The IMMA concept, developed by the IUCN Joint SSC/WCPA Marine Mammal Protected Areas Task Force (‘MMPA Task Force’ or ‘Task Force’), is modelled on the successful example of the BirdLife International process for determining ‘Important Bird and Biodiversity Areas’ (IBAs). After extensive scientific and public consultation between 2013-2015, eight criteria or sub-criteria, divided into four main categories were developed. These criteria and sub-criteria are meant to capture critical aspects of marine mammal biology, ecology and population structure and they encompass vulnerability, distribution, abundance, special attributes and key life cycle activities. These criteria are not hierarchical in design but it is advised that prospective IMMAs are assessed against each criterion sequentially in the given order. Therefore, any candidate need only satisfy one of the listed criteria and/or sub-criteria to successfully qualify for IMMA status. Though they cover a range of important attributes, and redundancies between them have been removed, there are some overlaps in the differing criteria that remain to assist assembled experts to identify IMMAs efficiently from that evidence best available.
A brief outline of the IMMA selection criteria are as follows below, and the full guidance dcument on the use of selection criteria for the identification of Important Marine Mammal Areas (IMMAs) is here.
Criterion A – Species or Population Vulnerability
Areas containing habitat important for the survival and recovery of threatened and declining species.
Criterion B – Distribution and Abundance
Sub-criterion B1 – Small and Resident Populations
Areas supporting at least one resident population, containing an important proportion of that species or population, that are occupied consistently.
Sub-criterion B2 – Aggregations
Areas with underlying qualities that support important concentrations of a species or population.
Criterion C – Key Life Cycle Activities
Sub-criterion C1 – Reproductive Areas
Areas that are important for a species or population to mate, give birth, and/or care for young until weaning.
Sub-criterion C2 – Feeding Areas
Areas and conditions that provide an important nutritional base on which a species or population depends.
Sub-criterion C3 – Migration Routes
Areas used for important migration or other movements, often connecting distinct life-cycle areas or the different parts of the year-round range of a non-migratory population.
Criterion D – Special Attributes
Sub-criterion D1 – Distinctiveness
Areas which sustain populations with important genetic, behavioural or ecologically distinctive characteristics.
Sub-criterion D2 – Diversity
Areas containing habitat that supports an important diversity of marine mammal species.