Marine Mammal Commission

Listing Status of West Indian Manatees

In April 2006, the U.S. Fish and Wildlife Service (FWS) completed a five-year status review of West Indian manatees. Such reviews are undertaken for species listed as endangered and threatened under the Endangered Species Act to determine if they should be reclassified or removed from the list. The 2006 review concluded that both Florida manatees and Antillean manatees (the other subspecies of West Indian Manatee) were stable or increasing throughout most of their ranges. FWS staff therefore recommended that the species as a whole, including Florida manatees, be down-listed from endangered to threatened. In 2006 and 2007, mortality of Florida manatees jumped to record or near-record highs in successive years and steps to act on the down-listing recommendation were deferred. Concerns about high mortality were further heightened when Florida experienced an unprecedented cold period in early 2010 causing a record number of cold-stress-related manatee deaths and a total death toll of 776. In 2011, another red tide event in southwest Florida and an algal bloom in the Indian River elevated annual mortality levels to another record of 840 animals.

In light of this series of years with unusually high mortality, the Commission wrote to the FWS on September 21, 2011. In our letter, we noted that given the minimum population estimate (then a count of 5,076 manatees) and the death of more than 1,000 animals in just two years, the population may have declined or been significantly affected. We therefore recommended that, as part of any reclassification proposal, the FWS incorporate an assessment of the effects of the high cold-stress mortality in 2010 and 2011 on the population’s status and that it consider the possibility that mortality events similar to those occurring in recent years, could occur more frequently in the future.

On December 14, 2012, the FWS received a petition from the Pacific Legal Foundation on behalf of Save the Crystal River, Inc., requesting that the West Indian manatee, including both the Florida and Antillean manatee be down-listed as had been recommended by FWS staff in 2006. After a delay in responding to the petition due to a decrease in agency funding, the Foundation filed a lawsuit on April 20, 2014 noting that the required timeframe for responding to the petition had not been met. It therefore requested public comments on the petition and asked for information that should be considered during the decision-making process on the petition.

The Commission responded on September 2, 2014 noting in part that the FWS had recently adopted a new policy for listing “distinct population segments” (DPSs) for parts of a species that occupy a “significant” portion of its range. In light of the new policy, we recommended that the agency (1) analyze the current listing status of the West Indian manatee under its new policy, and (2) review genetic, photo-identification, tagging, and other relevant data to identify West Indian manatee DPSs, and then assess DPS independently to determine whether any should remain listed as endangered, be listed as threatened, or be delisted entirely. At a minimum, we noted that strong consideration should be given to identifying the Florida and Antillean subspecies as separate DPSs. We also recommended that the FWS review manatee die-offs over the past five years using its core biological model to evaluate the effects of recent manatee mortality levels on population size and growth rates. In this regard, we also recommended that, before making a decision on reclassifying West Indian manatees, the FWS review all past Florida manatee mortality events to estimate the frequency of similar future events and possible effects on long-term manatee population trends. Finally, we recommended an assessment of effects from eventual power plant closures on the long-term viability of the Florida manatee population and the adequacy of assurances that work required to enhance and protect natural warm-water refuges will be carried out in the coming decades before power plants reach the end of their planned operational lives.

In January 2016, the FWS accepted the petition and published a proposed rule to reclassify the West Indian manatee as threatened under the Endangered Species Act. We provided comments on the proposal to FWS on April 8 2016. A final rule reclassifying the West Indian manatee as threatened was published on April 5, 2017.