Summary of current IMMAs

As of October 2020, 159 IMMAs have been identified following the hosting of six expert workshops in the regions represented in Table 1 below. There are an additional 24 candidate IMMAs (cIMMAs) and 129 Areas of Interest (AoI). Details of all these are in the searchable database and displayed on the e-Atlas. Table 1 shows the number of IMMAs by region.

Table 1 - Summary of the number of IMMAs, cIMMAs and AoI by Region
Australia, New Zealand and South East Indian Ocean3121346
African Atlantic1001
Extended Southern Ocean131721
European Atlantic1001
North East Indian Ocean and South East Asian Seas3073269
Pacific Islands2042044
Western Indian Ocean and Arabian Seas3732363
Grand Total15924129312

IMMA size

There is a huge range in size among different IMMAs, the largest is 2,861,819 km2 encompassing an area Prince Edward Island and Western Oceanic Waters in the Southern Ocean, and the smallest is 45 km2, the Akrotiri IMMA  which includes small breeding caves for the Mediterranean monk seal (Monachus monachus).

Criteria used to identify IMMAs

Table 2 provides a summary of the criteria that have been used to identify IMMAs: Criteria C, Key Life Cycle Attributes, which includes migration routes, reproductive areas and feeding areas has been the most frequently used criterion, and Criterion D, Special Attributes has been the least frequently used.

Table 2 - Summary of the criteria used to identify the 114 IMMAs identified as of January 2020 (note that one IMMA can meet multiple criteria, so the totals in the table are greater than 114).
CriteriaSpecies or Population Vulnerability


Distribution or Abundance


Key Life Cycle Attribute


Special Attributes


%of Total23243815

Figure 1 shows the number of IMMAs broken down by the sub-criterion applied.  After Criterion A (Species or Population Vulnerability (23%), the most frequently used sub-criteria were C1 (Reproductive Areas) (18%) and C2 (Feeding Areas) (16%).

Figure 1 – Number of IMMAs broken by subcriteria

Qualifying Species in each IMMA

The documentation for each IMMA includes a list of the qualifying marine mammal species that occur and that are fundamental to satisfying each criterion used in the IMMA identification.  Supporting species are marine mammal species that occur within the IMMA but which are not fundamental to satisfying the criteria.  Figure 2 shows the number of qualifying species listed for each IMMA.  The majority were identified on the basis of one or two qualifying species.

Fifty-eight different marine mammal species have been used as the qualifying species for an IMMA.  As shown on Figure 3, humpback whales (Megaptera novaeangliae), dugongs (Dugon dugon), Indo-pacific bottlenose dolphins (Tursiops aduncus), Sperm whales (Physeter macrocephalus) and spinner dolphins (Stenella longirostris) were the most commonly represented species.

Figure 2 – Number of qualifying marine mammal species listed for each IMMA

Figure 3 – Qualifying marine mammal species used to satisfy the IMMA criteria (only species listed as qualifying species more than 4 times are shown)