SECULAR TRENDS AT E. AUSTRALIAN COASTAL STATIONS : 1942-52 751 



station is linked with the variation in the development oi this counter 

 current. However, it has not been possible as yet to show any con- 

 sistent relationship between the variation in this counter current and 

 corresponding variation in the direction or strength of coastal winds. 

 It is possible that wind conditions over the Tasman Sea proper may be 

 more influential in this regard but scarcity of data prevents such an 

 analysis being made. 



VI. Discussion 



in studying the coastal hydrology of the east Australian region 

 with its comparatively narrow shelf and well-developed offshore current 

 system, the extreme variability of the coastal environment and the major 

 effects of the offshore current on such variation, are evident. This 

 paper serves to illustrate another longer term variation, which is im- 

 portant to the fisheries of the region and which has had very wide- 

 spread effects. 



It is obvious, however, that to advance beyond the mere descrip- 

 tion of coastal events, and of their probable genesis, to a more com- 

 plete and perhaps useful stage, requires the simultaneous collection of 

 information upon the dynamics and hydrological structure of the off- 

 shore in addition to the onshore regions. Moreover, it is clear that the 

 elucidation of the causes for long term fluctuations in east Australian 

 coastal conditions requires persistent and intensive investigation not 

 only of the coastal hydrology but also of the associated estuaries and 

 their flood contribution, as well as of the meteorological elements, par- 

 ticularly wind and rainfall, which enter into these cycles. 



