Chum is the largest salmon species that spawns on Bowen Island. Individual fish are typically in the 4 to 6 kg range as returning adults. Adult chum spend about four years fattening up at sea before returning to the stream where they were born to mate and die. Wildlife Club volunteers operate the Terminal Creek salmon hatchery and monitor the health of Bowen’s salmon bearing creeks and riparian areas.
Around Remembrance Day, many Bowen Islanders walk down to the spillway at the Causeway that separates the Lagoon from Kwilákm to watch the arrival and spawning of the chum in the gravel spawning beds just inside the Lagoon.
The viewing is easy. The arriving salmon wait for the incoming tide in the ocean waters near the causeway. At high tide they swim up the fish ladder or up the spillway under the bridge.
Many gather over the gravel bar constructed by Bowen’s Fish and Wildlife club just upstream of the bridge, where their spawning activities can be easily seen. Female chum have normal shaped jaws.
Watch how they flick their tails to dig shallow nests called redds in the coarse gravel.
Look for male chum. They have big jaws with large teeth. They use them to fight other males for chances to mate with the females.
Each female chum will have laid thousands of eggs. And like all Pacific salmon, chum males and females die soon after they mate.
The abundant eggs and salmon (both dead and alive) attract all sizes of predators and scavengers.
Watch for harbour seals in Kwilákm close to the Causeway. They come to intercept the salmon before they reach their spawning bed. Sometimes they will swim right into the lagoon to grab spawning salmon on the gravel bar.
Also look for fast swimming river otters who may come to dine on spawning chum.
Chum Salmon Fry Release
Bowen’s population of wild spawning chum salmon is supplemented by hatchery-reared fish raised by volunteers in the Bowen Fish and Wildlife Club working with the Department of Fisheries and Oceans Terminal Creek Hatchery (see Terminal Creek Fish Hatchery).
Marine birds are extremely sensitive to changes in their environment. Bird population trends are vital indicators of overall ecosystem health. A decrease in species population could be due to a reduction in their food supply, quality of food, or changing ocean conditions. By protecting marine birds, we improve the circumstances for many species, including humans.
Birds that flock together on Kwilákm are particularly vulnerable when vessels spill fuel, oil and other pollutants into shallow water. When oil sticks to a bird’s feathers, the feather’s waterproofing is harmed, exposing the bird’s skin to cold ocean water, resulting in hypothermia, meaning the bird becomes very cold. An oil-soaked bird is unlikely to recover.
Derelict and poorly maintained vessels pose a particular environmental hazard. To restore environmental and community well-being to the Bay, the Bowen Island Municipality has control over what happens in Kwilákm. Boaters with mooring buoys in the Bay are required to pay an annual fee to the Municipality. They also need to provide contact information and proof of third-party liability insurance. Living on a boat in Kwilákm is not permitted. For more information, search online using the terms: “Kwilákm Revitalization – Bowen Island Municipality”.
Bowen citizen scientists and volunteers have embraced restoring Kwilákm’s natural environment. For instance, Dive Against Debris is an annual event where volunteer divers, boaters, kayakers, and shore support come together to remove garbage from the bottom of Kwilákm. Over five years, volunteers hauled over 2,700 kg of debris. The SeaChange Marine Conservation Society is leading a volunteer effort to replant and restore the Bay’s eelgrass Meadows.
Eelgrass provides essential habitat for small fish and aquatic invertebrates to the benefit of loons, grebes, cormorants, and other fish-eating seabirds. Learn more at Eelgrass.
Herring are a cornerstone of the marine food-web and spawned in Snug Cove up until the 1970s.
Flocks of loon, merganser, cormorant, murrelets and grebes feed heavily on this oily little fish and during the herring spawn scoters, goldeneye, bufflehead, widgeon, and mallards gorge on herring eggs.
Herring like to lay their eggs on seaweeds and on wooden structures–wharf pilings are a favourite. The creosote used to preserve the wooden pilings, however, kills the herring eggs. Herring supporters recommend wrapping the dozens of creosoted pilings in Kwilákm and Snug Cove with nontoxic landscape fabric in the hope of restoring herring spawning that once occurred here.
