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Kristina M. Ramstad

Publications and source records attributed to Kristina M. Ramstad.

2 recordsLinked to original sources
USGS2003

Radio tag retention and tag-related mortality among adult sockeye salmon

Tag retention and tag-related mortality are concerns for any tagging study but are rarely estimated. We assessed retention and mortality rates for esophageal radio tag implants in adult sockeye salmon Oncorhynchus nerka . Migrating sockeye salmon captured at the outlet of Lake Clark, Alaska, were implanted with one of four different radio tags (14.5 × 43 mm (diameter × length), 14.5 × 49 mm, 16 × 46 mm, and 19 × 51 mm). Fish were observed for 15 to 35 d after tagging to determine retention and mortality rates. The overall tag retention rate was high (0.98; 95% confidence interval (CI), 0.92-1.00; minimum, 33 d), with one loss of a 19-mm × 51- mm tag. Mortality of tagged sockeye salmon (0.02; 95% CI, 0-0.08) was similar to that of untagged controls (0.03 (0-0.15)). Sockeye salmon with body lengths (mid-eye to tail fork) of 585-649 mm retained tags as large as 19 × 51 mm and those with body lengths of 499-628 mm retained tags as small as 14.5 × 43 mm for a minimum of 33 d with no increase in mortality. The tags used in this study represent a suite of radio tags that vary in size, operational life, and cost but that are effective in tracking adult anadromous salmon with little tag loss or increase in fish mortality.

Alaska↗
USGS2003

Lake Clark sockeye salmon population assessment

Radio telemetry was used to identify and map sockeye salmon spawning habitats in glacially influenced Lake Clark, Kvichak River watershed, Alaska. Two hundred eighty-two adult sockeye salmon were radio tagged and tracked to spawning grounds. Thirty-five spawning areas were identified, including 18 previously unidentified. Comparison of radio telemetry data with past aerial population surveys indicate sockeye salmon spawning habitat use and distribution in Lake Clark was underestimated, likely due to poor visibility associated with glacial habitats. Although glacially turbid waters are not considered suitable incubation environments because fine sediments can suffocate embryos, more than 60% of radio tagged fish spawned in such waters. Over 50% of identified spawning areas are along the shores of Lake Clark and Little Lake Clark and about 75% of spawning areas are adjacent to private land. Proposed development on these lands could negatively impact critical spawning habitats if protective measures are not in place.

Report↗