EEPORT OF THE COMMISSIONER OF FISHERIES. 21 



was necessarily affected, as the only source of supply is the fish 

 caught for market. As against more than 954,000,000 taken in 1920, 

 the past season's collections reached only 650,000,000. 



The shortage in cod eggs ma^' be ascribed to somewhat similar, 

 though not identical, conditions. The body of cod on the shore 

 grounds appeared to be smaller tlian usual, and as the market price 

 of haddock offered more lucrative employment for the fishermen 

 comparatively few boats engaged in the cod fishery. Egg collec- 

 tions of this species in the Gloucester field amounted to 210,040,000, 

 while 214,702.000 were secured from brood fish held at the Woods 

 Hole hatchery. Haddock eggs to the number of 629,120,000 were 

 obtained for the Gloucester station between January 22 and April 29, 

 1921, this number exceeding the previous records for that species. 



Weather conditions were generally favorable for flatfish propaga- 

 tion, and the egg: collections at all stations aggregated 1,980,291,000, 

 an increase of 1T5,()()(),0()0 over the jirevious year. High water-tem- 



Eeratures occurring toward the latter part of the season in the Woods 

 [ole region and an unusually early ending of the spawning in Maine 

 waters were factors in curtailing the take of eggs. 



The artificial propagation of the pole flounder {Glyptocephalus 

 cynoglossus) was undertaken by the Bureau for the first time dur- 

 ing the past year. The jiresence of this fish in New England waters 

 has long been known, but, because of its peculiarly small, soft mouth 

 it was not taken by fishermen on the hand lines and traAvl lines com- 

 monly used. With the coming into general use of the otter trawl in 

 the siiore fisheries of the section the pole flounder has made its ap-, 

 pearance in the markets in constantly increasing numbers, and be- 

 cause of its food value and excellent flavor it commands a ready mar- 

 ket at a high price. ^\'ith the view of encouraging and assisting a 

 new anil growing indiistrv an ex])erienced spawn taker was detailed 

 to investigate the spawning habits of this si)eiips. A close watch 

 was kept on the fish landed at the markets during April aud ^fay, 

 but no fully matured eggs were found until May 22. From that date 

 to the end of June 19,410,000 eggs were collected, fertilized, and 

 planted on the spawning grounds, and several small lots were taken 

 to tiie (iloucester hatchery for observation. The eggs are semibuoy- 

 ant, nonadhesive, and about 0.05 of an inch in diameter, measuring 

 approximately 462,000 to the fluid quart. Those placed in a Chester 

 jar for incubation did not survive, but the freer circulation of the 

 AIcDonald tidal box ai)peared to meet their requirements. It is be- 

 lieved that the hatching of this fish can be profitably extended during 

 the coming season. 



RESCUE OPERATIONS IN MlSSISSim VALLEY. 



The salvaging of food fislics in the o\'erflowed waters of the Mis- 

 sissippi and Illinois Ivivers jpis continued to be a prominent adjunct 

 of the lisli-cidtiiral sciNice. In the 19'i<) season, as eai'ly as the water 

 stages would i)f'rmit, this work was begun and continued without in- 

 termission as late as weatlier conditions were favorable. Owing to 

 the persistence of liiLdi water much beyond the usual time, many 

 millions of young fi.sn, which under ordinai-y circumstances would 

 iiave been left to perish in isolat<'d ])f)ols iind sloughs, were able to 



