52 U. S. ULlREAl' OF KLSIIKIilKS 



givatly increasod by tlie fact that it appears to be tlie most important 

 blueback spawnin<*: district now renuiinin<^ in the Columbia Basin; 

 that is, that part of the run which spawns in the Okanogan contrib- 

 utes the hirgest part of the commercial catch of this species in the 

 Columbia. Plans are being made to further investigate this district 

 during the coming season. 



FISHERIES OF CALIFORNIA 



The co()j)eration with the California Fish and Game Commission 

 in the study of the tuna and sardines has been continued. This 

 work is being done under the ellicient direction of William F. 

 Thompson, of the California connnission. Mr. Thomi)son ranks as 

 one of the leading scientists engaged in fishery research, and one of 

 the primary objects in entering into the ])i'esent co()])erative arrange- 

 ment was to make possible the training of additional investigators. 

 It is expected that one of the men tlius trained will be taken over by 

 the bureau in the near future and assigned to an independent inves- 

 tigation. The arrangement has i)roved very successful and will 

 doubtless be continued. 



riSHES OF El. SALVADOK 



Reports on the investigations in El Salvadoi- conducted by Samuel 

 F. Ilildebrand and Fred J. Foster during January and February, 

 1924, have been completed. A joint and final i-e})ort by these inves- 

 tigators, dealing with the status of the fisheries and embodying rec- 

 ommendations for the rehabilitation of the sadly depleted waters, 

 was prei)ared and forwarded to the (lovernment of El Salvador. 

 Mr. Ilildebrand also completed and submitted for i)ublication a de- 

 scriptive catalogue of the fresh-water fishes of El Salvador, which 

 embodies the descriptions of several new species, together with a list 

 of marine fishes taken at two of the ports of El Salvador. 



INVESTIGATIONS OF SHELLFISH AND TERRAPIN 

 OYSTERS 



Investigations relating to oyster culture were conducted during the 

 period July 1 to December Si, 1924, by Dr. P. S. Galtsoff at Woods 

 Hole, Mass., Herbert F. Prytherch at Milford, Conn., and by J. S. 

 Gutsell in Great South Bay, Long Island, N. Y. All of these investi- 

 gations have now been placed under the direction of Doctor Galtsoff , 

 whose wide experience with oceanographic research particularly fits 

 him for this difficult task. 



Previous observations in Long Island Sound have shoAAm that the 

 pollution of inshore Avaters by trade wastes is one of the factors 

 affecting the setting of the oyster larvte in the Sound. Since the 

 trade wastes discharged into Bridgeport Harbor, the Housatonic 

 River, and New Haven Harbor contain considerable amounts of in- 

 organic acids and consequently increase the hydrogen-ion concentra- 

 tion of the Avater, it Avas of interest to determine the effect of the in- 

 crease of hydrogen-ion c(mcentration u])on the fertilization of oyster 

 eggs and the vitality of ovster larva\ The experiments Avere carried 

 out at the Woods Hole laboratory by Dr. P. S. Galtsoff. The larvte 



