Effects Of Sea Otter Colonization On Soft-Sediment Intertidal Prey Assemblages In Glacier Bay, Alaska

Sea otter recolonization in Glacier Bay, Alaska, has demonstrated significant top-down structuring of soft-sediment intertidal prey assemblages over a multi-decadal timescale. As sea otter densities increased from zero to over 8,500 individuals between 1993 and 2012, clam populations showed a 50% probability of decline at densities of approximately 6 otters per km², with preferred prey species like Saxidomus giganteus declining even at lower densities (<2 otters per km²). Energy recovery rates for otters decreased significantly with increasing otter density, indicating that higher predator densities require more energy expenditure. The study, which sampled 45 intertidal sites before and after otter colonization, found consistent effects on clam populations similar to those observed in other habitats, highlighting the broader ecological impact of sea otters as a top predator.

Weitzman, B. P. (2013). Effects Of Sea Otter Colonization On Soft-Sediment Intertidal Prey Assemblages In Glacier Bay, Alaska. Unpublished. https://doi.org/10.13140/RG.2.2.16896.02563