FISHERY BULLETIN: VOL. 70, NO. 2 



and condition and spring abundance of larvae 

 has been largely confined to the Boothbay area; 

 the possibility of extending monitoring to other 

 areas of the coast is being investigated. Never- 

 theless, events in the ecology of the larvae in the 

 Boothbay area could represent those of the entire 

 coast of the Gulf. Seasonal changes in larval 

 abundance are similar along the coast and are 

 comparable to those in the coastal area off south- 

 west Nova Scotia (Das, 1968, see footnote 2) and 

 on Georges Bank (Boyar et al., 1971). Yearly 

 changes in oceanic conditions along the coast and 

 in the offshore Gulf of Maine are also related 

 (Colton, 1968). Further correlation between 

 ecological events in the Boothbay area and those 

 in other areas of the Gulf, at least adjacent areas, 

 is evidenced by the agreement of the winter mor- 

 tality estimates obtained in the Sheepscot and 

 the subsequent spring abundance there. Larvae 

 captured in the spring include emigrants from 

 areas other than Boothbay. Correct forecasts 

 of a poor fishery, to date, coincided with poor re- 

 cruitment to the fishery; unfortunately, fore- 

 casts have not been made during years of good 

 recruitment in the western sector. 



^■^"1 BOOTHBAY 



llllL 



a. 



V) 



l.5n 



10 



I 0,5 



COASTAL 



64 65 66 67 68 69 

 YEAR CLASS 



Figure 14. — Peak catches for larval herring in the spring 

 among year classes 1964-69 ; in the coastal area between 

 Cape Small and Penobscot Bay and in the Boothbay area. 



SUMMARY OF ABUNDANCE AND 

 DISTRIBUTION 



The abundance and distribution of larval her- 

 ring along the western coast of the Gulf of Maine 

 is determined by their movements and mortality. 

 Two inshore movements, one in the autumn and 

 the second in the spring, are separated by a pe- 

 riod of larval dispersal. Larvae hatch along the 

 coast in autumn and penetrate the bays and estu- 

 aries. Their inshore movement decreases by 

 early winter and in midwinter they disperse; at 

 this time concentrations of larvae are infrequent 

 inshore and along the coast. A second shore- 

 ward movement begins with the advent of 

 spring. Larvae which hatched the previous au- 

 tumn along the coast, and probably some which 

 hatched beyond our sampling area, aggregate 

 when making this shoreward movement. The 

 inshore movement is completed by the end of 

 spring when the majority of the larvae have 

 assumed their adult form. 



Mortality during the inshore movement in the 

 autumn is very high. Although it is lower in 

 the winter, mortality during this season may 

 determine the abundance of larvae in the spring 

 because the numbers are reduced by early winter 

 to a relatively common level each year. The low- 

 er winter mortality may be related to the dis- 

 persal of the often weakened larvae; dispersal 

 would reduce intraspecific competition for food 

 and space. The lowest mortality occurs in the 

 spring when the larvae are in good condition as 

 shown by their ability to avoid high-speed trawls 

 with large mouth openings. 



The movement of the larvae shoreward with- 

 in the complex currents of the coast is a striking 

 feature of their coastal ecology. 



LITERATURE CITED 



Anthony, V. C, and H. C. Boyar. 



1968. Comparison of meristic characters of adult 

 Atlantic herring from the Gulf of Maine and ad- 

 jacent waters. Int. Comm. Northwest Atl. Fish., 

 Res. Bull. 5:91-98. 

 BiGELOW, H. B., AND W. W. WELSH. 



1925. Fishes of the Gulf of Maine. Bull. U.S. Bur. 

 Fish. 40(Part I),567p. 



320 



