SPRING AND SUMMER MOVEMENTS 

 OF SUBADULT STRIPED BASS, 



MORONE SAXATILIS, 

 IN THE CONNECTICUT RIVERA 



The Connecticut River has no known spawning 

 population of striped bass, Morone saxatilis, but 

 there is an annual run of subadults in the late spring 

 and summer from Long Island Sound to Holyoke 

 Dam, 140 km upstream (Moffitt et al. 1982). In 

 1980-82, 80-90% were age II (the remainder were 

 age III); about 60% were males (Warner 1983). The 

 biological reason for such a run is unknown, but 

 feeding may be an important attractant to the river. 

 The major foods of striped bass collected at Holyoke 

 Dam are spottail shiners, Notropis hudsonius, and 

 the scales and body parts of adult American shad, 

 Alosa sapidissima, and blueback herring, A. aesti- 

 valis, that result from injury or death at the hydro- 

 power dam and fish lifts or from angling (Warner 

 and Kynard 1986). Factors other than food are un- 



iContribution No. 94 of the Massachusetts Cooperative Fishery 

 Research Unit, which is supported by the U.S. Fish and Wildlife 

 Service, Massachusetts Division of Fisheries and Wildlife, Massa- 

 chusetts Division of Marine Fisheries and the University of 

 Massachusetts. 



doubtedly important influences on the riverine 

 migration. 



The migration of subadult striped bass into natal 

 or nonnatal rivers was documented by Raney et al. 

 (1954) and Nicholas and Miller (1967), but the 

 reasons for the movement are not clear. We hy- 

 pothesized that detailed studies of subadult move- 

 ments in the Connecticut River could help reveal 

 some of the environmental factors that effect the 

 movements. We used radio telemetry of subadults 

 captured at Holyoke Dam to observe the use of river 

 habitats, diel activity, and the rates of upstream and 

 downward movements. We also investigated the 

 passage of striped bass at the Holyoke fish lifts in 

 relation to river temperature during 1979-86. 



Study Area 



Radio-tagged striped bass were observed after 

 they were transferred above Holyoke Dam into the 

 53 km of the Connecticut River, between the Hol- 

 yoke Dam and the Cabot Station hydroelectric 

 facility which is below Turners Falls Dam (Fig. 1). 

 The upstream 23 km reach is relatively straight, 

 with few areas deeper than 4 m; the lower 30 km 

 reach meanders, creating a deep channel and shoals 

 (Fig. 1). Bottom type is rubble and gravel in the 



Cabot Stotion {8).,^ 

 Monlogue Bridge (2) 

 Eost Deerfield (3) 

 Second Island (2)---..._ 

 Sunderland Bridge (2)-.. 

 S-Curve (4)-,,^ 

 N. Hadley Stait ( l).'^---._ 

 Hadley Turn (I), 

 Northampton Turn (I) "j^ 

 Shepherd Island (I ) 



Northampton 

 Oxbow Outlet (5 



Rt. 202 Bridge (I), 



Turners Falls 

 Dam 



Deerfield River 



1981 Release Site 



1982 Release Site 



lOkm 



•Coolidge Bridge 



Holyoke 



Holyoke Tailrace "-^--Dam 



Figure 1.— The 53 km of the Connecticut River above the 

 Holyoke Dam where the movements of radio-tagged striped 

 bass were observed in 1981-82. The 13 holding areas where 

 striped bass stopped are on the left side of the river (number 

 of stops in parenthesis). 



FISHERY BULLETIN: VOL. 85. NO. 1. 1987. 



143 



