431 



Before reasonable estimates of density distribution can be obtained, compre- 

 hensive catch and effort data have to be available. At present, certain statistical 

 data are generally iinavailable for large cetaceans caught off Spain, Chile, 

 Peru, Korea, China, Brazil, and for the operations of a fleet of unlicensed 

 whalers in the Atlantic. There are also inadequate data for animals caughit 

 in native and aboriginal fisheries. Better biological figures (length, sex, fetus, 

 and month of capture) and effort information are needed for all minke, bottle- 

 nose (Hyperoodon and Berardius separately), killer, pilot, and beluga fisheries. 

 There are incomplete data for beluga and nar\vhal fisheries in the Arctic and 

 no data for pilot whale catches at Okinawa, for example. Some of these figures 

 are handled by the Bureau of International Whaling Statistics already and 

 it is recommended that this bureau or some other central agency should handle 

 this extra work. In areas where a fishery involving small cetaceans is in operation, 

 provisions should be made for the collection by regional bodies of catch data 

 such as "species," niimbers and, if possible, tonnages killed. 



To obtain density estimates, more sighting work should be carried out by 

 scouting vessels and those engaged in marking, especially in regions where no 

 catching is done. Data for minke, killer, pilot, and all bottle-nose species should 

 be collected. In addition, annual trends in the abundance of protected species 

 should be monitored in as many areas as possible. Plots of regions of high density 

 give indications of areas %rtthin which a stock may be found. These preliminary 

 hypotheses can then be tested using one of the other four techniques. The cor- 

 relation of high densities with existing oceanographic information may also 

 assist in provisional estimates of stock boundaries. 



The working group gives high priority to the use of biochemical methods, 

 such as electrophoresis, immunology, and enzyme typing, as once the techniques 

 have been established, relatively rapid results can be obtained. The group assigns 

 the following priorities for this work : 



1. Spenm whales worldwide, especially in the Southern Hemisphere. 



2. Sei whales, Antarctic and North Pacific. 



3. Fin whales, Antarctic and North Pacific. 



4. Mn whales. North Atlantic. 



5. Medium-sized cetaceans, Noirth Atlantic. 



6. Minke whales, Antarctic. 



7. Bowheads, Pacific and Atlantic Arctic. 



This technique is highly desirable for other medium-sized and for small ceta- 

 ceams where fresh material may be readily available. 



Independently of any biochemical method, it is recommended that marking 

 of all cetaceans should be developed or intensified. The use of standard Discovery- 

 type marks for large mysticetes should be continued. Further trials of more 

 efficient streamer marks using larger and more conspicuously colored streamers 

 are required. There is a need for test firings of increased-charge marks into 

 sperm whale carcasses. The .410 Discovery-type marks also should be brought 

 into wider use for calves and minke whales. This type of marking could also 

 be carried out by non-whaling scientists from recognized institutions, and 

 restnicted to commercial species. Large spaghetti and other tags seem the most 

 useful for the bulk marking of medium-sized and small cetaceans, especially in 

 areas where there is a fishery. EJxperimental studies using radio-telemetry 

 packages, freeze-branding and laser beams should be encouraged. Whenever 

 possible, double marking, particularly using the Disoovery-type .410 or other 

 suitable tags, should be carried out on these animals. It is essential to consider 

 the question of a central agency to coordinate the marking information. Priorities 

 for species and areas are the same as those assigned for biochemical methods. 



In areas where other methods are not available, the use of morphometries is 

 recommended. Certain simple morphological characters such as right whale cal- 

 losities, flipper and baleen colorations in minke whales, the shape of Bryde's 

 whale baleen plates, and the detailed documentation of color patterns in Del- 

 phinidae may all prove useful. Biological indicators such as external parasites 

 and scarring, viral and bacterial flora, and possible dialects in vocalization may 

 have a limited value. 



In conclusion, the working group on regional populations recommends that 

 research efforts be concentrated on the following problems : 



1. The development of biochemical techniques for identification of popula- 

 tions. 



2. The intensification of marking of large cetaceans and the development of new 

 marks for all cetaceans. 



