6. Condition of the Stocks

(from "Chairman's Report of the Thirteenth Meeting")


The general condition of the whale stocks as estimated from the information available was reported on by the Scientific Committee.

With regard to the Antarctic stock, the Committee continued to feel considerable anxiety about the most important species. Their estimate of the position in this field may be summarized as follows:

(i) Blue Whales There is evidence of a further decline in this species and the view that total protection was required in the Antarctic for several years in the first instance was put forward more strongly than ever.
(ii) Fin Whales There are indications of a decrease in this stock extending over some years past.
(iii) Humpback Whales The stock in Group IV (Antarctic Area IV and west coast of Australia) is thought to be in a serious condition. Subject to revision when population estimates become available, the Scientific Committee consider the stocks to be now at a level at which only one to two hundred whales should be taken annually. There is also evidence of a decline in the stock of Group V (Antarctic area V and east coast of Australia and New Zealand) which, it has been suggested, with the reservation already mentioned, might not be capable of giving a sustained yield of more than 1,000 whales each year. The stocks in Group II (Atlantic region) and Group III (West Indian Ocean) have been substantially depleted and would not be expected to support any extra exploitation.
(iv) Sei Whales Increased catches of this species are being made but there are no data on the state of the stock. Such information is needed and more general research and marking is required for this species.
(v) Sperm Whales There has been a fall in the average length of sperm whales caught in the Antarctic but there is need for further general research on this species before the state of the stock can be defined.
(vi) Blue Whale Unit Limit The available biological evidence indicates that the overall catch limit in recent seasons has permitted excessive catches. The overall limit itself, however, is thought to be undesirable as it could permit the excessive exploitation of one stock while others might be under exploited. As soon as population studies allow stocks to be properly assessed, each stock should be made subject to special conservation measures.
With regard to the state of the stocks outside the Antarctic, the Scientific Committee had no substantial report to make. The Committee was opposed, however, in the absence of further scientific information, to any measures likely to reduce the present minimum size of whales on the grounds that the minimum sizes had been fixed in order to give protection to immature animals that had not yet reproduced themselves and, in the present state of knowledge, this seemed a safe conservation policy.

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