Log Booms, Estuaries & Salmon

Spotlighting Impacts of Log Storage on the Cowichan Estuary

Pacific salmon pass through estuaries and nearshore areas at two critical life stages; once when they first enter the ocean as juveniles [image left] and again when they begin their epic journey back to their spawning grounds as adults [image right].

Healthy estuaries give salmon the best chance of survival at these vital life junctures. But mouths of rivers are also home to big cities and where heavy industry has thrived in British Columbia for more than a century, damaging salmon habitat in the process.

Since the 1850s, the forestry industry has used estuaries to store logs in B.C. 1  Logs are moved down river from remote areas before being processed in local sawmills or transported by ship to other places.

Log booming is still very common in B.C. In 2019 alone, more than 15 million metric tonnes of logs were transported through the lower Fraser River. 1 

The Problem

Decades of research has shown that log booms stored in estuaries negatively impact salmon and local ecosystems.

Habitat Harm

When log booms are stored in river mouths, they don’t sit still. Turning tides, waves and currents mean large logs constantly scrape and scour the seafloor, disturbing benthic communities and destroying critical juvenile salmon habitat, like eelgrass.

Easy meal for seals

Log booms create artificial haul outs for seals - perfect ambush spots to grab an easy meal and prevent salmon from reaching their spawning grounds. Research has shown that thriving harbour seal populations affect salmon survival, as they readily prey on returning salmon that gather in estuaries before migrating upriver and juveniles on their out-migration.

Beach Pollution

Drifting timber also creates pollution on local beaches. Storms and strong currents can detach logs from their moorings, which end up clogging up beaches, altering the shoreline, and damaging forage fish spawning habitat.

Boating Hazard

Estuaries are busy waterways for marine traffic from tugboats to pleasure cruisers. Rogue logs floating in open water can easily bust a cruise ship’s propeller, damage a pier or sink a small fishing boat.

Booms in Cowichan Bay

Cowichan Bay is a wide estuary on the east coast of Vancouver Island where the Cowichan River and the ocean meet. The bay holds ecological, social, and cultural importance, particularly for members of Cowichan Tribes, the local Indigenous Peoples.  

Stseelhtun (salmon) are an integral part of our spiritual and cultural identity and they have been hit hard by the loss of marsh habitat, climate change, logging, and log boom operations in our territory.

said Cowichan Tribes Chief Cindy Daniels (Sulsulxumaat) in a joint press release with BCCF and PSF.

The river system has a long history of industrial logging. Logs began “running” down the Cowichan River in 1878 but the practice was banned in 1908 because logs would regularly destroy Cowichan Tribes' villages situated along the river. Despite this, log storage in Cowichan estuary continued to ramp up, peaking in the 1980s.

Log booms in Cowichan Estuary

Industry in the area has contributed to concerning heavy metal levels in local shellfish and alarmingly low salmon returns – only 500 Cowichan Chinook returned in 2009 compared to 10,000 in the late 1980s. 2 

To assess the impacts of log booms on salmon survival in Cowichan Bay, Cowichan Tribes, BC Conservation Foundation (BCCF) and the Pacific Salmon Foundation came together to track the migrations of returning Cowichan Chinook between 2017 and 2022.

“I commend our Luxumexun (Lands and Self Governance) department, BC Conservation Foundation and Pacific Salmon Foundation for their long-term commitment to this study which has delivered concrete data demonstrating the level of crisis our relatives, the salmon, are experiencing. With these results, we look forward to working with government, industry, and partners to take actions to reverse these impacts before it is too late.”

Cowichan Tribes Chief Cindy Daniels (Sulsulxumaat)

What did they find?

The presence of log booms in Cowichan Bay  decreases survival of Cowichan Chinook salmon .

The study also found that climate change will likely exacerbate poor survival rates. Low flows in the Cowichan River make it more difficult for salmon to reach their spawning grounds and prolong time spent in the lower river and estuary.

Extra waiting time in estuaries makes salmon more vulnerable to predation from seals who can rest on booms and prey on salmon who like to hide underneath them.

