Marine Mammal Commission

Enhancing Hawaiian Monk Seal Recovery

In August 2011, the National Marine Fisheries Service (NMFS) requested comments on a draft programmatic environmental impact statement analyzing several new research and management initiatives to enhance monk seal recovery. Principal among the initiatives considered in the draft statement were (1) conducting a two-stage translocation to temporally move weaned pups from areas with low survival to areas with higher survival, and then back to their natal sites once they reach the age of two or more (Baker et al. 2013); (2) monitoring seals for infectious diseases and developing vaccination protocols for two vectors of particular concern for monk seals (i.e., West Nile virus and morbillivirus); (3) testing and, as warranted, expanding deworming treatments to reduce parasite loads in monk seals; (4) testing and, as appropriate, using new methods to modify monk seal behavior patterns that place them at risk from interactions with people and fishing gear in the Main Hawaiian Islands (MHI); and (5) testing and, as appropriate, using drugs on male seals to reduce aggressive behavior toward pups, juveniles, and adult females. As part of that effort, NMFS applied to its permit office for an enhancement permit to authorize such activities under the Endangered Species Act (ESA) and the Marine Mammal Protection Act (MMPA).

The two-stage translocation proved to be highly controversial. At the time, NMFS considered the MHI to be the most effective temporary receiving site for Northwestern Hawaiian Islands (NWHI) juvenile seals because it was the area where the highest juvenile survival had consistently been observed. However, some people opposed moving seals to the MHI, even temporarily.

On October 24, 2011, we wrote to the NMFS commending the agency for its comprehensive evaluation of new or expanded recovery actions. Studies of monk seal diet in both the NWHI and MHI had revealed there was very little overlap between monk seal prey and the sizes and species of fish and shellfish caught by fishermen, and we therefore recommended that the agency move forward with the proposed two-stage translocation work as quickly as possible. We also recommended that the agency (1) consider alternative ecosystem-based management measures (e.g., enhancing monk seal prey habitat) to enhance juvenile survival in the NWHI; and (2) give high priority to further testing of a morbillivirus vaccine on captive monk seals to identify possible side effects of the vaccine on seals.

In April 2014, NMFS released a final programmatic environmental impact statement (PEIS) and the following June it issued a final record of decision on its selected options and an associated research permit. In view of opposition to moving seals from the NWHI to the MHI, the agency decided to select a limited two-stage translocation approach in which it could move weaned pups from areas of low juvenile survival to areas of high survival within the NWHI, within the MHI, or from the MHI to the NWHI, but not from the NWHI to the MHI. All other options were approved as initially proposed. Numerous ongoing and new recovery activities covered by the 2014 PEIS have been conducted, including pup translocations to improve survival, vaccination of wild monk seals to prevent or mitigate morbillivirus outbreaks, behavioral modification measures to enhance seal and public safety in the MHI, and the use of unmanned aerial vehicles and new devices for studying seal movements and behavior. Rehabilitation of seals in poor health is undertaken under the authority of NMFS’ Marine Mammal Health and Stranding Response Program.