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Articles 301 - 330 of 450

Full-Text Articles in Aquaculture and Fisheries

A Trophic Gradient Analysis Of Lake Powell: The 1994 Utah State University Aquatic Ecology Laboratory Analyses, Wayne A. Wurtsbaugh, Megan Barker, Ron Brunson, David Fogle, Scott Hawxhurst, Chad Mellison, Lis Phillips, Felipe Queiroz, Daniel Zamecnik Jan 1994

A Trophic Gradient Analysis Of Lake Powell: The 1994 Utah State University Aquatic Ecology Laboratory Analyses, Wayne A. Wurtsbaugh, Megan Barker, Ron Brunson, David Fogle, Scott Hawxhurst, Chad Mellison, Lis Phillips, Felipe Queiroz, Daniel Zamecnik

Watershed Sciences Faculty Publications

From 9-11 April, 1994, the Aquatic Ecology Laboratory Class (FW462) of Utah State University sampled the upper reaches of Lake Powell to assess if a trophic gradient existed. We °ampled physical and chemical parameters (temperature, oxygen, conductivity, and total phosphorus), phytoplankton chlorophyll a, littoral and pelagic zooplankton biomass and composition, littoral and profundal benthic invertebrates, and fish abundance measured in the littoral zone (gill nets) and the pelagic zone (hydroacoustics). Data was collected along the upper 50 miles of the reservoir between Bullfrog and the Hite marina near the Colorado River inflow.

Our field trip was done just prior to …


Habitat Selection By Lacustrine Rainbow Trout Within Gradients Of Temperature, Oxygen, And Food Availability, Chris Luecke, D. Teuscher Jan 1994

Habitat Selection By Lacustrine Rainbow Trout Within Gradients Of Temperature, Oxygen, And Food Availability, Chris Luecke, D. Teuscher

Watershed Sciences Faculty Publications

Rainbow trout (Oncorhynchus mykiss [Walbaum]) in Castle Lake, California were concentrated at certain depths during day and evening hours. A fish bioenergetics simulation model based on vertical gradients of temperature, oxygen concentration, and food availability indicated that rainbow trout selected habitats that maximized growth rate. In 1 of the 2 years of study, a strong pattern of diel vertical migration of rainbow trout was evident and was associated with vertical migrations of daphnids in the lake. The simulation model correctly predicted the occurrence and magnitude of fish migration. During the day some trout resided at depths with little potential for …


Modeling Oyster Populations. Iv. Rates Of Mortality, Population Crashes, And Management, E. N. Powell, J. M. Klinck, E. E. Hofmann, S. M. Ray Jan 1994

Modeling Oyster Populations. Iv. Rates Of Mortality, Population Crashes, And Management, E. N. Powell, J. M. Klinck, E. E. Hofmann, S. M. Ray

CCPO Publications

A time-dependent energy-flow model was used to examine how mortality affects oyster populations over the latitudinal gradient from Galveston Bay, Texas, to Chesapeake Bay, Virginia. Simulations using different mortality rates showed that mortality is required for market-site oysters to be a component of the population's size-frequency distribution; otherwise a population of stunted individuals results. As mortality extends into the juvenile sizes, the population's size frequency shifts toward the larger sizes. In many cases adults increase despite a decrease in overall population abundance. Simulations, in which the timing of mortality varied, showed that oyster populations are more susceptible to population declines …


Modeling Oyster Populations Ii. Adult Size And Reproductive Effort, E. E. Hofmann, J. M. Klinck, E. N. Powell, S. Boyles, M. Ellis Jan 1994

Modeling Oyster Populations Ii. Adult Size And Reproductive Effort, E. E. Hofmann, J. M. Klinck, E. N. Powell, S. Boyles, M. Ellis

CCPO Publications

A time-dependent model of energy flow in post-settlement oyster populations is used to examine the factors that influence adult size and reproductive effort in a particular habitat, Galveston Bay, Texas, and in habitats that extend from Laguna Madre, Texas to Chesapeake Bay. The simulated populations show that adult size and reproductive effort are determined by the allocation of net production to somatic or reproductive tissue development and the rate of food acquisition, both of which are temperature dependent. For similar food conditions, increased temperature reduces the allocation of net production to somatic tissue and increases the rate of food acquisition. …


Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation Jan 1994

Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation

Publications (WR)

Cover is an important component of aquatic habitat and fisheries management. Fisheries biologists often try to improve habitats through the addition of natural and artificial material to improve cover diversity and complexity. Habitat-improvement programs range from submerging used Christmas trees to more complex programs using sophisticated artificial habitat modules. Used automobile tires have been employed in the large scale construction of reefs and fish attractors in marine environments and to a lesser extent in freshwater and have been recognized as a durable, inexpensive and long-lasting material which benefits fishery communities.

Recent studies by the U.S. Bureau of Reclamation have quantified …


Description, Distribution, And Abundance Of The Blue Crab, Callinectes Sapidus (Rathbun), Spawning Stock Of The Lower Chesapeake Bay, Patrick John Geer Oct 1993

Description, Distribution, And Abundance Of The Blue Crab, Callinectes Sapidus (Rathbun), Spawning Stock Of The Lower Chesapeake Bay, Patrick John Geer

OES Theses and Dissertations

The lower Chesapeake Bay spawning stock of the blue crab, Callinectes sapidus, (Rathbun), is examined for seven years (1986 - 1992) in an attempt to better understand stock behavior. Three methods of post-stratification are used to describe the distribution and movement of the population over time. The three methods, density strata, geographic zones, and depth strata, did well in explaining movements of the population, indicating a trend of increased concentration of blue crabs near the eastern Bay late in the spawning season - October. The data suggest a bimodal period of spawning and a trimodal period of abundance. The …


Age, Growth, And Mortality Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Region, With A Discussion Of Apparent Geographic Changes In Population Dynamics, Luiz R. Barbieri, Mark E. Chittenden Jr., Cynthia M. Jones Aug 1993

Age, Growth, And Mortality Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Region, With A Discussion Of Apparent Geographic Changes In Population Dynamics, Luiz R. Barbieri, Mark E. Chittenden Jr., Cynthia M. Jones

OES Faculty Publications

Atlantic croaker, Micropogonias undulatus, collected from commercial catches in Chesapeake Bay and in Virginia and North Carolina coastal waters during 1988-1991 (n=1,967) were aged from transverse otolith sections. Ages 1-8 were recorded, but eight-year-old fish were rare. Marginal increment analysis showed that for ages 1-7, annuli are formed once a year during the period April-May. Otolith age readings were precise: >99% agreement within and between readers. Observed lengths-at-age were highly variable and growth rate decreased after the first year. Despite the high variability in sizes-at-age, observed lengths for ages 1-7 fit the von Bertalanffy growth model (r2=0.99; n=753) well. …


The Role Played By Semisubmersible Exploratory Drilling Platforms As A Vector In Marine Biological Introductions, Sean S. Bercaw Jan 1993

The Role Played By Semisubmersible Exploratory Drilling Platforms As A Vector In Marine Biological Introductions, Sean S. Bercaw

Marine Affairs Theses and Major Papers

Through discussion of Semisubmersible Exploratory Drilling Platforms and their role as vectors in marine biological introductions, this paper establishes a base of knowledge for future referral. Included in this project are details of semisubmersibles, their unique characteristics and operations, historical movements, past introductions, future operations, and continuing potential for invasions. The significance of semisubmersibles as biological vectors is further addressed. Three criteria will be used to assess the significance of the role of semisubmersibles in the introduction of alien species: first, what is the rate of SEDP movements over time; second, how are SEDP movements unique, and what role does …


Linking Management And Markets: The Northwest Atlantic Sea Herring Industry And The Case For "Regional" Quotas, Peter Jessup Moore Jan 1993

Linking Management And Markets: The Northwest Atlantic Sea Herring Industry And The Case For "Regional" Quotas, Peter Jessup Moore

