MARINE LIFE

Hokitika Guardian, 13 January 1930, Page 2

MARINE LIFE

THE FISHING INDUSTRY

ITS SCIENTIFIC STUDY,

WORK AT PORTOBELLO.

Fi-om both economic and scientific points of view! an intensive work in the study of the life history of fish on the Otago Coast still lies before the marine fisheries investigation station at Portobello. ‘ §inte it was opened 26 years ago Portobello station lias made many valuable contributions to the science of marine life and the economic advancement of the fishing industry. A wider vista of virgin field opens out now, and with the arrival from Auckland of Air David H. Graham at Portobello as biologist, unrelenting pioneer work of research will be initiated. The station, in Mr Graham’s opinion, has every chance- of becoming more widely known, and he sees in the work before him almost unlimited opportunity of providing specimens and knowledge for students of universities and schools, not only in New Zealand, but overseas, and through the study of life history of coastal waters, a tremendous contribution to the fishing industry, an economic natinal industry.

Herring ov\a have not yet been received, as they have not been carried overseas, but European lobsters, crabs and turbot (the finest of all European flat fish) have been successfully brought to Phrtobello nncl liberated in New Zealand seas.

Lobsters have been kept continuously more or less at the station since 1907, A few adults have I'qen liberated, and larvae to the number of probably SJ,QOO,060 have been set adrift year after year. The present stock of lobsters, a total of 36, which are in one of the big ponds, was brought out in 1928. The females are all egg-bearing, carrying o» the average over 10,090 eggs apiece. All the lobsters imported to Portobello have been about ten years old, and they have lived for another thirteen years. None of the liberated lobsters or their progeny has yet been recovered. Larval lobsters swim foi only three weeks and, then seek the bottom. However, the station board has strongly expressed the opinion that the experiment of lobster naturalisation is likely to prove successful. The majority of the larvae probably come to rest at the sea bottom at a compai atively short distance from the point of liberation, partly in Blueskin Bay, and partly in sheltered localities (such as Shag Point, Moeraki) within three weeks of liberation. Both adult European crabs and larvae, estimated at 13,000,000, have been liberated from the station, but no results have ever been obtained from this. The turbot have been only a side line. The matured turbot is estimated to produce about 5,000-,OCO eggs,-- but in the shallow water off Portobello ponds flat teh cannot emit their ova. After the turbot' has been - kept in ponds till some of them were as much as 23 inches in length, large fish,- about 180 in number, were all turned out in Tautuku Bay, south of long Point (where the was wrecked) About five or six years ago. They have not been met with since.

The hydrographic results are of importance in consideration of the distribution of diatons, peredinae, and other minute organisms on which fish feed, and the distribution of fish appears to depend on those and other marine organisms which go up the coast in tast numbers at various periods of the year. Slight changes in temperatures and salinity often determine the occurrence of these marine organisms. In the library at the station the shelves hold a unique collection of papers and hooks. Over 2000 are catalogued, and inquiries for information from references are fequently received from all parts of the Dominion.