WHAT IS TO BE DONE WITH THE SALMON?

Tuapeka Times, Volume VI, Issue 284, 10 July 1873, Page 5

WHAT IS TO BE DONE WITH THE SALMON?

The following paper on the above subject was read by the Curator, Mr A. M. Johnson, at the meeting of j k the Canterbury Acclimatisation Society: — Now that the introduction of English salmon into the Canterbury Province is an established fact, the question arises what can be done to render their acclimatisation successful? The plan hitherto adopted with the various shipments, both in Tasmania, Melbourne, and Otago — of liberating all the fish when ready to go to sea — has proved a very unsatisfactory course, and still leaves the question unsolved, as to whether the salmon have increased or whether they can be successfully acclimatised in the Southern Hemisphere. Comparatively little is accurately known with regard to the salmon after leaving the fresh water, but there is every reason to believe that out of a hatching one-half of the fish will be ready to go to sea at twelve months old, some at two years old, whilst a few will remain in the fresh water till three years old ; the greater portion of the first lot returning up the rivers to spawn at three years old, the remainder reaching maturity at four, five, and six years old. It will thus be seen that in the small number of forty-five fish the chances are not very favorable of a sufißcient number of mature fish of equal sexes escaping their numerous sea enemies, and returning after so long a period to the same river together. It is proposed, therefore, to confine the fish in a saltwater enclosure, and at the proper time removing or allowing the fish access to fresh water, with a view to obtaining an increase in the same manner as is done with the trout. As it would be undesirable to risk the whole experiment to one chance, a salt water enclosure in the gardens would not only afford double security, but greatly contribute to success. Two barrels of salt water a week would probably be found quite sufficient. The necessary power for obtaining a constant circulation and aeration of the salt water could be easily obtained in the gardens by means of the artesian wells, and the experiment conducted at probably much less expense than elsewhere. Should the trial prove unsuccessful, the ponds in the gardens would then be equally valuable for the salmon-trout, which also need access to the salt water, though not so absolutely essential as to the salmon. Whether the salmon is suited for the Canterbury Province can only be settled by actual experiment ; the fact of a number of living ova dying off during the very hot weather a few days after landing, in the natural temperatpe of the spring water, 55 deg., foreshadows difficulties, and may necessitate similar steps to be taken as was done with regard to the pheasants, viz., the infusion of distinct new blood. Under this impression, some ova of the best description of salmon from America was recently obtained at the expense of the Curator, but in both instances the eggs were all bad on arrival. It may be urged that the confining of salmon for artificial culture from the egg state to maturity is an untried experiment, and likely to prove too costly, but with equal justice it may fee urged that the novelty of the experiment will make it one of very great interest, and, if successful, of immense importance, whilst the ponds might be further utilised for other important objects connected with the marine zoology of New Zealand.