Marine Mammals

AGENCY:

National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.

ACTION:

Notice; availability of new criteria for designation of marine mammal Unusual Mortality Events (UMEs).

SUMMARY:

The National Marine Fisheries Service (NMFS) announces new criteria developed by the Working Group on Marine Mammal Unusual Mortality Events (Working Group) to help determine when a marine mammal Unusual Mortality Event (UME) is occurring.

FOR FURTHER INFORMATION CONTACT:

Teri Rowles, D.V.M., Ph.D. or Trevor Spradlin, NMFS, Marine Mammal Health and Stranding Response Program, Office of Protected Resources; telephone: (301) 713-2322; fax: (301) 427-2522.

SUPPLEMENTARY INFORMATION:

Background

Marine mammals strand for a variety of reasons. Some identified causes include: infectious disease (e.g., viral, bacterial, parasitic), non-infectious disease (e.g., stress, starvation, exposure to biotoxins or contaminants.), physical trauma (e.g., ship strikes, entanglements, predation, acoustic sources), behavioral changes (e.g., associated with prey shifts, social cohesiveness), weather and oceanographic conditions (e.g., hurricanes, tsunamis, El Nino), to name a few (Geraci et al., 1999; Dierauf and Gulland, 2001; Geraci and Lounsbury, 2005). Title IV of the Marine Mammal Protection Act (MMPA, 16 U.S.C. 1361 et seq.) defines a set of multiple strandings to be part of an “Unusual Mortality Event” (UME) if it has the following characteristics: (1) It is unexpected; (2) involves a significant die-off of any marine mammal population; and (3) demands an immediate response. In recent years, increased efforts to examine carcasses and live stranded animals and new diagnostic capabilities have improved our knowledge of mortality rates, patterns, and causes, allowing us to better understand population threats and stressors and to determine when a situation is “unusual.” These advancements have contributed significantly to conservation efforts for marine mammals. Understanding and investigating marine mammal UMEs is also important because they can serve as indicators of ocean status or health, giving us insight into larger environmental issues which also may have implications for human health and welfare (Reddy et al., 2001; Wells et al., 2004) and population management. From 1991 through 2006, there have been 37 formally recognized UMEs in the United States involving either single or multiple species and dozens to hundreds of individual marine mammals per event.

The Working Group on Marine Mammal Unusual Mortality Events

The National Marine Fisheries Service (NMFS) or the U.S. Fish and Wildlife Service (USFWS) formally declare an UME upon the recommendation of the Working Group on Marine Mammal Unusual Mortality Events (The Working Group or WGMMUME). The Working Group was first established in 1991 by NMFS in response to large numbers of marine mammal mortalities in the late 1980s involving humpback whales in the Northeast U.S., bottlenose dolphins along the Atlantic coast and the Exxon Valdez oil spill (Geraci et al., 1999; Dierauf and Gulland, 2001; Gulland, 2006), and was formalized when Congress passed the 1992 amendments to the MMPA as the Marine Mammal Health and Stranding Response Act. As statutorily defined, the Working Group's primary role is to determine when an UME is occurring and to help direct the response and investigation. From 1991 through 2006, the Working Group has consulted on 37 marine mammal UMEs throughout the United States involving numerous species of cetaceans (whales, dolphins and porpoises), pinnipeds (seals, sea lions), manatees and sea otters (Gulland, 2006).

The Working Group is comprised of members from scientific and academic institutions, conservation organizations, and state and/or Federal agencies who have a wide variety of expertise in biology, toxicology, medicine, pathology, ecology, and/or epidemiology. The members are appointed for three-year terms and meet annually in person, and engage in discussions throughout the year by e-mail or conference call to review and consult on individual cases, events, or disease issues. In addition to the core members, there are two international participants (one from Canada and one from Mexico) and Federal Government representatives (currently including NMFS, the U.S. Fish and Wildlife Service (USFWS) and Marine Mammal Commission) who, although they have no voting privileges, contribute significantly to the data reviews, internal discussions, sample analyses, and overall UME investigations. Responses to UMEs are coordinated by either the NMFS or USFWS Regional Offices depending on the species (NMFS has jurisdiction for all cetaceans and most pinnipeds (seals and sea lions), whereas USFWS has jurisdiction for walrus, sea otters, manatees and polar bears) and the regional stranding networks, as well as other Federal, state and local agencies. Investigation of such events has led to a greater understanding of the impacts of human-related and natural causes of mortality in marine mammal populations.

In order to determine whether an UME is occurring, the Working Group developed seven criteria to evaluate mortality events, which were published in the National Contingency Plan for Response to Unusual Marine Mammal Mortality Events (Wilkinson 1996):

(1) A marked increase in the magnitude of strandings when compared with prior records.

(2) Animals are stranding at a time of the year when strandings are unusual.

(3) An increase in strandings is occurring in a very localized area (possibly suggesting a localized problem), is occurring throughout the geographical range of the species/population, or spreads geographically with time.

(4) The species, age, or sex composition of the stranded animals is different than that of animals that normally strand in the area at that time of the year.

(5) Stranded animals exhibit similar or unusual pathologic findings or the general physical condition (e.g., blubber thickness) of stranded animals is different from what is normally seen.

(6) Mortality is accompanied by behavior patterns observed among living individuals in the wild that are unusual, such as occurrence in habitats normally avoided or abnormal patterns of swimming and diving.

