FISH HATCHERY.

Dominion, Volume 2, Issue 476, 7 April 1909, Page 4

FISH HATCHERY.

a » EXPERIMENTS AT PORTOBELLO. HOW DIFFICULTIES HAVE BEEN OVKKCOME. (DI TEI.EGKArn.—SriCLVL COItItESrON'DENT.) Christchurch, April 6. Mr. G. M. Thomson, M.1 , ., gavo a "I'rcss" reporter somo interesting information about tho l'ortobeilo marino fish hatchery. "It is twelve years," ho said, "since. I began to investigate the problem of establishing a biological station licre. We got information from tho Scotch fishery board, and from tho English biological laboratory as to the possibility of tho transmission of fish, and desirablo Crustacea. Wo found tho onrriago of sea fish was going to be an extremely difficult matter. -Most of them have floating eggs, so that we. could not bring tho ova, but had to take tho fish with them. Tho difficulty was to retard development, and we have been trying to got experiments carried out by the Scotch board in that mattor. They cannot retard the development for over thirty days, but wo would iirfjuirc a minimum of forty-two." Mr. Thomson went on to say that he brought tho matter beforo the Otago Institute, and the site at I'ortobello (in Diuicclin Harbour) was ultimately fixed upon.' Tho Otago Institute and the Acclimatisation Sociecy mado grants of £250 each, and tho Government supplemented this with a £ for £ subsidy. Ultimately Mr. Seddon took tin matter up, and promised £250 a year for five years. The station was estimated fcy tho Public Works Department to cost £3000, but the Instituto built it for £1400, the Government finding tho difference between tho Institute's funds'and the actual cost. Tho Government had afterwards assisted with the cost of a shipment or two (about £100) and also provided a good oil launch. "Tho station," Mr. Thomson continued, "has done very well up to the present. AVe have just completed the fivo years' arrangement made with the, late Mr. Seddon, and are now waiting until the Cabinet have considered the situation for tho future. V"> have run tho thing cheaper than a.iy concern tho Government has. anything to do with. It has never icost one farthing for supervision or secretarial work. We are asking for £500 a year from tho Government in future, so that wo may/ bo able to appoint an assistant to our curator, who has simply been overworked. With two men we can do the work.' Wo hope to go into attempts to introduce desirable species of Home fish. The only work we have done hitherto in regard to importations from Home waters, is tho introduction of the Homo lobsters, and the large edible crab. We have a stock of both in the ponds now. This year we havo probably turned out about 100,000 lobster fry, and from three to ■ fivo million crabs. All these Crustacea have been liberated into the waters of Otago Harbour. As for economic results, when tho lobster and crab, aro to become part of the general food supply, the public will have to wait for four or fivo years. Even if a small proportion of tho myriads , liberated survive until maturity tho problem .will bo solved and. tho harbour stocked." Mr. Thomson is a great admirer of the lobster as a battler for existence.. "Once stocked they aro quite safe- to look after themselves;" .ho . said; •" The lobster is a most aggressive crustacean as compared with the crayfish. You have only to egg tho two in a tank together—the lobster always marches forward with his fighting equipment ready for offensive action, and tho crayfish retreats-backward, always oil the defensive. I havo seen the lobster chasing the crayfish round the tanks, giving him no chance whatever. If the lobsters begin to find their wav to the bottom of the harbour they will ho all right. In their early stages they are swimming on the surface, and they havo to. go through half a dozen moults beforo they sink critical timo for the'lobster, but if lie survives he is well on the way to be a permanent denizen of tho deep.". -• - -■.--. .. Tho station lias done, valuable- work in-con-nection with New Zealand fish. The development of tho two species of solo, the common flounder, and also somo of the smaller shoro fishes has been worked out. A lot of information has been gathered concerning tho migration of fish, their feed, hatching time, and tho kind of eggs they produce. One particularly interesting discovery solved the problem of the comparative absenco of fish from Otago Harbour during tho winter months. "When the temperature at tho station fell to about 32deg., it was found that all the blue cod in a pond' were- dead. It had previously been noticed that as the cold weather came.on. the fish became rather sluggish, and a fall of snow was responsible for ; the final Tho Otago "Harbour is shallow, with tho exception of some channels, and the temperature in winter falls to about. 40deg. As tho sea never falls below SOdcg., tho fish make for the deep water and the harbour fishermen have to follow them there. As a result of the observations made. Mr. Thompson arranged with the Scotch Fishery Board to conduct a reries of experiments with Home fish to ascertain the effect of low temperatures on them. The reports have-not .yet been received, but they promise to throw an interesting light on ail important subject.