Life Sciences Commons^™

The Infection Dynamics Of Sea Lice On Atlantic Salmon (Salmo Salar) In Cobscook Bay, Maine, Usa, Catherine Anne Frederick

Electronic Theses and Dissertations

Sea lice (Lepeophtheirus and Caligus spp) are parasitic copepods that infect the external surfaces of fish hosts. Salmon lice (L. salmonis) outbreaks are commonly reported by operations in Canada, Norway, Scotland, Ireland, and the United States and are a primary concern in aquaculture because of their fish health and economic impacts. When farmed fish mortalities and treatments are accounted for, annual losses from sea louse infestations exceed $300,000,000 (Costello 2009). Farms experiencing sea lice infections risk on-site re-infection and transmission to wild populations and other farms that are hydrographically connected. In Maine, Atlantic salmon farms are located in the northeast, …

Black Soldier Fly Larvae As Value-Added Feed For Aquaculture In Maine, Joshua Villazana

Electronic Theses and Dissertations

Black soldier flies (BSF), Hermetia illucens (Linnaeus) (Diptera: Stratiomyidae) consume decaying organic waste as larvae (BSFL) and can be used for recycling a variety of biogenic wastes. BSFL can also be processed into value-added animal feeds, including those used in aquaculture. An overarching goal of this project was to obtain additional insights into BSF biology to improve their rearing and handling in future mass-production facilities serving Maine aquaculture.

We tested BSFL growth in the laboratory on seven seafood wastes from Maine fish processing facilities. Substrates potentially suitable for BSFL rearing included finfish trimmings, wet sea cucumber, dry quahog, and sea …

Investigating Present-Day Health Issues Of The American Lobster (Homarus Americanus), Deborah A. Bouchard

Electronic Theses and Dissertations

The American lobster, Homarus americanus, H. Milne Edwards, 1837, supports the most economically valuable fishery along the North Atlantic coast of North America. A collapse in lobster populations in Southern New England (SNE) has coincided with increasing ocean temperatures and emerging diseases. This research investigated the etiologies of limp lobster disease (LLD) and epizootic shell disease (ESD), two diseases that continue to cause significant mortality in natural lobster populations. Mortality from LLD is associated with the bacteria Photobacterium indicum and is more intense in impounded lobsters. To more clearly define the community ecology of this suspected opportunistic pathogen, the microbial …

Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish

Electronic Theses and Dissertations

Of the most iconic fish species in the world, the Atlantic cod (Gadus morhua, hereafter, cod) has been a mainstay in the North Atlantic for centuries. While many global fish stocks have received increased pressure with the advent of new, more efficient fishing technology in the mid-20^th century, exceptional pressure has been placed on this prized gadoid. Bycatch, or the unintended catch of organisms, is one of the biggest global fisheries issues. Directly resulting from the failed recovery of cod in the GoM, attention has been placed as to possible sources of unaccounted catch. Among the most …

Incorporating Environmental Variability Into Assessment And Management Of American Lobster (Homarus Americanus), Kisei Tanaka

Electronic Theses and Dissertations

The American lobster (Homarus americanus) support one of the most valuable fisheries in the United States. A growing body of literature recognizes the importance of environmental variables in regulating this species’ biogeography and population dynamics. However, the current lobster stock assessment and management do not explicitly consider the impact of environmental variables such as water temperature and assumes spatiotemporal variabilities in the lobster environment as random background noises. Furthermore, while climate-induced changes in marine ecosystems continue to impact the productivity of lobster fisheries, studies that model lobster response to altered environmental conditions associated with climate change are lacking. …

Assessing Economic Performance Of Maine's Lobster Fleet Under Changing Ecosystem Conditions In The Gulf Of Maine, Alexa M. Dayton

Electronic Theses and Dissertations

This research evaluates lobster producer efficiency and considers fleet wide economics and policy implications in support of changing marine ecosystems in the Gulf of Maine. We conducted a comprehensive lobster industry survey to assess costs and effort expended at the producer level for a representative fishing year, and establish a series of production function performance baselines for future comparison. The demographic data, attitudes and valuations collected allow us to characterize the fishing effort and regional dependency on the resource. We look at the Maine Lobster limited entry licensing system, to understand how the future participation in the fishery might change, …

Social Conflict On The Seas: Links Between Overfishing-Induced Marine Fish Stock Declines And Forced Labor Slavery, Jessica L. Sparks

Electronic Theses and Dissertations

Despite media attention detailing labor abuses in fisheries, social-ecological systems research has largely failed to consider whether fish stock declines could be contributing to increases in forced labor slavery. Empirical fisheries data suggests, though not a ubiquitous response to declining stocks, many vessels will fish longer, farther from shore, and deeper in waters to maintain yields. This effort intensification increases production costs, and Brashares et al. (2014), consistent with slavery theory, posited cheap and/or unpaid labor as an approach to offset increasing costs and continue harvesting fish species at a rate otherwise cost-prohibitive.