Surf scoters feed in large flocks close along the shore, right in the dangerous drag of the breakers. As the steep waves curl over, scoters scoot neatly beneath the roaring white lines of foam in search of mussels.
Bowen photographer Mary Le Patourel has spent hours observing surf scoters’ feeding technique: Surf scoters have discovered that the secret to breaking into densely packed carpets of mussel, their staple food, is to work as a team, employing a system of diving in long chains. The head of the lineup goes down and loosens the mussels, then the next ones go down and break up the shells and start to dine … then the third group comes in to clean up the high-grade. The ducks from the front of the line then go back to the end of the line and carry on the process, so everyone gets food.
After a winter of feasting off Bowen shores, our surf scoters fly inland in spring to nest on the borders of subarctic marshes. In the fall, parents lead their young to spend the winter on the coast.
How well are surf scoters doing in our waters? Twenty years of citizen science data, collected by the British Columbia Coastal Waterbird Survey, shows a decline in Salish Sea surf scoters of almost 2.25%/year between 1999 and 2019. This sharp loss is balanced by a 3.75% increase in the surf scoter population along BC’s outer Pacific Ocean coast.
Bird population numbers have become important indicators of both environmental success and environmental stress. The Lower Howe Sound Christmas Bird Count covers almost all islands at the mouth of the Sound, including Bowen.
Bowen birders can spot three species of loon in nearby waters. Pacific loons and the red-throated loons are occasional visitors, while the common loon is the most abundant loon species you can see fishing in Kwilákm. Common loons are winter migrants to Bowen waters, drawn from breeding populations from Saskatchewan, western Nunavut, the Northwest Territories, and west to BC’s coastal waters when forced off northern nesting lakes by winter cold and ice. Their migration to Bowen is more or less over by the end of September. During the winter, the common loon’s dramatic black-and-white breeding plumage moults to a drab grey.
Peering through winter’s fog and rain, you can recognize the common loon by its large size and habit of hunting its fishy prey by peering down into the water while swimming. Loons use their powerful hind legs to pursue prey underwater at high speed. They feed primarily on fish and, occasionally, small crabs and aquatic invertebrates. They consume most of their prey underwater and swallow it headfirst. Larger items will be taken to the surface and manipulated before swallowing. Peak foraging occurs in water less than 20 metres deep.
As the days get longer, loons prepare to head back to their northern nesting lakes. Loon migration peaks during late April to early May when loons from further south join with Bowen’s birds to return north to the deep lakes with plenty of fish where they nest and raise a family. As common loons prepare to head north, they will “tune up,” calling out with a shortened version of their wild, piercing yodel. Loons reserve the full haunting chorus until they arrive at their breeding territory.
Hear a recording of common loons calling and with young:
How are the common loons who overwinter in the Salish Sea faring? Twenty years of citizen science data, collected by volunteers with the British Columbia Coastal Waterbird Survey, shows a decline in Salish Sea common loons between 1999 and 2019. This loss of Salish Sea loons is balanced by an almost equal increase in the common loon population along BC’s outer Pacific Ocean coast.
Researchers hypothesize that species who are both long-distance migrants (common loons can travel thousands of kilometres from summer nesting lakes to winter waters) and depend upon lots of small fish to eat, will follow the availability of small fish in deciding where to settle for the winter. In recent decades, while Pacific sardine stock has increased, the abundance and availability of Pacific herring in the Salish Sea has declined. Loons may be choosing to spend the winter where they can find the most available fish.
Bird population numbers have become important indicators of both environmental success and environmental stress. The Lower Howe Sound Christmas Bird Count covers almost all islands at the mouth of the Sound, including Bowen.
When winter’s freeze forces Barrow’s goldeneye from their nesting ponds in BC’s interior, the ducks head to the coast. Starting late October, you can often find goldeneye gathered along Bowen’s shores and sometimes in Kwilákm.
Goldeneye are here for the sheltered waters and fine food. Eighty per cent of their winter diet is blue mussels and the rocky shores of Kwilákm have a good supply.
