350 



Fishery Bulletin 88(2), 1990 



Virginia Capes and proceeds northeastward to spawn 

 off the New Jersey and Long Island coasts from mid- 

 April to early May. By midsummer, the southern com- 

 ponent reaches the Gulf of Maine where it remains 

 throughout summer (Anderson and Paciorkowski 

 1980). Migration out of the Gulf of Maine begins in 

 autumn as the southern component returns to deeper, 

 offshore waters. The northern component migrates fur- 

 ther north in spring along the Nova Scotian shelf to 

 the Gulf of St. Lawrence where spawning occurs dur- 

 ing June- July (Anderson and Paciorkowski 1980). The 

 northern component begins leaving the Gulf of St. 

 Lawrence in September and returns to the mid- 

 Atlantic region to overwinter. 



The seasonal DWF mackerel fishery occurs in the 

 mid-Atlantic region during the winter when both com- 

 ponents of the mackerel population concentrate primar- 

 ily along the shelf edge (Anderson and Paciorkowski 

 1980), although commercial quantities are sometimes 

 encountered in waters as shallow as 30 m. 



ceans killed per day (kill-rate) in the 1984-88 Nether- 

 lands and the GDR mackerel fishery. Data for Poland 

 were not included, because that country did not begin 

 commercial fishing until 1988. Because a Mann-Whit- 

 ney test examines only differences in paired data sets, 

 a Friedman rank sums test (Hollander and Wolfe 1973) 

 was used to examine the kill-rates between Italy, Spain, 

 and Japan in the 1984-86 Loligo squid fishery. 



Randomly selected samples of 334 trawl logs from 

 the 1985 Atlantic mackerel fishery (from Netherlands) 

 and 1018 trawl logs from the 1985 Loligo squid fishery 

 (from Italy) were used to determine the expected level 

 of fishing effort (number of tows) for each of three time 

 periods-Day (0800-1600), Dawn/Dusk (0400-0800 and 

 1600-2000)," and Night (2000-0400)-within each fish- 

 ery. The Chi-Square Statistic was then used to deter- 

 mine whether there were significant differences in the 

 numbers of common dolphins and pilot whales inciden- 

 tally taken in each fishery (relative to fishing effort) 

 due to time of day of the take. 



Methods and materials 



Data collection on incidental take 



Observers monitor compliance with applicable fishing 

 regulations, collect biological data and samples, and 

 serve in a liaison role, when needed, between foreign 

 and domestic captains. In the northeast region, ob- 

 server training is the responsibility of the NMFS 

 Observer Program. Between 1977 and 1985, observers 

 routinely recorded the number of marine mammals 

 taken incidentally in foreign fishing activities. In 1986, 

 a new sampling protocol was implemented to collect 

 additional information on marine mammals, sea turtles, 

 and marine debris. Obsei-vers are now required to com- 

 plete sighting forms, document the circumstances of 

 capture and obtain biological data on incidentally cap- 

 tured marine mammals* and sea turtles. Marine mam- 

 mal biological sampling includes five straight-line body 

 measurements (e.g., snout to fluke notch, flipper length, 

 flipper width, fluke width, and dorsal fin height), girth 

 at pectorals, sex, and total weight. Additionally, when 

 feasible, incidentally caught marine mammals are 

 frozen whole, brought ashore, and later examined by 

 researchers at the Smithsonian Institution. 



Data analysis on incidental take 



A paired Mann-Whitney test (Zar 1974) was used to 

 test for differences between the total number of ceta- 



*In this paper, an incidental take i.s defined as any live marine mam- 

 mal or any carcass caught during foreign fishing activity. 



Data analysis on stomach contents, 

 sex and total length 



A total of 95 common dolphins and 169 pilot whales 

 taken between 1986 and 1988 were measured (total 

 standard length) and sexed at sea. Stomach contents 

 from 33 of the common dolphins were examined by 

 Smithsonian Institution personnel, and the information 

 was provided for this paper. Prior to 1986, stomach 

 contents and sex data were not collected. 



Results 



Observers reported 538 marine mammals incidentally 

 caught during foreign fishing activities in the EEZ off 

 the northeast United States between March 1977 and 

 December 1988 (Table 1). Pilot whales were the most 

 frequently caught marine mammal with 297 caught, 

 representing 55% of the total marine mammal take 

 between 1977 and 1988 (Table 1). Common dolphins 

 were the next most-frequently-taken cetacean with 203 

 caught, composing 38% of the total incidental takes. 

 Approximately 5% of the total catch consisted of three 

 other members of the Delphinidae: Atlantic white-sided 

 dolphin Lagenorhychus acutus, bottlenose dolphin Tur- 

 siops trvncatus, and Risso's dolphin Graynpuft griseus 

 (Table 1). 



Six large whales were reported caught or entangled 

 during fishing operations. One subadult or juvenile 

 right whale Eubalaena glacialis (based on observer 

 identification and estimated length of 6 m) and one 

 unidentified baleen whale were taken in the Loligo 

 fishery. A humpback Megaptera novaeangliae, minke 



