Octocoral Epiphaxum, Recent And Fossil: A Monographic Iconography, Frederick M. Bayer

Studies in Tropical Oceanography

No abstract provided.


Fisheries Under The Extended Jurisdiction Of Sri Lanka, Hewawasan S.G. Fernando Jan 1992

Fisheries Under The Extended Jurisdiction Of Sri Lanka, Hewawasan S.G. Fernando

Marine Affairs Theses and Major Papers

Fishing has been an important economic activity in Sri Lanka for generations. Firstly, the fisheries sector provides employment to a substantial portion of the population particularly in the coastal area. Secondly, it provides 65 percent of animal protein consumed by the people of Sri Lanka. Thirdly, the fishing industry has proved its capabilities as an earner of foreign exchange through the export of marine product such as prawns, lobsters and other varieties. In 1977 Sri Lanka declared its 200 miles Exclusive Economic Zone (EEZ) under the new regime for the Law of the Sea. The government of Sri Lanka formulated …


Sea-Surface Temperature Related Fisheries And Resource Markets, Jeffrey Michael Rasinski Jan 1992

Sea-Surface Temperature Related Fisheries And Resource Markets, Jeffrey Michael Rasinski

Marine Affairs Theses and Major Papers

This thesis addresses the potential application of sea-surface temperature (SST) data to economic resource markets. It considers the revolution in technology and the accessibility of timely, accurate SST observations for resource markets. Specifically, it addresses issues related to pelagic fisheries and the fish meal industry. The thesis presents a discussion and overview of the upwelling ecosystem of Peru and the Peruvian anchovy (Engraulis ringens) including quantitative analysis and forecasts for the fishery and fish meal prices. This analysis is used to demonstrate the commercial application and relationship between SST and related resource markets. The thesis establishes a bioeconomic statistical model …


Effects Of The Hol Chan Marine Reserve (Belize) On Associated Coral Reef Finfish Populations, Pamela Barrick Baker Jan 1992

Effects Of The Hol Chan Marine Reserve (Belize) On Associated Coral Reef Finfish Populations, Pamela Barrick Baker

Marine Affairs Theses and Major Papers

People throughout the Caribbean depend on fishery resources for subsistence and income. Overfishing is a concern in many areas and the need for resource management is apparent. Coral reef protected areas are being used to maintain sustainable tropical reef fisheries. This research examined the effectiveness of the Hol Chan marine Reserve (HCMR), Belize, in meeting fisheries management objectives. Fishes were surveyed within the HCMR and in a comparable non-protected site to examine changes in fish community structure over time in the HCMR and between protected and non-protected sites. Results show that abundance, mean length, biomass, and species richness of commercially …


Summer 1992, Nsu Oceanographic Center Jan 1992

Summer 1992, Nsu Oceanographic Center

Currents

No abstract provided.


Fall 1992, Nsu Oceanographic Center Jan 1992

Fall 1992, Nsu Oceanographic Center

Currents

No abstract provided.


Spring 1992, Nsu Oceanographic Center Jan 1992

Spring 1992, Nsu Oceanographic Center

Currents

No abstract provided.


Podocerus Chelonophilus, A Testudinous Amphipod Newly Recorded From The Western Atlantic Ocean, James Darwin Thomas, J. L. Barnard Jan 1992

Podocerus Chelonophilus, A Testudinous Amphipod Newly Recorded From The Western Atlantic Ocean, James Darwin Thomas, J. L. Barnard

Marine & Environmental Sciences Faculty Articles

Podocerus chelonophilus (=P. cheloniae), an amphipod inhabiting the carapace of the loggerhead turtle, Caretta caretta, is reported for the first time from the western Atlantic Ocean.


