48 



BIOLOGICAL REPORT 31 



piles, left by the Native Americans in areas around 

 the bay shores. In these shell middens, as today, 

 quahogs were the dominant species, with fewer 

 oysters and soft-shelled clams (Kitteridge 1930; 

 Emery 1979). 



Other species of edible shellfish are also found 

 in Buzzards Bay waters but provide little recre- 

 ational or commercial harvest. Black clams, 

 Arctica islandica, similar in appearance to qua- 

 hogs, can be found throughout the bay. Although 

 they generally inhabit deep waters, they are also 

 found in shallow regions. Pilar morrhuanus or the 

 "duck clam" is also fairly common in soft bottom 

 areas but is generally not harvested because of its 

 strong flavor and weak shell. The common razor or 

 Atlantic jacknife clam (Ensis directus) is abundant 

 in the lower intertidal to subtidal sandy and muddy 

 regions. As the clam burrows deeply, the sharp edge 

 of its long slender shell can inflict a significant cut to 

 the unaware barefoot clammer. Although it supports 

 a recreational shellfishery, this clam's rapid escape 

 into deep burrows limits the catch per unit effort in 

 comparison to other species. 



The only major crustacean harvested is the lob- 

 ster (Homarus americanus). Lobstering represents 

 an important commercial resource for Buzzards Bay 

 and supports a small recreational fishery. Buzzards 

 Bay is a spawning ground for lobsters. Larval lob- 

 sters hatch in Buzzards Bay beginning in late May, 

 and the earliest larval stage is no longer found by 

 mid-July (Collings et al. 1 983 ). Significantly greater 

 numbers of gravid females as a proportion of the 

 total catch are typically observed in Buzzards Bay 

 compared to regions north of Cape Cod. In 1987 

 the catch percentage of gravid females for Buzzards 

 Bay was 3 1 %, in strong contrast to the state aver- 

 age of 9.2%, and about double the 1 9% reported 

 for the lobster fishery of the Outer Cape (Estrella 

 and McKiernan 1988, 1989). The higher larval 

 densities in Buzzards Bay compared to other Mas- 

 sachusetts and New England waters north of Cape 

 Cod are likely due to warmer temperatures, result- 

 ing in the more rapid maturation of females and en- 

 hanced spawning stock levels (Lux et al. 1983). 

 The bay's water residence time and warm spring to 



fall temperatures help to make it one of the more 

 favorable areas for growth and spawning of lob- 

 sters in New England. In fact. Buzzards Bay "ex- 

 ports" significant numbers of larvae ( 1 0-20 million 

 per year) through the Cape Cod Canal (Collings et 

 al. 1 983). The Buzzards Bay larvae and spawn from 

 lobsters residing in the rocky bottom of the canal 

 presumably help to support the lobster fishery in 

 Cape Cod Bay. 



Primarily nocturnally active invertebrates, lob- 

 sters generally hide during the daylight hours in rock 

 or grass shelters, emerging during twilight hours to 

 feed. Small lobsters frequent shallow waters near 

 shore, while larger individuals (occasionally up to 

 22.7 kg) are more prevalent in deeper offshore 

 waters. Relatively slow moving in their four-legged 

 walk, lobsters have the ability to rapidly propel 

 themselves backward for short distances by the 

 contraction of their tails. The characteristic claws 

 of the lobster perform two functions: the larger of 

 the two, or "crusher," is designed for cracking hard 

 objects like the shells of snails or bivalves; the 

 smaller, sharper claw, or "cutter" is used for tearing 

 apart prey (generally fish) or plant material. Lob- 

 sters are also known for their cannibalistic behav- 

 ior, frequently eating other lobsters in their soft-shell 

 (just past molting) stage and even their own young 

 (Meinkoth 1981; Davis 1989). 



Fish. Only limited quantitative data are avail- 

 able on the fish populations in Buzzards Bay be- 

 cause prohibition of net fishing in bay waters nearly 

 a century ago eliminated catch records available from 

 this source. There is, however, sufficient informa- 

 tion to identify the prevalent species that make the 

 bay home for part or all of their life cycles. The 

 fisheries of Buzzards Bay are discussed in Chapter 

 5. 



Reviews of the available data on Buzzards Bay 

 fisheries identify 1 dominant fish species (exclud- 

 ing salt marsh fish described in a following section) 

 currently found in bay waters (Table 4.2), with nu- 

 merous other species occasionally present. As in 

 other embayments, these include residents and non- 

 residents (migratory species), some commercially 

 and recreationally valuable and others not. With its 



