398 U. S. BUREAU OF FISHERIES 



were received, of which 250,320,000 came from the Port Chnton and 

 North Bass fields. The remainder were derived from the fisheries at 

 Middle Bass, Catawha Island, Put in Bav, and Toledo. No nets 

 were operated in the formerly prolific field around Monroe Piers, 

 Mich., owing to the poor results attained there in recent years. The 

 cause of the failure here has not been definitely ascertained. Some 

 of the fishermen have attributed it to the discharge of pollution into 

 the lake from the Maumee, Raisin, and Detroit rivers, while others 

 claim that so many gill nets were set across this portion of the lake 

 that the passage of the fish to their spawning grounds in its western 

 end was efl'ectually cut off. 



Shipments of green whitefish eggs to the number of 78,760,000 

 were made to otiier hatcheries, 9,080,000 of inferior fjuality were 

 planted on the reefs near the hatchery immediately after being 

 fertilized, and 5,760,000 e3^ed eggs were forwarded to the Lincoln 

 Park Zoo at Chicago, 111. From the remainder, 148,000,000 fry 

 were realized, the proportion of hatch being slightly more than 67 

 per cent of the retained eggs. All of these were released in the lake 

 at points ranging from 2 to 12 miles distant from the hatchery. 



On April 3, nearly three weeks after the legal opening of the pike- 



Ecrch fishing season, the spawning grounds in the western end of 

 ake Erie were still covered with ice, which interfered with the set- 

 ting of nets. In some instances the fishermen placed their nets where 

 open water was found, with the result that many of them were 

 destroyed by ice fields with the shifting of the winds. 



Despite the unfavorable prospects, spawn takers were stationed at 

 the various collecting centers at the usual time, though no eggs were 

 available until April 19. Between that date and May 3 a total of 

 117,425,000 eggs were received, nearly all of them being taken at the 

 Toledo and Port Clinton fisheries, these fields jdelding 72,625,000 

 and 36,575,000 eggs, respectively. Green eggs to the niunber of 

 13,825,000 were forwarded to the Iowa State hatchery, and from the 

 remainder 36,000,000 fry were hatched and liberated. 



Although the fishermen had been requested in advance of the pike- 

 perch spawning season to save all available eggs of the sauger and 

 yellow perch, only 8,400,000 of the former and 4,350,000 of the latter 

 were secured. It is believed the collections of these species would 

 have been much more satisfactory- had weather conditions not inter- 

 fered. In each instance the eggs were of good quality, yielding a 

 good percentage of strong vigorous hj. The sauger eggs were eyed 

 in 7 days, and mcubation was completed at the expiration of 10 days 

 additional in a mean water temperature of 51°. 



As with the other spring-spawning species, the results of carp 

 propagation in the Port Clinton and Sandusky Bay fields were quite 

 disappointing. The commercial fishermen captured only about one- 

 half tlie number of fish taken the previous year, and egg collections 

 were correspondingly reduced, the total take amounting to 41 ,825,000, 

 or about one-fourth that obtained in June, 1923. It would appear 

 that the unfavorable natural conditions had the effect of reducing 

 the run of fish to their customary spawning grounds. Egg collections 

 of this species were made between June 5 and June 30. 