Marine Affairs Theses and Major Papers

This review and characterization of the U.S. Atlantic sea herring fishery and industry analyzes opportunities for and constraints to developing the herring resource more fully. Chapter 1 describes the herring resource, the existing fishery, and reviews current research into the international transboundary migrations of the Atlantic sea herring. Chapters 2 and 3 describe the development of the herring fishery management plan in the context of the global herring market and the management complications that arise from the transboundary migrations of the stocks. Examples of successful linkages between fisheries management and market development are described in Chapter 4 to illustrate the …


Conflicts In Use: The Impacts Of The Oil And Gas Industry On The Herring Fishery In The North Sea, Cornelia Ann Pasche Jan 1993

Conflicts In Use: The Impacts Of The Oil And Gas Industry On The Herring Fishery In The North Sea, Cornelia Ann Pasche

Marine Affairs Theses and Major Papers

The interaction of the herring (Clupea harengus) with the oil and gas industry in the North Sea is reviewed. The population crash of the herring in the early 1970's and the subsequent closing of that important fishery between 1977 and 1983 has drawn considerable attention to the influences, both biotic and abiotic, affecting the recruitment to the North Sea stock. Current accepted theory points to a change in oceanic current and the subsequent decrease in salinity in the North Sea region, resulting in a change in plankton availability for larval herring as the cause of the recruitment failure during the …


Snake River Sockeye Salmon Habitat And Limnological Research, David Teuscher, Doug Taki, Wayne A. Wurtsbaugh Jan 1993

Snake River Sockeye Salmon Habitat And Limnological Research, David Teuscher, Doug Taki, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Historically, thousands of Snake River Sockeye salmon returned to the Sawtooth Valley to spawn. Evermann (1896) reported that the Sawtooth Valley Lakes were teeming with red fish. Bjornn (196~) estimated that 4,360 sockeye returned to Redfish Lake in 1955. These numbers no longer exist. In the 1980's, less than 50 Snake River sockeye salmon survived to spawn (Bowler 1990). Since 19-90, only 13 sockeye have returned. Because of recent declines, the Shoshone-Bannock Tribes (SBT) petitioned the National Marine Fisheries Service (NMFS-) to list Snake River sockeye as endangered. As a result, Snake River sockeye were listed and the Bonneville Power …


Spatial And Temporal Occurrence Of Spanish Mackerel Scomberomorus Maculatus In Chesapeake Bay, Mark E. Chittenden Jr., Luiz R. Barbieri, Cynthia M. Jones Jan 1993

Spatial And Temporal Occurrence Of Spanish Mackerel Scomberomorus Maculatus In Chesapeake Bay, Mark E. Chittenden Jr., Luiz R. Barbieri, Cynthia M. Jones

OES Faculty Publications

No abstract provided.


Age, Growth, And Reproduction Of Tautog Tautoga Onitis (Labridae: Perciformes) From Coastal Waters Of Virginia, E. Brian Hostetter, Thomas A. Munroe Jan 1993

Age, Growth, And Reproduction Of Tautog Tautoga Onitis (Labridae: Perciformes) From Coastal Waters Of Virginia, E. Brian Hostetter, Thomas A. Munroe

Biological Sciences Faculty Publications

Tautog Tautoga onitis are gaining popularity in Virginia's coastal waters as a recreational and food fish. Adult tautog are seasonally abundant on inshore hard-bottom habitats (1-10 m) and inhabit offshore areas (10-75 m) year-round. Juveniles, especially newly-settled recruits, inhabit vegetated areas in shallow water (usually < 1 m). From March 1979 to July 1986, tautog were collected in lower Chesapeake Bay and nearby coastal waters to examine age, growth, and sexual maturation. Age estimates were determined from annular marks on opercle bones: 82% of the fish were age-10 or younger, 18% exceeded age-10, and 1% were age-20 or older. Marginal increment analysis revealed that annuli formed concurrent with a protracted spawning season (April-July). The von Bertalanffy growth equation, derived from back-calculated mean lengths-at-age, was l(t) = 742 [1-e-0.085 (t-1.816)]. Tautog are long-lived (25+ yr) and attain relatively large sizes (672 mm TL) slowly (K for sexes combined = 0.085). Growth rates of both sexes are similar, although males grow slightly faster (K = 0.090 vs. 0.085 for females). Maturity occurs at age-3 in both sexes. Growth rates for tautog from Virginia are similar to those reported nearly 25 years ago for tautog in Rhode Island. Growth rates for tautog are similar to those of other reef fishes, such as snappers and groupers. Habitat restriction, slow growth, great longevity, and increasing popularity by user groups may contribute to over-exploitation of this species in Virginia waters.


