REPORT ON OCEANOGRAPHY 23 



R. R. V. "Discovery 11" in 1950-51 worked 300-mile section lines, are 

 off Sydney, Eden, Pt. Culver, Albany, and Rottnest Island. The data 

 are not yet published but certain results are given in a paper entitled 

 "A Comparison of the Hydrological conditions off the Eastern and West- 

 ern coasts of Australia." (I.P.F.C. Section II Proc. Madras meeting.) 



Through the courtesy of her owners, the T.S.M.V. "Wanganella" 

 is now collecting surface salinity and temperature observations on her 

 regular fortnightly cruises from Sydney to New Zealand. 



The salinity temperature characteristics of the surface Tasman Sea 

 water masses have now been determined and their seasonal variation in 

 position, particularly as they affect coastal waters, will be followed in 

 the future. 



ii) Coastal Studies 



The monthly sampling at various coastal stations in Eastern and 

 Western Australia has been continued. A very interesting long term 

 trend in productivity and other hydrological characteristics is now ap- 

 parent in E. Australian coastal waters during the period 1942-1952 and 

 an account of this phenomenon is now being prepared for publication. 

 The annual hydrological cycles at various latitudes along the Eastern 

 Australian coasts have now been established. A paper is being prepared 

 giving a comparative study of these annual cycles. This coastal data 

 up to 1950 are contained in volume 4 of O.S.L. 



iii) Estuarine Hydrology 



Since the publication of the comparative results to date of estuarine 

 hydrological studies, (A.J.M.F.R. Vol. 2 No. 1 June 51,) these studies 

 have concentrated on the detailed dynamics and the productivity fea- 

 tures of selected estuarine systems. The productivity characteristics of 

 the intertidal region particularly in relation to oyster production, have 

 been intensively studied and a generalized account of this work ap- 

 peared in Rapp. et Proc. Verb. Vol. 131, 1952-C.I.E.M. 



Australian Fisheries Biology Since 1948 



A. Unutilized or little-utilized stocks of aquatic organisms (discovery, 

 fishing tests, stock identification, life histories, fluctuations):— 

 (i) Tunas. As small fishery for Thunnus thynnus maccoyi, the 

 outcome of investigations and fishing tests in the previous decade be- 

 gan in southeastern waters. It is becoming evident that shoals of 

 this species may occur further out to sea than was once supposed, and 

 are sometimes scarce near the coast. These fluctuations in availability 

 are being studied. New facts about the distribution of Katsuwonus pe- 

 lamis in southeastern waters, including its apparent preference for wa- 



