The sampling problem in benthic ecology
The importance of the role of benthic invertebrates in the bionomics of demersal fisheries is very considerable for it is almost entirely through their agency that the demersal fish are able to utilise as food the organic material in the deposits of the continental shelves (Longhurst, 1958a). Yet quantitative ecology of the benthos lags far behind that of the plankton, in a ratio that seems disparate with the bionomic—and certainly with the economic—importance of the two subjects; it is fairly clear that the reason for this relative neglect lies in the nature of the material and the difficulties inherent in an assessment even of an instantaneous standing crop. The benthic fauna is buried in, or attached to a substratum of varying consistency into which the gear must make uniform bites; the individual organisms are arranged patchily, both on a large and on a small scale; they may be extremely divergent in size and so sparsely distributed that much time will be expended in obtaining sufficient numbers for statistical treatment. The comparisons between this and a plankton sample with quantitative gear are so obvious as to need no enumeration.