.■•: WESTERN IMMATURE HERRING 



O'^ .^ 



EASTERN IMMATURE HERRING 



GEORGES BANK SPAWNING 

 POPULATION 



NOVA SCOTIA SPAWNING 

 POPULATION 



MASS. 



-^ 



Figure 7. --Major Bay of Fundy and Gulf of Maine herring groups as determined by serological 



and parasitological methods. 



Resiilts demonstrate that there is no 

 mass movement of herring away from the 

 Quoddy Region from April to November. 

 Because the tags remained on the fish for 

 short periods, no information was obtained 

 on movements into or away from the 

 Region during the winter months. 



Behavior . - -To determine whether her- 

 ring could withstand anticipated changes 

 in hydrographic conditions in Passama- 

 quoddy and Cobscook Bays, temperature, 

 salinity, and pressure tolerances were 

 investigated. The behavior of herring in 

 currents, their swimming speeds, and 

 depth distribution provide a basis for 

 prediction of fish movements in the ap- 

 proaches to the dams and the turbines. 



Morteilities of herring at various tem- 

 peratures were determined for newly 

 caught fish. Large herring were more 

 acutely ciffected by high temperatures 



than were small herring. The temperature 

 at which 50 percent of the herring would 

 die in 48 hours was calctilated to lie 

 between 66° and 70° F. for 3^- to 12- 

 inch herring. 



The tolerance of herring to various 

 salinities was tested, and it was found 

 that salinities as low as 5 parts per 

 thousand are not injurious. 



Resistance of herring to rapid changes 

 in pressure was investigated to determine 

 whether they covild survive the pressure 

 changes encountered during passage 

 through the turbines. Sardine herring 

 accustomed to surface pressure with- 

 stood an increase of 67 pounds per square 

 inch (equivcilent to a water depth of 150 

 feet) at a rate of 0.8 pounds per square 

 inch per second. Sardines accustomed 

 to a pressure of 20 pounds per square 

 inch survived decompression at a rate of 



12 



