N.Z. FISH SUPPLIES

Evening Post, Volume CXX, Issue 117, 13 November 1935, Page 16

N.Z. FISH SUPPLIES

USE OF' TRAWLERS

CAUTION URGED

AX OFFICIAL VIEW

The need for the scientific study of New Zealand's marine fish supply," the spawning seasons, particularly of flatfish, and keeping a watchful eye on the depletion possibilities in regard to other fish also, is stressed in the annual report of the Chief Inspector of Fisheries (Mr. A. E. Hefford). Considerable space is devoted to trawlers and the effect of trawling as regards the fish supply, and the example of New South Wales, which has not proceeded with the necessary caution, is cited. "A development to be recorded as of interest to the history of New Zealand fishing grounds, if of no further moment, is the fact that during the past year a steam trawler from Sydney has paid several visits to our coasts and is reported to have returned to her home port in New South Wales with good catches," says the report. "The first intimation that the fishing grounds on this side of the Tasman Sea were receiving attention from Australian fishermen was when the steam trawler Alfie Cam put into Manukau 'Harbour, to land an injured member of the crew, in January, 1933. The results of the earlier voyages would appear to have been encouraging, and it is possible that in the future the New Zealand fishing grounds will be regularly exploited by Australian trawlers just as those of Iceland and even more remote countries in the North Atlantic region have for many years been within the normal range of operations of steam trawlers from Britain. It is a case of history repeating itself. First comes vigorous exploitation of the fishing grounds near at hand, followed by depletion which reduces their yield of fish to a degree that makes longer voyages a more profitable undertaking in spite of the higher expenditure incurred. NORTH SEA COMPARISON. "There is no doubt but that the trawling grounds of New South Wales have deteriorated very considerably as the result of about fifteen years' intensive exploitation. It is probable that the grounds off the New Zealand coasts are endowed by Nature with more fish and certainly with better quality fish than those of Australia. And so far as sea fisheries proper (as distinct from harbour and estuary fisheries) are concerned, they have been less intensively fished than those of New South Wales. It is quite certain, however, that the fish stocks in the seas round our coasts are not so abundant as those of the historic fishing regions •in the Northern Hemisphere, and their exploitation has hitherto been but slight -in comparison with the vast intensity of fishing that has been going on for half a century or more in the European seas. That European fishing grounds have been depleted is evident from the fact that greatly augmented efforts, by way of longer fishing voyages and the employment of more efficient fishing gear, are necessary to enable supplies to be maintained at a level approximating to the quantities of former years; and the quality (the sizes of fish caught and the proportion of the more valuable fish in the total catches) has very definitely declined. As the result of intensive fishery investigations carried out by international collaboration the facts of the condition of the fisheries in the North Sea and neighbouring areas are thoroughly well undei-stood. The relation between natural production (by spawning and growth) and artificial abstractions (by fishing operaItions) has been elucidated by research. "So far as the known fishing grounds off the coasts of New Zealand are concerned it is agreed by all who are acquainted with the facts that as the result of fishery operations the fish stocks are deficient in comparison with former years. In the absence of statistical records, and in view of the very limited amount of special investiga--tional work that has been carried out with regard to our fisheries, it is not possible to indicate what degree of deterioration has been reached up to the present, nor precisely what relation the fishery factor bears to Ihe other (natural) factors affecting the existence of the marketable fishes that constitute the natural assets of the fishing industry of New Zealand. So far as I am able to judge, concerning the history of the New South Wales trawling industry, the impoverishment of the fishing grounds has been accelerated by the excessive catches of fish that were aggregated on spawning grounds and by the excessive destruction of undersized fish, both undesirable effects of trawling which are not easily obviated. Unless developments at present unforeseen take place there is no reason for fearing that occasional visits of Sydney trawlers may affect the conservation of our trawl fisheries so long as our visitors confine their operations to waters outside the three-mile limit, where they have as much right to fish as anyone else. LIMITS AND DEPTHS. I "The erroneous impression is held by many people that trawling is illegal inside three nautical miles from the coast, but this is not the case so far as New Zealand trawlers are concerned, though trawling is prohibited in certain inshore areas in the Hauraki Gulf, the Bay of Plenty, Hawke's Bay, and off parts of the Canterbury coast. So far as my own knowledge goes, the best trawling grounds off these coasts are within three nautical miles of land, and certainly a large proportion of fish landed from trawlers is obtained from these inshore grounds. The depth of water increases very quickly towards the open sea, the 100-fathom line lying no more than about ten or twelve miles from the land off most parts of the East Coast, except where there are definite bays. At a comparatively short distance from land, therefore, the water is too deep for ordinary trawlers to operate, if, indeed, the fish are there to induce them to work at such depths. Out of the total of 55 trawlers that fished regularly out of New Zealand ports during the past year 39 are small oil-engined vessels incapable of working in more than about 40 fathoms and confining their operations to depths generally between 10 fathoms and 30 fathoms; and of the 16 I steamers only three would at present I be capable of towing a trawl in depths of more than 60 fathoms. "In the Atlantic Ocean trawling is carried on in water of over 200 fathoms depth, and the same might be done here if catches could be made to repay for the additional power required. Whether fish are to be found in payable quantities beyond the grounds that have Hitherto been exploited must remain for the present an unsettled and doubtful question. While New Zealand's fleet of large trawlers remains at its present low number there would appear to be no reason for the imposition of further territorial restrictions on this method of fishing. There is, however, an essential need for keeping all fishery operations under the closest observation possible by maintaining truly statistical records of catches and by extending our present exiguous understanding of the biology of the more important fishes. Such information is essential as a basis for fishery regulation to j ensure that our resources may be util- j > r°d rationally, today and preserved'