(from "Chairman's Report of the Thirty-Eighth Annual Meeting")

13.1.1 Sperm whales
(a) Western North Pacific stock
The Scientific Committee now has new catch data coded and assessment models validated. Because of the time taken it had not been possible to run sensitivity tests, and the Scientific Committee was concerned that, once again, no assessment was possible and so it was unable to recommend a classification for this stock. It has made arrangements for work in the coming year, including coding of effort data, which should allow assessment to be carried out at the next meeting.

(b) North Atlantic stock
New sightings data from the Azores were noted with interest by the Scientific Committee.

Post-mortem examination of a sperm whale taken off Iceland in 1981 showed that nematodes can cause ulcers in the stomach which could be lethal. Ingested floating debris found in the small intestine could have affected the animal's fitness.

The Scientific Committee agreed that independent estimates of population size are needed.

Iceland and Denmark expressed their concern over marine pollution which could affect whale stocks.

(c) Research in the Galapagos and Sri Lanka
It is possible to study sperm whales at sea by following them closely and identifying individuals by natural markings. Results from these studies have implications for the population model used for sperm whales with respect to pregnancy rate and site fidelity of the whales. The Scientific Committee recommended support for a research proposal for continued studies of the social organisation of sperm whales.

13.1.2 Minke whales
(a) Southern Hemisphere stocks
The Scientific Committee paid most attention to an analysis of data collected during the 1984/85 IDCR sightings cruise in Area IV, particularly the results of the experiments conducted. A new analytical technique was developed and population estimates for the western half of the Area were calculated. It was recommended that results from earlier cruises be analysed in the same way. The Scientific Committee recommended a further cruise in 1986/87 in Area II.

The size at recruitment had been calculated from Japanese data and a similar analysis was recommended for the Soviet catch. Two views about current recruitment rates were expressed - that there is no basis for estimating them or that it has stabilised at 2 - 4%. Marking data were recommended for coding preparatory to a full review.

Effort data from the Brazilian fishery were used with the standard assessment model, but because they showed an increasing trend led to no estimates. Some members of the Scientific Committee therefore concluded that catches were having very little effect on this stock, while others believed that the data series did not provide a useful index of abundance.

The unbalanced sex ratio in the catches must continue to be taken into account. No new population estimates were calculated for other Areas, but attention was drawn to the estimates calculated last year.

Because of the variety of views on the stock status and trends the Scientific Committee was unable to recommend classification for these stocks. Similarly, there was no agreement on whether there was a basis for estimating replacement yields or believing that the current rates are 2 - 4%.

In discussion in the Technical Committee it was established that the results of the experiments carried out on the 1985/86 cruise will be available and analysed before the plans for the next cruise are made.

(b) Northeastern Atlantic stock
The Scientific Committee considered a number of questions concerning catch records, catch per unit effort (CPUE) series, fitting methods, and population dynamic models common to all North Atlantic stocks. The Scientific Committee agreed to use a revised assessment model for estimation of depletion levels and replacement yields for all North Atlantic stocks.

For the northeastern Atlantic the catch history has changed over the years, and two estimates of the recruited stock size used for analysis were 22,000 and 30,000. Assessments ranged from projections of depletion between 4 - 85% with yields of 0 - 1,502.

As a result, some members of the Scientific Committee believed that the stock is depleted to below the threshold for protection level, while others believed it not possible to classify the stock. It was noted again that there are general difficulties in interpreting CPUE series, and as yet no complete model to explain them. The Scientific Committee made recommendations for further analysis requiring new information, particularly on age and length data and the continuation of sightings surveys, preferably coordinated throughout the area.

In the Technical Committee the USA noted the widely differing results from the different data series both for this stock and for the Central Atlantic stock discussed below. It also noted that the Scientific Committee recommended "that to assess this stock effectively age data and/or length composition are required as well as closer analyses particularly with regard to age specific selectivity in the catch". The USA also re-emphasised the Scientific Committee recommendation that further sighting surveys be carried out. In the past, data have been provided in an aggregated form to the Bureau of International Whaling Statistics and the Commission. In order to meet the full requirements of the Schedule, the USA requested Norway and Iceland to provide the data required by the Schedule, including lengths of individual whales by sex, for their respective past and present operations in the Northeastern and Central Atlantic so that needed analyses can be carried out to resolve the status of these stocks. Australia, India and the UK supported this position.

