Miner, Jonathan Neal, 1969-2009-11-112009-11-111993Miner, Jonathan Neal. Analysis of the Lower Distributional Limit of Callianassid Shrimp in South Slough National Estuarine Research Reserve. Thesis (M.S.)--University of Oregon, 1993, 1993.https://hdl.handle.net/1794/9934Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 77-80). Description: xii, 80 leaves : ill. ; 29 cm.The lower distributional limits (fronts) of callianassid shrimp populations were observed at five sites in South Slough, Coos Bay estuary, Oregon. Fronts at four sites exhibited similar shoreward-seaward movements while the remaining site showed drastic population reductions. Shrimp density and body size were found to be significantly greater above than below the front. There was no consistent pattern found in grain size or interstitial water content across the front. In a controlled predator-exclusion experiment, resulting shrimp densities were not significantly different among treatments. Front shifts showed no pattern in response to treatments. These results imply that fish predation is not responsible for front placement. Trawls taken on both sides of the front produced similar densities of a predatory fish, Leptocottus armatus. Because predation pressure was calculated to be roughly equal above and below the front, Leptocottus is not expected to be responsible for position and movements of these fronts.en-USGhost shrimps -- Oregon -- South Slough National Estuarine Research Reserve -- Geographical distributionEstuarine ecology -- Oregon -- South Slough National Estuarine Research ReserveEstuarine animals -- Oregon -- South Slough National Estuarine Research Reserve -- Geographical distributionSouth Slough National Estuarine Research Reserve (Or.)Thesis