Abstract

The recovery of the Southern sea otter (Enhydra lutris nereis) has been a slow (over 30 years) and painful process, and in the last decade and a half has been retarded by high adult prime age animal mortality. Health of the population, and particularly several infectious diseases and intoxications that have terrestrial origins and are forms of pollution, distinguish Southern sea otter populations from their more northern cousins. Marginal nutrition may exacerbate, complicate or cause disease problems of sea otters. Arguably, without much of the mortality caused by anthropogenic health problems, sea otters in California could have reached the designated threshold for recovery under ESA by or before 2012.

Pathogenic protozoa, bacteria, fungi, organic chemical pollutants, biotoxins, and nutrients that cause the elaboration of biotoxins, are the primary causes of sea otter death in California that can be ascribed to terrestrial and anthropogenic sources. Almost 2 decades of study have revealed the various pathways of many of the organisms and toxins, but only in a few cases have interventions been attempted. Interestingly, almost all of these organisms also cause illness and sometimes death in people or owned animals. The discharge of any or all of these, or any substance that causes illness or death in marine animals, is illegal under various State and Federal laws. Why has this been allowed to continue? What can be done about it? Some possible answers will be presented.