PORTOBELLO BIOLOGICAL STATION.

Otago Witness, Issue 3869, 8 May 1928, Page 24

PORTOBELLO BIOLOGICAL STATION.

During last month the arrival of the Antarctic whaler C. A. Larsen produced a very disagreeable state of affairs in the harbour, owing to the large amount of oil which was liberated. For several days quantities of oil passed through the channel between Quarantine Island and the station, and covered the beaches. The only way of keeping the ponds at Portobello fairly clear of the oil was to close the top valves, and change the water only after half-tide. Though whale oil is not such a deadly material to marine life as minerals oils are, it is very destructive to the smaller organisms living between tide-marks, and to all swimming animals which live near the surface ano depend upon a liberal supply of oxygen in the upper strata of water. The amount of oil in the harbour may be guessed at fron the fact that in less than two hours during one day over two barrels of oil were scraped off the embankment. Had this not been removed much of it would have found its way into the ponds, and would have imperilled the lives of the lobsters recently imported from Britain.

These crustaceans are thriving quite satisfactorily, and. as is usual during the colder months of the year, they become sluggish an-’ eat little food. Several have cast their shells. The temperature of the pond water on May 1 was tr.ree degrees (centigrade) below the lowest readings recorded in March.

About this time of year most of the larger fish in the harbour move out to sea. where the water is always at considerably higher temperature than in shallow, enclosed areas. They return in the spring months. During last season the first kelp-fish were taken in the end of September, though set-nets were placed continuously in the deep-water channel close to the station throughout August and September. The first moki was taken on December 1.

The lowest temperature recorded in the ponds last winter was 4dog C. (equal to 39.02 deg F.) on July 15, the harbour water outside the ponds standing at 4.sdeg C.