Sea Turtle Conservation Program, Broward County, Fl 1992 Report, Curtis M. Burney, Catherine A. Mattison Jan 1992

Sea Turtle Conservation Program, Broward County, Fl 1992 Report, Curtis M. Burney, Catherine A. Mattison

Marine & Environmental Sciences Faculty Reports

Since 1978, the Broward County Environmental Protection Department (BCEPD) has provided for the conservation of endangered and threatened sea turtle species within its area of responsibility. Broward County is within the normal nesting areas of three species of sea turtles: the loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas) and the leatherback sea turtle (Dermochelys coriacea). The loggerhead is listed as a threatened species, while the green and leatherback are listed as endangered under the U.S. Endangered Species Act, 1973, and Chapter 370, F.S.

Since these statutes strictly forbid any disturbance …


A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp Jan 1992

A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp

Watershed Sciences Faculty Publications

Between 26 April and 2 May 1992, students in a utah state university aquatic ecology class visited Lake Powell to do a study of trophic gradients of the reservoir. The main axis of the reservoir was surveyed, as well as less detailed analyses of Moki and Escalante Canyons. The work was conducted in collaboration with personnel from the u.s. Bureau of Reclamation headed by Bill Vernieu, and from the u.s. Geological Survey (Dick Marzolf). Some of their data appear in the physical-chemical section of this report.

Each student was responsible for compiling a report on one of the following specific …


Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe Jan 1992

Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe

Watershed Sciences Faculty Publications

This report outlines long-term planning and monitoring activities that occurred in 1991 and 1992 in the Stanley Basin Lakes of the upper Salmon River, Idaho for the purpose of sockeye salmon (Oncorhynchus nerka) recovery. Limnological monitoring and experimental sampling protocol, designed to establish a limnological baseline and to evaluate sockeye salmon production capability of the lakes, are present:ed. Also presented are recommended passage improvements for current fish passage barriers/impediments on migratory routes to the lakes. We initiated O. Nerka population evaluations for Redfish and Alturas lakes; this included population estimates of emerging kokanee fry entering each lake in the spring …


Phytoplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson Jan 1992

Phytoplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson

Journal of the Arkansas Academy of Science

Phytoplankton samples were collected quarterly from 1981-1990 at five stations representing discharge water from Arkansas Nuclear One, a nuclear generating station, and four "control" or "dispersal evaluation" stations. Seventy-five taxa representing five divisions were identified and enumerated. Community structure was evaluated using abundances, number of taxa, and Margalef's Richness, Shannon's Heterogeneity and Pielou's Evenness indices. No long-term trends were identified, but the beginning of cyclic variations, with a 7-year periodicity, in abundance, number of taxa, and Shannon's and Pielou's indices were apparent. Margalef's index values were constant during most of the study period. For all samples, t-tests and Mann-Whitney U …


Distribution Of Foraminifera And Pollen In Coastal Depositional Environments Of The Southern Delmarva Peninsula, Virginia, U.S.A., Han Jun Woo Jan 1992

Distribution Of Foraminifera And Pollen In Coastal Depositional Environments Of The Southern Delmarva Peninsula, Virginia, U.S.A., Han Jun Woo

OES Theses and Dissertations

The coastal zone of the southern Delmarva Peninsula exhibits a wide variety of barrier island system subenvironments. This study investigates whether 20 a priori subenvironments can be distinguished from each other on the basis of abiotic environmental variables, pollen assemblages, living foraminiferal populations, and total (living plus dead) foraminiferal assemblages.

The physical data collected from the coastal zone were subjected to canonical variate analysis which discriminated 83% of the stations in 19 groups. These groups were clustered into two internally overlapping sets which represented the inside and outside of the inlet.

Twenty-two pollen types were found in low-energy marsh and …


Molecular And Physiological Responses Of Diatoms To Variable Levels Of Irradiance And Nitrogen Availability: Growth Of Skeletonema Costatum In Simulated Upwelling Conditions, G. Jason Smith, Richard C. Zimmerman, Randall S. Alberte Jan 1992

Molecular And Physiological Responses Of Diatoms To Variable Levels Of Irradiance And Nitrogen Availability: Growth Of Skeletonema Costatum In Simulated Upwelling Conditions, G. Jason Smith, Richard C. Zimmerman, Randall S. Alberte

