FISHERY BULLETIN: VOL. 70, NO. 2 



'^^. 



\,^- Cape Ann 



0.5 



Figure 4. — (a) Isohalines (%c) during a spring cruise, March 28-April 13, 1967. Feath- 

 ered arrows indicate shoreward intrusions of coastal water (from Graham, 1970b), and 

 unfeathered arrows indicate current directions along the coast (from Bumpus and Lauzier, 

 1965). (b) Isolines of larval catch rates (no/100 m^) for the above cruise. 



catches made at the three outer estuarine, three 

 lower estuarine, and two upper estuarine sta- 

 tions, and plotting them in a time series. Peaks 

 in larval abundance progressed from outer to 

 upper estuarine stations with time, suggesting 

 an inshore movement of the larvae (A, B, and 

 C in Figure 6). Two such progressions were 

 obtained in 1966 and one in both 1964 and 1965. 

 In 1964, larvae passed the outer and lower sta- 

 tions between our scheduled cruises and ap- 

 peared first at the upper stations as a peak in 

 abundance in early October. In spring, larvae 

 were always more abundant at the upper estu- 

 arine stations, and progressions in peaks of 

 abundance up the estuary were not apparent. 



LARVAL LENGTHS 



5 10 20 30 40 50 60 70 80 90 95 98 99 

 STATION DIFFERENCES (Percent Accumulated ) 



99.8 99.9 



Figure 5. — Accumulated frequency distributions of sta- 

 tion-to-station differences from west to east along the 

 coast. The cruise in 1968 began to the east of that in 

 1966. 



Larval movements up the estuaries during 

 autumn were easier to detect in the Boothbay 

 area because larvae were transported inshore 

 primarily by tidal flows (Graham and Davis, 

 1971 ) . Tidal flows followed the inshore-offshore 

 axes of the estuaries and embayments; thus the 

 landward movement was detected by grouping 



The rate of increase in average length varied 

 seasonally and geographically. Data from the 

 coastal and Boothbay areas showed a marked 



312 