Norway recalled that in 1983, there had been a consensus in the Scientific Committee, on the basis of an in-depth analysis by Norwegian and other scientists, that a catch of 635 was appropriate. This drastic reduction in the harvest had been accepted by Norway. Subsequently, the attention of the Scientific Committee had turned from a consideration primarily directed towards replacement yield as a basis for management advice to a consideration of development trends in the stock as compared to initial stock level. This had led the Scientific Committee to present an ambiguous recommendation last year, suggesting classification of the stock as PS, but at the same time suggesting as an alternative that catches should not exceed 360 in 1986. Norway noted that the national catch limit of 350 was within this figure. In response to questions, Norway noted that submission of catch data to the Commission had followed a format agreed with successive Chairmen of the Scientific Committee. Norway was of course ready to provide to the Commission the further information which had now been requested.

The UK was glad to note the latter statement, and also expressed the hope that those countries which had maintained objections to Schedule paragraph 10(e) would be able to withdraw them as soon as possible. Some countries have confirmed their intention to abide by that decision now or at a future date. It urged Norway to consider its position very carefully in the light of the damage it may be doing to this particular stock and its national reputation. Norway responded by recalling the deep divergence of scientific views over its stock, and it took its decision with the greatest seriousness.

(c) Central North Atlantic stock
The Scientific Committee used the new assessment model on four CPUE series which were possibly confounded by several problems similar to those in the Northeastern stock, such as that of the mixed species fishery. The Scientific Committee could come to no unanimous agreement regarding the appropriate CPUE series. Some members believed the stock should remain without classification while others believed it should be classified as a Protection Stock.

New Zealand expressed its concern over this situation in the Technical Committee, and indicated that in the absence of further information, there would be a strong case for classifying as a Protection Stock.

Iceland stated its view that the stock is above the Protection Stock level. Noting the bias in recent data it considered any change in classification premature. It will carry out further analyses and has plans for aerial surveys this year in coastal Icelandic waters and a three vessel survey on a larger scale in 1987.

(d) Okhotsk Sea - Western Pacific stock
A new assessment submitted to the Scientific Committee this year expressed doubt about the biological identity of this stock, and reached different conclusions from an assessment presented last year using data similar in principle. The Scientific Committee recommended that a revised analysis should be presented next year using correct catch series. There is no scientific basis for classification of this stock, or for estimating current replacement yields at present.

(e) Sea of Japan - East China Sea - Yellow Sea stock
Revised catches and CPUE series were used with two simple models with widely different assumptions about the stock recruitment relationship. These gave similar estimates of the degree of depletion of this stock to about 37 - 38% of its initial level in 1962. It was again recommended this stock be a Protection Stock but no guidance could be given concerning replacement yields. A full analysis was recommended for next year.

13.1.5 Bryde's whales in the western North Pacific
The Scientific Committee regretted that no new assessments were presented this year. It recommended that this stock should be given priority at the next meeting, and that the effort data now with the IWC should be entered into the IWC database.

13.1.3, 13.1.4. 13.1.6 Fin, sei and bottlenose whales
The Scientific Committee made no new assessments of these stocks at this year's meeting.

13.1.7 Protected species
The Scientific Committee strongly recommended continued monitoring of the South African right whale population as a means of obtaining information on the population responses of whales at low densities. It also recommended that numerical simulation studies on the effect of unbalanced age structure on observed rates of increase in such stocks be undertaken.

The Commission, on the recommendation of the Technical Committee, noted the summarised information on all the other stocks not specifically considered by the Scientific Committee this year.

13.2 Action arising
13.2.1 Okhotsk Sea - Western Pacific stock of minke whales
The Technical Committee agreed by consensus to recommend that this stock should be unclassified, as the Scientific Committee had been unanimous in its recommendation. This was agreed by consensus in the Commission, which took note of a statement by Japan that this stock had not been a priority Item for the Scientific Committee this year and so it had not prepared specific material. This will be provided next year, and Japan recorded its preference to make no change in classification.

13.2.2 Dates in the Schedule
On the recommendation of the Technical Committee, the Commission agreed to continue the whale stock classifications and catch limits not otherwise modified at this meeting by inserting the dates of the 1986/87 pelagic season and the 1987 coastal season in the appropriate Schedule paragraphs and tables.

13.2.3 Data required
Switzerland expressed its belief that the advice of the Scientific Committee is crucial to the work of the Commission. It noted many references to incomplete data, statistics and information, and urged Contracting Governments to comply with the reporting requirements under the Convention and Schedule. The Netherlands endorsed this view, and urged submission of data before the next meeting of the Scientific Committee to allow analyses to be completed in advance of the meeting. Sweden also supported these views.

In order to clarify the situation, the USA asked that the Secretary provide a document for the 1987 meeting setting out exactly what detailed data are available and being received regularly from 1976 to the present with respect to the requirements of Schedule paragraphs 27 and 28. This was agreed.

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