Lobsters for New Zealand

Dominion, Volume 28, Issue 58, 1 December 1934, Page 20

Lobsters for New Zealand

(By

J. Drummond,

FOR 70 years, persistent efforts have been made to introduce the common European lobster into New Zealand. The first effort was by Mr. A. M. Johnson. He had an aquarium and fish ponds at Opawa, Christchurch, where die made many important experiments in acclimatisation. During a visit to the Old Country in 1864. he obtained 26 lobsters in Wales. He kept them in a tank on the vessel. Full of light, they carried it to a finish until only one was left alive Mr Johnson sold it to a first-class passenger. Twelve lobsters taken on board a vessel in England by Mr. S. C. Farr for the North Canterbury Acclimatisation Society’ could not stand the heat of the tropics and died. The first lobsters landed in New Zealand were shipped to Dunedin 41 years ago. There were nine of them. All wore liberated at the entrance to Otago Harbour. They were not heard of again. From 1906 to 1908. 47 lobsters arrived at the Portobello Marine Fish Hatchery. Twenty-four were females. As usual with lobsters they laid innumerable eggs. In 1908 36,000 young lobsters were hatched in the tanks, and in 1909 100,000, and young lobsters were liberated in the sea near Otago Harbour. In 1913 another consignment of adults, 14 males and 28 females, arrived from England.

A moderate estimate by the Hon. G. M. Thomson, who entered heart ind soul into the work at the hatchery, placed the number of lobster fry liberated from Otago Harbour during the first 15 years of the attempts at more than 1,000,000. He knew that the young lobsters would live mainly concealed among rocks and sea.weed, and that they probably would not be caught, but he always hoped to learn that some had been seen near the coast, a hope that was not gratified.

"We are still trying to roar lobster fry in our tanks to a stage when they can deal with their enemies,” Professor IV. B. Benham wrote from Dunedin on November 10 last. “In 1931 we liberated 200,000 youngsters

F.L.S., F.Z.S., for “The Dominion.”)

in the sea, but they were in such an early stage of development that they, doubtless, fell an easy prey to fishes and other enemies. As to results, I grieve to state that up to the present no undoubted lobster has been caught or seen in our seas. We are still trying to rear them to a stage when, we hope, they will be sufficiently strong or active to deal with all inimical conditions of life. In spite of a reduced Government grant, we keep the station in good order, but until our former grant is reinstated we are merely marking time.”

Experiments in rearing lobsters have been conducted at the Marine Biological Station at Port Erin, Isle of Man, by the Oceanography Department of Liverpool University. As a young lobster increases in size, it sheds the whole of its covering in one piece, and forms a new and a larger one. The moults are frequent. A lobster that is two inches long has moulted 14 times, one five inches long 20 times, one ten inches long, when it is four years old, 25 times. The moults are very dangerous times for the lobster. Unless they are performed skilfully, the lobster will die. At Port Erin, 99 lobsterlings were taken after their third moult and were kept under strict observation. Each was kept for eleven months in a. separate glass jar filled with sea water.

Only four died while casting their coverings or soon afterward. Deaths occurred mainly when moulting recommenced after the term of no growth in the winter. There was slight evidence that a lobster usually moults seven times in its first growth term, five times in its second year, twice in its third and fourth years and once a. year after that, until the tenth year at least. Moulting and growth were most marked when the atmospheric temperature was high, showing that temperature is an important factor in a lobster’s development. Au account of these observations is in the official report on the Lancashire Sea-fisheries Laboratory, edited by Dr. R. J. Daniel. The laboratory has a high reputation for its valuable research.