A make pink salmon makes its way upstream to spawn. New research out of SFU suggests during healthy spawns of one species, competition among other dominate fish feeding on their eggs breaks down, allowing smaller fish to share in a critical, nutrient-rich food source. (Michael Penn file photo)

Abundance of one salmon species affects all others, B.C. study suggests

Feeding on other fishes eggs more critical to health survival than previously thought

A healthy spawning run from one salmon species may play an important role in the health of others, new research from Simon Fraser University suggests.

It’s widely understood when salmon returns are low, dominant fish from other species will push out all smaller competitors to feed on the eggs. But in a study published this week in the journal Ecosphere, researchers from SFU’s Salmon Watershed Lab found when returns are high, the dominant fish will still fill their bellies, but also make room for the younger ones to share in the nutrient-rich feast.

“What we found really interesting is that the competition broke down,” Colin Bailey, lead researcher and PhD candidate said. “Typically when you read about competition with stream fish, the larger fish hold their territory — the larger or more dominate species out-compete the smaller fish. In this case, where we placed a high but realistic number of eggs, the competition dissolved. Small fish gained access to a really really high-quality food source.”

READ MORE: Record-low returns continue for Fraser sockeye despite success of Big Bar passage

For the study, Abundance of salmon key to feeding ‘underdog’ stream fishes, Bailey and biological sciences professor Jonathan Moore added between six and 3,575 pink salmon eggs in different locations of the Keogh River on Vancouver Island.

Fish were captured and lightly anesthetized to have their stomachs flushed and examined. (The fish recovered in an in-stream container before their release back into the river.)

The team found young coho salmon, small steelhead trout and bottom-dwelling sculpins were able to access large deposits of pink salmon eggs despite other dominant fishes.

The results suggest one species’ spawning numbers impacts food resources for entire fish communities.

READ MORE: B.C.’s steelhead need our support: Fraser-Nicola MLA

Bailey is planning future research on the subject, including this study’s possible connection to his previous research looking at the impacts of pink salmon runs on juvenile steelhead. In that study he found higher runs of pink salmon in the fall coincided with an earlier out-migration of steelhead in the spring. He said it’s commonly accepted in the scientific field that younger fish have less chance of survival during out migration, but there may be more to it.

“If you go to sea smaller you may not have a good chance of surviving, but maybe all that energy you acquire from pink salmon eggs the previous fall compensates for that,” Bailey said.

If the results follow his reasoning, it could potentially influence fisheries management policy in such ways as limiting harvests of large salmon runs where steelhead are struggling.



quinn.bender@blackpress.ca

Fisheries and Oceans Canadasalmon stocksScience

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

“We have to make a call out to address this now so our people don’t have to feel fearful,” said Tribal Chief Mina Holmes. (Carrier Sekani Tribal Council Facebook photo)
Carrier Sekani Tribal Council seeks Indigenous-led task force in northern B.C. hospitals

Request made in an open letter to federal minister Carolyn Bennett

NDP headquarters on election night, Oct. 24, 2020. (Katya Slepian/Black Press Media)
ELECTION 2020: Live blog from B.C. party headquarters

BC NDP projected to win majority government – but celebrations will look different this election

B.C. Green Party leader Sonia Furstenau outlines her party's climate action platform at Nanaimo's Vancouver Island Conference Centre earlier this month. (News Bulletin file photo)
Green leader Furstenau declared victor in her home riding on Vancouver Island

Cowichan Valley voters elect freshly minted party leader for her second term

Submitted
BC VOTES 2020: John Rustad re-elected in Nechako Lakes riding

The result is based on preliminary vote count and the final results will be available after Nov.6

John Horgan has been re-elected the MLA for Langford-Juan de Fuca. (File-Black Press)
Horgan trounces challengers to be re-elected in his Vancouver Island riding

MLA has represented constituency of Langford-Juan de Fuca and its predecessors since 2005

Carolyn and Steve Touhey came across a pod of humpback whales while on their boat Sunday, Oct. 25. Photo supplied
VIDEO: Boaters encounter pod of humpbacks in Georgia Strait

Pod spotted between Comox and Texada Island

Prime Minister Justin Trudeau provides an update on the COVID pandemic during a press conference in Ottawa on Tuesday, Oct. 27, 2020. THE CANADIAN PRESS/Sean Kilpatrick
Trudeau says pandemic ‘really sucks,’ and that Christmas gatherings are up in the air

The prime minister encouraged residents to continue to follow the advice of local health authorities

The Williams Lake Indian Band is stipulating no-go zones for mushroom picking in areas burned by last summer’s wildfires. 100 Mile Free Press photo
Who controls mushroom harvesting on Indigenous lands?

‘We don’t necessarily know where the mushrooms grow, how old the stands need to be, those types of things.’

Canadian and American flags fly near the Ambassador Bridge at the Canada/USA border crossing in Windsor, Ont. on Saturday, March 21, 2020. THE CANADIAN PRESS/Rob Gurdebeke
U.S. election results one factor that could impact immigration to Canada next year

The survey polled 1,523 Canadians between Oct. 23 and Oct. 25

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

The voting station mimicked a real voting station in Nicole Choi’s classroom at Chilliwack middle school on Oct. 22, 2020, where students had to show their ID (student cards), be checked off a list, and mark a secret ballot behind a screen. (Jessica Peters/ Chilliwack Progress)
B.C. students choose NDP majority in mock election

More than 90,000 youth took part in school-based election process

Crew transport bus at the Trans Mountain pipeline project work site in Burnaby, March 2020. (Trans Mountain)
Check your workplace COVID-19 safety plans, Dr. Henry urges

Masks in public spaces, distance in lunchrooms for winter

B.C.’s Court of Appeal is in Vancouver. (File photo: Tom Zytaruk)
Judgment reserved in Surrey Six slayings appeals

Six men were killed in suite 1505 of the Balmoral Tower in Whalley on Oct. 19, 2007

Most Read