Chapter 9: Implementation and Logistical Considerations
The discussion of alternative reintroduction scenarios is continued and expanded in this Chapter, where the practical and logistical considerations of a reintroduction program are addressed. Logistical considerations include some of the topics addressed elsewhere in the report (e.g., selection of a source population and potential release sites), but also include methodological issues such as how to capture, transport, release, and monitor sea otters. While this chapter in no way represents a detailed proposal for a sea otter reintroduction, it does provide a useful overview of the topics that would need to be addressed in a detailed proposal.
Several strategies should be considered for reintroducing sea otters to the Oregon Coast. These strategies include options for source populations, release locations, and specific attributes of reintroduced animals. Source populations with sufficient numbers to support a reintroduction program include those in Washington and Southeast Alaska. Sea otters from California should be considered to both support the conservation and recovery of southern sea otters and establish a genetic bridge between southern and northern subspecies. Evidence from historic reintroductions suggests multiple introductions may improve the probability of establishing a viable population in a new area.
Although sea otters may eventually occupy all nearshore habitats within their range, not all habitats will support equivalent densities. In general, shallow, high-relief rocky habitats that support canopy-forming kelp colonies may be preferred. High densities of sea otters also occur in many estuarine and shallow soft sediment habitats throughout their range. Selection of release locations should consider habitat preferences, but sites that allow for access to both exposed and sheltered shorelines (or estuaries) may increase the potential for success. It is critical to realize that in past translocations, sea otters have often not remained where they were released but have become established a considerable distance from release sites.
Although not explicitly demonstrated, the sex and age composition of reintroduced sea otters may affect success. There is reason to suspect that younger animals captured for translocation may not have well established home ranges and so may be more likely to become established at or near the release site. It is also possible that a sex ratio biased toward females will contribute to the reproductive potential of the founding population.
A variety of capture methods—dip nets, tangle nets, and scuba-operated Wilson traps—are available to achieve the desired abundance and age/sex composition. Appropriate care and monitoring of the health status of captured animals during transport and holding is essential, and intensive post-release monitoring of animals will also help ensure success.