(7) Critically endangered species are stranding. Stranding of three or four right whales, for example, may be cause for great concern whereas stranding of a similar number of fin whales may not.

The Working Group considers that a single criterion or combination of criteria may indicate the occurrence of an UME.

The process of declaring an UME involves the Working Group reviewing all available information on the event within 24 hours of receiving a request for a formal consultation from concerned stakeholders (e.g., government officials, the marine mammal stranding network, scientific researchers, wildlife conservation organizations, etc.). The Working Group reviews historical stranding data and current population trends for the species of marine mammals involved, as well as environmental factors. After the Working Group announces their decision, which is achieved by a majority vote from a quorum of responders, NMFS or USFWS (depending on which agency has jurisdiction) has an additional 24 hours to officially declare the event an UME and appoint an Onsite Coordinator to oversee and administer the investigation. If an UME is declared, the Working Group will provide advice on how the investigation should be conducted, and individual members may serve on the investigation team. When an UME is officially declared, money from the Marine Mammal Unusual Mortality Event Fund may be made available to help reimburse some of the “special costs” incurred during the investigation as specified in Section 405 of the MMPA and the National Contingency Plan for Response to Unusual Marine Mammal Mortality Events (Wilkinson 1996).

New Criteria for Determining Marine Mammal UMEs

At the Working Group's 2004 annual meeting, the members reevaluated the original seven criteria used to determine an UME and have revised them to include morbidity, pathology and population-level declines in an effort to improve detection of events that could have significant impacts on populations of marine mammals (e.g., unusual disease outbreaks that do not necessarily result in mortalities). Steady declines in population abundance can influence numbers of animals detected by the stranding network, this in turn influencing the likelihood of a stranding event being declared “unusual” under the current criteria. An emphasis on considering mortalities in the current criteria may also delay a response that could be crucial to identify causal factors. Elevating the importance of “morbidity” could initiate consideration of an UME sooner, and improve the effectiveness of a subsequent investigation. Therefore, the UME criteria have been revised as follows:

(1) A marked increase in the magnitude or a marked change in the nature of morbidity, mortality or strandings when compared with prior records.

(2) A temporal change in morbidity, mortality or strandings is occurring.

(3) A spatial change in morbidity, mortality or strandings is occurring.

(4) The species, age, or sex composition of the affected animals is different than that of animals that are normally affected.

(5) Affected animals exhibit similar or unusual pathologic findings, behavior patterns, clinical signs, or general physical condition (e.g., blubber thickness).

(6) Potentially significant morbidity, mortality or stranding is observed in species, stocks or populations that are particularly vulnerable (e.g., listed as depleted, threatened or endangered or declining). For example, stranding of three or four right whales may be cause for great concern whereas stranding of a similar number of fin whales may not.

(7) Morbidity is observed concurrent with or as part of an unexplained continual decline of a marine mammal population, stock, or species.

As with the original criteria, the Working Group considers whether a single criterion or combination of the revised criteria may indicate the occurrence of an UME. The Working Group agreed to use the revised criteria on a pilot basis beginning in July 2004 and evaluate their utility after applying them to several consultation requests throughout 2005 and 2006. The Working Group has since determined that the revised criteria have been more applicable to current stranding events than the original criteria and has voted to adopt them as the new official UME criteria to be used for all future consultations (or until such time when they are reevaluated and revised again).

Additional information on the MMHSRP and UME program, including frequent updates, can be found on the Internet at: http://www.nmfs.noaa.gov/pr/health/

Authority: 16 U.S.C. 1361 et seq.

References

Dierauf, L.A. and F.M.D. Gulland. 2001. Marine Mammal Unusual Mortality Events. In: L.A.Dierauf and F.M.D. Gulland (Eds.), Handbook of Marine Mammal Medicine. CRC Press, Boca Raton, Florida. Pgs. 69-81.

Geraci, J.R., J.H. Harwood and V.J. Lounsbury. 1999. Marine Mammal Die-Offs: Causes, Investigations, and Issues. In: J.R. Twiss, Jr. and R.R. Reeves (Eds.), Conservation and Management of Marine Mammals. Smithsonian Institution Press, Washington, D.C. Pgs. 367-395.

Geraci, J.R. and V.J. Lounsbury. 2005. Marine Mammals Ashore: A Field Guide for Strandings, Second Edition. National Aquarium in Baltimore, Baltimore, MD. 371 pp.

Gulland, F.M.D. 2006. Review of the Marine Mammal Unusual Mortality Event Response Program of the National Marine Fisheries Service. Report to the Office of Protected Resources, NOAA/National Marine Fisheries Service, Silver Spring, MD. 32 pp.

Reddy, M.L., L.A. Dierauf and F.M.D. Gulland. 2001. Marine Mammals as Sentinels of Ocean

Health. In: L.A. Dierauf and F.M.D. Gulland (Eds.), Handbook of Marine Mammal Medicine. CRC Press, Boca Raton, Florida. Pgs. 3-13.

Wells, R.S., H.L. Rhinehart, L.J. Hansen, J.C. Sweeney, F.I. Townsend, R. Stone, D.R. Casper, M.D. Scott, A.A. Hohn and T.K. Rowles. 2004. Bottlenose dolphins as marine ecosystem sentinels: Developing a health monitoring system. EcoHealth, 1: 246-254.

Wilkinson, D.M. 1996. National Contingency Plan for Response to Unusual Marine Mammal Mortality Events. NOAA Tech. Memo. NMFS-OPR-9. 118 pp.