Table 1. Methodology used for determining consumption of herring by marine mammal species in the Gulf of Maine.

Species and
estimate
Population size
CV
Body mass (kg)
Days in GOM
Individual consumption (kg/day)
Population consumption (kg/day)
Populaion consumption (mt/year)
Proportion of herring in diet
Total herring consumption (mt/year)
 

[A]

[B]

[C]
A x C = [D]
D x 182 or 365 = [E]
[F]
E x F = [G]
Fin whale
 
 
 
 
 
 
 
 
 
   High estimate
4,293
0.59
30,000
182
469.5
2,015,563
366,833
0.17
62,362
   Best estimate
2,700
0.59
30,000
182
469.5
1,267,650
230,712
0.17
39,221
   Low estimate
1,107
0.59
30,000
182
469.5
519,737
94,592
0.17
16,081
 
Minke whale
 
 
 
 
 
 
 
 
 
   High estimate
3,472
0.31
4,500
182
102.9
357,269
65,023
0.34
22,108
   Best estimate
2,650
0.31
4,500
182
102.9
272,685
49,629
0.34
16,874
   Low estimate
1,828
0.31
4,500
182
102.9
188,101
34,234
0.34
11,648
 
Humpback whale
 
 
 
 
 
 
 
 
   High estimate
2,828
0.067
25,000
182
405.8
1,147,602
208,864
0.17
35,507
   Best estimate
2,650
0.067
25,000
182
405.8
1,075,370
195,717
0.17
33,272
   Low estimate
2,473
0.067
25,000
182
405.8
1,003,543
182,645
0.17
31,046
 
Pilot whale
 
 
 
 
 
 
 
 
 
   High estimate
1,035
0.55
850
365
27.1
28,059
10,242
0.05
512
   Best estimate
668
0.55
850
365
27.1
18,103
6,608
0.05
330
   Low estimate
301
0.55
850
365
27.1
8,146
2,973
0.05
149
 
Harbor porpoise
 
 
 
 
 
 
 
 
 
   High estimate
61,902
0.14
41
365
2.4
148,565
54,226
0.51
27,655
   Best estimate
54,300
0.14
41
365
2.4
130,320
47,567
0.51
24,260
   Low estimate
46,698
0.14
41
365
2.4
112,075
40,907
0.51
20,863
 
White-sided dolphin
 
 
 
 
 
 
 
 
   High estimate
33,252
0.63
120
365
5.7
189,536
69,181
0.5
35,591
   Best estimate
20,400
0.63
120
365
5.7
116,280
42,442
0.5
21,221
   Low estimate
7,548
0.63
120
365
5.7
43,024
15,704
0.5
7,852
 
Harbor seal
 
 
 
 
 
 
 
 
 
   Best estimate
30,990
none
61
365
3.3
102,267
37,328
0.13
4,853
 
Gray seal
 
 
 
 
 
 
 
 
 
   Best estimate
2,010
none
94
365
4.7
9,447
3,448
0.38
1,310
   Note: For all marine mammal species pooled, estimates of herring consumption are: high estimate 189,898 mt/yr; best estimate 141,341 mt/yr; low estimate 93,802 mt/yr.