24: EIGHTH PACIFIC SCIENCE CONGRESS 



ters of 16 to 18 °C., were brought to light. A survey of tropical Austra- 

 lian waters in the latter half of 1949 showed Kishinoella tonggol and 

 Euthynnus alletteratus to be the most abundant tunas. In the waters 

 of Australian New Guinea the principal species appear to be E. allette- 

 ratus and Katsuwonus pelamis. 



(ii) Clupeoids and carangids. The existence of several stocks of 

 Sardinops neopilchardus and Engraulis australis was demonstrated. Pro- 

 blems of age-determination from scales of Sardinops were studied. As 

 a result of previous investigations a small fishery arose on one stock 

 of Sardinops in southwestern Australia. Echo sounder traces of shoals 

 of Sardinops, Engraulis, and the carangid Trachurus novaezelandiae 

 were identified. 



(iii) Archibenthic fishes. The larger teleosts and elasmobranchs of 

 the continental slope, at depths of about 200 to 800 metres, are being 

 investigated by long-lining in southeastern waters. 



(iv) Algae. Studies were made of the availability of the giant kelp 

 Macrocystis pyrifera and its rate of regeneration after cutting. 



(v) Other exploratory investigations included: Continuation of sur- 

 veys of fish resources in New Guinea, the northwest, and elsewhere; a 

 special survey of unutilized stocks of Palinurid crayfishes in north- 

 western waters; and attempts to locate reported new beds of pearl oysters 

 (Pinctada) in the northeast. 



B. Utilized stocks (stock identification, life histories, natural fluctua- 

 tions, effects of fishing):— 



(i) Barracotta (Thyrsites atun). Progress was made with the iden- 

 tification of different stocks, all of which appear to be under-fished. 

 Considerable seasonal changes in bodily condition were observed. 



(ii) Australian salmon (Arripis trutta). Progress was made with 

 the identification of different stocks. As a result of previous investiga- 

 tions two salmon canning firms now use aircraft to locate shoals. There 

 are no clear signs of over-fishing. 



(iii) Humpback whale (Megaptera nodosa). The fishery revived 

 on the west coast of Australia and commenced on the east coast. Biolo- 

 gical data are being obtained at whaling stations. The length of this 

 whale at first maturity appears to be less than was previously thought. 



(iv) Western crayfish (Palinurus longipes). The fishery expanded 

 greatly, partly as a result of previous scientific surveys of the resource. 

 Studies were made of intraseasonal migrations of crayfish from deep to 

 shallow water, and across the shallows. As with the preceding stock, 

 the possible necessity for future control of exploitation is being borne 

 in mind. 



