Aquaculture and Fisheries Commons^™

What Is The Value Of A Sea Turtle?: A Case Study Of The Conservation Ethics Of Sea Turtle Fishermen In The Caribbean Coast Of Nicaragua, Alicia Conte

Independent Study Project (ISP) Collection

The sea turtle populations on the Caribbean Coast of Nicaragua have dramatically decreased as a result of human use and consumption. All species of sea turtles are endangered and at risk of extinction. This is an environmental issue because if sea turtles go extinct, many other plants and animals in marine ecosystems will be negatively impacted by this loss, and the environment will be drastically altered. This is also problematic for locals who depend on this resource for food and as a source of income. Conservation efforts have been initiated by an international NGO, the Wildlife Conservation Society (WCS); however, …

An Assessment Of Icthyofauna And Artisanal Fishing From The Port Of Pedregal In The Golfo De Chiriquí., Kathleen A. Carey

Independent Study Project (ISP) Collection

The artisanal fishery based out of Pedregal, on the Pacific Coast of Panama in the Chiriqui Province was studied to analyze the biodiversity and community structure of the icthyofaunal population and investigate the practices and opinions of the fishermen there. The study area is located in the Gulf of Chiriqui, and is heavily influenced by freshwater runoff from anthropogenically influenced rivers during. This is especially relevant during the rainy season. During two weeks in November, at the end of the rainy season, fishermen from one port in Pedregal were accompanied for the purposes of data collection and interviewing. The data …

Accumulation Of Polonium-210 In Different Species Of Fish In Lake Mead, Suraj Ghevarghese John, Shungmugam Nallaperumal, Vernon Hodge

Festival of Communities: UG Symposium (Posters)

Discovered by Pierre Curie and Marie Skłodowska-Curie in 1898, polonium is a chemical element with an atomic number of 84. This rare naturally occurring radioactive element is chemically similar to bismuth and tellurium, and forms in uranium ores. Polonium-210 is an naturally occurring radioactive element with a half-life of 138.376 days(1). This element is found in trace amounts in most organisms. Our research is focused on the accumulation of polonium-210 in fish that occupy in Lake Mead.

The sample species is chosen based on varying lake stratification (layers of the lake). This gives us a good idea of the difference …

Using The Judas Technique To Locate And Remove Wintertime Aggregations Of Invasive Common Carp, P. G. Bajer, Christopher J. Chizinski, P. W. Sorensen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Radio- and acoustic telemetry in three Midwestern lakes demonstrated that common carp, Cyprinus carpio L., aggregate as water temperatures descend below 10C. Particularly dense aggregations formed at temperatures <5 >C, and once located, these aggregations could be removed with an efficiency of up to 94% using seine nets. Carp aggregated just below the surface of the ice (approximately 1.5 m) and rarely descended to warmer waters, which extended down to 10 m. Although aggregations consistently formed close to shore, their locations could not be explained by temperature or dissolved oxygen. The aggregations also moved frequently, making radio-tagged fish invaluable to locate …

Mixed-Source Reintroductions Lead To Outbreeding Depression In Second-Generation Descendents Of A Native North American Fish, David D. Huff, Loren M. Miller, Christopher J. Chizinski, Bruce Vondracek

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Reintroductions are commonly employed to preserve intraspecific biodiversity in fragmented landscapes. However, reintroduced populations are frequently smaller and more geographically isolated than native populations. Mixing genetically, divergent sources are often proposed to attenuate potentially low genetic diversity in reintroduced populations that may result from small effective population sizes. However, a possible negative tradeoff for mixing sources is outbreeding depression in hybrid offspring. We examined the consequences of mixed-source reintroductions on several fitness surrogates at nine slimy sculpin (Cottus cognatus) reintroduction sites in south-east Minnesota. We inferred the relative fitness of each crosstype in the reintroduced populations by comparing …

Implications Of Community Concordance For Assessing Stream Integrity At Three Nested Spatial Scales In Minnesota, U.S.A., Christine L. Dolph, David D. Huff, Christopher J. Chizinski, Bruce Vondracek

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

1. Fish and invertebrate assemblage data collected from 670 stream sites in Minnesota (U.S.A.) were used to calculate concordance across three nested spatial scales (statewide, ecoregion and catchment). Predictive taxa richness models, calibrated using the same data, were used to evaluate whether concordant communities exhibited similar trends in human-induced taxa loss across all three scales. Finally, we evaluated the strength of the relationship between selected environmental variables and the composition of both assemblages at all three spatial scales.

2. Significant concordance between fish and invertebrate communities occurred at the statewide scale as well as in six of seven ecoregions and …

Breeding Bird Response To Partially Harvested Riparian Management Zones, Christopher J. Chizinski, Anna Peterson, Joann Hanowski, Charles R. Blinn, Bruce Vondracek, Gerald J. Niemi

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We compared avian communities among three timber harvesting treatments in 45-m wide even-age riparian management zones (RMZs) placed between upland clearcuts and along one side of first- or second-order streams in northern Minnesota, USA. The RMZs had three treatments: (1) unharvested, (2) intermediate residual basal area (RBA) (targeted goal 11.5m²/ha, realized 16.0m2/ha), and (3) low RBA (targeted goal 5.7m²/ha, realized 8.7m²/ha). Surveys were conducted one year pre-harvest and three consecutive years post-harvest. There was no change in species richness, diversity, or total abundance associated with harvest but there were shifts in the types of …