Important Marine Mammal Areas

Lead: Giuseppe Notarbartolo di Sciara, Tethys Research Institute


Marine mammals tend to be large, conspicuous and charismatic, eliciting awe, curiosity and admiration from humans, who have for centuries included them in folklore and rituals.  Yet for the most part, marine mammals live their lives underwater, preferring undisturbed natural environments and showing sensitivity to perturbation.  Many species depend on shallow fishing grounds and beaches to breed, while others spend their lives travelling the global ocean or diving to great depths to feed.  Some species of marine mammal have complex social structures and acquired behaviour patterns that are passed on from one generation to the next.  Like most long-lived animals, they are slow-growing, late to mature, and invest heavily in the upbringing of few offspring.  This combination of characteristics renders them vulnerable to – and slow to recover from – sudden, unpredictable or prolonged perturbations to the environment.

The human fascination with marine mammals can work in favour of other species too, as any effort spent in protecting marine mammals, given their size, distribution and range, will encompass the needs and protection of countless other organisms.  As such, marine mammals can be considered as catalytic species, their conservation promoting, entraining and augmenting that of entire ecosystems, their functions and services.  Therefore, knowledge of areas that are important for marine mammals should facilitate the balancing of human activities in the oceans with the imperative of conserving marine biodiversity.

This work is intended to support the identification of Important Marine Mammal Areas (IMMAs) – discrete portions of habitat, important to marine mammal species, that have the potential to be delineated and managed for conservation.  The concept of IMMAs was developed by the IUCN Marine Mammal Protected Areas Task Force, following an extensive consultation period, for use as a layer of information for consideration by governments, intergovernmental organisations, conservation groups, and the general public.  It is hoped that IMMAs will eventually be a standardised input to the EBSA process.

During the course of the work, five regional workshops are being organised, covering the Indian and South Pacific Oceans, thus expanding the areas of the global ocean assessed against the IMMA criteria.  Attending experts will apply scientifically agreed criteria to identify IMMAs, using as a starting point data already identified in the EBSA process, and submit their findings to a rigorous process of review and eventual designation.  Given the notion that marine mammals are catalytic species, the creation of a network of IMMAs represents a cost-effective approach to large-scale conservation of marine biodiversity and whole ecosystems.


  • To identify Important Marine Mammal Areas (IMMAs) in the Indian and South Pacific Oceans with data from EBSA descriptions.
  • Propose a network of IMMAs to the CBD and CMS.


This work involves the following steps:

  • Organisation, coordination and execution of five regional IMMA workshops covering the Indian and South Pacific Oceans, each resulting in the production of a workshop report that lists and justifies candidate IMMAs against agreed criteria.
  • Peer-review and validation of candidate IMMAs identified in workshop reports according to IUCN protocols.
  • Identification of three target areas within the regions covered by the workshops to use as pilot areas for the analysis of threats to marine mammals and devise appropriate conservation tools and management plans.
  • Engagement with stakeholders at the national and international level for the selection of conservation tools and optimum management plans, including network approaches, for the selected pilot areas.


By highlighting the presence of marine areas of particular ecological value, IMMAs will serve the function of promoting the conservation of a much wider spectrum of species, biodiversity and ecosystems, well beyond the specific scope of conserving marine mammals.  Indications of the presence of IMMAs will help to identify marine areas valuable in terms of biodiversity during the process of Marine Spatial Planning.  IMMAs and the process by which they are identified will also become an effective way of building institutional capacity at the international and national levels, with particular benefit to isolated or remote communities where formal expertise is scarce and the cultural significance of marine mammals is often high.  Marine mammals are indicators of ocean ecosystem health and thus will support both the CMS’s resolutions and the CBD’s portfolio of EBSA descriptions as a basis for promoting environmental protection and developing management plans for specific areas in the world’s oceans.

Progress to date

Two of the five scheduled regional IMMA workshops in the southern hemisphere have been convened, one in Apia, Samoa, covering the southwest Pacific Ocean, the other in Kota Kinabalu, Malaysia, covering the northeast Indian Ocean and the South East Asian Seas region.  Together, both workshops have proposed 73 candidate IMMAs (29 and 44, respectively) and several Areas of Interest (AoI) for future consideration as further supporting data become available.  In addition, an IMMA and AoI proposed during the workshop in Apia have been identified as a pilot area for the analysis of threats to marine mammals and the devising of an appropriate management plan by local experts and stakeholders.  Another such area in the Andaman Sea is also under consideration.

The IMMA concept, its processes and its results to date were presented at the 12th Conference of the Parties to the Convention on the Conservation of Migratory Species of Wild Animals (CMS) in October 2017.  Subsequently, the CMS adopted a resolution – the ‘IMMA resolution’ – that recognises this novel process to formalise areas of the seas that are important for marine mammals.

With the concept and utility of IMMAs now recognised, the GOBI-IKI led initiative has attracted further support, with an additional IMMA workshop being organised for the Southern Ocean, sponsored by the French Biodiversity Agency.