Cowichan Watershed Board

  • Email
  • Facebook
  • RSS
  • YouTube
MENUMENU
  • About
    • Collaborative Governance
    • Our Principles
    • Board Members
    • Staff Team
    • Non-Profit Society
    • Supporters (Coming Soon)
    • Contact Us
  • Targets
    • Water Quality
    • Estuary Health
    • Salmon Sustainability
    • Wise Water Use
    • Watershed Connections
    • Water Flows
    • Riparian Plants
    • Target Working Groups
  • Projects
    • Drought Response
    • River Cleanup
    • Koksilah
    • Twinned Watersheds Project
      • Riparian Plants
      • Indigenous Flows
      • Fish Habitats
      • Big Dancing Fish
    • Weir Ready
      • Weir Ready FAQ
    • Speakers Series
    • Past Projects (Coming Soon)
      • Water Challenge (Coming Soon)
      • Superheroes (Coming Soon)
  • Library
    • Board Meetings
    • Governance Documents
    • Maps
    • Media
    • Presentations
    • Videos
    • Reports
      • CWB Reports
      • Other Reports
    • All Library Items
  • Latest News
You are here: Home / content / [The Skeena] Massive Fish Die-Off Mystery on Vancouver Island Explained

[The Skeena] Massive Fish Die-Off Mystery on Vancouver Island Explained

September 24, 2023 by Jill Thompson

by The Skeena September 2023

New report by the DFO says environmental stress killed hundreds of fish in the Cowichan River

New report by the DFO says environmental stress killed hundreds of fish in the Cowichan River.

A new report just published by Fisheries and Oceans Canada (DFO) explains the mystery behind a massive fish die-off in the Cowichan River on Vancouver Island.

This past July, swimmers near Skutz Falls in Cowichan River Park stumbled upon numerous dead salmon and trout with lesions all over their bodies.

“Hundreds, perhaps thousands of baby trout and salmon. Some of them up to two years old.”

Parker Jefferson, Cowichan Stewardship Roundtable

“They noticed silver spots all over the bottom of the river,” Parker Jefferson of the Cowichan Stewardship Roundtable told CTV News at the time of discovery.

Skutz Falls with healthy water levels. Source – Wirestock

“Hundreds, perhaps thousands of baby trout and salmon,” he reported. “Some of them up to two years old.”

Even The New York Times published a large spread last week about the Cowichan River incident within the context of an unprecedented year of heat, drought, and wildfires in Canada.

“It was the first time, not just in my career, but the first time in my life, that I had seen anything like that,” Cowichan Tribes member and biologist Tim Kulchyski told the American paper after he stumbled upon dead fry and even more dead adults further down the river.

Mystery Uncovered

After collecting samples and conducting toxicology tests, DFO released its findings this week. The lesions were credited to environmental stress, which is connected to low oxygen and elevated pH in the water. They noted excessive algae growth, which can be a result of “low flows, hot, dry weather and availability of nutrients such as nitrogen and phosphorus.” 

“This report from DFO has to be setting off a few alarm bells,” Jefferson told CBC in response to the release.

“We’ve known that the river’s in bad shape for a long time.”

Tom Rutherford, Cowichan Watershed Board

Community planning public meetings are part of a process that will explore future water use needs alongside various potential water supply and storage options. Source – Cowichan River Water Supply

Many advocates have been alarmed for years about worsening conditions on the Cowichan River. Rising temperatures from climate change and low water levels are resulting in the water drying up and fish populations suffering. 

“We’ve known that the river’s in bad shape for a long time,” Tom Rutherford of Cowichan Watershed Board said to CBC. The Watershed Board is part of a coalition of local governments and the Cowichan Tribes First Nation to monitor the area and advocate for watershed security. He says if the water levels get too low this season, his team is prepared to catch and relocate salmon to spawning grounds to help them survive.

The current weir pumping water from the Cowichan Lake into the Cowichan River. According to the Cowichan Water Use Plan Public Advisory Group, the weir at Cowichan Lake needs to be raised to increase the water storage during the late spring and summer seasons. Source – Cowichan River Water Supply

New Weir Needed

Rutherford and other concerned citizens have long been calling for a new weir to be built on the Cowichan River. A weir is a small dam that controls the flow of the river, holding water in the winter and releasing it in the summer when water levels are lower.

“I think this is an indication of what can happen and what probably will happen in the future unless we can start to mitigate and adapt to the effects of climate change.”

Tom Rutherford, Cowichan Watershed Board

New weir design based on recommendations from the 2018 Cowichan Water Use Plan (WUP), stakeholder engagement, feedback on the preliminary design, Provincial and Federal legislation, and industry-accepted practices. Fish passage and riparian environment objectives are the priority in the design and the basis for the project funding. Source – Cowichan River Water Supply

However, the existing weir was built in 1957, and many say it is too small to produce the needed volume for the current low water levels.

The Watershed Board has produced a new weir design and now says it is up to the provincial and federal governments to come through with the necessary funding. 

Rutherford is worried that without this change, they may be unable to prevent another massive fish die-off. 

Filed Under: content, Library, Media, News, Weir Ready

Weir Project Website

screenshot cowichanlakeweir.ca

Click to visit the weir project website.

Fish Kill Report

cover - fish kill report

Click to read. This report details the lessons and response to the massive 2023 fish kill in Cowichan River.

Watershed Board Meeting Info – click image.

CoChairs Daniels and Segall

Click image for Board Meeting Packages. Photo of CWB Co-Chairs, Cowichan Tribes Chief Cindy Daniels, CVRD Chair Kate Segall (Cowichan Tribes photo)

Why Fish Need Water

Why Fish Need Trees

Why Fish Need People

Latest News

  • [Chek News] ‘It’s dropped so fast’: Low snowpack impacts Cowichan River
  • [Times Colonist] Comment: Let’s give a dam for Vancouver Island’s only heritage river
  • [The Discourse] Local advocates look ahead to a healthier year for Somenos Lake
  • Why BC Needs Watershed Boards

Sign up for E-News!

Board Meeting Notifications

Event Notifications

CWB Website

Home
About Us
Contact
Board Meetings
Annual Reports
Library
Privacy
Terms

Targets

CWB Targets

Water Quality
Estuarine Health
Salmon Sustainability
Water Use
Watershed Connections
Water Supply
Riparian Area Protection

Cowichan Watershed

Cowichan Lake
Quamichan & Somenos Lakes
Cowichan Estuary
The Weir
Koksilah

Logo Email

[email protected]

Mailing Address
4335 Riverside Road
Duncan, BC, V9L 6M8

Copyright © 2025 Cowichan Watershed Board - All Rights Reserved. | Design by MAC5 | Site Maintenance by Web321

cowichan tribes logo cvrd logo polis logo refbc logo pacific salmon logo

The Cowichan Watershed Board (CWB) gratefully acknowledges the financial support of the above organizations.