Trout Introduction to New Zealand

of the importation of trout ova into Tasmania, and their cultivation, we find, in four years, that country sending ova, taken from fish How to obtain it. 121 on the natural spawning beds, to New Zealand. We find also that those eggs were successfully hatched there, and from this small stock a beginning was made, and there seems to be little doubt that from these eggs trout originated in New Zealand. So successfully was the work carried on there, that the New Zealand Government very wisely took it in hand, and the result was a considerable importation of ova into the colony. Take the state of things in New Zealand to-day, and what do we find ? Why, that the rivers of that country are, many of them, full of magnificent trout that have grown beyond all expec- A tation. Trout-culture in New Zealand is a grand success. friend, writing to me from Tasmania, August yth, 1 890, says : "The English brown trout that have been acclimatized here have done remarkably well, and attain a great size." So then, in Tasmania also, trout-culture, though carried on under the great difficulty of importing ova from Britain at a time when its treatment was but very imperfectly understood, has proved a decided success. In the United States the rivers of the Pacific Coast which contained no shad, were successfully stocked with those fish by transferring ova from the East Coast rivers. At first a million | ova were carried in suitable apparatus, the incubation going on | during transit. This proving a success, several cars were run conveying five millions each, and by means of these ova the rivers of the West Coast were stocked. The fish, which are pro- lific, multiplied very rapidly, and had become so plentiful that they were sold at three cents a pound. In 1886, a quantity of the ova of the smelt (Osmerus mordax) were sent to Cold Spring Hatchery, on the north of Long Island. They were hatched and turned out in Cold Spring Harbour, and in two years a number of fish from these eggs were taken in Oyster Bay, which adjoins the harbour on which the hatchery stands, and into which they were turned, and they have also been seen in the streams. Great success has in very many instances attended the plant- ing of fry in the United States as well as in Canada. Had " fully " eyed ova been judiciously planted in artificial beds, probably the results would have been more satisfactory still. In 122 How to obtain it. Canada, the magnificent river, Restigouche, flowing into the Bay of Chaleur, was depopulated, until the catch of salmon by anglers was only twenty fish in a season, and the whole commercial yield of the river was only 37,000 Ib. weight. Hatching was commenced, and the yield in ten years was up to 500,000 Ib. The United States Fish Commission succeeded in intro- ducing salmon (Salmo salar} into the Connecticut river, where previously it had disappeared for three-quarters of a century. In 1878 several hundred salmon, from 10 Ib. to 15 Ib. in weight, were caught running up this river, the result of fry planted there in 1874. A considerable volume could easily be filled with accounts of the successful results attending the stocking of waters, and in our own country we have many cases in which the most satisfactory results have accrued. As I write, by the side of a natural trout stream, I can see the trout disporting themselves in numbers, nearly every fish in the pool before me being the result of artificial culture, whilst in an artificial stream close to, on which are many deep and spacious pools, and where the fish are fed, large quantities of magnificent fellows up to several pounds in weight may at any time be seen. Over the hill in the next valley is an artificial lake, which is well stocked with fine trout, nearly all of which have been artificially bred, and beyond this other lakes, reservoirs, and ponds, all well stocked with magnificent fish. If we go further afield we have Loch Leven, the statistics of which, extending over many years, are strikingly in favour of fish culture. In Wales, too, we have the well-known Lake Vyrnwy, the fish supply in which is now kept up by a well-ordered system of artificial cultivation. The successful introduction of grayling into the Nith and many other rivers is another proof, if any more be needed, to say nothing of many Highland lakes which are now well stocked with trout, where, in some cases, no trout were before. Of the success of trout culture there can be no dispute, and I maintain that what can be done with trout may be done on a far greater and more profitable scale with salmon. That is a point about which I am quite convinced, and I would carry it further and apply it to many other fishes than those belonging to the How to obtain it. 123 Salmonida. There is, however, this difference, that trout being retainable in fresh water ponds can be successfully cultivated by the individual, whereas salmon must be allowed to go to sea if they are to produce the highest results, and this renders individual action somewhat impracticable. By a well-directed system of co-operation amongst owners of fisheries, it is beyond any doubt that splendid results may be obtained. Of one point I have no doubt that no investment would pay a much better dividend if : properly managed. It has often been stated by scientists and others that only | / about one trout or salmon egg in a thousand deposited in our V streams, produces a mature fish. This, probably is not far from the mark. Anyhow, we are quite sure of one thing, and