11. Northern Queen Charlotte Sound/Hecate Strait/Gwaii Haanas

Site Overview

Hecate Strait is situated between mainland British Columbia and the Queen Charlotte Islands. The southern half of the island group, excluding its coastal waters, forms part of the Gwaii Haanas National Park Reserve, north of Queen Charlotte Sound. This PCA is on the continental shelf, with a trough extending from off the southern tip of QCI roughly northward into the strait. The movement of water in this area is governed by coastal currents, tides, winds, and freshwater from the island on the west and the mainland on the east.

Along iceberg-scoured troughs are globally unique glass-sponge (hexactinellid) reefs, prospering in the low-sedimentation, high-silica waters at depths of between 165 and 230 meters (550 and 750 feet; Department of Fisheries and Oceans Canada—DFO 2000). The sponge reefs form mounds 18 meters (60 feet) tall in complexes as large as 300 square kilometers (115 square miles). Three species form the framework of the sponge reefs, Chonelasma calyx, Aphrocallistes vastus and Farrea occa. For 9,000 years, these reefs have provided shelter for a suite of associated marine species, ranging from bryozoans and gastropods to rockfishes, crabs and shrimp.

Hecate Strait is rich in marine life, including many commercially important species. Pacific cod, Pacific Ocean perch, and many other rockfishes, as well as Halibut, Flounder, and Dover (Microstomus pacificus) and English soles (Parophrys vetulus) are targeted by trawl fisheries. Troughs such as Moresby Gully are home to the rockfishes. Sablefish use Hecate Strait as their nursery area and juvenile sablefish are found near to shore and on the shelf. Herring spawn in numerous small inlets of the strait, including Porcher Island and Big Bay (northeast Hecate Strait), but the QCI herring stock is in decline. Many of the rivers feeding into the strait are where eulachon spawn, an important food source for marine mammals and birds. Salmon are present along both sides of the strait. Up to four million pink salmon cross this area each year on their journey toward the spawning streams (DFO 1999a). Lingcod live on the strait’s shallow rocky bottoms and are sought after by commercial and recreational fishermen. Geoduck clam and Dungeness crab are also found here. Northeast Hecate Strait supports an important crab fishery.

Not only do underwater species thrive in this marine realm, but marine birds and mammals are abundant too. Here cormorants and shearwaters feed, tufted puffins gather, and Cassin’s auklets and ancient and marbled murrelets breed. Cassin’s auklet and the two species of murrelets disperse southward in the winter along the coasts of Washington, Oregon and California, and as far south as the Gulf of California. Half of the world’s population of ancient murrelets (256,000 pairs) nests in the Queen Charlotte Islands, with a concentration in Gwaii Haanas, but some colonies are showing signs of decline (Harfenist et al. 2002). This area is a major passageway for Pacific Coast marine waterfowls and offers excellent nesting sites for a wide range of shorebirds. Albatross, shearwaters and Xantus’ murrelet (Synthlibiramphus hypoleucus) are occasionally seen around QCI. This area is also used by marine mammals such as humpback and killer whales, sea lions and sea otters.

Fishing operations pose a threat to this unique area because of their potential to incidentally kill non-target species and destroy the fragile seafloor habitat. As in many areas, introduced species such as rats are having an impact on nesting sites of sea birds such as murrelets.