2023 marked the 10-year anniversary of the IUCN Marine Mammal Protected Areas Task Force. In 2013, the Task Force began to develop a conservation tool—Important Marine Mammal Areas (IMMAs)—that marine spatial planners, protected area practitioners, governments, industry stakeholders and scientists could use to protect whales, dolphins and other marine mammals and their habitats. As of March 2024 the Task Force has worked with more than 300 scientists to examine 74.3% of the global ocean, identifying 280 IMMAs.

Important Marine Mammal Areas are defined as discrete portions of habitat, important to marine mammals, that have the potential to be delineated and managed for conservation. They are not legal designations but independent, peer-reviewed assessments based on criteria supported by data. Important Marine Mammal Areas are now being used in spatial planning in Malaysia, to create marine protected areas in Bangladesh and Viet Nam, by the United States Navy to avoid using low-frequency sonar in cetacean habitat, to establish International Maritime Organization Particularly Sensitive Sea Areas in the Mediterranean where fin and sperm whales are struck by ships, and by shipping companies transiting the Indian Ocean for route planning to reduce the risk of hitting whales. In total, the freely available IMMA package of shapefiles has been downloaded over 725 times from the IMMA website (marinemammalhabitat.org/imma-eatlas).

Endangered Black Sea bottlenose dolphin Tursiops truncatus ponticus in an Important Marine Mammal Area in the war zone in the Black Sea. Photo: Elena Gladilina.

Yet, despite recent identification, some IMMAs are already threatened. In the Upper Gulf of California IMMA, the Critically Endangered vaquita Phocoena sinus has been reduced to c. 10 individuals despite numerous efforts to save the species from extinction. In six IMMAs created along the Ukrainian coast of the Black Sea around the habitat of threatened dolphin and porpoise subspecies, Black Sea harbour porpoises Phocoena phocoena relicta and Black Sea bottlenose Tursiops truncatus ponticus and common dolphins Delphinus delphis ponticus are dying and stranding in what has become a war zone. In the Bazaruto Archipelago to Inhambane Bay IMMA, off Mozambique, the Critically Endangered East African subpopulation of the dugong Dugong dugon, and the Endangered Indian Ocean humpback dolphin Sousa plumbea are threatened by seismic surveys for oil and gas development.

The Marine Mammal Protected Areas Task Force, joined by Whale and Dolphin Conservation (UK), is now initiating a programme to monitor and implement Important Marine Mammal Areas.