that is, that the rule applies to over ninety-nine per cent, of the ova deposited naturally in our streams ; seventy-five per cent of this loss probably occurrs before the eggs are hatched, and during the hatching period. It will be apparent at a glance, that by taking charge of the ova and actually hatching over ninety per cent, of it we are doing good work. It is necessary, however, that it be done properly, and that is just what has often not been done in the past, and cases of failure which the practised fish culturist could foresee, and which were inevitable owing to the means employed, have tended to bring fish culture into bad repute. Circumstances are entirely altered now, however, and the facilities which are provided for sowing good well-eyed healthy ova in our waters, will ere long produce good results if properly utilised. There are some individuals who still assert that fish culture is a failure. So there were those in years gone by who pronounced the steam engine a failure. Anything that is not absolutely perfect in all its details is pronounced a failure by a certain class of individuals, and probably always will be. Fish culture, however, as applied to the SalmonidcR, has been proved by the results to be a great success, and I venture to say that in the future it will be still more so. It is now being successfully applied to the growth of other fish, both marine and fresh-water, and as information is gained by experience, and difficulties are bridged over, its practical use will be found to be of great service in the management of our fisheries. % *v of; CHAPTER V. THE HATCHERY. Selection of the water Its importance Construction Out-door hatchery In- door hatchery Frost-proof building Lighting Filtration of water Concrete floor Drainage The apparatus How to construct Carbonizing Trap boxes Catchpool No admittance Beware of visitors Early days of the Solway Fishery Care required in a hatchery. ETOR the benefit of those who wish to do their own work from the commencement I will endeavour, in as few words as possible, to describe the various needs and processes of the practical fish culturist. The first thing essential is a hatchery of some kind. It may be large or small according to the amount of work required to be done, and may be fitted up in different ways, but although the details may vary, yet the principle of construction is the same, whether small or large. It must be near a good supply of pure water. I do not mean chemically pure, but naturally so that is, it must not contain any excess of mineral matter of any kind, and it must be free from mud or sediment. The water which flows from a good clear spring and is wholesome to drink is usually good. But the best way of proving f it is by means of the fish themselves. Do trout frequent and ' it, do they spawn in it freely ? If they do, it is probably all right ; if they do not, then be careful, and should it seem clear, on examination, that they avoid it, then be very cautious in using such water. By all means have it analysed, and find out exactly what it contains, and what it does not, before commencing work. Brook water is the best for growing the fish, but spring water is usually acknowledged to be safer for hatching the ova, and chiefly for two reasons regularity of temperature, and freedom from organic and mineral matter in the form of sediment. How to obtain it. 125 Suitable water is such an important factor in the successful working of a hatchery, that too much caution can hardly be used in the selection of the site for the building. Some very clear and good-looking waters are not good, and it really becomes the work of an expert to decide what is suitable and what is not. I have seen excellent work done in a hatchery where only river water has been used, and I have seen spring water that to look at appeared perfection itself, yet did not do its work at all satisfactorily. Some spring waters contain too much iron, lime, or other deleterious ingredient, and hence the great care that is required in the selection of a suitable supply. Therefore, where the incubation and hatching of ova is to be carried on on an extensive scale, it is better to consult an expert. Where limited operations only are intended, test the water by keeping some trout in it, and, if possible, hatch a few ova, and rear the fry for a season by way of experiment. Have the water analysed. Having selected a suitable spring, the next consideration is the construction of a hatchery. I have seen several sets of hatching apparatus worked out in the open air. The objections are that such hatcheries are exposed to the action of frost, which in very severe weather is likely to cause damage, and they are liable to be tampered with by man or beast, which should not be the case. I once had a spring which threw a copious supply of excellent water, never below 38 Fahrenheit. Such water would answer well for an outdoor apparatus, as it could easily be made to pass through a series of hatching boxes before being reduced to the freezing point. But most water would be likely to give trouble at times. Therefore, if it be practicable, place the hatching apparatus inside a frostproof building. In our climate an ordinary stone and lime wall is sufficiently frostproof for the purpose ; an ordinary slated roof is not. Thatch will do, but it has the objection that it needs constant repair and harbours vermin. Underground hatcheries, when the situation will permit their construction, are excellent. But an ordinary stone-built