The 1946 Convention does not define a 'whale', although a list of names in a number of languages of a dozen whales was annexed to the Final Act of the Convention. Some governments take the view that the IWC has the legal competence to regulate catches only of these named ‘Great Whales’. Others believe that all cetaceans, including the smaller dolphins and porpoises, also fall within IWC jurisdiction.

Traditionally, those species not considered to be one of the ‘Great Whales’ are called ‘small cetaceans’ even though some of them can be as large as a minke whale (the smallest Great Whale). Common names often end in ‘whale’, ‘dolphin’ or ‘porpoise’ although there is no formal definition of each – for example the killer whale, Orcinus orca, is in fact a member of the family Delphinidae.

The Commission has agreed that the Scientific Committee can study and provide advice on small cetaceans and the Committee has established a sub-committee on small cetaceans which has operated since 1979. Like the Great Whales, small cetaceans are potentially vulnerable to a number of anthropogenic threats including bycatch in fishing gear, hunting, pollution, habitat degradation, coastal and offshore developments and climate change.

Despite the different views of the member countries over the question of legal competence, the IWC does recognise the need for further international co-operation to conserve and rebuild depleted stocks of small cetaceans. It has encouraged countries to seek scientific advice on small cetaceans from the IWC and also invited IWC member nations to provide technical or financial assistance to countries with threatened small cetaceans stocks. The IWC has also established a very successful voluntary fund to encourage research projects focussed on small cetacean conservation with an emphasis on capacity building within developing countries.

Each year the Scientific Committee, through its sub-committee on small cetaceans, identifies priority species/regions for review. Topics considered under such reviews include distribution, stock structure, abundance, seasonal movements, life history, ecology, status, potential threats and directed and incidental takes. A list of the sub-committee’s primary topics and recommendations can be found here.

1. the recovery of the vaquita – a critically endangered species of porpoise endemic to the Gulf of California, Mexico;
2. use and effectiveness of bycatch mitigation measures e.g. acoustic devices, to reduce the large numbers of small cetaceans incidentally caught in fishing gear;
3. cooperation with ASCOBANS on implementation of a recovery plan for harbour porpoises in the Baltic Sea;
4. updates of progress on any previous recommendations made by the Scientific Committee.

Representatives from the Scientific Committee are invited to attend as observers at meetings of ASCOBANS, ACCOBAMS and CMS amongst other international organisations, to facilitate cooperation on matters of small cetacean conservation.