Fish, forests, and fires: how ancient technologies can rebalance BC’s natural systems

While you might think of nature as untouched by human activity, people have always cared for the lands and waters around them. "Environmental stewardship" refers to the ways that people manage our natural surroundings. These activities help to keep our habitats in balance.

Dr. Teresa (Sm'hayetsk) Ryan is an ecologist and a member of the Gitlan tribe of the Tsimshian Nation. She researches Indigenous knowledge systems for managing natural resources, particularly the eulachon fish.

For the Tsimshian people, environmental stewardship is a way of life.

“It’s based on observation of the environment and understanding its cycles of renewal and regeneration,” she explains.

By observing those cycles over time, one can notice when things are out of balance or need attention. “For example, heavy rains might bring extra sedimentation into a stream,” says Ryan. “So there may be a need to go into the stream and use a cedar bough to sweep away that substrate.” 

Stewarding healthy ecosystems

Coastal First Nations would also steward the fish populations, as these were an important source of food.

Ryan explains that the Tsimshian people would ensure that the largest chinook salmon were not harvested. Instead, these fish were released to spawn, so their offspring could replenish the population. 

Part of Ryan’s research focuses on tidal stone traps, an ancient technology that First Nations used for more than 5,000 years along the central and north coasts of British Columbia.

These traps, also called weirs, were built in rivers to catch salmon. Some would be harvested for food, while others would be released to spawn. But the traps also allowed Indigenous people to monitor the fish. They could observe the size of the population, the temperature of the stream, and other data.

Ryan’s research will use stone to show scientifically how this technology was used to successfully manage the chinook salmon. The data and evidence from her research can be used to help restore the health of the species. 

Changing environments and changing climates

Ryan’s research is especially important now, as chinook salmon populations have declined in the past 150 years.

Part of the reason for their decline is the changing climate. It's also due to the impacts of commercial logging and fishing on the environment. Most of British Columbia’s old growth forests have been cut down since the 1860s. This logging has affected the health of the watersheds and the species that live in them.

Trees absorb rainwater and release it gradually for consistent flow of water, while their foliage shades and cools the streams. When trees fall, their trunks and branches provide fish with shelter from predators, and the nutrients released as they decay nourish aquatic plants. 

Removing Indigenous methods of environmental stewardship has affected the environment too.

First Nations in the Interior had a historic system of wildfire management. It involved setting controlled fires to clear the underbrush at specific times of year. This would reduce the risk of a more dangerous forest fire during the hottest and driest time of year. These cultural burns also helped the forest regenerate. They increased growth of grasses and plants that, in turn, sustained the health of many animal species.

But this practice was banned by the B.C. government in 1874. 

“We disrupted a fire ecology cycle, and we’ve also had intensive clear-cut logging on slope after slope. During the same period, we’re seeing our salmon populations decline,” explains Ryan. “There’s an impact that’s man-made, and it's compounded by what’s going on with the climate.”

Climate change will bring more unpredictable weather, and with it more extreme floods and wildfires. These conditions are even more dangerous without environmental stewardship.

The 2021 wildfire season in B.C. was one of the worst ever recorded. The town of Lytton, B.C., was destroyed by fire after reaching a temperature of 49.6 degrees Celsius. “Losing an entire town is an indication of the intensity of these changes,” says Ryan. “And it also has to do with the way the habitat is being cared for.”

Restoring healthy environments

Responding to climate change will require many different strategies. But Indigenous ways of managing the environment are one way to rebalance these natural systems. 

In recent years, First Nations in B.C. Interior have renewed the practice of cultural burning. These methods are now recognized as an effective form of wildfire management. They also improve wildlife habitats and increase the resilience of forests.

Healthier forests will lead to healthier watersheds, by reducing runoff from heavy rain events. This prevents sediment, pesticides and other chemicals from seeping into the water.