Byers-Conroy-Harvey-Sinnett Islands ER#103 Biological and Physical Overview

Posted January 9, 2002 | Categories : 103,Management,Rare Species,Reports,Species List |

ORIGINAL PURPOSE: To protect nesting seabirds, raptors and marine environments

The land area, less than 4% in total, is comprised of four significant islands and many associated islets and reefs, located in four groups. These are the outermost islands of the central mainland coast, located within an area of low relief along the eastern edge of Hecate Strait. Reserve waters are mostly less than 20 m in depth, but reach 110 m in the north.

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The largest islands support forest cover dominated by Sitka spruce. This covers most of the land area. Small areas of herbaceous meadow, in which cow-parsnip is conspicuous, and windswept grassy headlands are present. The combination of tidal channels, protected bays, sandy beaches and rocky intertidal areas provides varied habitat for extensive kelp beds and associated invertebrates.

The following numbers are from the first version of the Ecological Reserve Guide published in 1993. Eight species of seabirds nest on these islands. An estimated 2000 pairs of Leach’s and fork-tailed storm-petrels nest on the forest floor at scattered locations where substrates are suitable for burrowing. In excess of 7000 pairs of Cassin’s auklets and 1500 of rhinoceros auklets, as well as burrow-nesters, utilize open forest and grassy slopes near shoreline. A colony of 50 pairs of tufted puffins, the only significant breeding site along the Mainland Coast, is present on grassy slopes at Byers Island. A population of about 250 pairs of glaucous-winged gulls nest on exposed headlands, while an estimated 50 pairs of black oystercatchers utilize rocky headlands and some beaches as nest sites. At least two pairs of peregrine falcons nest in trees here, the only recent occurrence of such nesting known in North America. Their usual nest sites, steep cliffs, are lacking but food in the form of seabirds is abundant, therefore the falcons have resorted to using old bald eagle nests.



Killer Whale (West Coast Transient population) Red Listed

Northern Abalone Red Listed

Sea Otter Red Listed
Grey Whale Blue Listed,
Harbour Porpoise Blue listed,
Humpback Whale  Blue listed,


Climate Change:

Raised sea levels, and increased storm activity may degrade and/or reduce the habitat on this reserve. Warming sea surface temperatures may alter life cycles and distribution of some subtidal and inter-tidal marine species, effectively changing the predator/prey dynamics on the islands, and altering the community composition. Impacts of this loss of synchronism may be visibly reflected in the seabird populations.

Access: Public access threatens nesting sea bird colonies.

Harvest: Log theft from Conroy Island removes valuable biomass from the ecosystem.

Recreation: There is a large amount of accumulated human waste due to recreation on Conroy Island as well as on other areas of the coast.

Transportation: There is a risk of fuel spills due to marine vessel traffic off the coast of BC.

Flora : cow-parsnip (Heracleum maximum)


Abalone, Northern (Haliotis kamtschatkana)
Auklet, Cassin’s (Ptychoramphus aleuticus)
Auklet, Rhinoceros (Cerorhinca monocerata)
Eagle, Bald (Haliaeetus leucocephalus)
Falcon, Peregrine, pealei subspecies (Falco peregrinus pealei) Gull, Glaucous-winged (Larus glaucescens
Otter, Sea (Enhydra lutris)
Oystercatcher, Black (Haematopus bachmani)
Porpoise, Harbour (Phocoean phocoena)
Puffin, Tufted (Fratercula cirrhata)
Storm-petrel, Fork-tailed (Oceanodroma furcata)
Storm-petrel, Leach’s (Oceanodroma leucorhoa)
Whale, Grey (Eschrichtius robustus)
Whale, Humpback (Megaptera novaeangliae)
Whale, Killer (Orcinus orca) (West Coast Transient population)