Sperm Whale Population Status
Population structure for sperm whales on an oceanic scale is largely unknown. Genetic, photographic, and molecular studies suggest that the female units largely remain in their natal waters, with males moving around the oceans and perhaps around the globe. There appears to be differences in social, vocal, and diving behaviour between regions in the North Atlantic and given recent United Nations resolutions, it suggests that management should be made on the regional scale rather than across broad arbitrary oceanic “stocks” as they are currently.
The community using the waters in the eastern Caribbean has been estimated to be fewer than 300 whales. While globally it is estimated that there are around 360,000 sperm whales down from about 1.1 Million prior to ancient and modern mechanized whaling which only stopped in the late 1980’s, not so long ago.
While whaling of sperm whales has largely stopped, humans are still the sources of the major threats to sperm whales. Chemical and heavy metals are being found in the tissues of animals from around the world, including those as far away as Antarctica. Animals can become entangled in fishing gear including longline, gill nets, and FADs; and ship strikes are a concern for sperm whales, particularly in island areas like the Caribbean where everything is imported and fast ferries transit between islands. But ocean noise is increasingly being seen as a major threat to cetaceans around the world.
Sperm whales are listed or protected under a number of legal frameworks:
- The IUCN Red List of Threatened Species lists the sperm whale as being "Vulnerable"
- The United States Endangered Species Act list sperm whales as "Endangered"
- Listed under Appendix I and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) as sperm whales have been categorized as being in danger of extinction throughout all or a significant proportion of their range (Appendix I) and they have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements (Appendix II)
- Sperm whales are covered by the Specially Protected Areas and Wildlife (SPAW) Protocols in the Wider Caribbean.
Currently, there are no legal protections for sperm whales in Dominica.
We have estimated that the current community in the eastern Caribbean is decreasing at around 3% per year.
Its likely that most of that mortality is human caused.