ATLANTIC SALMON

Press, Volume LX, Issue 18015, 6 March 1924, Page 16

ATLANTIC SALMON

AN INTERESTING ADDRESS.

An interesting address on salmon, entitled "Salmo saiar at Home and Abroad," was given at a meeting of the Philosophical Institute of Canterbury last evening by Mr M. H. Gcdby.

the president. After expressing his appreciation of j the honour conferred upr.n him by | electing him president of the Insti- ; tuto, .Mr Ucxll.y .said that the custoI mary course oi the president to adi dress the Scrieiv on recent advances ' in some branch of science was denied ! to him. and lie therefore turned to a. ■subject that had been to snme extent : his hobby for the last few years. This ; year w.ts the diamond jubilee of the ; successful transportation of live salmon | and trout ova to Tasmania. He there- ■ fore thought it not inappropriate to ; say something about Salmo salar (At-

; huitic salmoni in his native haunts, j unci the long list of attempts to introI (luce the species to Tasmania and New ! Zetland and the measure of success | which had only recently been attained. ' The lish appeared to have originated ; in the North Atlantic, which was it j present habitat. It was found on the j American side as far south as Cape ' Cod, and extended in a northerly direction to Hudson Bay, Greenland, Iceland, the British Isles. Norway and 1 Sweden, and down the western coast of Europe as far as the Bay of Biscay, entering all suitable rivers to spawn. There was evidence of its existence in the oast in the waters of the Mediterranean.. That salmon spawned in fresh water about October and November had been w-ell known for many years, but it Tvas only in the early sixties that the little fish called '•parr," so romraon in many rivers, were definitely proved to I>e young salmon. At the beginning of the present century the best'scientific opinion might have been summed up as follows: —After spending a year or two in the river, the parr assumed their silvery travelling dress in May, when they were known as "smolts," and started on their migration to the sea as fish of six to eight inches long, weighing an ounce' or two. Once arrived at the rich feeding grounds of the sea they were credited with extraordinary powers of growth, and were supposed to return in July and August of the same year as grilse, weighing from three to eight pounds, or even more. Having spawned in the autumn, the grilse ke'lts returned to sea, it was believed, and in a month or two a proportion were ready to return to the rivers as "small spring fish" in March and April, others remaining longer in the sea, and returning throughout the summer and autumn to spawn. Thereafter the process was repeated annually, so that a. forty-ponnder would be regarded as a fish that had survived many spawning ascents. The first real light on the life history of salmon was obtained when Johnston in 1905 marked 6500 smolts descending the Tay. It was not until the following June that a grilse of under three pounds bearing a mark was recaptured in the Tay. This proved that grilse were a year older. than had previously been supposed. Scale reading gave much more information. It was now definitely known that the parr remained in fresh water for from one to three. years. After migration, only a trifling percentage returned as grilse after spending one winter in the Bea. Another proportion, varying with different rivers, returned to fresh water in the spring following the second winter as "small spring fish." A somewhat larger proportion returned in the summer and autumn of the same year as "small, summer fish," but others remained a further winter in the sea, returning the next year for the first timo as "large spring fish" and "large summer fish," while a small residue re-" mained one more .winter in the sea, and returned as "very large spring fish." After dealing with the difference in spawning habits, Mr Godby said the whole tendency of recent investigations seemed to point to the importance of heredity in determining the characteristics of a salmon. A very thorough and systematic investigation of the sock'eye salmon of the Pacific Coast of American had definitely established the existence of a number of different races with quite distinct characteristics. The lecturer dealt at length with the attempts to introduce salmon and trout ova to Australia, and of the many disappointments suffered. The first trout was hatched in Tasmania on May 4th, 1864, and on the following day the first salmon was hatched. The introduction of trout to the antipodes was successful, but with salmon there was a different story. The young fish flourished and descended' to the sea as smolts, and were never seen again. This, the history of the first shipment, had been the history of every shipment since, whether to Australia or New Zealand, until quite Recent times. Partial success had been attained at Jast by importing large quantities of ova at a time and liberating all the fry in the one river. After dealing with the differences between salmon and trout, the lecturer referred to the difficulty of distinguishing between some New Zealand salmon and trout, and suggested, as a possible solution, that crossing between 6almon and trout had occurred. On the motion of Dr. Hilgendorf, Mr Godby was accorded a vote of thanks for his address.