252 POPULATIONS OF THE SEA 



work of this kind has already been done, though perhaps not 

 consciously from this angle, e.g., Wilson's study of the factors 

 affecting the settlement and metamorphosis of polychaete larvae 

 (various papers, see Wilson, 1958). In all these problems of larval 

 settlement, and some (e.g., fouling) are of great economic im- 

 portance, there is the continual question : Do they settle in a certain 

 spot because they choose to do so or because purely fortuitous 

 circumstances compel them? How far can a fish larva come to 

 terms with its environment as was asked earlier, by taking ad- 

 vantage of this eddy or that turbulence and with what success? 

 The dispersal of fish larvae by wind-induced and other currents 

 has been the subject of many papers, in which it has been generally 

 assumed that the larvae are transported passively by and helplessly 

 with the current. Bishai (1960), also working at Cullercoats, has 

 established that even newly hatched herring (Clupea harengus L.) 

 larvae orientate themselves into and are able to maintain them- 

 selves against current velocities of between 0.6 cm and 1.0 cm/sec 

 and that against higher velocities they still orientate head into 

 the current and drift less than the current velocity. There is 

 clearly need for much more precise observation here and it might 

 well be that the fine structure of the current systems of the seas 

 are more important in larval distribution, through the stimulation 

 of local effort, than gross pattern. 



Only a few of the possibilities open to ethology of throwing light 

 on biological oceanography have been indicated here. The modern 

 ethologist, however, regards the exploration of innate behavior as 

 the spearhead of his approach. In practical research terms this 

 means first the drawing up of ethograms, systematic descriptions 

 of instinctive movements (for example, Baerends and Baerends- 

 van Roon 1950; Morris, 1958). This is an occupation which is not 

 to everyone's taste, and for it to be successful there must be the 

 enthusiasm and the patience to watch animals closely for long 

 periods often under great discomfort. Moreover, if he is to occupy 

 himself with marine animals, he will want more facilities for quiet 

 observ'ation than are at present generally available to him at the 

 marine laboratories.. 