Using fuzzy cognitive mapping - a participatory, …

Impacts On Salmonid Rearing Performance With Use Of Dietary Bioprocessed Plant-Based Protein And Water Velocity, Jill Voorhees

Electronic Theses and Dissertations

The inclusion of bioprocessed soybean (Glycine max) meal was evaluated in five experiments using either Rainbow Trout (Oncorhynchus mykiss) or Brown Trout (Salmo trutta). In the first experiment, adult Erwin x Arlee strain Rainbow Trout were fed diets formulated so that bioprocessed soybean meal (BSM) replaced 0, 60, or 80% of the dietary fishmeal. There were no significant differences in gain, percent gain, feed conversion ratio, specific growth rate, intestinal morphology, relative fin lengths, or organosomatic indices. In the second experiment, juvenile Plymouth strain Brown Trout were fed diets formulated so that BSM replaced 0, 60, 80, or 100% of …

Western Prairie Stream Fisheries: An Assessment Of Past And Present Fish Assemblage Structure, Biotic Homogenization, And Population Dynamics In Western South Dakota Streams, Stephen Jones

Electronic Theses and Dissertations

Biodiversity is declining globally, especially in in aquatic systems. Prairies are one of the most endangered ecosystem types in North America, and their conversion into agriculture or development as a result of urbanization has had negative effects on prairie stream fish communities. Continued monitoring of fish assemblage change and the population dynamics of prairie stream fishes will provide researchers and managers with valuable information needed to detect and mitigate past and future negative impacts on prairie stream aquatic ecosystems. Sampling was conducted in the mainstem and tributaries of the Grand, Moreau, Cheyenne, Bad, and White rivers within western South Dakota. …

Nutritional Value Of Modified Novel Oilseed Meals In Teleost Diets, Tom Kasiga

Electronic Theses and Dissertations

Carinata Brassica carinata and camelina Camelina sativa are being genetically modified to improve their composition for biofuel production and other agricultural applications. After oil extraction, the residual de-oiled meals (40%) in protein. However, their inclusion in animal feeds is limited to 10% because of high levels of antinutritional factors (ANFs), mainly glucosinolates (GLS), sinapine, and crude fiber that limit diet intake, nutrient utilization, and lower thyroxine production, resulting in reduced growth. The nutritional value of carinata and camelina seed meals to fish were assessed by subjecting cold pressed (CP) carinata and camelina meals to extrusion (EX), solvent extraction (SE) and …

Walleye Fishery Ecology In Lake Oahe Of The Dakotas, Eli Felts

Electronic Theses and Dissertations

Walleye Sander vitreus is among the most popular sport fishes in North America and is the most sought-after fish in both South Dakota and North Dakota. Lake Oahe, a large main stem Missouri River reservoir, spans state boundaries and provides one of the most popular and productive Walleye fisheries in both Dakotas. The Walleye population of Lake Oahe has experienced wide fluctuations in abundance and size structure over the last 25 years which has caused high variability in angler use and satisfaction. Much of this variation is thought to be driven by Rainbow Smelt Osmserus mordax, which are the dominant …

Effects Of Large-Scale Density Reduction On Brown Trout Growth And Movement In Spearfish Creek, South Dakota, Travis Rehm

Electronic Theses and Dissertations

Density-dependent growth is often observed in stream-dwelling Brown Trout Salmo trutta populations. In Spearfish Creek, South Dakota, biomass of adult Brown Trout (>200 mm) is about three times greater than that reported for similar Black Hills streams while mean length of adult fish is about 30% less. Here, we evaluate large-scale density reduction as a management tool for improving growth rate of stream-dwelling Brown Trout. We compared age-specific growth of wild Brown Trout in stream sections receiving 50% reductions in fish abundance. We also assessed the effect of fish density manipulation on Brown Trout movement patterns and home range …

Predictors Of Fish Assemblage Structure And Dynamics In Atlantic Coastal Plain Streams, Rebecca Scott

Electronic Theses and Dissertations

Effective management of freshwater fishes requires a mechanistic understanding of the drivers of assemblage composition; in other words, what determines who is where and when. Stream fish assemblages are potentially influenced by environmental factors that act on multiple spatiotemporal scales, but the relative influence of these drivers may vary between geophysically distinct regions. This study sought to determine the patterns and drivers of fish taxonomic and functional assemblage composition in the coastal plain, a region possessing unique hydrologies, faunas, and physiochemical conditions. I addressed this goal using two complementary chapters, both of which utilized environmental and biotic data collected from …

Evaluating Elasmobranch Bycatch And Shark Depredation In The Georgia Shrimp Fishery, Matthew M. Scanlon

Electronic Theses and Dissertations

The Georgia shrimp fishery has seen a dramatic decrease in profit and productivity since the 1980’s due to a number of economic factors. Additional, yet undocumented, pressures on this fishery include interactions between foraging sharks with trawl gear. Fishermen report that sharks frequently bite nets in an attempt to prey on netted fish, resulting in large holes in the gear. Further elasmobranch interactions with trawl gear occur as bycatch; shrimp trawls represent nearly 100% of elasmobranch commercial bycatch in Georgia state waters, the species composition of which is largely unstudied. Shark interactions with nets were detailed through fishery-dependent observations on …