THE FUTURE OF WHALES AND WHALING 4O9 



of a British Antarctic expedition based on Graham Land. On crossing the 

 frozen Crown Prince Gustav Canal between James Ross Island and 

 Graham Land, they noticed holes in the ice, which Little Piked Whales 

 had used all their strength to keep open, so that they could come up for 

 air. They also observed Killers and at least one Berardius. The whales had 

 obviously been cut off from the open sea when the Canal had frozen, 

 and in the course of a few weeks holes of a diameter of 200 yards were seen 

 to shrivel down to a few yards. The expedition was convinced that the 

 fate of these whales was sealed. 



Some Cetaceans, e.g. Belugas, continue to fall victim to Killers even 

 when they are fully grown, and many species of dolphins occasionally 

 perish through mass strandings (see p. 199). However, mass strandings 

 are probably spectacular rather than of serious consequence to the 

 continuance of the species. On the contrary, all we know about 

 Cetaceans in general and about big whales in particular indicates that 

 these animals live under optimum biological conditions, i.e. they are not 

 seriously threatened by enemies, by parasites, by serious diseases, or 

 by climatic effects, and that they have adequate supplies of food. 



They are, of course, afflicted with parasites (see Chapter 2) ; after wean- 

 ing^'fïiöst porpoises, especially, become infested with parasitic round- 

 worms {Strongylidae) which they swallow with the fish. These worms are 

 then found in the air passages, in the middle ear, and in the cavities 

 surrounding the ear bone, and occasionally also in the heart and blood 

 vessels. It is, however, quite possible that only heavily infested animals 

 are caught or run aground and that healthy specimens rarely do. Dudok 

 van Heel has stated that, in any case, porpoises succumb to parasitic 

 infections more readily when they are undernourished. 



Other Odontocetes, and Sperm Whales in particular, are always found 

 to be infested by intestinal parasites, and especially by nematodes and 

 tape-worms. Rorquals, on the other hand, suffer less from these than from 

 the nematode worm Crassicauda crassicaiida, which infests their kidneys and 

 ureters. Parasites are not at all unusual in wild animals, few of which 

 suffer serious consequences once they have survived early infancy, when 

 some sort of equilibrium between host and parasites is usually established. 



Nor are whales subject to serious illnesses. True, Ross Cockrill, Rewell 

 and Willis, and Stolk have described a number of inflammations and 

 tumours and two cases of cirrhosis of the liver in Rorquals, and in 1959 a 

 case of pneumonia was diagnosed for the first time in a Fin Whale (South 

 Georgia), but such conditions are certainly very rare. Internally, on their 

 organs or between their muscles, Rorquals occasionally have round or 

 oval masses which can weigh anything from a fraction of an ounce to a 

 few pounds (see Fig. 225). These masses, - known as 'husks' - consist of a 