Goldeneye are strong swimmers. They can dive down to four metres with tail fully spread as a rudder, propelled by strong kicks with their webbed feet. Wings are closed and held tight to body. They can stay beneath the surface for over 30 seconds.
From the moment, the male goldeneye arrives on their wintering grounds, they begin an elaborate variety of postures and bizarre sounds as they court the females and launch disputes with perceived rivals. Threat displays (sketch above) seen from water level, consist of a male or female swimming low in the water with head stretched forward. If the intruder does not leave, the defender may dive and swim towards the intruder underwater, with neck extended, to come up head-first right at the belly of the victim.
When a number of feeding goldeneye come together you can see courtship displays, mixed with brief bursts of threat and counterthreat. As quickly as it began, this activity relapses back into feeding or preening. These complex courtship behaviors help form and strengthen pair bonds. In March, when herring spawn, Barrow’s goldeneye may depart Kwilákm to feast on eggs and fatten up for spring migration to the interior of BC and breeding.
This pair was observed mating in the Bay just offshore of Sandy Beach.
Photo sequence: Will Husby
Courtship begins on the wintering grounds. Copulation occurs once the nest has been established near the nest site. Egg laying occurs over +- 14 days, 1 egg every second day.
Migration north for most pairs is initiated by the female. She tends to head to the pond she was born. The male follows. These two birds in the photo above may have a nest nearby. Why have these birds chosen not to migrate? She must like it on Bowen.
Goldeneye are cavity nesters, using natural cavities in live or dead trees close by water. Heights to entrance of nest holes is 2 to 15 metres.
Common mergansers are year-round residents of Kwilákm, and a common sight along any Bowen shore, and top predators in the aquatic food chain. When you look over the ducks in the Bay or the Lagoon, common mergansers are handsome birds. Distinguishing the drake (male) from the hen (female) is easy when the birds are in breeding plumage from roughly October to June. He has a bright red bill and metallic green head, while the hen sports a copper-coloured crest. Between late summer and mid-autumn, however, things become a bit confusing as males nonbreeding plumage looks very similar to female plumage. Come springtime, the females appear to vastly outnumber the males because many first-year male mergansers have not grown into adult plumage and still look mostly like females. But just because a merganser looks like a female, does not necessarily mean it is a female.
Common mergansers’ main food is medium-sized (5 to 30 cm) fish such as herring, anchovy, young salmon, shiner perch, sculpins, stickleback, and flatfish.
Their narrow, unducklike bill has evolved to help in the capture and handling of fish. Toothy serrations along the edge grip struggling fish. The prey is seized and forced head-first down the expandable gullet. When schools of fish are available, mergansers can fish in packs, rushing upon their prey in line, darting and seizing.
Researchers have determined the average daily consumption of fresh fish by an adult common merganser is about 450 grams.
Gulls often follow mergansers as they forage, waiting for the ducks to come to the surface with a fish, and then try to steal their prey. This practice is called kleptoparasatism.
Common mergansers are cavity nesters. The hen searches for a large, old or decaying tree or snag. They prefer a site near water and 3 to 8 metres up a tree. Mergansers cannot chisel their own cavity, so they take advantage of excavations left by pileated woodpeckers.
Landowners near Kwilákm are encouraged to preserve large snags on their land as important nesting habitat for woodpeckers and the merganser families that will inherit those nest sites when the pileated woodpeckers are through with them.
Bowen’s citizen scientists have observed mergansers nesting in tree cavities along Terminal Creek by the Meadows. Bowen has many suitable snags with woodpecker holes for nesting. The large population of common mergansers living on Bowen attest to this. When such holes are not available, mergansers may nest on the ground or use nesting boxes such as those erected by the ramp at the Union Steamship Company (USSC) Marina.
Nest boxes can take the place of woodpecker nest holes if your property is small and/or all larger trees have been removed from your lot. Cornell University’s Ornithology Lab offers common merganser nest box information and free building plans: nestwatch.org/learn/all-about-birdhouses/birds/common-merganser.
