U.S. Fish & Wildlife Service


FREQUENTLY ASKED QUESTIONS ABOUT THE BIOLOGICAL OPINION ON THE CONTAINMENT
PROGRAM FOR THE SOUTHERN SEA OTTER

July 20, 2000

What is a biological opinion?
A biological opinion is a document written by the U.S. Fish and Wildlife Service (FWS) in response to a proposed action by any federal agency (including the FWS itself) that is likely to adversely affect a species listed as endangered or threatened under the Endangered Species Act. This procedure is referred to as the consultation process. The FWS has the responsibility during the process to review all relevant information, evaluate the current status of the species and the effects of the action, and formulate its biological opinion as to whether the action is likely to jeopardize the continued existence of the listed species. If new information indicates that the listed species may be affected in a manner that was not previously considered, the federal action agency must reinitiate the consultation process.


What is the conclusion of the biological opinion on the containment program for the southern sea otter?
It is the FWS's biological opinion that continuing the containment program and restricting the southern sea otter to the area north of Point Conception (which marks the current legal boundary between the parent range and the management zone, with the exception of the translocation zone at San Nicolas Island) is likely to jeopardize the species' continued existence. Critical habitat has not been designated for this species, therefore, none will be affected.


What was the basis for the conclusion?
The FWS reached its conclusion for the following reasons:
Reversal of the southern sea otter's population decline is essential to its survival and recovery. Continuation of the containment program will result in the capture, transport, and release of large numbers of southern sea otters from the management zone into the parent population. These actions may result in the direct deaths of individuals and disrupt social behavior in the parent population to the degree that those affected individuals will have reduced potential for survival and reproduction. These effects will exacerbate the recent decline of the southern sea otter population.

In addition, expansion of the southern sea otter's distribution is essential to its survival and recovery. Continuation of the containment program will result in the exclusion of southern sea otters from the area south of Point Conception. This effect will perpetuate the species' artificially restricted range and its vulnerability to the adverse effects of oil spills, disease, and stochastic events.


Why did the FWS reinitiate consultation on sea otter containment under the translocation plan?
The original biological opinion was written in 1987. Reinitiation of consultation began in 1998 and was prompted by the Service's receipt of substantial new information on the population status, behavior, and ecology of the southern sea otter that may reveal effects of the action on this species that were not previously considered. Specifically, the following information and circumstances prompted this reinitiation:

1. In the winters of 1997-1998 and 1998-1999, southern sea otters moved into the management zone in numbers that were much greater than had previously occurred during the preceding years of the translocation program.

2. Analysis of carcasses has shown that southern sea otters are being exposed to environmental contaminants and diseases which could be affecting the health of the population.

3. The number of southern sea otters range wide has been declining, based on information obtained from regular surveys.

4. More recent information indicates that southern sea otters at San Nicolas Island may not be isolated from the potential effects of a single, large oil spill. Consequently, a larger range occupied by southern sea otters along the mainland coast is important for their protection from oil spills.

5. Given that the population along the mainland has been declining, the capture and release of large numbers of southern sea otters may have adverse effects that were not considered in the original biological opinion.


How many sea otters are periodically moving into the management zone?
As defined by the regulations implementing Public Law 99-625 (the Sea Otter Translocation Program), the management zone extends from Point Conception south to the border with Mexico, exclusive of the translocation zone around San Nicolas Island. In late winter and early spring of 1997-1998, approximately 100 southern sea otters moved south of Point Conception. By the fall of 1998, most of the otters had retreated north of Point Conception. In December 1998, approximately 50 southern sea otters again inhabited the area south of Point Conception. Although the number of otters in the area decreased greatly during the summer, 152 individuals were present by January 1999. In May 1999, 58 southern sea otters were residing along the mainland coast from Point Conception to about Ventura. By October 1999, one dependent and three adult southern sea otters were observed at San Miguel Island during an aerial survey; an additional otter was found along the mainland. These were the only individuals detected in the management zone. In February 2000, FWS was unaware of any southern sea otters along the mainland coast south of Point Conception. However, in May 2000, 78 southern sea otters were detected in the management zone during aerial surveys, roughly between Point Conception and Refugio State Beach.

Repeated expansions of southern sea otters into the management zone and subsequent retreats such as those experienced in the spring of 1998 through May of 2000 will likely continue until at some point, if they are not contained, southern sea otters will likely become permanent residents of the current management zone.


