Disease
The risk of disease transmission from released sea otters to wild populations is an important and legitimate concern. Following the EVOS, some pathologists and the Alaska Department of Fish and Game were opposed to releasing rehabilitated otters because of concern about disease transmission to wild populations (Spraker, 1990). The risks to the wild population from disease potentially originated both from pathogens that existed in localized populations of sea otters prior to capture, and which could be spread more widely following relocation, and from novel pathogens to which the sea otters were exposed during captivity. It is Fish and Wildlife Service policy in Alaska that whenever release of rehabilitated animals to the wild is contemplated, state-of the-art measures for disease transmission prevention shall apply (USFWS, in preparation).
Duration of Captivity
The length of time sea otters are held in captivity should be minimized. Limiting holding times may reduce the risks of disease transmission and may reduce the risks of captive sea otters becoming dependent on humans for food.
Composition of Receiving Population
Because sea otters tend to segregate by sex, it may be advantageous to release rehabilitated animals in areas having otters of the same age and sex as those being released (Ralls et a1., 1992). This may reduce social stress and may enhance the probability of sea otters remaining in the release area.
Holding at Release Site
Ralls et a1. (1992) suggest that holding relocated sea otters at the release site enhances the probability they will remain in the release area. In their experimental relocation of California sea otters, these investigators held individuals for forty-eight hours. Although Rathbun et a1. (1990) did not come to a similar conclusion, it may be prudent to use prerelease holding facilities at the release site until better information on the efficacy of the technique is available.
