250 REPORT OF COMMISSIONER OP FISH AND FISHERIES. 



shore. An inquiry disclosed that the position of tlie favorable zone 

 fluctuates under the influence of a variety of causes. During the his- 

 toric period the level of the lake has undergone extensive oscillations, 

 large areas of land being flooded during periods of high water and 

 conversely the bottom of the lake being laid bare at low-water stages. 

 There is an annual oscillation having the same effect in a minor degree, 

 and the seasonal variation in the discharge of the rivers causes a wide 

 range in the density of the lake near their mouths. Finally there are 

 irregular variations due to the influence of the winds in driving the 

 lake water up on sloping lee shores. 



If the conditions as found at any given time were constant there 

 would be no difficulty in introducing such sessile marine organisms as 

 the oyster, but the frequent, almost continuous, fluctuations in the 

 density of the water make the atteuqjt entirely unfeasible. It is not 

 improbable that places could be found where a few adult oysters would 

 survive, but the conditions are such as would inevitably prove fatal to 

 the oyster fry which, as a free-swimming organism, would be certain 

 to be wafted by the currents into water, on the one hand too dense, or 

 on the other too fresh, to be withstood by its delicate and sensitive 

 organization. The adverse and unsuitable conditions would also be 

 sure to be reflected in the inferior condition of such adults as might 

 be able to survive. 



The writer is convinced from his examination that neither self-sus- 

 taining beds, replenished by their own reproductive activity, nor those 

 maintained by annual importations from the coast, as practiced by the 

 planters in San Francisco Bay, can be introduced in Great Salt Lake 

 with any assurance of commercial success. 



None of the brackish springs contain sufficient salt to be utilized in 

 their natural condition, but there are reasons to believe, as has been 

 set forth on page 240, that by excavating j)onds their waters might be 

 used. The expense would be great, however, and it is doubtful if they 

 would prove to be commercially successful, even if their experimental 

 feasibility should be proved. 



The objections to the planting of fish, oysters, etc., in Great Salt 

 Lake are based on physical rather than biological conditions. There 

 is an abundant food supply, the water teeming with brine shrimps and 

 insect larv«. The available fish food exceeds in quantity that usually 

 found in the sea, its abundance being largely due, no doubt, to the 

 fact that there are no fish to consume it. The lake is also exceedingly 

 rich in minute plants, especially diatoms which constitute the chief 

 food of the oyster, but from a practical point of view this fact has no 

 value when we are confronted by the absolutely prohibitive physical 

 conditions which the present examination disclosed. 



There is much greater probability of attaining valuable results by 

 introducing cat-fish into the fresh sloughs near the mouths of the rivers 

 than by attemijting the introduction of marine species into the lake. 



