A COSTLY ENTERPRISE.

Otago Daily Times, Issue 20870, 9 November 1929, Page 11

A COSTLY ENTERPRISE.

NEW FISH HATCHERY. THE WAITATI SCHEME. ACCLIMATISATION SOCIETY'S PROPERTY. Claimed to be the latest and most up-to-date of its kind in the Dominion, the Otago Acclimatisation Society's new hatchery at Waitati ia now almost an accomplished fact. The society's property, comprising about 53 acres of land, upwards of 20 acres of which is in native bush, is situated'practically on the banks of the Waitati Stream, from which the water supply is drawn, about two miles from the _ railway station. Though the property is at present in a rough state, it was obvious to a Daily Times reporter who, in company with the chairman of the council of the society (Mr C. A. Wilson) , the secretary (Mr R. Hanning), the architect (Mr H. M'Dowell Smith), and several members of the council, visited it yesterday, that it will • lend itself admirably to improvements of many kinds, such aa tree-planting, and the laying-out of flower gardens and paths. In comparison with the property; at Clinton, on which the society's activities in breeding trout for the Otago streams have been carried out for about 40 years, the new hatchery is superior in many ways^ The two chief reaspns for shifting the scene of .this important work were that in summer the water supply was frequently inadequate and some of the ponds were developing a tendency to leak, so that the former difficulty was being aggravated to an extent that .was becoming more and more serious as season succeeded season. Both these difficulties will Ire overcome, howeve'r, at the new premises, for an excellent ■ supply of water is assured. The main supply, of course, Is taken from the Waitati Stream, but, in •the event of the water from this source falling so low as to occasion inconvenience, provision has been made for an auxiliary supply from a smaller stream which flows through thia property. As this stream is fed from a spring, the supply is constant and reliable. A race has been cut from it to the settling pond through which all the water used in the hatchery must p:iss for purposes of filtration. Again, the water from this supply is not affected to the same extent as that in the larger stream by a fall of rain which almost invariably causes the latter to become dirty. The water supply for the curator's residence will also come from the spring. The hietovy of the new hatchery commences in January of this year, when the housing accommodation for the eggs was put under way. At the same time men were i>ut on to build the protecting walls and groynes at the proposed intake of the water supply. The pipe lines both, for supply and overflow were also put in hand, and all this work ia now complete. There are to be 12 ponds, but all these have not yet been finished, only three of them having the water turned in. The ponds have all been constructed in the form of small dams, the walls being constructed of concrete, so that it is unlikely that these will give trouble by leaking, as did the ponds at the Clinton hatchery. Another decided improvement is the installation of electric lighting throughout. With regard to the hatchery, figures comparing the new premises with the old will be of interest. At Clintori the staff was able to handle 1,500,000 eggs at one time, but in the new hatchery, with the boxes already installed, it wiii be possible to have 2,000,000 eggs. in stock at once. It is unlikely that it will be found desirable to handle a larger number than this, but, if in the future the society's activities should increase to such an extent as to make it desirable that a larger number of eggs should be.put through,-it would be possible to accomnfodate another , 1.000,000. The hatchery, which is of attractive design and finished in white rough-cast ,s u 3O J eet Ion ?' and Contains 124 boxes

each of which is capable of accommodating 16,000 eggs. At the old hatchery" there were two buildings, but at Waitati all .the boxes are- under one roof. ■The water supply runs down the length oE the budding in a trough attached to the outside wall, through which* taps lead to the various boxes. » The stock fisb ranging from one to three years old. which are at present at Uinton, will be transferred to Waitati but it will not be until stripping operations are carried out on these fish • and others that the main operations will bo commenced in the hatchery. This will take place about June of next year. . The process of hatching the eggs into young trout is an interesting one, and it lit'also one requiring the greatest care and assiduous attention on the part of the hatchery staff. When the eggs are t ak 5 n . tr , om *&? fish they are first of all fertilised. They are then put down in the hatchery m trays made of a very fine netting, which allows the water to run through without carrying any eggs away, Jor about 40 days they are left in the trays before the fish become visible. Jnis, it should be mentioned, is the time taken at the Clinton hatchery, but, as variations in temperature have an fffeet- it is possible that the period may be different at the new hatchery. During this period only the' most careful of handling is possible; indeed, it is better not to handle the eggs at all if it can be avoided. The first part of the young hsh to become visible ie the eyes, and when these appear, the eggs are put through a siphon, which consists of a piece of hose pipe. The bumping the eggs experience in this process causeathe infertile egga to turn white, and they are removed as soon as possible. If they are not removed soon", a fungus • grows on them aild attaches itself to any other eggs it touches, rendering them use- \™ a - Cleanliness is , the watcbword of the whole process. Most of the eggs treated are sent away by rail or other means of conveyance to wherever they may be required, and they have to be very carefully packed for transmission. Special • boxes are used for this purpose, each box containing several trays of the eyed ova. If the consignment is to be pent a considerable distance, a sea voyage for instance, the boxes have to be lined with ice to prevent the eggs from hatching out before reaching their destination* About 25,000 ova can be put into each tray, and they are packed between layers of moss and gauze. After reaching the eyed stage the ova take about 23 days to become ready for shipping. The best temperature for a hatchery is about 50 degrees. The ova' that are" not sent away finally hatch out and become tiny fish, each with its yolk sac attached underneath. This

provides its nourishment for the next six weeks, gradually diminishing in size as , the nutriment is absorbed. The fish are then able to take their food from the water. At first, of course, the food has to be provided for them, and this ia usually finely minced liver in the form of an emulsion. The colour of the eggs varies with different fish. This is mainly accountable to the difference in the food and other conditions found in the various streams. Eggs from trout in the Leith are usually of a deep pink colour, while those of Waiwera trout are almost milky. Stock fish at the hatchery do not get the same type of food as wild fish, and their eggs, in consequence, are a milky white or a very light brown. At the Waitati property, in addition to the native bush, which includes practically every ‘variety of native tree found in this neighbourhood, it is proposed to institute a programme of tree planting with the object of attracting bird life. There will also be a duck pond and other improvements will be made as money is available. The cost of the new property and building is between £4OOO and £SOOO. The Clinton property has already been disposed of to Mr J. Judd, of that district, the amount realised being £IOOO. As it has been agreed that the purchaser shall have possession on December 21, the curator will be in occupation at Waitati about the same time or earlier. Work is now progressing on the curator’s house, and it should be completed in a short time. - It is anticipated that some sort of official opening ceremony will be held when the hatchery is in operation, but nothing definite has been settled in this direction as yet.