QUINN AT SALMON IN OPIHI

Timaru Herald, Volume CXXXVII, Issue 19408, 6 February 1933, Page 5

QUINN AT SALMON IN OPIHI

"FISH ARE A MENACE." At Saturday’s meeting of the South Canterbury Acclimatisation Society in Temuka the ranger (Mr F. W. Pellett) submitted a report on the prevalence of quinnat salmon in the Opihi river, and on their detrimental effect on trout fishing. “Quinnat salmon,’’ the report said, “like the German owl. are a menace: the former to trout life and the latter to bird life.” Quinnat salmon were essentially a salt water fish. They spent most of their life in salt water, and consequently they did not afford the angler the same amount of sport as do trout. There was not the same amount of skill in angling salmon when hooked as there was in trout. Salmon, like trout, were identical in their spawning habits, and needed shallow running water and gravel bed wherein to deposit ova. There was a difference of nine weeks between the spawning of salmon and that of trout. Both fish spawned on the same bee's. Salmon were a voracious fish and would domineer trout. The same remark applied to the parr fish cf salmon; they also would fight parr trout for an existence. In the matter of food fossiling salmon parr would outstrip trout parr, as also rainbow parr fight off brown trout parr when it came to procuring food. As botn quinnat and rainbow fish were near allied in nature, and both species were a gormandising fish it could easily be understood that either of these species existent in any river must depreciate the well being of brown trout for these reasons alone.

“Matured salmon get possession of the spawning beds,” said Mr Pellet:. “and the resultant parr salmon hatched each year take toll of the natural food supplies that belong to the brown trout, and salmon parr need more food supplies to maintain them than co brown trout, because salmon are a fast growing fish. Finally there is no doubt these fish are a menace to a purely brown trout stream such as the Opihi, which cannot be classed in any way as a salmon fishing river such as a snow fed one—the Waitaki or Rangitata for instance. The Government, no doubt, had good intentions when these fish were introduced some years ago, and even some societies were in favour of acclimatising these fish and it goes to show that before any further importation of fish from outside New Zealand takes place, full inquiries should be instituted. The evil is here and the vexed question is how to minimise it (for it cannot now be eradicated). Taking a stream such as the Opihi, this is a river subjected to floods. There is a large amount of rubbish cut down and left laying along the banks just at flood level. The bed is composed of gravel and subjected to scouring. Anything in the nature of an obstruction to prevent or catch salmon can only be of a temporary nature, for if piles were driven acroj.s stream the first good fresh would bring down no end of rubbish and block up the openings, and a scour would take place around the ends at banks and allow fish to go past. In America in the est„uaries of some of the salmon streams where there is no current of water piles are driven and blocks are made whereby fish are cornered up and lifted for canning purposes. Then again floating nets and set nets are also used for the purpose of catching fish. But in no case are the rivers completely blocked so that no fish can ascend upstream. Floating and set nets could be used at Milford, but these would not completely overcome the difficulty. In 1931 a salmon block and trap was erected in the Opihi river at the power lines, costing something like £lO. This block was in position for some eight weeks, having been put in at the beginning of February. After a time a good fresh came down stream and naturally a let of debris also came down, with the result that the wing of the block gave way under the strain and fish got upstream, and when the Opihi river gets into flood the water comes down a milky white colour, and you cannot see the bottom of the river. Consequently if the wing of a block or trap goes down one cannot see. what is going on in the river bed, and perforce has to wait until the stream clears again. Before anything can be done another thing regarding a block or trap is that I met with some resentment from two or three anglers who considered that it impeded the movement of large trout upstream. I may say that when the trap was in I caught four good sized trout.” Mr Pellett said that it seemed to him that whatever was done can only be of a temporary nature. If a low river was met with from February 1 until May, then success should be attained. Mr H. G. Naylor said that he had only fished two or three times in the Opihi, but had not caught any salmon.

Mr C. H. Coxhead said that one member had told him that he had not caught one salmon there. The chairman (Mr J. McDonald' said that it was evident there were not many at this time of the year. The habit of the quinnat was to go up the Opihi. They probably entered the river on account of the lagoon. The Opihi was now fished quite a lot, but was different from the Rangitata. the latter was from a snowfed watershed, and the former a rainfed one. Mr M. Metcalf said it was hard to stop salmon from going up the rivers. The chairman said that fishing at the mouth would counteract the salmon from going up the river. Mr H. G. Ellis pointed out that 'it was only within the last two years that salmon had gone up the Opihi. The discussion then dropped, and members went on to discuss the matter of fish in poor condition, on which there was a divergence of opinion. Opinions were freely expressed that the Research Committee should investigate on request. Mr Pellett, the curator, attributed the result to over-fishing. The report was adopted.