FISHERY BULLETIN: VOL. 84, NO. 2 



Table 1.— Stratified mean number of sand eel per tow + SE (in 

 parentheses) and the number of sampling tows (lower number) by 

 region and year. 



Region 



1978 1979 



1980 



1981 



1982 



Georges Bank 

 shoals 



northern edge 



shelf edge 



central bank 



Gulf of Maine 

 central gulf 



southern 



southwest 



1.117 



(0.233) 



15 



0.000 



9 



0.100 

 (0.707) 

 15 

 0.941 

 (0.182) 

 21 



0.000 



64 

 0.000 



9 



0.670 



(0.371) 



20 



1.200 



(0.305) 



30 



0.256 



(0.211) 



16 



0.000 



2.752 



(0.590) 



15 



0.000 



8 

 0.000 



1.850 



(0.499) 



15 



0.747 



(0.464) 



8 



0.000 



2.846 



(0.691) 



15 



0.000 



8 

 0.000 



14 14 



0.410 0.236 



(0.202) (0.132) 



38 18 



10 14 



0.654 0034 



(0.396) (0.341) 



19 19 



0.012 

 (0.012) 

 61 



0.141 

 (0.101) 

 47 



0.055 



(0.545) 



45 



0.625 0.116 



(0.422) (0.115) 



12 6 



1.286 1.240 



(0.289) (0.384) 



34 16 



0.000 



47 



1.077 0.116 



(0.617) (0.115) 



6 6 



2.422 0.860 



(0.756) (0.318) 



18 21 



(Table 2). Over 90% of the humpbacks/effort ob- 

 served each year in the combined Georges Bank-Gulf 

 of Maine waters were seen in the Gulf of Maine. The 

 increased number of humpbacks/effort observed was 

 significantly different between regions in the Gulf 

 of Maine (F = 7.098, df = 2, 8). The greatest con- 

 centrations of humpbacks in the Gulf of Maine are 

 located in the southwest region (Table 2). Between 

 1978 and 1982, 82% of the total humpbacks/effort 

 in the Gulf of Maine were observed in the southwest 

 region. The importance of this region for feeding 

 humpbacks has been previously reported (Kenney 

 et al. 1981; Hain et al. 1982). 



Although there were no significant differences 

 between the number of humpbacks/effort seen by 

 year (F = 0.824, df = 4, 12) or region (F = 0.609, 

 df = 3, 12) on Georges Bank, the number of hump- 

 backs/effort observed on the bank has steadily de- 

 clined since 1978. Sixty percent of the humpbacks/ 

 effort observed on Georges Bank between 1978 and 

 1982 occurred during 1978 (Table 2). 



We examined the apparent increase in the south- 

 west Gulf of Maine more thoroughly by dividing it 

 into two smaller components (Table 3), a southern 

 which extends from the Great South Channel north 

 along the outside of Cape Cod (NMFS/NEFC strata 

 23, 25, from Figure 1) and a northern which centers 

 on Stellwagen Bank (NMFS/NEFC strata 26, 27, 

 from Figure 1). The number of humpbacks/effort 

 observed within the southwest Gulf of Maine-north- 



ern segment steadily increased by an order of mag- 

 nitude from 1.86 x 10 ~ 2 whales/effort in 1978 to 

 29.01 x 10" 2 whales/effort in 1982. Therefore, the 

 observed increase in the number of humpbacks/ 

 effort in the southwest Gulf of Maine since 1978 has 

 occurred primarily in the northern half of this region 

 (NMFS/NEFC strata 26, 27). 



Table 2.— The number of humpback whales per linear km x 10 " 2 

 (humpbacks/effort) seen during shipboard observations and the 

 total number of linear km surveyed (in parentheses) by region and 

 year. 



Region 



1978 



1979 



1980 1981 



1982 



Georges Bank 

 shoals 



northern edge 



shelf edge 



central bank 



Gulf of Maine 

 central gulf 



southern 



southwest 



— 0.189 — — — 



(480.9) (529.0) (190.0) (342.6) (744.5) 



1 .500 — — 



(200.0) (176.8) (66.5) 



(230.0) (213.6) (115.6) 



0.168 0.285 0.299 

 (593.6) (701.9) (334.4) 



0.750 

 (933.1) 



2.449 

 (489.8) 



1.174 

 (681 .2) 



0.119 

 (841.7) 



0.828 

 (482.8) 



2.817 

 (745.4) 



(966.0) 



(267.6) 



7.679 

 (547.0) 



(89.8) 

 (207.0) 



(895.9) 



0.855 

 (467.6) 



0.393 

 (254.2) 



11.172 



(454.9) 



(222.7) 



0.225 

 (198.6) 



0.116 

 (863.5) 



(1,172.8) 

 1.662 



(223.5) 

 6.814 



(692.5) 



-2 



Table 3.— The number of humpback whales per linear km x 10 

 (humpbacks/effort) seen during shipboard observations and the 

 total number of linear km surveyed (in parentheses) within the par- 

 titioned southwest Gulf of Maine. 



Region 



1978 



1979 



1980 



1981 



1982 



Northern 1.864 2.655 10.794 22.469 29.014 



(strata 26, 27) (34.9) (263.6) (333.5) (252.6) (299.6) 



Southern 0.556 3.113 2.811 1.987 3.308 



(strata 23, 25) (359.3) (481.8) (213.5) (202.3) (392.9) 



Correlation Between 



Humpback Whale Distribution 



and Sand Eel Abundance 



A significant correlation (r = 0.81, df = 13) ex- 

 ists between the observed number of humpbacks/ 

 effort and the log-mean number of sand eel/tow by 

 region within the Gulf of Maine (Fig. 2). This in- 

 dicates that within the Gulf of Maine the distribu- 

 tion of humpback whales do co-occur with dense 

 patches of sand eel in that region. The greatest den- 

 sities of sand eel in the Gulf of Maine and the 

 greatest observed numbers of humpbacks/effort 

 have both occurred in the southwest Gulf of Maine 

 since 1978. This supports the hypothesis by Kenney 

 et al. (1981) that within the Gulf of Maine, the 



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