17 



The oyster does not breathe in, the water, in the true sense of the 

 word, but it can be said to breathe the oxygen that is mixed 

 or dissolved in the water. Here again, if there are no currents, 

 the water immediately surrounding the oyster becomes exhausted 

 of its supply of oxygen, and the growth of the oyster correspond- 

 ingly retarded. The surface of the water in contact with air dis- 

 solves a certain portion of it — in fact, it may be saturated with 

 air. This air is then distributed to all parts of the water mainly, 

 though not entirely, through currents. Cold water will dissolve 

 _as much more air in proportion, than warm water ; as hot water 

 will sugar, more than cold. Consequently, the water on oyster 

 beds that lie in sheltered shallow bays, where there are no cur- 

 rents, and where the sun warms the water to such an extent 

 that it may actually feel hot to the touch, contains little oxygen 

 which oysters may use. So here the currents by bringing supplies 

 of water containing air, aid the growth of the oyster. 



Thirdly, and lastly, the currents carry off the waste matter. 

 All excretions, sediment that is collected and thrown off, and 

 everything of that nature, which, even though it may not be 

 actually detrimental to the life of the oyster, naturally retards 

 its growth, is carried away, and the oyster kept clean and 

 healthy. 



The currents then play a very important role in the life of 

 the oyster. Upon that principally depends the rapid growth 

 of the young. An oyster in a sheltered cove may take several 

 years to attain the same size as one that is situated where there 

 is a constant current of water in one direction or another. There- 

 fore it is an all important consideration in locating a bed to 

 determine the currents, not only the fact that there are cur- 

 rents, but as we shall see later from ivhence those currents come. 

 On our coast there is no current too swift for an oyster, in fact 

 it may be said that other conditions being equal, the faster the 

 current, the greater the growth. 



The tides on the coast east of the Mississippi river are slight, 

 averaging but 11-2 feet, with only this rise and fall on the 

 coast line, it is not surprising that in many of the inland bays 

 and bayous there is no noticeable tide. The tides are. however, 

 influenced to a large extent by the direction of the wind, and it 

 can be said that the water will rise or fall according as the wind 