OES Faculty Publications

Molecular mechanisms that drive metabolic acclimation to environmental shifts have been poorly characterized in phytoplankton. In this laboratory study. the response of light- and N-limited Skeletonema costatum cells to an increase in light and NO3 availability was examined. C assimilation was depressed relative to N assimilation early in enrichment, and the photosynthetic quotient (O2: CO2) increased, consistent with the shunting of reducing equivalents from CO2 fixation to NO3- reduction. The concomitant increase in dark respiration was consistent with the increased energetic demand associated with macromolecular synthesis. The accelerations of N-specific rates of …


The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin Jan 1992

The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin

Masters Theses

Dam construction by beavers creates wetlands which have the potential to improve water quality, especially in areas near urban centers. However, beaver dams may also cause flooding problems which can result in the removal of the beaver(s) and the destruction of their dam. A further understanding of how beaver-created wetlands affect water quality will provide additional data which can be utilized in beaver management decisions.

In this study, 41 chemical parameters were examined from water taken above and below beaver-created wetlands that existed in DuPage County, Illinois between May and September 1991. This study was designed to examine the effects …


Winter 1992, Nsu Oceanographic Center Jan 1992

Winter 1992, Nsu Oceanographic Center

Currents

No abstract provided.


Zooplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson Jan 1992

Zooplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson

Journal of the Arkansas Academy of Science

Zooplankton samples were collected quarterly from five stations representing the discharge bay and four "control" or "dispersing impact" stations. Rotifers dominated all samples numerically and by the number of taxa. All major groups (Rotifera, Cladocera, Copepoda, and Protozoa) exhibited greatest abundances during the summer. Quarterly variations in abundance and number of taxa were documented. Except for an increase in taxonomic analysis detail between 1981 and 1984 resulting in several more taxa added to the list, no long-term increases, declines or repeating cycles were apparent. Margalef's Richness Index reflected this change and showed a long-term increase with evidence of a 5- …


Using Physical, Chemical And Biological Indicators To Assess Water Quality On The Ouachita National Forest Utilizing Basin Area Stream Survey Methods, J. Alan Clingenpeel, Betty G. Cochran Jan 1992

Using Physical, Chemical And Biological Indicators To Assess Water Quality On The Ouachita National Forest Utilizing Basin Area Stream Survey Methods, J. Alan Clingenpeel, Betty G. Cochran

Journal of the Arkansas Academy of Science

The Ouachita National Forest (ONF) has developed a series of Best Management Practices (BMP's) designed to protect water quality and associated beneficial uses (fisheries, municipal water supplies, etc.). A monitoring program is necessary to document the effectiveness of that protection. The Basin Area Stream Survey (BASS) methodology provides a monitoring link from BMP's to the aquatic ecosystems. The goal of BASS is to identify the physical, chemical and biological characteristics of a stream in a format that will allow comparisons with other streams, and indicate when a stream is being impacted. Six index streams within two ecoregions were selected and …


A Study Of The Summer Steelhead, Oncorhynchus Mykiss In Several Intermittent Tributaries Of The Satus Creek Basin, Washington, Joel Denney Hubble Jan 1992

A Study Of The Summer Steelhead, Oncorhynchus Mykiss In Several Intermittent Tributaries Of The Satus Creek Basin, Washington, Joel Denney Hubble

All Master's Theses

The summer steelhead, Oncorhynchus mykiss population was studied in three intermittent tributaries in the Satus Creek Basin. There was a strong tendency for post emergent fry, resulting from redds located in intermittent reaches to move downstream. However, survival to perennial flow conditions was very low. Steelhead production in Dry Creek appears to be lower than in Logy Creek, because of elevated water temperatures and minimal spring and summer stream flow.


Seasonal Phytoplankton Development Within Three Rivers In The Lower Chesapeake Bay Region, Harold G. Marshall, Lewis F. Affronti Jan 1992

Seasonal Phytoplankton Development Within Three Rivers In The Lower Chesapeake Bay Region, Harold G. Marshall, Lewis F. Affronti

Biological Sciences Faculty Publications

The seasonal and inter-annual concentrations of phytoplankton were studied over a 50 month period in the lower James, York and Rappahannock Rivers (USA). Differences in the onset, duration and magnitude of major seasonal growth periods varied from year to year. There was a tendency for spring, summer and fall maxima, with a winter period of reduced abundance. An additional study of picoplankton over a 12 month period indicated greatest abundance during summer and fall, with least development in winter.


