Grey whale (Eschrichtius robustus) COSEWIC assessment and status report: chapter 11
Special significance of the species
Ecological significance
Grey whales have been described as a keystone species of benthic ecosystems in the Arctic. As the major benthic predator in shallow arctic seas, they maintain the structure and diversity of benthic invertebrate assemblages (Nerini 1984; Oliver and Slattery 1985). Nerini (1984) estimated that in the early 1980s, grey whales turned over an area of 3565 km2 in the Arctic or 9% of the available amphipod community each season. This figure has increased substantially since. Bottom-feeding grey whales rearrange soft sediments and thus mobilize chemical nutrients bound in benthic substrates (Feder et al. 1994; Oliver and Slattery 1985). By feeding on benthic biomass but defecating and urinating in the water column, grey whales also return nutrients to the water column (Reeves and Mitchell 1988). Due to their coarse baleen, grey whales only filter relatively large (> 6 mm) invertebrates from the sediments and smaller invertebrates are expelled near the surface where they serve as food for marine birds and fishes (Obst and Hunt 1990; Grebmeier and Harrison 1992).
Cultural and economic significance
Since grey whales usually travel close to shore, native peoples along the migratory corridor and the feeding grounds have relied on grey whales for subsistence for several millennia (O'Leary 1984). Subsistence use of grey whales continues in the Arctic and off Washington State. Several native groups including the Haida and Tsimshian in British Columbia used stranded whales for food (O'Leary 1984). Sanborn (pers. comm.) states that the Kwakwaka'wakw of northern Vancouver Island and the adjacent mainland coast did not actively hunt grey whales, but used bones from stranded whales to make tools.
In the waters off western Alaska, the Aleuts historically hunted grey whales from small skin boats (O'Leary 1984). The Koniaq inhabiting Kodiak Island and the adjacent coast of Alaska also hunted whales (O'Leary 1984). Along the Bering, Chukchi and Beaufort seas, the Yup’ik, IñupiaQ and Chukchi people occasionally hunted grey whales, but evidence suggests that they preferred bowheads (Balaena mysticetus) whenever they could get them (Marquette and Braham 1982; Krupnik 1987).
Along the west coast of North America, whaling was probably most developed among the Nuu-chah-nulth of southwestern Vancouver Island and the Makah of adjacent Washington State (O'Leary 1984). The two closely related groups hunted both humpback and grey whales, with a preference for humpbacks (Happynook, pers. comm.). The remains of humpback whales slightly outnumber those of grey whales at the pre-contact archaeological site of Ozette (Huelsbeck 1988). This is in spite of the fact that grey whales would presumably have been more accessible to the Makah inhabitants of Ozette due to their inshore distribution, and also suggests that humpback whales were preferred. Whaling was of great spiritual and economic importance to the Makah and Nuu-chah-nulth (O'Leary 1984; Huelsbeck 1988; Happynook 2002).
Whale-watching is now a major commercial activity and grey whales have become the mainstay of many whale-watching communities along the west coast of North America. In British Columbia, tour operators offer grey whale viewing along the west coast of Vancouver Island, with the greatest number of vessels operating out of Tofino and Ucluelet (Duffus 1996), and to a lesser degree Bamfield and Port Renfrew. While some trips operate during the northbound migration, most whale-watching activity takes place during the summer months. For this reason summer-resident grey whales are the primary focus of whale-watching trips in this area (Duffus 1996).
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