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Full-Text Articles in Physical Sciences and Mathematics

Shortnose Sturgeon (Acipenser Brevirostrum) Spawning Potential In The Penobscot River, Maine: Considering Dam Removals And Emerging Threats, Catherine Johnston Aug 2016

Shortnose Sturgeon (Acipenser Brevirostrum) Spawning Potential In The Penobscot River, Maine: Considering Dam Removals And Emerging Threats, Catherine Johnston

Electronic Theses and Dissertations

Dam removals from the Penobscot River in Maine restored access to freshwater habitat critical for the life cycle of endangered shortnose sturgeon. Prior to the dam removals, shortnose sturgeon spawning activity had not been documented. Instead, evidence suggested that individuals emigrated from the Penobscot River to spawn in the Kennebec complex, 140 km away. A central question of this thesis was whether spawning activity would commence in the first two years following dam removal. Consistent with pre-dam removal movement patterns determined using acoustic telemetry, the majority (78%) of tagged individuals emigrated from the Penobscot River at some point over the …


Assessment Of A Hatchery Based Rainbow Smelt Supplementation Effort, Andrew O'Malley May 2016

Assessment Of A Hatchery Based Rainbow Smelt Supplementation Effort, Andrew O'Malley

Electronic Theses and Dissertations

Rainbow Smelt (Osmerus mordax) are an important fish distributed throughout northeastern North America with both anadromous and landlocked populations. Abundance, size at age, and maximum size vary widely among populations and life histories. In order to compare anadromous and landlocked populations, we collected spawning adults in 2014 from four anadromous and three landlocked populations. Scales and otoliths from the anadromous fish were examined and compared for estimates of bias and precision in ageing. Analysis of both scales and otoliths provided age estimates that were acceptable, but estimates from scales were more precise and had less bias. Otoliths were …