Spiny Lobster Recruitment In South Florida: Quantitative Experiments And Management Implications, Mark J. Butler Iv, William F. Herrnkind Jan 1992

Spiny Lobster Recruitment In South Florida: Quantitative Experiments And Management Implications, Mark J. Butler Iv, William F. Herrnkind

Biological Sciences Faculty Publications

Understanding recruitment and identifying factors critical to that process are imperative if adult spiny lobster Panulirus argus stocks are to be conserved and properly managed. The goal of our research has been to obtain ecological information linking inshore postlarval spiny lobster recruitment to later life stages, thereby providing the basic framework for assessing and predicting adult stock. Since 1983, we have investigated various aspects of spiny lobster recruitment including: postlarval time-to-metamorphosis, postlarval/juvenile habitat selection and selection cues, postlarval/juvenile crypticity and susceptibility to predation, juvenile food preference and emigration, juvenile sociality, and the effect of habitat degradation (i.e., siltration) on postlarval/juvenile …


Development And Standardization Of A Short-Term Assay For Evaluating Polluted Estuarine And Coastal Environments: The Medaka Embryo-Larval Assay, Michael Frederick Helmstetter Jan 1992

Development And Standardization Of A Short-Term Assay For Evaluating Polluted Estuarine And Coastal Environments: The Medaka Embryo-Larval Assay, Michael Frederick Helmstetter

OES Theses and Dissertations

The eggs of the Japanese medaka (Oryzias latipes) were employed in a number of studies to develop a routine, standardized assay which can assess the acute and sublethal impacts of individual toxicants and complex mixtures. The eggs of this Cyprinodont minnow were topically treated with each toxicant or mixture dissolved in membrane permeable dimethylsulfoxide (DMSO) solvent. Nine chemicals were initially evaluated with two, pentachlorophenol (PCP) and tributyltin chloride (TBTCl), subsequently selected for extensive evaluations of salinity tolerance and the accuracy of the topical exposure method for representing a typical immersion exposure. The amount of material actually penetrating the eggs was …


Limnology Of Two New Lakes, Mount St. Helens, Wa, Valerie Jean Kelly Nov 1991

Limnology Of Two New Lakes, Mount St. Helens, Wa, Valerie Jean Kelly

Dissertations and Theses

Coldwater Lake and Castle Lake are two new lakes which were formed in the aftermath of the volcanic eruption of Mount St. Helens, WA in May, 1980. This research describes the limnology of these lakes ten years later, and includes physical, chemical, and biological parameters. The two lakes are compared and contrasted. Previous research on the eruption and its aftermath, as well as earlier studies of the lakes are described.


Carbonate Deposits In Marine Fish Intestines: A New Source Of Biomineralization, Patrick J. Walsh, Patricia Blackwelder, Kenneth A. Gill, Eva Danulat, Thomas P. Mommsen Sep 1991

Carbonate Deposits In Marine Fish Intestines: A New Source Of Biomineralization, Patrick J. Walsh, Patricia Blackwelder, Kenneth A. Gill, Eva Danulat, Thomas P. Mommsen

Marine & Environmental Sciences Faculty Articles

Marine teleostean fish are hypo-osmotic to seawater. As part of a multiorgan osmoregulatory strategy they drink seawater and selectively absorb water and minerals across the intestinal epithelium. Notably, divalent cations (Ca2+ and Mg2-) are left behind. We report here that in the gulf toadfish, Opsanus beta, the ionic by-products of osmoregulation in the intestine contribute to de novo formation of a carbonate mineral, tentatively identified as calcian kutnohorite. Our data suggest that intestinal mineralization is a general feature of osmoregulation in marine teleosts and that this process is an unrecognized and possibly substantial source of marine …