Young mergansers can swim and feed easily as soon as they leave the nest, although for the first few days, most of the food is obtained on the surface. Fledglings at first feed mainly on aquatic insects. They become skilled divers within eight days of leaving the nest and by about 12 days can catch fish. The brood responds quickly to female alarm calls and runs in unison across the water when fleeing from a perceived threat. Young common mergansers become independent in five weeks; are able to fly when about 65 days old; become reproductively mature by their second summer; and can live for a dozen years.
Because of mergansers’ fish diet, putting them at the top of the food chain, common merganser are important indicators of the overall health of aquatic ecosystems. Common mergansers seem to be doing well in our waters. Twenty years of citizen science data, collected by the British Columbia Coastal Waterbird Survey (BCCWS), has examined trends in abundance of 50 species in the Salish Sea. The BCCWS data shows a steady increase in Salish Sea common mergansers of almost 3%/year between 1999 and 2019.
A Merganser Nest Box in Snug Cove
Bowen photographer Mary Le Patourel caught this picture of mother merganser taking a break from sitting her clutch of 9 to 12 eggs in this box at the Union Steamship Marina in Snug Cove. The hen incubates continuously through the night for about 30 days. She takes several recesses during the day, such as seen here. Once hatched, the young remain in the nest for a day or two before tumbling from the nest cavity to follow the female to nearby water.
Mary tells of the events leading to her photo of mother common merganser with her ducklings in the Lagoon.
These young mergansers fledged from the merganser boxes at the USSC Marine. There are two boxes and each year two broods emerge about the same time as the Round Bowen Island Sailboat Race in early June. This year, this brood hatched the same day as the Race and as the sailors were heading up the ramp to the beer garden, mother duck was below, urging her chicks out of the bird box at one-day-old. Mother quickly assembled her youngsters on her back, and she swam under darkness to Kwilákm. There were more than 10 chicks to start with and the last time I saw them, there were four left. That’s pretty good considering the eagles and crows have to feed their young at the same time of year.
Many of the seabirds seen around Bowen during winter months breed in BC’s interior and the far north and then migrate when northern lakes freeze over to south coast wintering grounds.
Looking out over Kwilákm’s shoreline and water through the cold months, a keen observer can watch lots of easy-to- see marine birds: ducks, loons, grebes, herons, and geese, all going about their daily business. Ben Keen, ardent Bowen birder, is a big fan of birding here: “You can get closer to the birds in Kwilákm than anywhere else on the island. Even non-birders without binoculars love this location.”
During winter storms, Kwilákm offers protection from wild wind and big waves. This is a fine spot to be a winter seabird.
Seabirds move about in search of food, The numbers change seasonally and daily. At any time, they might not be in Kwilákm, but they are likely not far away. Because Howe Sound regularly attracts good numbers of many different kinds of seabirds, Birdlife International, a world leader in bird conservation, declared the Sound south of Anvil Island an Important Bird Area for its importance to three species at a global level: Barrow’s goldeneye, surf scoter, and western grebe.
Scoters and goldeneyes are attracted to Deep Bay’s shores to feast on the abundant blue mussels in the intertidal and subtidal zones. Western grebes are here to chase schools of small fish.
How are the birds who migrate to overwinter in the Salish Sea faring? Twenty years of citizen science data, collected by the British Columbia Coastal Waterbird Survey, has examined trends for over 50 species in the Salish Sea and the Pacific Coast. Results suggest that most species’ populations are stable, though downward trends were observed for surf scoter, western grebe, and common loons, while populations of harlequin ducks and glaucous-winged gulls increased. Bird population numbers have become important indicators of both environmental success and environmental stress. The Lower Howe Sound Christmas Bird Count covers almost all islands at the mouth of the Sound, including Bowen. The Christmas count is an opportunity for everyone to get involved and provides valuable long-term data about the state of local birds.
If you stand quietly on the shore of Kwilákm, you may notice small fish darting here and there in the shallows, sometimes breaking the surface as they feed. These fish may be shiner perch or stickleback, but they also might be young salmon.
