In Lake Pontchartrain Basin, commercial fishing in estuarine habitats impacts many non-target species collected as bycatch. I investigated the bycatch assemblages collected by commercial vessels and compared these to assemblages collected by typical fishery-independent methods. I compared assemblages using analysis of similarity (ANOSIM) and determined important species by weight and abundance using similarity percentages analyses (SIMPER). I also examined differences in size-class distributions by gear type using density kernel plots and Mann-Whitney U tests. The two gear types collected significantly different assemblages (ANOSIM R = 0.522, p = 0.001) and gear type explained more composition differences than other factors such as month, daytime, or location. Fishery-independent gear underestimated the importance of many species. Although fishery-independent data are invaluable for monitoring assemblage dynamics, fishery-independent gear collects different assemblages than commercial gear. Larger fishes of important species were caught less often in bycatch, but completely absent from fishery-independent gear.
","abstract_html":"<p>In Lake Pontchartrain Basin, commercial fishing in estuarine habitats impacts many non-target species collected as bycatch. I investigated the bycatch assemblages collected by commercial vessels and compared these to assemblages collected by typical fishery-independent methods. I compared assemblages using analysis of similarity (ANOSIM) and determined important species by weight and abundance using similarity percentages analyses (SIMPER). I also examined differences in size-class distributions by gear type using density kernel plots and Mann-Whitney U tests. The two gear types collected significantly different assemblages (ANOSIM R = 0.522, p = 0.001) and gear type explained more composition differences than other factors such as month, daytime, or location. Fishery-independent gear underestimated the importance of many species. Although fishery-independent data are invaluable for monitoring assemblage dynamics, fishery-independent gear collects different assemblages than commercial gear. Larger fishes of important species were caught less often in bycatch, but completely absent from fishery-independent gear.</p>","abstract_has_math":false,"creators":["Eustis, Scott P"],"institution":null,"degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Earth and Environmental Sciences","degree_department":null,"school":null,"contributors":["O'Connell, Martin","Georgiou, Ioannis","Kulp, Mark"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-12-01T08:00:00Z","date_published":"2011-12-01T08:00:00Z","updated_at":"2026-07-24T05:29:24Z","subjects":["bycatch","gear type","assemblage","catfish","diet","Lake Pontchartrain","Ecology and Evolutionary Biology","Life Sciences","Other Ecology and Evolutionary Biology","Terrestrial and Aquatic Ecology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.uno.edu/td/1419","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["O'Connell, Martin","Georgiou, Ioannis","Kulp, Mark"]},{"key":"dc:creator","label":"Author","values":["Eustis, Scott P"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Earth and Environmental Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["bycatch","gear type","assemblage","catfish","diet","Lake Pontchartrain","Ecology and Evolutionary Biology","Life Sciences","Other Ecology and Evolutionary Biology","Terrestrial and Aquatic Ecology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.uno.edu/td/1419"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In Lake Pontchartrain Basin, commercial fishing in estuarine habitats impacts many non-target species collected as bycatch. I investigated the bycatch assemblages collected by commercial vessels and compared these to assemblages collected by typical fishery-independent methods. I compared assemblages using analysis of similarity (ANOSIM) and determined important species by weight and abundance using similarity percentages analyses (SIMPER). I also examined differences in size-class distributions by gear type using density kernel plots and Mann-Whitney U tests. The two gear types collected significantly different assemblages (ANOSIM R = 0.522, p = 0.001) and gear type explained more composition differences than other factors such as month, daytime, or location. Fishery-independent gear underestimated the importance of many species. Although fishery-independent data are invaluable for monitoring assemblage dynamics, fishery-independent gear collects different assemblages than commercial gear. Larger fishes of important species were caught less often in bycatch, but completely absent from fishery-independent gear.
"]},{"key":"dc:title","label":"Title","values":["Bycatch of the Lake Pontchartrain Basin inshore shrimp fishery and its effect on two sea catfish species: the gafftopsail catfish (Bagre marinus) and the hardhead catfish (Ariopsis felis)"]}]}],"canonical_facts":{"dc:contributor":["O'Connell, Martin","Georgiou, Ioannis","Kulp, Mark"],"dc:creator":["Eustis, Scott P"],"dc:description.abstract":["In Lake Pontchartrain Basin, commercial fishing in estuarine habitats impacts many non-target species collected as bycatch. I investigated the bycatch assemblages collected by commercial vessels and compared these to assemblages collected by typical fishery-independent methods. I compared assemblages using analysis of similarity (ANOSIM) and determined important species by weight and abundance using similarity percentages analyses (SIMPER). I also examined differences in size-class distributions by gear type using density kernel plots and Mann-Whitney U tests. The two gear types collected significantly different assemblages (ANOSIM R = 0.522, p = 0.001) and gear type explained more composition differences than other factors such as month, daytime, or location. Fishery-independent gear underestimated the importance of many species. Although fishery-independent data are invaluable for monitoring assemblage dynamics, fishery-independent gear collects different assemblages than commercial gear. Larger fishes of important species were caught less often in bycatch, but completely absent from fishery-independent gear.
"],"dc:identifier":["https://scholarworks.uno.edu/td/1419"],"dc:subject":["bycatch","gear type","assemblage","catfish","diet","Lake Pontchartrain","Ecology and Evolutionary Biology","Life Sciences","Other Ecology and Evolutionary Biology","Terrestrial and Aquatic Ecology"],"dc:title":["Bycatch of the Lake Pontchartrain Basin inshore shrimp fishery and its effect on two sea catfish species: the gafftopsail catfish (Bagre marinus) and the hardhead catfish (Ariopsis felis)"],"thesis:degree_discipline":["Earth and Environmental Sciences"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."]},"updated_at":"2026-07-24T05:29:24Z"}