Digital Commons Network^™

The Fate Of Atmospherically Deposited Mercury In Mountain Lake Food Webs, And Implications For Fisheries Management, Ariana Martos Chiapella

Dissertations and Theses

Mountain lakes are an iconic feature of the landscape in the Mountain West. They hold significant ecological and cultural value, and are important sentinels of environmental change. Despite their pristine image, these remote waterbodies are subjected to numerous anthropogenic stressors. Mountain lakes are naturally fishless systems, but historical fish stocking has led to major changes in mountain lake food web structure, including declines of resident amphibians, large-bodied zooplankton, and emergent insect populations. Atmospherically deposited contaminants, such as mercury, can accumulate in mountain lake food webs, leading to relatively high levels in the fish relative to the water. Managing for these …

The Economic Importance And Management Of Mercury Contamination In Pelagic Fisheries, Tina Marie Willson

LSU Doctoral Dissertations

The presence of mercury in the U.S. fish supply is a growing public health concern. At high levels, mercury can be harmful to humans and ecosystems, and represents a growing threat not only to public health, but also to the economic and ecological viability of many fisheries. This research examined the economic issues surrounding mercury contamination in fish, developed a population dynamics and bioeconomic model to investigate the problem, and compared a variety of management actions to reduce consumer exposure to contaminants. The dissertation begins with an overview of contamination issues in U.S. fisheries, including a review of the historical …

Do Size Differences Of Juvenile Snapper (Pagrus Auratus) In Two Regions Of Shark Bay, Western Australia, Reflect Different Environmental Conditions, Nadia Tapp

Theses: Doctorates and Masters

Aspects of the population biology of juvenile Pagrus auratus in the western gulf of Shark Bay, Western Australia, were investigated to explore the causes of an observed size difference between 0+ fish (first year of life) in the northern and southern regions of that gulf. Five trawl surveys were conducted in each region of the western gulf, from November 2000 to December 2001, to collect juvenile P. auratus. The 0+ fish from the northern region were found to be consistently greater in length by between 10 and 20mm LCF, than those in the southern region, thereby confirming those observed size …

The Effect Of Recreational Fishing On Targeted Fishes And Trophic Structure, In A Coral Reef Marine Park, Mark B. Westera

Theses: Doctorates and Masters

Recreational line fishing is highly targeted at predatory fishes, making them vulnerable to overfishing. These same fishes play a role in trophic structure by regulating prey species. Despite increasing numbers of fishers, few studies have investigated the potential effects of recreational fishing on fish populations and subsequent trophic effects. This project investigated whether there were differences in fishes and benthos between unfished and recreationally fished areas, and whether the removal of targeted fishes influenced trophic structure. The study was conducted at the Ningaloo Marine Park, Western Australia, which had Sanctuary (no-take) and Recreation {recreationally fished) Zones. Data were collected from …

Modeling The Role Of No-Take Marine Reserves In Fisheries Management, Deidre F. Gilbert

Electronic Theses and Dissertations

In recent years there has been increasing interest in the potential of no-take marine reserves to benefit fisheries management. Scientific reviews have shown that reserves often lead to substantial increases in the density, biomass, size and diversity of marine fishes inside their boundaries. However, little empirical work has been done to determine the effect of reserves on the fisheries outside their boundaries, such as potential changes in yield, size of fleet, or variability in catch. In order to explore the interaction between the biological growth and dispersion processes of the harvested stock and the changing economic incentives of harvesters created …

Marine Protected Areas In The Gulf Of Maine: Policy For A Common Resource, Carolyn F. Skinder

Electronic Theses and Dissertations

In the wake of 25 years of unsuccessful single-fisheries management in the Gulf of Maine, there has been growing support for reform. Ecosystem management has been proposed as one alternative, but the information needed to manage whole ecosystems is greatly lacking. Implementing fully-protected marine protected areas (MPAs) is one way to preserve habitat while at the same time acquiring data for future ecosystem management. Under the current institutional arrangement in the Gulf, engineering agreement for MPAs is difficult due to the differing goals of varied user groups. The situation is reflective of a common property resource problem in that there …

Recreation Specialization And Preferences Of Utah Anglers, Bruce P. Andersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purposes of this study were to gain a better understanding of anglers and angler preferences and to examine differences between subgroups of anglers based on level of specialization. Understanding these similarities and differences between user groups will provide valuable input for more effective fisheries management.

A randomized mail survey was sent to resident, adult fishing-license holders in Utah. A 68% response rate yielded 1216 usable returns for data analysis. An analysis of three recreation specialization dimensions (participation, equipment and investment, and lifestyle) and further analysis of participation and investment variables were used to develop a typology of Utah anglers. …

Fisheries Development Of Somalia, Kawdan

World Maritime University Dissertations

No abstract provided.

Influence Of Angler Motivations, Expectations, And Opinions On Fishery Management Practices In The United States, James E. Brogdon

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This report is concerned with the behavioral inputs into the decisions concerning fishery resource management. Topics discussed are motives, expectations, and opinions of fishermen concerning the fishing experience and present-day fishery management practices and regulations; how management agencies and sportsmen organizations have dealt with recreational fishing; the need for managers to utilize this behavioral information in forming management decisions; and where past people-wildlife research has been and where it must lead in the future. Material for this paper came from copies of published articles and library research.

The Food Of Three Centrarchids And An Ameiurid In Northern Utah During 1949-50, Robert L. Eberhardt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This is a study of the food of pond fish in northern Utah. The species examined in the family Centrarchidae were largemouth black bass, Micropterus salmoides (Lacepede), green sunfish, Lepomis cyanellus Rafinesque, and common bluegill, Lepomis macrochirus Rafinesque, together with black bullhead, Ameiurus melas (Rafinesque) of the family Ameriuridae. Specifically it is a report of the macroscopic food found in the stomachs of sub-adult and mature fish. Although such a study is of predominant interest to the biologist, who is interested in life history and ecological relationships of fish, the farmer or small businessman can find the data applicable. This …