QUINNAT SALMON

New Zealand Herald, Volume LXX, Issue 21505, 31 May 1933, Page 16

QUINNAT SALMON

; SOUTH ISLAND RUNS } STOCKING OF RIVERS MARINE DEPARTMENT'S WORK I " Tho general impression is that the , quinnat salmon run this year has been below..the average—that not so many r.s usual have come up tho rivers," said Mr. A. E. Hefford. chief inspector of | fisheries, in Christchurch recently. *' That is not absolutely certain, however, for the rivers have been in flood, and not so many of the fish would be seen. It is significant also that at Hakataramea, where tho Marino Department's hatchery is, not so many salmon as usual have been running into the traps. They will be running for another week or two; but I do not expect that there will be an increase in the number." Mr. Hefford said that previously the department had been stocking the "Wairau with quinnat and it also had tent a certain quantity to Westland, while for some years it had consignments of ova to Tasmania; but this year it was hatching the ova mainly 'to stock the Hakataraniea River. The • department would probably stop trapping and stripping when 500,000 . ova had beou collected. ' Asked whether the Wairau showed prospects of being a good sqhnou :stream, Mr. Hefford said it did -not seem to be a 1 river that "was definitely ; favoured by quinnat. At tho Waiau ! River, in Southland, the department [had two men stripping Atlantic salmon, I the idea being to liberate them in the .tributaries of the Wairau, which did not • pass through lakes, so that the salmon /would become sea migrants, instead of \remaining in the lakes, as many of them 1 undoubtedly did. Sockeye in Lake Ohau ; Years ago, a shipment of ova of the sockeye or blueback salmon—the : great canning fish of the Pacific. Coast ; of North America —was brought to New Zealand, and the fish hatched out and liberated. These salmon settled in Lake Ohau. Whether any sockeye ever ran to sea or back up the rivers could not !bo ascertained, said Mr. Hefford, be- ' cause no definito specimen had been /seen. Now a variety of dwarfed sockeye lived in the lake.

_" The question has been raised in -New Zealand whether it is worth while j carrying on hatchery operations at a time when the Government is practising .rigid economy," said Mr. Hefford. "One important point, however, is that the ; temporary or seasonal employees in hatchery work are experienced and j highly-trained men, and once the department lost them it would be diffi- . cult to train newcomers. You pay very heavily for ignorance and inexperience in fish work, and a man who puts up ] with the discomforts of it morning after morning in icy rivers must have a personal interest in it —he does not do it . merely for the wages."

JtSturn of Marked Salmon i Mr. Hefford has taken to Wellington ; a few small packets of scales taken from quinnat salmon. To most people, those ■ scales would appear to be dull exhibits t indeed; but two of them were taken from marked salmon which have run . lo the sea and back to their parent river. By examining them under the . microscope experts will bo able to deteri mine the age of tho fish and find out / a good deal about their life in the sea. " For the last three years." said Mr. Hefford, " we have been marking small salmon by cutting certain of their fins, j after which, of course, they are liberated in the rivers and go to sea. This j year r<t Hakataramea we got back two ■/ of them, which bad been liberated in j 1931. They weighed more than 121b." Questioned about the idea popularly j held some years ago that quinnat ; salmon almost invariably stayed in the sea for four years, Mr. Hefford said ; that since the method of determining ; 'he age of fish by examination of their scales had been practised and proved to he reliable, naturally a good deal had been learned. It had been shown that the fish came hack at two, three, four, or five years. Most of the New i Zealand quinnat, however, returned to the fivers when they were about to complete their fourth year. Value ol Uneven Migration Divided migration was really a good thing, Mr. Hefford said. If a whole generation returned to a river "at one />timc, in the event of adverse circumstances, it might be decimated or wiped out.; but that was not possible when the fish made their run at different ages. The interesting thing was that the marking of the fish would help to provide a eheck on the scale reading. It was usual to take a number of scales from each marked fish. If a fish's scales were rubbed off, they always grew again; but in doing so they did not fiiow the normal lines of growth, so it was wise to take scales from different parts of the fish. " When I first started fish research /work," said Mr. Hefford, "scale reading was practically unknown. A Dutchman named Hook drew attention to it a l)o lit a coil pie of centuries ago; but only in recent times has it been generally accepted."