The kelp forest ecosystems that line the rocky outer coast of the archipelago, providing habitat for the fish and invertebrate species that are important prey, would have developed relatively quickly after the coastline was established in approximately its present configuration.

Sea mammals — harbor seals, sea otters, Steller sea lions — would have colonized the productive new habitat rapidly.

In this context, Shuká Káa was alive in a world that was rich in marine resources but still developing its terrestrial ecological complexity.

The balance of his diet — strongly marine, as the isotopes indicate — may reflect not only cultural preference and technological capability but also the specific ecological reality of a landscape where the marine environment was more fully developed than the terrestrial one.

The Question of Population Size