Stellwagen Bank Final EIS and Management Plan 



Page 25 



The physiological adaptations of leatherbacks to 

 pelagic environments make this species poorly- 

 equipped to deal with obstructions in shallow 

 waters. Leatherbacks regularly become entangled 

 in fishing nets and lobster pot lines, situations which 

 are compounded by this species' inabihty to either 

 maneuver easily or to swim backwards. In addition 

 to these problems, leatherbacks have been reported 

 to die from intestinal blockage following 

 consumption of plastic bags, which they presumably 

 mistakenly identify as jellyfish. Collisions with boats 

 also occasionally result in leatherback mortaUty. 



Loggerhead (Caretta). Although loggerhead sea 

 turtles are the most widespread and numerous 

 species along the eastern seaboard, they are 

 generally absent in shelf waters north of Cape Cod, 

 including Cape Cod Bay and the Gulf of Maine. 

 Water temperature is the primary factor in marking 

 Massachusetts as the northern tolerance limit for 

 this endangered species. Following nesting activity, 

 loggerheads disperse northward, and there are 

 limited sightings along outer Cape Cod and the 

 islands during mid-summer through fall. 

 Occasionally, loggerheads become trapped inside 

 Cape Cod Bay in late fall and winter, resulting in 

 cold-stunning and death. 



Green (Chelonia mydas ). Juvenile green sea turtles 

 are rare summertime stragglers as far north as Cape 

 Cod Bay. This endangered species generally is 

 found in waters warmer than 20°C. 



f. Marine Mammals 



Thirteen species of marine mammals are known 

 to frequent the waters over and around Stellwagen 

 Bank, and rare sightings of an additional two 

 species have been recorded. Resources of the Bank 

 environment provide important sources of food for 

 a seasonal variety of large and small cetaceans, and 

 serve as nursery grounds for some of these species. 

 Two species of pinnipeds have also been 

 documented in the Stellwagen Bank area. 



1. Endangered Cetaceans 



Humpback whales (Mepaptera novaeangliae ; 30 to 

 60 feet, or 9.1 to 18.3 meters in length) are perhaps 

 the most easily identified of large cetaceans due 



both to their distinctive markings and long flippers 

 and to their highly-visible feeding and socialization 

 behaviors. The species was first scientifically 

 described based on observations made of an 

 individual taken off the coast of Maine, and hence, 

 the Latin name novaeangUae . which means "New 

 England". In spite of this description, humpback 

 whale populations may be found in all oceans, 

 although overall numbers remain depleted 

 compared to pre-exploitation levels. The species 

 has been protected from commercial hunting since 

 1962, and classified as "endangered" under the 

 Endangered Species Preservation Act since 1970. 

 (The Endangered Species Preservation Act was the 

 predecessor to the 1973 Endangered Species Act). 

 The Western North Atlantic population of 

 humpbacks is currently estimated at 5,505 animals 

 (NMFS, 1991). 



Migrating north from calving and mating grounds 

 in the eastern central Caribbean, a significant 

 number of humpback whales, estimated at around 

 550, arrive in the Massachusetts Bay area annually, 

 beginning approximately in early March, when they 

 are first observed within Cape Cod Bay waters. By 

 April, humpbacks begin to move farther offshore 

 toward the Bank, where they generally remain until 

 mid-November, intensively engaged in feeding 

 activities. Primary prey of the humpback whales in 

 this area is the American sand lance (Ammodvtes 

 americanus), whose populations are seasonally 

 prolific in the Bank environment. Other species of 

 fish occasionally taken by humpbacks include 

 herring, mackerel, cod, and hake. Generally, 

 humpbacks consume 95% fish, 5% zooplankton. 

 North of Stellwagen Bank, capelin (Mallotus 

 villosis ) is the preferred prey. The Bank also serves 

 as an important nursery area for mothers with 

 calves. This "residency" period of approximately 7- 

 1/2 to 8 months of the year in the Stellwagen Bank 

 vicinity is one of the longest such periods known 

 anywhere in the world. By mid- to late-November, 

 the humpbacks begin their annual migration south 

 to warmer coastal waters. 



Due to their distinctive fluke patterns, photo 

 identification has been possible for at least 500 

 individual humpbacks by local cetacean research 

 organizations during the past 12 years. The growing 

 photographic and other data bases on humpback 



