Near-shore marine ecosystems face unprecedented challenges at global and regional scales, with threats arising from both the adjacent lands and oceans. From the ocean, challenges include acidification, sea level rise, and warming. From the continents, challenges include growing levels of pollutants associated with large human populations along coastlines. We are investigating how sea otter populations and their near-shore ecosystems are affected and responding to these and other factors.
We focus on a food web where kelps are primary producers and energy is transferred through clams, crabs, and urchins to high-level consumers such as some fishes, birds and mammals. Six geographically distinct sea otter populations, (including two populations listed as “Threatened”) are contrasted to identify factors contributing to variation in density and trend in abundance. The study incorporates ecosystem productivity, watershed inputs, and diet and nutrition as the primary factors potentially regulating population abundance and growth rates.
We estimate ecosystem productivity through the growth rates of near-shore fishes and satellite imagery and remotely sensed data. Sea otter diet and nutrition is estimated through direct observation of foraging. The combined data sets on near-shore productivity, watershed inputs, sea otter diet/nutrition, and sea otter gene expression supports the analysis of factors likely responsible for the present status and trend of sea otter populations, and the near-shore ecosystem.
Pacific Nearshore Project