136 DISCOVERY REPORTS 



Perhaps the only animals playing a comparable ecological role in these southern waters are the 

 swarming anomurans Munida siibnigosa (White) and M. gregaria (Fabricius), with its pelagic post- 

 larval Grimothea stage, upon which, it has so often been recorded,i such a multitude of predators, 

 whales, seals, birds and fish, gorge and fatten in the lower latitudes of the Patagonian shelf and along 

 the coasts of New Zealand. Clearly, however, Rayner (1935) under-emphasises the importance of the 

 krill when he states that these other swarmers ' fulfil in the economy of the Falkland Islands region a 

 role similar to, but wider than, that of krill, Euphaiisia superba, in south Georgian waters '. For surely 

 it is the krill, in every sense, and above all geographically, that fulfil the wider role. 



Rayner's work on the growth of the Falkland species of Munida, as Hart (1946) observes, shows 

 that, as compared with E. superba, they are comparatively long-lived (5 years or more of post-larval 

 life in M. subrugosa) and are sexually mature from the end of the first year of post-larval life. It may 

 be, therefore, as Hart concludes, that the ' distinctive differences ' in pelagic life of the Patagonian 

 and Antarctic regions are ' affected by this difference in the life history of their respective key-industry 

 animals '. 



It has sometimes been suggested by commercial interests that these teeming and seemingly 

 inexhaustible fields of southern shrimps might themselves be harvested, with advantage to the whales 

 that for so long have suffered at the hands of the industry. For in addition to the oil and protein upon 

 which the whales build up their huge bodies the krill, especially in their eyes, provide a rich source 

 of preformed vitamin A^ which the whales concentrate and store in their livers. If, therefore, effective 

 measures could be devised for the capture and processing of the euphausians themselves a major 

 reduction in the wholesale slaughter might be expected to follow and the southern whale population 

 as a whole preserved safe from extinction perhaps for many years to come. As Fisher (1958) remarks, 

 however, so long as the whale stocks are allowed to survive through annual control of the catch, they 

 will continue to concentrate fat and protein in their bodies and vitamin A in their livers far more 

 cheaply and efficiently than any man-made krill-catching factory could do. ' Meanwhile ', he adds, 

 'the innumerable krill remain as a huge reservoir of concentrated vitamin A, on which all larger 

 marine animals, and ultimately man, may draw'. As Davis (1955) has said of the plankton as a whole, 

 its main value to man 'will undoubtedly remain an indirect value for a long time to come, in its role 

 as the primary food for larger animals '. No doubt it will. But no doubt too when the time comes it 

 will be to the immeasurable^^ wealth of plankton animals in the polar seas, and above all perhaps to 

 the southern krill, that one day he will turn and as Hardy (1930) wrote over 30 years ago, 'take both 

 food and power direct from these vast planktonic stores of solar energy '. 



Bogorov (1958) calls attention to the annual toll of organisms now being harvested from the sea, 

 observing that it has already reached the staggering figure of thirty million tons, adding that progress 

 in mechanisation and advances in fishery technique generally will soon set a limit to our exploitation 

 of the known, mainly onshore, fishing grounds, making it necessary in the near future, if overfishing 

 'with all its catastrophic consequences' is to be avoided, to exploit the riches of the world ocean in 

 distant waters. Again, perhaps, it might be to the Antarctic that the fisherman will turn, for no one 

 really knows what quantities of fish it may hold, or at any rate could hold, by virtue of the super- 

 abundance of its krill. 



It may indeed take a long time before such visions become fact, for as yet, as Jackson (1954) points 

 out, there seems little prospect of our developing a plankton harvesting industry that could be run 

 as an economic concern. Even so, as Baalsrud (1955) has emphasised, that is no reason why further 



1 Chilton (1909); Matthews (1932); Ommanney (1933); Hamilton (1934a); Rayner (1935); Hart (1946) et al. 



2 Thompson, Ganguly and Kon (1949); Batham, Fisher, Henry, Kon and Thompson (1951); Fisher and Kon (1959). 

 ' Perhaps some day, a long way ofF, it will be measurable. 



