The Center for Biological Diversity, Harvard Animal Law & Policy Clinic, Miami Waterkeeper, and Frank S. González García served the U.S. Fish & Wildlife Service (FWS) with a notice of intent to sue under the citizen suit provision of the Endangered Species Act (ESA) for failing to protect the West Indian manatee. The notice letter follows a November petition for rulemaking urging FWS to relist the species as endangered. FWS downlisted the West Indian manatee to threatened in 2017 but since then the population has significantly declined. FWS failed to make a determination whether the petition presented substantial information indicating that uplisting the manatee may be warranted within 90 days as required by federal law.