4.1 Time since recolonization 
Time since recolonization affects the prey composition of sea otter diets. Although clams comprise the majority of the diet in all regions of POW, there were differences in prey items across recolonization zones. The areas of POW that have been colonized for the least amount of time (zone 3, colonized for > 7 years) had the lowest species diversity in prey and highest energy recovery rates. In this zone, clams were overwhelmingly present in the diets of sea otters. This was similar to previous studies in mixed sediment communities in Southeast Alaska, where sea otters focus on fewer, high-quality prey species (e.g., sea urchins in rocky habitats, large clams in soft-sediment habitats) in newly occupied areas, and eventually diversify prey species as sea otter populations persist . Lipid content in sea otter diets was consistent across recolonization zones, but overall energy rate gain was slightly higher in zone 3, which may be due to the ability to obtain larger prey in newly colonized areas. Foraging records for the areas where sea otters had been present the longest (zone 1, colonized for > 30 years) had an intake rate that was comparable to previous studies where sea otters were at carrying capacity . This shows that the sea otters in this recolonization zone of POW are likely at or near carrying capacity, which is in line with modeling from aerial survey data from the region .
When considering sea otter diets and how sea otter invertebrate removal can affect the nearshore system, it is important to look at diet variation across recolonization zones as diets in the newly colonized areas were less diverse, which is similar to past studies in Alaska . In rocky habitats of Southeast Alaska and British Columbia, sea otters in newly colonized regions consumed a majority of red sea urchins . In the present study, the areas we observed where sea otters are newly colonizing were soft-sediment habitat ripe with large butter clams, which were the overwhelmingly predominant prey item.