and slated building will be found in practice to answer all requirements if felt be laid under the slates. The temperature inside it may be kept at any desired point by means of hot water pipes, which 126 How to obtain it. answer well, and prevent any mischief during the severe frost. The heating apparatus should be outside. Never have a stove of any kind in a hatchery. I was once persuaded by a man who " knew everything " about fish culture to try one, and never was a greater nuisance. However well kept, smoke would at times escape, and anything of this sort is to be carefully avoided. For the same reason I have found it necessary strictly to forbid tobacco smoking in the hatchery. I did not do this at first, the building being large and well ventilated, but carefully watched the effect of it on the alevins, and found it very hurtful. Lighting a hatchery when work has to be done, as done it must be during the dark hours of winter, is a matter that requires the greatest care. Oil lamps of any description are to be most carefully avoided. I have never from the first allowed anything to be used except candles (not tallow), with the exception of the watchman's bull's-eye or other lantern when on his rounds during the small hours. Even this, although most carefully used, and A according to strict rules, was found to give trouble. very small drop of oil may do harm should it get into the water, and where oil is used there is always a danger. Candles only are now allowed in the hatchery, and are found to work well. They are [ carried on simple wooden candlesticks, each made to hold three 1 candles. These give enough light for the laying down of the ova, which is almost invariably done after six p.m. Occasionally candle droppings may get into the water, but as they float and immediately solidify, they are quite easily picked out again, and I have never found them do any harm. Except when there is a great press of work, spawning is not, as a rule, commenced before ten a.m. Fish spawn better later in the day when the temperature rises a little, and the eggs taken in the afternoon are carefully washed and placed in bowls in the hatchery, ready to be laid on the grilles as soon as the spawning operations are over for the day, and the fish removed from the spawning tanks. The water should be brought into the hatchery from the spring in glazed earthenware socket and faucet pipes. The joints should be well cemented, and the pipes laid underground. It will probably require filtration, although sometimes it is sufficiently How to obtain it. 127 pure to do without. But this is a very rare exception. At or near the point where it enters the hatchery then, construct the niters. For pure spring water half-a-dozen or more flannel screens will usually be found ample, and~oiYeri" three or four wnTdo. It is better to have too many than too few, for they play a very important part in the success of the work. For fifteen years I have worked with no other filter, and now that a much larger volume of water is required in the hatchery the same method is essentially successful, except that the water is first passed through a couple of settling tanks, which are found very useful adjuncts. Fig. 6. A simple filter shown in Fig. 6 explains itself. It consists of a wooden box, six wooden frames with coarse flannel stretched on them, sliding into groves at a moderate angle, an inlet and an outlet, and the whole charred inside. The size depends entirely upon the amount of work to be done and the state of the water. As an example, I may say that I have incubated successfully half a million ova in the water discharged through a set of four (occasionally increased to five) flannel screens, of about seventy A square inches each. double set of these (for convenience in cleaning), each in a separate box, is used, the whole water sometimes passing through one box, but, as a rule, both boxes working. The filter boxes I have at present in use are twenty-four inches by twenty-four inches, and two of these boxes now working will pass 200,000 gallons of water per day, or enough to incubate four millions of ova. Behind each filter are two settling tanks built of concrete. This applies to the main hatchery only, two 128 How to obtain it. other buildings which are used as accessories having an additional supply. By way of caution to^beginners I would say that concrete should in all cases be very well seasoned by use, before allowing the water passing over it to be used in the hatchery. All work is done at the Solway Fishery, as far as possible, a season in advance, or in early summer, and by allowing the water to run for a few months, everything is rendered perfectly safe. I have seen places where the work has only been finished the day before the eggs have been laid down, and where the water supply has actually had to be cut off afterwards in order to rectify little matters that had been overlooked. These are the sort of places that bring A discredit upon fish culture. fish hatchery and everything about it should be clean and sweet as a dairy, and should be kept so, and on this largely depends its success or failure. Good ventilation is essential, just as it is in a house for growing plants. Too much light should be avoided, and especially large windows facing the south, which would let in the glare of the noon-day sun. It does not matter much how the place is lighted, if attention be paid to these points. It may be by sky-lights or by side windows. I commenced work thirty years ago in a conservatory, which