COD EGGS IN MASSACHUSETTS BAY, 1924-1925 



267 



LOCAL PRODUCTION IN MASSACHUSETTS BAY 



The Plymouth grounds could easily be established as the production center for 

 locally spawned eggs throughout the season of 1924-25; and even during the great 

 influx of haddock and cod eggs from the east in the late spring (fig. 8), as will be 

 described later, the charts show unmistakable evidence of local production. 



Figures 6 and 7 indicate the distribution of eggs in early-cleavage and late- 

 embryo stages, based on the results of the first eight cruises. In Figure 6, extending 

 all along the western shore from station 17 to station 8, the large percentages of 

 eggs in early cleavage indicate the production area. By comparing this figure 

 with Figure 7, it will be seen that elsewhere in Massachusetts Bay later stages 

 dominate. 



Production on the Plymouth grounds is illustrated further by the following 

 table, showing the number of eggs taken on each cruise at station 15, on the northern 

 part of the grounds, and the increased numbers that had accumulated by the time 

 the drift reached station 10, on the southern part. The percentage of eggs in cleavage 

 stages is included to show that locally spawned eggs were being dealt with and not 

 immigrants from some distant source. 



Table 3 



Cruise 



Station 15 



Total 

 number of 

 eggs taken 



Percentage 

 in early 



Station 10 



Total 

 number of 

 eggs taken 



1 



2. 

 3 

 4. 

 5. 

 6 

 7 

 8. 



77.8 

 100.0 



58.8 

 100.0 



75.0 

 0.0 



53.3 

 100.0 



28 



14 

 519 



26 

 298 



17 

 265 

 243 



EXTENT OF THE SPAWNING SEASON ON THE PLYMOUTH GROUNDS 



The collections also afford considerable information on the duration of the 

 spawning season on the Plymouth grounds in 1924-25. Before starting the regular 

 cruises with the Fish Hawk, two visits were made to these grounds, the first on 

 November 12. Spawning had already begun at that time, although the temperature 

 of the water had dropped to only 10.1° C. A 20-minute haul with a foot net (No. 0 

 silk) yielded 53 eggs, all in early-cleavage stages. These can safely be called cod, 

 both because of the abundance of ripe cod present and also because haddock spawning 

 had not begun. Of 11 adult cod, ranging from 5 to 50 pounds, taken at random from 

 a trawl at this time, 6 were females and 5 were males. One female was still green, 

 one nearly ripe, two ripe, and two nearly spent. Of the males, one was green and 

 four were ripe. On November 20 a second haul on the same grounds yielded 65 

 cod eggs, all, with the exception of one (an early embryo), in cleavage stages. Some 

 73363—28 3 