No species is better connected to all parts of our estuary—Terminal Creek, the Lagoon, and Kwilákm—than our salmon. Adult chum salmon return each year from the Pacific Ocean to lay their eggs in gravel by the Causeway or in Terminal Creek. And when salmon fry rise from the gravel the following spring, they drift downstream to Kwilákm, where they spend the next several months feeding along the shorelines and fattening up before heading towards the open ocean. Even more salmon fry in Kwilákm come from the hatchery in Crippen Park, where volunteers raise both chum and coho salmon eggs over the winter and then release the fry into Terminal Creek and the Lagoon. See Chum Salmon.
Once in Kwilákm, the juvenile salmon, now 4 to 5 cm long, feed on tiny ocean plankton animals as well as insects from shoreline vegetation. But there are challenges. These fresh water fry need to adapt to the salt water of the ocean. They must also avoid predators such as the stalking heron, the fish-eating merganser, and the fast-moving cutthroat trout. Beds of eelgrass and seaweed in the shallows provide important refuges for young salmon where they can both hide and feed.
If all goes well and the juvenile salmon survive their summer in Kwilákm, the young salmon, now about 8 to 10 cm long, are ready to head to the open ocean. After two to four years, if they have avoided all the predators at sea, and the fishing boats along the coast, they will return to the Lagoon and Terminal Creek, following the scent of the stream waters where they were born.
If you snorkel from Pebbly Beach on Kwilákm at a low tide, you may see the extensive beds of eelgrass just off shore. The flowing blades of this undersea tall grass meadow host rich life such as schools of small fish, crabs, and other invertebrates.
Eelgrass beds (green on map) form a discontinuous band and patches in shallow waters just offshore from Pebbly Beach in the north to the shores of Snug Point in the south.
The Voluntary No Anchor Zone protects most of the bay’s eelgrass beds.
Although eelgrass looks like a seaweed, it is a flowering plant and a relative of grasses that occur on land. Beds or meadows of eelgrass grow on sandy floors of shallow sheltered bays throughout Atl’7katsem/Howe Sound. In Kwilákm, eelgrass blades can grow up to a metre in length, creating a dense underwater jungle for small fish and other life on the seafloor. This seafloor jungle provides critical habitat for many species such as juvenile salmon, crab, shrimp, and herring. It is estimated that along our coast, 80 per cent of commercial fish and shellfish species depend on eelgrass habitat at some point in their lifecycle.
Eelgrass is so rich because its blades become covered with a coating of algae (diatoms) that provide a rich food for small invertebrates. These small bugs are in turn a rich food supply for small fish and crustaceans. Eelgrass beds are busy with life.
Kwilákm has been a popular boat anchorage for many years. Wind and tides push a boat around, dragging the anchor chain across the ocean floor, and damaging anything the chain encounters. It is likely that eelgrass beds in Kwilákm have been fragmented by past anchor chain damage. In 2020, the Sea Change Marine Conservation Society worked with community volunteers to transplant eelgrass from nearby healthy beds to damaged areas.
This restoration work is coupled with efforts to protect both existing and newly transplanted eelgrass beds in Kwilákm, so that the eelgrass meadows can recover. It is easy to avoid damaging eelgrass, as it only grows to shallow waters up to a depth of about seven metres. If boats are moored in deeper water, their anchor chains won’t damage eelgrass. A voluntary no-anchor zone was established in 2021 in the shallow near-shore waters of Kwilákm.
This is the zone where the action is — biologically speaking. Here the water is shallow enough for light to reach the bottom making it ideal habitat for eelgrass and many types of marine algae or seaweeds.
These plants provide food and shelter to a myriad of small creatures ranging from prawns and crabs to small fish. The sand and mud bottom is also ideal habitat for burrowing creatures such as clams, sandworms and ghost shrimp.
Click on the map to learn more about each area of the Shallows Zone.
This abundance of “small fry” attracts larger predators such as adult salmon, marine birds, seals, and sea lions. Occasionally Biggs killer whales cruise the shallows looking for unwary seals for dinner.