Where does Terminal Creek’s Water Come From?

Photo: Will Husby

Signal Crayfish

Female signal crayfish on rocks underwater.

Photo: Astacoides, Creative Commons

Terminal Creek

Signal Crayfish

(Pacifastacuc leniuscuslus)

Discover Kwilakm » Story » Terminal Creek

by Bob Turner

Until I stuck my facemask into Terminal Creek, I had no idea we had crayfish on Bowen Island.

Crayfish underwater
Crayfish in lower Terminal Creek. Photo: Bob Turner

But there it was, a reddish brown fresh-water cousin of the lobster, crawling out from under a rock, claws held high. Signal crayfish are BC’s only native crayfish. They range from southern BC to northern California and east to the Rockies.

Signal crayfish on land
Photo: Will Husby

Crayfish are fascinating crustaceans, cousins of shrimp, prawns and crabs. They live inside hard exoskeletons that they shed and rebuild (molt) as they grow, leaving them vulnerable during the molting process. They are omnivores, eating a variety of foods such as decaying roots, leaves, stream bottom insects, smaller crayfish, and fish.

Crayfish in someone's hand
Photo: Will Husby

Signal crayfish are solitary animals, living alone in crevices or in burrows under rocks. They breathe through feather-like gills, have compound eyes on the ends of long stalks, feel their way along with antennae, walk on their many feet, but can dart quickly if alarmed, with a flick of their tail.

Crayfish close-up on eyes
Photo: Will Husby

Adult crayfish are on the lookout for predatory mink and otter, while juvenile crayfish can be prey to larger crayfish, merganser ducks, and larger trout. The presence of crayfish in Terminal Creek is a sign that the water quality is good, as crayfish are very sensitive to pollution.

Terminal Creek Fish Hatchery

Photo: Will Husby

Terminal Creek

Terminal Creek Fish Hatchery

Discover Kwilakm » Story » Terminal Creek

Tucked away in the forests of Crippen Regional Park, about a 15-minute walk from the Causeway towards Killarney Lake, is the salmon hatchery run by the Bowen Island Fish and Wildlife Club.

Moving fry from truck to hatchery
Loading a truck at the hatchery with fry for transport to release sites. Photo: Len Gilday

In partnership with the Department of Fisheries and Oceans (DFO), club members raise juvenile salmon from eggs and release them in creeks on Bowen, including Terminal Creek and the Lagoon. Volunteers also monitor the health of Bowen’s salmon-bearing creeks and riparian areas.

New fish hatchery location on Bowen Island
Location of Terminal Creek Hatchery. Photo: Will Husby

Each fall, DFO provides the hatchery with eggs taken from spawning adult salmon caught on the tributaries of the nearby Squamish River at the northern end of Atl’7katsem/Howe Sound. The type and number of eggs received each year can vary, but typically they include chum, coho, and sometimes pink salmon eggs.

Salmon egg tray
A hatchery volunteer sorts developing coho eggs. Photo: Will Husby

The eggs arrive at the hatchery during the salmon spawning season and are incubated in dark, cool, slowly flowing oxygenated water within trays that mimic the conditions of wild eggs laid by salmon in stream gravels. When the eggs hatch, young salmon with an attached egg sac wriggle out. These juveniles, called alevin or sac fry, feed on the nourishment contained in the egg sac until it is used up. At that point, the young salmon are called fry and are moved to large tanks of water where volunteers feed them until release time.

Fry Close Up
Close up of chum salmon fry. Photo: Len Gilday.

Chum salmon fry are ready for release in April. They are let go into the Lagoon, where they have only a short swim to the ocean. This matches the experience of wild chum fry as upon hatching they quickly swim downstream to the estuary and sea. Wild coho salmon fry, on the other hand, spend a year in their stream after rising out of the gravel. During this period, coho are preparing for life in saltwater. Hatchery volunteers release their coho fry into various creeks on Bowen well upstream from the ocean.

Coho salmon smolts
Coho salmon fry spend much more time in the hatchery and grow much bigger. These three are big enough to be released. Photo: Will Husby.

This release is in May (coho spawn later in the winter and so eggs mature later in the spring) and the Club invites the public to participate in the release during the Coho Bon Voyage celebration.

Salmon fry leave the hatchery
Coho Bon Voyage: A hatchery volunteer giving a bucket of coho fry for release by a Bowen family. PhotoWill Husby

On Earth Day 2021, Terminal Creek Hatchery volunteers escorted Bowen’s graduating class of young chum salmon from the hatchery where they were born down to the Lagoon to prepare for life at sea.

The team netted the young salmon from the hatchery’s giant tanks. At the shore, they tipped their pails to release approximately 70,000 fish into the shaded, shallow, and cool water of the Lagoon.

Scooping salmon fry for release
A volunteer scooping chum salmon fry from tanks in hatchery for release in Lagoon. Photo: Len Gilday.
Release of fry into lagoon
Volunteer releases chum salmon fry into Lagoon. Photo: Len Gilday.
Close up of salmon fry release
Chum salmon fry at the moment of release into the wild. Photo: Len Gilday.

A further 30,000 were released into Davies Creek in Snug Cove. Each fish weighed roughly two-thirds of a gram (the weight of three toothpicks) and was about the length of your baby finger. The fry spent from a few hours to a couple of days in the sheltered water of the Lagoon or Davies Creek. Then they ventured out to begin their life in the ocean.

Here, as young fry, they spend several weeks near shore, hunting for food in the eelgrass beds of Kwilákm, then further months in local waters before heading to the north Pacific. Chum salmon spend about four years fattening up at sea before returning to the stream where they were born to mate and die. Chum is the largest salmon species that spawns on Bowen Island. Individual fish typically from four to six kg as returning adults.

Terminal Creek

Photo: Will Husby

Every winter, Grafton and Killarney Lakes, the island’s largest, fill to the brim.

Killarney Lake
Photo: Will Husby

The Killarney Creek beaver wetland stores thousands of litres of freshwater.

Beaver Wetland
Photo: Will Husby

This system ensures a year-round flow of freshwater habitat for many stream creatures, which in turn provide food for baby salmon.

Mayfly Nymph
Mayfly nymph Photo: Will Husby
Stonefly Nymph
Stonefly nymph Photo: Will Husby
Caddisfly Larva with Case
Caddisfly larva Photo: Will Husby

Terminal Creek also acts as a conveyor, moving nutrients and leafy debris from the inland forest into the lagoon and Kwilákm.

Wrack and leafy debris
Autumn is when vast quantities of leaves and twigs are flushed downstream into Kwilákm. Photo: Will Husby

Many marine creatures and plants feast on this abundant food. In this way, the fresh waters of the creek increase the abundance and diversity of the bay’s marine ecosystem.