Southern Nevada Effluent Wetlands: A Proposed Cooperative Venture Between The Bureau Of Reclamation & City Of Las Vegas, Bureau Of Reclamation Nov 1992

Southern Nevada Effluent Wetlands: A Proposed Cooperative Venture Between The Bureau Of Reclamation & City Of Las Vegas, Bureau Of Reclamation

Publications (WR)

Throughout North America there is a growing interest in constructed wetlands, both as relatively inexpensive, low-maintenance systems for removing nutrients from wastewater, and as a means of using municipal wastewater to enhance wildlife habitat and create public use opportunities. Because wetlands appear to have good potential as a component in the overall management of scarce water resources, the Bureau of Reclamation (Reclamation) has undertaken several cooperative research and demonstration projects to evaluate their effectiveness in a variety of local environments. While a number of projects have demonstrated that wetlands can be beneficially employed to improve water quality, few such projects …


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 …


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 …


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.


Mariculture Management For Pohnpei State, Federated States Of Micronesia, Kevin Brooks Foster Jan 1991

Mariculture Management For Pohnpei State, Federated States Of Micronesia, Kevin Brooks Foster

Marine Affairs Theses and Major Papers

The Marine Resources Division of Pohnpei State, Federated States of Micronesia is currently engaged in development activities that include the establishment of family scale mariculture projects for community members of remote villages and outer islands. The goal of this undertaking is to supplement subsistence and income generation ventures for community members through the wise use and exploitation of the marine environment. These aims may be jeopardized unless a management plan is devised that reflects the customary marine resource practices as embraced by islanders from each community. The intent of this thesis projects is to devise a mariculture management model that …


Factors Influencing The Role Of Women In Indonesian Fisheries Development, Melissa A. Upton Jan 1991

Factors Influencing The Role Of Women In Indonesian Fisheries Development, Melissa A. Upton

Marine Affairs Theses and Major Papers

Gender consideration is an essential component of fishery development activities. The purpose of this thesis is to help guide planners and decision-makers who are concerned with understanding the role of women in fisheries development in general as well as in the Republic of Indonesia. Thus, it is partially based upon field research conducted in Indonesia among fishing communities which are representative of different types of fisheries. Justification for research concerning the role of women in the fisheries sector and the reasons why women should be included in development policy and planning are presented in Chapter I. The general research setting, …


The Gulf Of California As A Large Marine Ecosystem, Patricia A. Morrissey Jan 1991

The Gulf Of California As A Large Marine Ecosystem, Patricia A. Morrissey

Marine Affairs Theses and Major Papers

Large marine regions characterized by unique bathymetry, hydrography and productivity, within which marine populations have adapted reproductive, growth, and feeding strategies constitute large marine ecosystems (LME) (Sherman and Alexander, 1986). The Gulf of California a semi-enclosed sea off the western coast of Mexico qualifies as a LME as it presents physical and biological characteristics not found in the adjoining Pacific. This area sustains the largest commercial fishery in the country which is the sardine fishery. the sardine population resident in the Gulf of California has coupled its reproductive and migration strategies to the environment of this region. Fluctuations of the …


Prospects For Fisheries Development In West Africa, Steven K. Ireland Jan 1991

Prospects For Fisheries Development In West Africa, Steven K. Ireland

Marine Affairs Theses and Major Papers

The production of food is a primary concern for the countries of Africa. Marine fisheries can contribute toward alleviating undernutrition and provide employment opportunities in developing countries. In West Africa there are substantial marine fisheries resources but there is a need for development and improved management of these resources. Fisheries development efforts have thus far achieved limited success in the region. However, there is considerable potential for increasing the contribution of fisheries to economic development if the problems of fisheries development can be overcome.


