A Sargasso Sea Commission supported proposal for a humpback whale migratory corridor passing Bermuda has been formally approved. The ‘Important Marine Mammal Area’ (IMMA) stretches from the West Indies to the Barents Sea, covering the annual migratory route for North Atlantic humpback whales based on satellite telemetry analysis.
IMMAs are defined as discrete portions of habitat, important to marine mammal species, that have the potential to be delineated and managed for conservation. They are designated by the Marine Mammal Protected Areas Taskforce, supported by the Internation Union for the Conservation of Nature (IUCN). The IMMA process is science-led and carries no management obligations, though the designation can be used to justify arguments for conservation.
The proposal, based on satellite telemetry analysis from several sources, was put forward as part of the North Atlantic Important Marine Mammal Area (IMMA) workshop in Cancun, Mexico, in May 2024 by geographer Bea Smith, then part of Duke Marine Geospatial Ecology Laboratory (MGEL), with support from Fae Sapsford, Sargasso Sea Commission Marine Research Fellow. This proposal was reviewed by the participants of the workshop, including expert partners to the Sargasso Sea project Andrew Stevenson, a Bermuda whale researcher, and Dr Lea-Anne Henry, a reader in Marine Ecology at the University of Edinburgh.
The North Atlantic Humpback Whale Migratory Corridor has now been formally accepted as an IMMA following peer review. It will be added to the IMMA e-Atlas, a hands-on tool for use by conservation scientists, policymakers, the wider scientific community, and the general public to view important areas for marine mammals at a glance.
The migratory corridor IMMA also intersects with the Somers Isles and Adjacent Seamounts IMMA proposed by Andrew Stevenson and Dr Lea-Anne Henry based on their research in Bermuda, which focuses on the importance of the upwelling phenomenon created by the Bermuda platform for several species of marine mammals including Cuvier’s beaked whales, bottle nose dolphins, and sperm whales as well as humpback whales.
Humpback whales travel great distances each year past Bermuda on their way from breeding and calving grounds in the West Indies to feeding grounds in more northern latitudes. The numbers are increasing every year, and Grove et al reports “up to 1434 whales visited Bermuda annually from 2011-2020.”
This designation carries important implications for the conservation of the Sargasso Sea. Research from Duke MGEL shows that the shipping routes that have emerged in the Sargasso Sea intersect with humpback whale migratory routes, with obvious risks of collisions with cetaceans and of noise pollution which impedes whale communication.
Duke’s research also shows that mean vessel speed has slightly increased over time in the Sargasso Sea. At 15 knots, the probability of lethal injury to cetaceans is ~80%, meaning that keeping ships below that speed threshold would have beneficial outcomes when ships come into contact with cetaceans at the surface.
As part of its stakeholder engagement strategy under its Global Environment Facility (GEF)-financed project, the Sargasso Sea Commission has held two stakeholder engagement workshops with members of the shipping industry in order to explore voluntary measures that could be implemented to strengthen the stewardship of the Sargasso Sea, and will hold a third this February in Singapore.
The IMMA designation emphasizes the critical role this area plays for the life cycles of Atlantic humpback whales and highlights the importance of further discussion on the possible enactment of conservation measures for their benefit on the Sargasso Sea.
More about Sargasso Sea Commission Projects
The Global Environment Facility funded Common Oceans Sargasso Sea project is committed to facilitating a collaborative, cross-sectoral and sustainable stewardship mechanism to put in place a comprehensive conservation framework to protect the unique ecosystem of the Sargasso Sea. Led by UNDP, implemented by IOC UNESCO, and supported by a comprehensive network of partners, it brings together the regional fisheries management organizations, national agencies and intergovernmental organizations and initiatives, the private sector, civil society and academia.
Funded by the French Facility for Global Environment, and supported by the University of Western Brittany, Mar Viva, and the Sargasso Sea Commission, the ‘SARGADOM’ project focuses on two remarkable high seas sites – the Sargasso Sea in the North Atlantic (‘SARGA’) and the Thermal Dome in the Eastern Tropical Pacific (‘DOM’). The aim of the project is to contribute to the protection of biodiversity and ecosystem services, and to facilitate the development of hybrid ocean governance approaches for the two sites.
Learn more about the Sargasso Sea Commission on our website: sargassoseacommission.org