IWC Scientific Committee on Maui dolphins

19 Jun 2015

IWC Scientific Committee reports humpback whale recovery,
developments in management of aboriginal whaling, and new work
on endangered Maui dolphins and the vaquita.

Recovery of humpbacks in the Southern Hemisphere, progress in the management of aboriginal whaling, a collaboration with New Zealand on Hector’s and Maui dolphins, and new management information for the critically endangered vaquita are just some of the developments recorded by the Scientific Committee of the IWC in its annual report, published today.

The report is the work of approximately 200 experts who form the IWC Scientific Committee and meet each year. Over two weeks, a broad, ongoing programme of work is first evaluated and then developed. This incorporates fieldwork conducted all over the world, and complex computer modelling to understand the status of the world’s cetacean populations and their sustainability in the face of many threats. The implications of whaling (both indigenous and under special (scientific) permit), environmental concerns like climate change and chemical pollution, and direct human impacts such as ship collision were all on the agenda at the 2015 meeting in San Diego.

Evidence of the continued recovery of humpback whales in the Southern Hemisphere was one of the highlights of this year’s meeting. An eight year review of their status was completed and showed total numbers of around 97,000, contrasting with a low due to whaling of around 7,000, and a pre-whaling total of around 140,000. Different patterns of recovery have been observed in different populations, with those off the east coasts of South America, Africa and the west coast of Australia almost fully recovered, whilst those off Brazil and in the Oceania region are still recovering, but more slowly.

Developments were also reported in management of aboriginal whaling. The Commission continues to regulate a number of small-scale, indigenous hunts and the Scientific Committee has been developing long-term, safe and precautionary ways to estimate sustainable catches for each one. The aim is to complete this complex task by 2018, when each hunt quota will be considered for renewal by the Commission. This year the Committee completed the task for the Greenlandic bowhead whale hunt, the sixth of eight hunts, and reported that it’s on track to complete the final two (Greenlandic fin and common minke whale hunts) ahead of the 2018 deadline.

The Scientific Committee also provides advice to member governments on conservation issues concerning small cetaceans (dolphins and porpoises). Particularly serious concerns remain over the survival of the vaquita in Mexican waters, and the Hector’s dolphin (especially the Maui dolphin sub-species) of New Zealand. For both species, the major problem is by-catch in fishing gear.

For Hector’s dolphins, some progress was made this year with an expert group established by the Committee to work with local scientists. This collaboration will re-analyse existing data and produce an agreed abundance (population) estimate for the Hector’s and Maui dolphins which it’s hoped will help inform policymaking.

Having heard that a continuing decline means there may be as few as around 100 vaquita left, the Committee commended the Mexican government for its recent introduction of a two year ban on gillnets in the vaquita’s range. However it stressed that the ban should be made permanent and enforcement strengthened. It also urged the USA and China to do all they can to stop the illicit trade in totoaba, the endangered fish targeted by an illegal fishery whose gillnets accidentally catch the vaquita. The swimbladder of the totoaba is smuggled out to fetch extremely high prices in China.

Attracting some media attention at this year’s meeting was the issue of special permit (scientific) whaling and Japan’s proposal for a new special permit programme in the Southern Ocean, known as NEWREP-A. An Expert Panel had already met to assess this proposal in February. Their report and Japan’s response to it were examined by the Scientific Committee at the meeting in San Diego.

It was not possible for the Scientific Committee to reach a consensus view of the overall programme and so the report contains a summary of the discussion, highlighting areas of agreement where they existed (all recognised the value of the Expert Panel’s report) and concise statements of the differences of opinion where agreement did not exist; some scientists believed that the additional information provided by Japan was sufficient to allow the programme to go ahead as planned and others did not. All recognised the importance of continuing to work on additional analyses.

In total, the thirteen sub-committees of the Scientific Committee considered more than 100 research and working papers during two weeks of parallel sessions and plenaries. This is just a flavour of the breadth of work covered, more of which will be highlighted on the IWC website over the coming weeks.

To read the Scientific Committee report click here.

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