Possibilities For A Common Fisheries Development And Management Policy For The Organization Of Eastern Caribbean States (O.E.C.S.), Daven C. Joseph Jan 1991

Possibilities For A Common Fisheries Development And Management Policy For The Organization Of Eastern Caribbean States (O.E.C.S.), Daven C. Joseph

Marine Affairs Theses and Major Papers

The fisheries resources within the EEZs of countries in the Organization of Eastern Caribbean States is not being exploited at their maximum sustainable yield. Fisheries development has however been hampered by a history of these states, little or no sectoral development planning. If member states are to realize any increased socio-economic growth in the fisheries sector, it is imperative that a common fisheries management and development strategy be implemented by these states, in an effort to rationalize the use of scarce financial and technical resources. Such a strategy would involve the pursuance of common goals and objectives and the provision …


Striped Bass Management In Rhode Island, Thomas N. Fetherston Ii Jan 1991

Striped Bass Management In Rhode Island, Thomas N. Fetherston Ii

Marine Affairs Theses and Major Papers

The management of highly migratory marine species is a difficult and complex task. No creature better represents the myriad problems faced by those attempting interstate fisheries management than the striped bass of the Atlantic coast. Their high stock levels in the late 1960s attracted unprecedented attention from commercial and sport fishermen alike. The dramatic crash of these stocks in the late 1970s, subsequent attempts at coastwide management, eventual Federal intervention and finally the rebound of the Atlantic striped bass population is an interesting case study. This paper will focus on what transpired in the State of Rhode Island during this …


Malaysia And The Law Of The Sea, Mohd Fadzil Shuhaimi Jan 1991

Malaysia And The Law Of The Sea, Mohd Fadzil Shuhaimi

Marine Affairs Theses and Major Papers

The new legal regime of the oceans has brought many changes in the Malacca Strait. The most recent one in the enactment of the Malaysian Exclusive Economic Zone Act 1984 as corollary to its proclamation on the Exclusive Economic Zone in 1980. A year later, the Fisheries Act 1985 was enacted by Malaysia as a result of increasing needs to address new issues in fisheries protection and management in the Malaysian fisheries waters. The conclusion of the 1982 United Nations Convention on the Law of the Sea, among other things, has improvised the concept of transit passage in the straits …


Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration Dec 1990

Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration

Publications (WR)

The Lake Mead Fertilization Project is a research program designed to investigate the potential for using large-scale artificial fertilization to enhance the game fisheries of this reservoir through an increase in the population of threadfin shad, the system's primary forage species. A substantial decline in the population of largemouth bass, together with poor condition of adult striped bass, are the two major issues affecting the Lake Mead game fisheries. Both issues have been hypothesized to be a result of an inadequate amount of forage in the reservoir. Previous studies have in turn suggested that a major factor limiting the shad …


The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White Oct 1990

The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White

OES Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and benzo[a]pyrene (B[a]P) are common in the water column and sediments of estuarine and coastal areas. The mud crab Rhithropanopeus harrisii was exposed to varying concentrations of Nap or B[a]P to determine the effects on reproductive success, embryological development, larval physiology and mortality. Nap and B[a]P decreased hatching success and prolonged embryological development. Both pollutants produced high abnormality frequencies for egg exposed larvae. Molt frequency and respiratory rates of larvae from non-exposed eggs were more chronically affected by these pollutants than were egg exposed larvae. The EC50 concentrations were determined for …


Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager May 1990

Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager

Publications (WR)

Procambarus clarkii are found in extremely low numbers throughout Lake Mead, AZ-NV. The crayfish are an important dietary component for game fish. Enhancement of the crayfish population would broaden the fishery forage base. Crayfish were stocked and monitored in a study cove on Saddle Island to determine if the Procambarus clarkii population could be enhanced. A trapping survey of the area after the following reproductive season yielded low numbers of crayfish. A comparison of pre-stocking and post-stocking catch per trap day (CPTD) values revealed no significant increase in the population. Procambarus clarkii growth is limited by environmental factors in Lake …