So, as the frequency of summer drought periods gets worse, so will the journey for returning salmon. Removing barriers to survival, such as log booms, will help stem that tide.

This bar graph represents Chinook terminal survival in high, average, and low river discharge levels. It depicts survival when log booms are present in blue, and when logs are absent in gold. The black lines represent the 95% confidence interval bars. They cover a range of values that we are 95% certain contain the true mean of the population.

Coast-Wide Issue

Log booming is not an issue unique to Cowichan Bay. In fact, you’ll find logs in river estuaries up and down B.C.’s coast from the Kitimat to Nanaimo rivers.

Location of log booms in (1) Campbell River, (2) Nanaimo River Estuary, (3) Fraser River Estuary, and (4) Cowichan Estuary. Additional estuaries with log booms circled in yellow.

What if there were no logs?

Juvenile Chinook in an estuary

Imagine if log booms were removed from estuaries and the effect it would have on restoring important salmon populations like the Cowichan Chinook.

Existing log booms in Cowichan Bay are in shallow water in the intertidal zone – an area that is home to mudflats, eelgrass, shellfish, and migratory bird habitats. Removing log booms, or moving them to deeper waters, would have benefits to many species that use this critical habitat, such as salmon.

Removing booms has been considered before by policymakers in Ottawa. In 2003, Fisheries and Oceans Canada and Environment Canada funded a consulting firm to develop a guidebook which identified environmentally sustainable log handling facilities in B.C.

The report deemed the locations of booms in Cowichan estuary as unsuitable for log booming. However, the recommendations from the report were never acted upon.

Working Together for Solutions

Logging remains one of the largest industries in British Columbia. On Vancouver Island, 80 per cent of felled timber is still transported by marine corridors or sorted in-water. 3 

It’s important to find ways to work together with the forestry companies to improve industry practices.

Log booms being transported on the Fraser River

BCCF has worked with Cowichan Tribes to propose alternative log boom operations in the Cowichan Bay region based on current estuarine literature and recent Cowichan Bay studies.

They suggested considering the following:

Using dryland sorting facilities.

Moving existing log booms to deeper waters.

Expanding log boom operations to other locations with less critical habitat for salmon.

Thank you for reading

Acknowledgements

Thank you to British Columbia Conservation Foundation and Cowichan Tribes for their partnership and leadership on this initiative.

To donate to PSF please visit

Production Date

June 19, 2024

Last Updated

June 19, 2024

Photo/Video Credits

Please see the (i) icon in each photo/video.

Produced by

Pacific Salmon Foundation

Story Author

Oscar Beardmore-Gray

Story Developers

Paulina Salinas Ruiz and Ben Skinner

Additional Editors

Jamieson Atkinson (BCCF), Nicole Christiansen and Isobel Pearsall

References

1

Kussin-Bordo, N., S.G. Hinch, Y. Asadian, D.C. Scott. 2024. Effects of log booms on physical habitat, water quality, and benthic invertebrates in the lower Fraser River and estuary. Canadian Journal of Forest Research. In press.

2

Berz, K.L. (2021, Nov 28). Swimming upstream: For B.C.’s Cowichan Tribes, life by the river fraught by climate change and a fight for return of their chinook salmon tradition. Toronto Star. https://cowichanwatershedboard.ca/document/swimming-upstream-for-b-c-s-cowichan-tribes-life-by-the-river-fraught-by-climate-change-and-a-fight-for-return-of-their-chinook-salmon-tradition/

3

Smith, M., & Wright, M. (n.d.). Water-based log handling impacts to marine nearshore habitats in WCVI: WCVI Chinook marine risk assessment [PowerPoint slides]. M.C. Wright and Associates Ltd.

Log booms in Cowichan Estuary

This bar graph represents Chinook terminal survival in high, average, and low river discharge levels. It depicts survival when log booms are present in blue, and when logs are absent in gold. The black lines represent the 95% confidence interval bars. They cover a range of values that we are 95% certain contain the true mean of the population.

Location of log booms in (1) Campbell River, (2) Nanaimo River Estuary, (3) Fraser River Estuary, and (4) Cowichan Estuary. Additional estuaries with log booms circled in yellow.