REPORT OF THE COMMISSIONER OF FISHERIES XXV 



fort, N. C. During the course of the investigation 225 ships were 

 examined and data on the length of voyage, routes covered, and 

 l)orts visited were secured for each ship. These are now being 

 studied and a report on the work is nearly completed. 



It has been found that the fouling organisms are almost ex- 

 <'hisively those found on rocks and other submerged structures near 

 sliore, which bears out the earlier conclusion that fouling occurs 

 mainly when ships are in harbor. The seasonal periodicity for the 

 attachment of many of the organisms has been studied in different 

 harbors in order to correlate the fouling that occurs with the place 

 of attachment. It is believed that the results of this study will 

 make it possible to determine, from a knowledge of the cruising 

 cione by the ship and the time spent in various ports, when she 

 should be sent to the dry dock for cleaning. If this can be done 

 it will mean a distinct saving in expense for the maintenance of 

 both Navy and commercial vessels. 



ACTIVITIES or THE BUEEAU's IXVESTIGATORS 



During the past jenv the bureau has been requested to assign 

 trained scientists to several important investigations of great gen- 

 eral interest. Dr. C. J. Fish, general assistant, and Marie D. P. 

 Fish, junior aquatic biologist, accompanied the oceanographic ex- 

 j:!edition of the New York Zoological Society under the direction of 

 AVilliam Beebe. The steamship Arcfurus was fitted out for ocean- 

 ographic work and made extensive observations in the region of 

 the Sargasso Sea and in the Pacific Ocean between Central America 

 and the Galapagos Islands. The two representatives of the bureau 

 had entire charge of the work in physical and chemical ocean- 

 ography and of the plankton, including the eggs and larvae of fishes. 

 At the close of the fiscal year the expedition was still in the field, 

 but preliminary reports submitted indicate that the results will be 

 of more than usual interest and im^Dortance. The larval histories 

 of a number of fishes have been worked out, and valuable observa- 

 tions were made on the tuna of the Pacific. 



Dr. Walter Koelz, associate aquatic biologist, left in June with 

 the MacMillan Arctic Expedition, which will explore the region to 

 r]\e north of Greenland. Doctor Koelz will make collections and 

 observations on the fishes of that region and will also secure oceano- 

 graphic data and collections of the plankton. This is the first time 

 tliat a trained ichthyologist has accompanied such an expedition, 

 and interesting results are antici])ated. 



At the request of Dr. E. L. Mark, of the biological station at 

 Bermuda, Dr. P. S. Galtsoff, naturalist, made a short visit to Ber- 

 muda in June for the jDurpose of securing oceanographic data across 

 the Gulf Stream in a line from New York to Bermuda. The Gulf 

 Stream has great influence on the distribution and life of all the 

 organisms of the north Atlantic, but our knoAvledge of this most 

 important factor of the ocean, especially as it affects the life of our 

 food fishes, is very inadequate. Observations were made on tem- 

 perature, salinity, and color of the sea water. It is expected that 

 similar observations will be conducted under the direction of Doctor 

 :SIark. 



