202 POPULATIONS OF THE SEA 



acquired in the course of the classical oceanographic expeditions 

 such, for example, as the Challenger voyage in 1873-1876, or the 

 Meteor expedition of 1925-1927. Further knowledge has been 

 added from the normal working cruises of many laboratories. 

 Special programs have sometimes been organized such as the 

 cooperation between European laboratories from 1902 to 1908 

 which led to the important charts and notes on the distribution 

 of plankton published by the International Council for the Ex- 

 ploration of the Sea. 



All these surveys, however, were of limited duration, mostly 

 lasting from one to three years, or were dependent on sampling 

 at irregular intervals of time and space from ships using a variety 

 of collecting gear. The distributions which are charted from such 

 sources are static; that is, there is little or no information about 

 gradients of abundance, or of seasonal and annual changes in the 

 location of the center or range of distribution of an animal. Or 

 as Hedgpeth (1957a) has said, "much of the current literature of 

 biogeography is . . . systematic and historical rather than ecologi- 

 cal in its approach." On the other hand, Darlington (1957) criti- 

 cized the tendencies to make zoogeography a subdivision of 

 ecology and to glorify historical zoogeography at the expense of 

 the study of present "static" distributions. 



The attempt to draw fine distinctions between the two sub- 

 jects seems to me to be as unprofitable as discussing whether 

 biochemistry is biology or chemistry. Ecology and biogeography 

 are no more than convenient words for ov'erlapping and ill-defined 

 disciplines, each of which contributes toward knowledge about 

 biological processes; they provide tools which can be distorted or 

 molded into new shapes for each new problem. Many problems 

 in ecology can be answered only from a knowledge of the dy- 

 namics of distributions. 



The difficulty of sampling pelagic organisms has led to a special 

 weakness in the present static distributions, which usually show, 

 by dots on a chart, all the positions in which an organism has 

 been captured. Frequently the location of these dots appears to 

 reflect the activities of the great expeditions or the proximity of 