is now about the last place I would choose for the purpose, but yet I got on very well. The floor of the hatchery should be of concrete, or of stone, or suitable pavement of some kind. Whatever material is used, take care that it is rat^rpof. The level is also a matter for con- sideration. Some fish culturists advocate dry floors, the waste water being carried off in pipes, and drained away underneath. This may be all very nice, but in a working hatchery it does not answer very well. There is no harm in having the floor wet, if the house be properly ventilated, apd as water must often be spilled or even emptied upon it, it is, for several reasons, better to have open gutters under the hatching boxes than drains laid underneath the floor. There are two great objections to such drains. One is, that if anything should happen, and they have to be examined, it necessitates the pulling up of the floor, and should anything go wrong in the middle of a hatching season it might be a very awkward matter ; another is that drains are apt to encourage How to obtain it. 129 rats and foul smells. There are also many other inconveniences. I have tried both systems, and I am greatly in favour of open gutters on the surface. They are simple, and add but little to the cost of the hatchery ; they are convenient and clean, and are Always open to view. The floor itself, I need hardly say, should not be level, but : should have a fall one way or the other to suit circumstances, and to : cause all water to run off immediately into -the gutters. It '.should be frequently washed, not with a floorcloth, but with clean ..water and a broom. This should be done by the manager himself, iOr by someone working directly under him, as it requires to be ; done with care. . On no account should any carelessness or undue -roughness be tolerated in a hatchery. .The disarrangement of a t, pipe :or a. tap, or a blow on one of the hatching boxes, may do -_ serious damage, and whoever cleans the floor should be acquainted with the working of all such contrivances. The door of a hatchery should be kept shut, or rats, mice or birds will get in, and it is sometimes difficult to get them out again. Rats seem naturally attracted to a hatchery, and if they can get in they will. The outlet for the water should be carefully guarded by a grating, and every precaution taken to prevent any intruders of this kind gaining access to the hatching boxes. . Where lead or iron pipes are used for bringing in the water, it should be borne well in mind that either may be very injurious. I have seen excellent work done with them, and I have also seen great destruction caused by them. The first hatchery I ever built, which was erected in one of the suburbs of a large town, was ; supplied from the waterworks at the rate of sixpence per thousand gallons. The water was excellent, but occasionally repairs were done by the company, and on these occasions it would fora short time run very thick and yellow, and would poison my little fishes. In the same way when the water has been shut off a hatchery for a few months during the summer the pipes would corrode, and afterwards send down a quantity of poisonous matter, which might do great injury. Care should, therefore, be taken that they are thoroughly clean before hatching begins. This applies not only to the supply pipes, but also to the hatchery itself, and all the apparatus which it contains. K 130 How to obtain it. A So much for the house now about the furniture. glance at the accompanying illustration will give a general idea as to what is required. First of all, two distributing tanks. These are two long wooden boxes or troughs which receive the water from the filters, one being used for distributing the spring water to the hatching boxes, and the other being used for the brook water. Place them overhead if practicable, but in cases where the water cannot be got up to that level, they may be placed three or three and a half feet above the floor. In the latter case a series of round holes one inch in diameter, and short tin or lead pipes four inches long will be all that is needful for supplying the hatching boxes. Bore a hole, and fix a pipe so as to deliver the water into the upper end of each hatching box or set of boxes, which must be placed just below the bottom level of the distributing tank. Regulate the supply by a small piece of tin or wood, sliding in a groove made by nailing two slabs on to the inside of the tank. The tanks themselves may be nine inches wide by nine inches in depth. The advantage of placing the tank overhead where practicable is that it allows the operators to pass along that end of the hatchery, which is a consideration when each range of boxes is close on eighty feet long. The outlets for supplying the hatching boxes can then be made in the bottom of the distributing tank, and by using short pieces of lead pipe, each with a flange a quarter of an inch from the end, for nailing to the inside bottom of the distributing tank, a screw-tap can be attached, which is a great convenience in regulating the water, and on the whole better than the small-scale sluice already alluded to. Fix a short piece of indiarubber hose pipe on to the tap and the whole is complete. Take care that all is well seasoned before using the water. The hatching boxes are very simple contrivances, but require to be propen^maaeorthey may be found not to answer their A purpose satisfactorily. very good size to make them is twelve feet long, by nine inches wide, and six