Marine Work in Ceylon

Abstract

THE Administration Report of the Marine Biologist, Mr. A. H. Malpas, for 1935 (Part IVEducation, Science and Art (G), Marine Biology: published May 1936) shows that the inspection of the pearl banks again reveals an absence of sufficient spatfalls of both southern and northern paars to provide fisheries within the next three years, despite the presence of sexually mature oysters in sufficient quantity to repopulate the banks. Although conditions of the kind have always been attributed to adverse currents carrying away the free-swimming larvse into deep water where they are lost, there seems to be some justification for the belief that hydrobiological conditions in the Gulf of Manaar are the more important factors in. so far that adult pearl oysters can be stimulated to maximum spawning only under particular conditions of salinity and temperature, which are the exception, rather than the rule, and therefore the pelagic larvae are not developed in sufficient numbers to produce spatfalls except when these conditions obtain. The scheme referred to in last year's report for the establishment of a Fisheries Research Station at Colombo combined with an aquarium has been modified, and the suggested aquarium available for the public abandoned, a more comprehensive scheme with experimental aquaria and provision for a fish hatchery on a fairly large scale being substituted. This will provide not only for facilities for investigating the bionomics of marine and freshwater animals of economic importance but also for experiments in hatching and rearing the more important freshwater food fishes.