How are environmental contaminants, diseases, random environmental events and other factors potentially affecting sea otters?
While some of the factors (disease, parasitic infection, contaminants) that may be contributing to the long-term, slow growth of the southern sea otter population are known, their involvement in the recent decline are not well understood and thus cannot be easily addressed. Although the cause(s) for the decline is uncertain, possible factors include: exposure to contaminants that adversely affect the immune system, endocrine suppressors, increase in exposure to diseases, reduction in available food resources, accidental drowning in fishing traps, chronic changes in oceanographic conditions, and random environmental events, such as El Niño.


What is the current status of the population?
In four of the past five years (1996, 1997, 1998, and 1999) the total number of southern sea otters counted during spring population surveys has progressively declined. In spring 1995, the number of sea otters was the highest number recorded to date; a total of 2,377 animals was counted. In the spring of 1996, the number fell to 2,278. By the spring of 1997, it was down to 2,229, in spring 1998 a total of 2,114 animals was counted, and the 1999 spring count observed only 2,090 sea otters. This represents a decline of just under 12 percent between 1995 and 1999. The spring 2000 survey counted a total of 2,317 otters (2,053 independents plus 264 pups). This represents nearly an 11 percent increase since 1999, but is still below the highest count of 2,377 obtained in the spring 1995. The most recent spring survey results are encouraging; however, year to year variation in the counts is expected. For this reason the southern sea otter recovery team has recommended the use of three year running average to incorporate the existing degree of uncertainty in assessing population counts. The spring 2000 count represents an increase in both the annual counts and the three year running average However, the information from the spring 2000 is not sufficient evidence that the recent decline in the southern sea otter population is reversed. Survey data from future years will be needed to determine if the population counts continue to increase and demonstrate an upward trend.


Why do oil spills continue to be a major threat for the southern sea otter population?
Oil spills from coastal vessel traffic still pose a risk to the southern sea otter. Efforts to establish an experimental translocated population large enough at San Nicolas Island to reduce the threat from oil spills have not been successful. Even if a viable population was eventually established, a southern sea otter colony at San Nicolas Island may not provide substantial protection to the species in the event a large oil spill contacted the parent population. Observations from the Exxon Valdez oil spill demonstrated that impacts from such a spill could be far reaching. For example, oil dispersed from the Exxon Valdez spread over 400 linear miles in 30 days; this area greatly exceeds the present range of the southern sea otter, including San Nicolas Island. The efforts to contain the oil spilled from the Exxon Valdez and to capture and rehabilitate sea otters proved to be ineffective in protecting a substantial portion of the sea otter population.


Why is there concern that the capture and release of large numbers of otters would affect the parent population?
The concern pertains to sea otter socialization and interactions with introduced individuals. The movement of large numbers of southern sea otters from the management zone into the parent range would likely cause substantial disruption of the latter's social structure and increased pressure on food resources and, consequently, result in jeopardy to the listed species. Such impacts could include increased mortality and population instability, which would likely continue, if not accelerate, a decline in the parent population.

At the time the translocation program was being proposed, why was the area south of Point Conception considered not necessary for recovery of the sea otter? In 1986, the population ranged from Point Año Nuevo south to the Santa Maria River. The FWS believed that there was sufficient habitat north of Point Año Nuevo and south of the Santa Maria River to Point Conception to accommodate range expansion to recover the sea otter under the requirements of the Endangered Species Act. The southern movements that occurred over the last two years has resulted in a large number of sea otters from the main population probably moving many miles, and residing within the management zone. As the range of the southern sea otter becomes larger, the likelihood that a single stochastic event could cause irreparable damage to the population decreases. Because of the generally slower movement of southern sea otters to the north, their ability to expand the range to the south increases in importance.


What is the next step for FWS and interested parties?
As a result of this biological opinion, FWS will not capture, transport, and release southern sea otters from the management zone into the parent population. The FWS will begin a comprehensive review under the National Environmental Policy Act, involving state agencies and the public, of its southern sea otter translocation program to determine whether it should continue, be modified or be terminated. Alternatives to the translocation program including the containment component will be identified and evaluated. The FWS will publish a notice of intent (NOI) to prepare a supplemental environmental impact statement pertaining to the southern sea otter translocation program later this month. Public scooping meetings will be held in August. Announcement of dates, times and locations of these meetings will be published in the NOI.