APPENDIX 1. Data sources used in generating estimates of consumption of herring by eight species of marine mammals in the Gulf of Maine, USA
Abundance estimates
All abundance estimates with the exception of humpback whales
NMFS, Northeast Region (1999)
U.S. Atlantic Marine Mammal Stock Assessments (1998)
NOAA Technical Memorandum NMFS-NE-116. Woods Hole, Massachusetts
Humpback whales
Abundance estimate was calculated as one-fourth (10,600/4 = 2,650) of the entire North Atlantic humpback population due to the existence of four major feeding stocks.
Low and high population estimates
Low and high estimates were calculated using the above abundance data and the coefficient of variation (CV) from the NMFS Stock Assessment report.
Estimates of abundance were generated from surveys conducted in the following periods:
Humpback whales, 1992–1993, Gulf of Maine
Fin whales, 1991–1992, Gulf of Maine
Minke whales, 1991–1992, Gulf of Maine
Pilot whales, 1993, Gulf of Maine
Harbor porpoises, 1991–1995, Gulf of Maine
White-sided dolphins, 1991–1992, Gulf of Maine
Harbor seals, 1997, Coast of Maine
Gray seals, 1994, Coast of Massachusetts
Data on body mass
Harbor porpoises
Read, A. J. (1990–1994),
unpublished data
Harbor seals
Boulva and McLaren (1979)
Gray seals
Mohn and Bowen (1996)
Fin whale, Minke whale, humpback whale, pilot whale, white-sided dolphin
Kenney et al. (1985)
Data on diet
Pilot whale
Gannon et al. (1997)
White-sided dolphin
Palka et al. (1997)
Harbor porpoise
Recchia and Read (1988)
Gannon et al. (1998)
The proportion of the diet consisting of herring was calculated by averaging the results from these two studies.
Gray seal
Bowen et al. (1993)
Harbor seals
Ferland (1999)
Humpback whale, fin whale, Minke whale