As a keystone species, sea otters have unusually large effects on marine ecosystems, which means that the socioeconomic impacts of sea otter recovery are correspondingly large. These effects often disrupt existing social and economic activities, sometimes positively and sometimes negatively. The full range of effects is diverse, but they can generally be divided into two categories:

• Direct effects of sea otter predation, which are generally negative from a human perspective because they often involve shellfish species that humans would rather harvest themselves (commercially, recreationally, or as part of subsistence fisheries)
• Indirect effects that result from food web interactions, which are probably mostly positive from a human perspective

The direct and indirect effects, while relevant to any feasibility study and important, are difficult to assess—in part because of uncertainties over sea otters’ ecological effects, in part because of the differing currencies people use to value natural resources, and in part because of the different ways people embrace these differing values. While putting monetary values on the effects is the single most common method of conducting a socioeconomic analysis, it is important to remember the non-monetary values and recognize there may be no obvious way forward that all or even most people will find completely fair and reasonable.