| OCR Text |
Show 1870.] INTRODUCTION OF SALMON INTO TASMANIA. 23 fishes; and it was difficult to assign any reason for their deaths. Owing to an unusually hot and dry autumn, the Plenty was very low, and the temperature of the water rose above its ordinary summer heat. This may have been the cause of the mortality, especially as the Salmon-pond then consisted almost entirely of still water; and the Commissioners therefore determined to liberate the bulk of the parr at once. Up to the 19th of March nine more fish died; and on that and the two following days the pond was lowered, and 419 Salmon parr were liberated into the River Plenty, half a mile above its junction with the Derwent. Fourteen of the smallest fishes caught were retained in the pond; and a number which could not be caught, and of which number no accurate estimate could be made, still remained. Many of the parr liberated exceeded 5 inches in length, being then ten months old. Every thing progressed favourably from the end of March ; and on the 23rd of October, 1865, the first fish which had assumed the Smolt dress was seen in the Salmon-pond, and between that time and the end of the year thirty-three fine Smolts were liberated. In January, 1866, some alterations were made in the clearing-pond ; thirty-eight Trout (Salmo fario) were then liberated into the Plenty, 133 being returned to the pond. The Tasmanian Government, encouraged by the success of the attempt in the ' Norfolk,' determined to obtain a second shipment, that no chance might be lost of rapidly carrying the undertaking to a successful issue ; and on the 8th day of February, 1866, the ship ' Lincolnshire' left Plymouth bound for Melbourne, having on board about 103,000 ova of Salmon (Salmo fario) and 15,000 ova of Sea-trout (Salmo trutta) stowed in an ice-house of rather larger capacity, but of much the same construction as that built in the ship ' Norfolk ' for the same purpose two years before. The whole of the arrangements for shipping were superintended by Mr. James A. Youl, who again exhibited the determined zeal upon which so much depended in the former experiment. The method of packing the ova in the boxes and the boxes in the ice-house was identical with that adopted in the 'Norfolk.' After a rather long passage of seventy-nine days, the ' Lincolnshire' arrived at Hobson's Bay on the 30th of April, 1866, and the ova and ice were at once transhipped to the steamship ' Victoria,' again most liberally placed at the disposal of the Tasmanian Salmon Commissioners by the Victorian Government, and arrived in the Derwent on the 4th of May, and by 8 P.M. on the following day the last of the ova were placed in the hatching-boxes at the Plenty, the water, by the help of the remaining ice, being reduced to 45° F. One remarkable fact in this experiment was the forward state of the larger portion of the ova, the fish being distinctly visible, furnishing abundant proof that a large number, at any rate, had been successfully impregnated. This was especially observable in the Sea-trout, the pupils of the eyes in which last stood out as black spots on a yellowish-white ground, the enveloping tissue being more transparent than in Salmon-ova. |
