52 



BIOLOGICAL REPORT 31 



inshore in spring and offshore to deeper waters in 

 late fall. The diet of adults consists of crustaceans, 

 fish, and mollusks. Juvenile black sea bass utilize 

 Buzzards Bay as a nursery ground and, as bottom 

 feeders, eat primarily mysids in the shallow areas. 

 Sea bass are born as females, transforming into 

 males after their first spawning. As a result females 

 tend to predominate due to their high percentage in 

 young age classes. In contrast, recreational catch 

 consists primarily of males, their larger size making 

 them sought after by sport fishermen. The selective 

 recreational catch may impact populations by al- 

 tering sex ratios and decreasing the number of males 

 available for reproduction (Davis 1989). 



Tautog ( Tautoga onitis). Tautog is an impor- 

 tant sport fish; moving in from offshore waters in 

 spring, this species is abundant in bay waters from 

 May through September. As it does for most of the 

 major species, the bay provides critical spawning 

 and nursery habitat for tautog. Tautog spawning in 

 Buzzards Bay is noted in historical records (Davis 

 1 989) and the continued abundance of tautog is 

 noted on species lists from 1620 to present. This 

 species spawns in weedy, inshore areas, thus the 

 many sub-embayments and coves, especially those 

 with extensive eelgrass beds, are highly suitable for 

 reproduction. The Weweantic River estuary is a fre- 

 quent spawning ground for this species (Clayton et 

 al. 1 978). The buoyant eggs and juveniles remain 

 inshore, with juveniles overwintering within the es- 

 tuary, particularly in vegetated areas. The primary 

 diet of tautogs consists of mollusks, blue and ribbed 

 mussels, crabs, worms, and lobsters. The tautog 

 population in Buzzards Bay may be slowly increas- 

 ing based on the catch since 1 980, which is prima- 

 rily from recreational fishing and lobstering; how- 

 ever, no quantitative assessment exists at present. 



Butterfish (Peprilus tri acanthus). Butterfish 

 spawn during summer months in shallow waters 

 throughout the mid-Atlantic Bight, and Buzzards 

 Bay provides a nursery area for the species. Juve- 

 nile butterfish grow quickly and migrate offshore to 

 deeper waters in late fall, returning again in April. 

 The diet of the butterfish consists primarily of cope- 

 pods, small fish, jellyfish, and polychaetes; in turn, 

 butterfish are a prey source for bluefish, silver hake 



(Merluccius bilinearis), red hake (Urophycis 

 chuss), and striped bass. It is an important com- 

 mercial species all along the mid- Atlantic shelf and 

 is frequently identified in the historic literature as 

 being an abundant and important species for Buz- 

 zards Bay (Davis 1 989). The schooling behavior 

 and therefore patchy distribution of this fish results 

 in variable year-to-year catch statistics. These varia- 

 tions are thought to be due primarily to limitations in 

 catch rather than significant changes in the 

 population (Davis 1989). 



Bluefish (Pomatomus saltatrix). Seasonal 

 migrations of bluefish represent an important recre- 

 ational and commercial fishery during summer 

 months in Buzzards Bay. Although spawning off- 

 shore, juveniles (known as "snapper blues") move 

 in large numbers into the warmer inshore waters of 

 the bay. These fish are voracious feeders, consum- 

 ing a wide variety offish and invertebrates in the 

 water column. Mackerels, menhadens, alewives, 

 herrings, and weakfish, as well as shrimp, lobsters, 

 squid (Loligo opalescens), crabs, mysids, and an- 

 nelid worms, are all part of the bluefish's diet. So 

 efficient are they as predators, bluefish were fre- 

 quently blamed for decreases in other fish species 

 within Buzzards Bay waters (Baird 1 873; Belding 

 1916). The abundance of juveniles in shallow 

 nearshore waters also provides an important source 

 of prey for other predaceous species. Large fluc- 

 tuations in bluefish populations occur from year to 

 year, but these fluctuations are attributed more to 

 environmental factors than to human disturbances. 

 The value of the recreational fishery, primarily surf- 

 casting, party boat, and individual hook and line 

 fishing, is estimated to exceed that for the commer- 

 cial fishery for bluefish along the mid- Atlantic (Saila 

 and Pratt 1 973 ). Bluefish has been a consistently 

 important food fishery for at least the past 1 00 years 

 in Buzzards Bay. This species is also important in 

 estuarine food chains; juveniles exploit prey in wet- 

 lands and embayments, and adults feed on the 

 abundant larger prey species. 



Striped bass (Morone saxatilis). Except 

 when migrating, striped bass, another anadromous 

 fish, is primarily a nearshore and brackish water 

 species. The young remain in their natal estuary 



