A close up image of an algae bloom in Shuswap Lake near Ashby Point taken in April 2020. (Interior Health photo)

Shuswap Lake Algae bloom the result of “perfect storm” of factors

Shuswap Watershed Council states influx of nutrients and increased sunlight are causes

The Shuswap Watershed Council (SWC) says the large algae bloom in Shuswap Lake is the result of various factors which amount to a “perfect storm scenario.”

Program manager Erin Viera said algae is a natural part of Shuswap Lake’s aquatic ecosystem but changes in conditions can cause more prominent blooms. She said blooms are common when sunlight increases and runoff down creeks and rivers brings a fresh supply of nutrients into the lake.

Referring to a recent SWC study on the origins of the nutrients that are brought into Shuswap Lake by the Shuswap and Salmon Rivers, Viera noted that most of the nutrients from the rivers come from the valley bottoms. Agriculture, housing and commercial development in the watershed all affect the nutrient levels in the river.

Read More: Interpretive salmon classes at Kingfisher Creek get financial aid

Read More: Local governments call on Okanagan boaters to keep wakes low in shallow water

Viera said that as 2020 has been a very wet year, the Salmon River has been running higher than usual for months. The soil in the valley bottoms has also been saturated by rain causing nutrients to be flushed out of the soil into the river and down stream to Shuswap Lake. As the nutrients — particularly phosphorous — from the river settled in Salmon Arm bay, favourable conditions for the growth of large amounts of algae were created.

She said a similar effect was probably created in Tappen Creek and White Creek, which also flow into Salmon Arm Bay.

Viera added that the heavy rains this year might’ve contributed to the release of “legacy phosphorous” which is stored in soil for years or even decades. Septic systems near the lake and the Salmon Arm wastewater treatment plant are also sources of nutrients, but Viera said water quality monitoring has shown that they are smaller sources than the Salmon River.

Read More: Algae bloom highlights nutrient concerns in Shuswap water quality report

Read More: Money available to curtail nutrient pollution of Shuswap watershed

Nutrient increases lead to algae blooms in Salmon Arm Bay more than other parts of the lake because its shallow depth causes it to warm up more quickly. It is also relatively stagnant, and conditions are favourable to algae growth if the water isn’t mixed by currents or windstorms.

Water quality monitoring is also ongoing on the algae bloom itself. Viera said authorities are ensuring the bloom doesn’t pose a safety risk to swimmers or beach goers. If it becomes hazardous, notices will be posted at affected sites.



jim.elliot@saobserver.net

Like us on Facebook and follow us on Twitter

Environment

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

Just Posted

Revelstoke City Council approves replacement of $160,000 snow removal machine

It is one of three scheduled to be replaced over the next five years

Revelstoke could further delay byelection to save funds

It’s been roughly eight months since Steven Cross left city council

Nine new COVID-19 cases announced in Interior Health region

The total number of cases since the pandemic started is now at 531 for the region

Revelstoke Chamber of Commerce celebrates 125 years

The organization has outlasted 16 Canadian prime ministers

Netflix star Francesca Farago seen hanging in the Okanagan

Farago got her big break as a reality TV star in Netflix’s ‘Too Hot to Handle’ in 2020

105 new COVID-19 cases, 1 death as health officials urge B.C. to remember safety protocols

There are currently 1268 active cases, with 3,337 people under public health monitoring

Peachland resident finds severed bear paw on driveway

Tracie Gordon thought it was a Halloween prank, but it turned out to be a real bear paw

B.C. nurses report rise in depression, anxiety, exhaustion due to pandemic

A new UBC study looks into how the COVID-19 response has impacted frontline nurses

National child-care plan could help Canada rebound from COVID-induced economic crisis: prof

A $2 billion investment this year could help parents during second wave of pandemic

Search suspended for Indigenous elder last seen mushroom picking in northwest B.C.

Mushroom picker Thomas (Tommy) Dennis has been missing since Sept. 16

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

16 MLAs retiring from B.C. politics add up to $20M in pensions: Taxpayers Federation

Taxpayers pay $4 for every dollar MLAs contribute to their pensions

‘Bonnie’ and ‘Henry’ among latest litter of service dog puppies

B.C. Alberta Guide Dogs names two pups after provincial health officer

Zero new COVID-19 cases in Interior Health

Five cases remain linked to an outbreak at Calvary Chapel in Kelowna

Most Read