COASTAL WINDS AND THEIR INFLUENCE UPON FISH. 33 



2. The bulk of the spawning takes place in proximity to 

 the open ocean where the floating eggs (and afterwards 

 the young larvae) are at the mercy of the coastal currents. 

 These flow as a rule in a southerly direction past the head- 

 lands and the mouths of the estuaries, and thus it happens 

 that the "pelagic stage " is carried back towards the 

 locality whence the parents came. The old fish are replaced 

 by young which remain in the estuary until ready to 

 migrate and spawn; then the process of redistribution is 

 repeated. 



Analogous cycles of migration and drift have been found 

 to exist in other parts of the world, notably in the North 

 Sea, and there is reason to believe they are, with modifi- 

 cations, quite universal in connection with the distribution 

 of fishes having pelagic eggs. It is well known that but 

 an infinitely small percentage of the millions of eggs that 

 a single fish may produce, will succeed through the various 

 stages of development and attain maturity, and it is also 

 very apparent that this great loss or destruction takes 

 place mainly during the least protected stages — that is 

 while the eggs or the young fry are drifting helplessly 

 about in the open waters. Under these circumstances it 

 would seem that the favourableness or otherwise of certain 

 physical conditions, notably the currents, should in a general 

 way afford an index to the relative successes and losses of 

 a hatching season, and it is in this direction that my 

 inquiries have succeeded through indirect channels, i.e., 

 the winds. 



Some peculiarities in our Coastal Winds.— Through the 

 courtesy of Mr. Hunt, I have had an opportunity of examin- 

 ing the Sydney anemometer records for the last twenty-four 

 years. They contain parallel sets of figures representing 

 respectively (1) the number of hours the winds blew from 

 each point of the compass, and (2) the corresponding 



C— June 5, 1907. 



