Conserving white sturgeon in BC

2021-08-09

 |  Biodiversity/Conservation

White sturgeons live on the west coast of North America. In BC, they live in the Fraser and Columbia rivers and estuaries. They are the biggest freshwater fish on the continent and can live to be over 100 years old. Sturgeon have been around for almost 200 million years! In recent decades, dams, overfishing, and water pollution have threatened this prehistoric species.

White sturgeon typically begin to reproduce in the second decade of their life and spawn once every few years. They feed on salmon, lampreys, and other freshwater fish as adults. 

In 2003, white sturgeon in BC were listed as endangered by the Committee on the Status of Endangered Wildlife in Canada. In 2012, sturgeon were divided into four populations; Upper Columbia River, Upper Kootenay River, Upper Fraser River, and Lower Fraser River.

All of the populations are listed as endangered except the Lower Fraser River population, which is threatened but not endangered.

Several factors impact white sturgeon:

White sturgeon are illegally fished in large numbers for their meat and caviar. Fishing sturgeon for caviar takes a heavy toll on the population because white sturgeon only spawn every few years. 

The Nechako white sturgeon population is impacted by a hydroelectric dam in the Nechako River. The dam was built in 1952 and has changed the river’s water level, flow, and quality. With the dam reducing water flow, silt has settled over the gravel where sturgeon lay their eggs. Silt does not hide eggs as well as rough gravel, leaving eggs and larvae more vulnerable to predators.

Adult sturgeon do not have predators, but many animals prey on young and juvenile sturgeon. Northern pike are native to northeastern BC but were introduced to southern BC and other regions of Canada for sport fishing. These fish feed on juvenile sturgeon and contribute to the collapse of food webs by overfeeding on salmon, trout, and other prey. A recent study by a UNBC graduate student found that otters in the Nechako river eat juvenile sturgeon, and may be an explanation for low survival and spawning rates post-release of hatchery sturgeon.

Conservation efforts are making progress:

Sturgeon begin breeding late in life, during their second decade, and only spawn every two to four years. Their reproduction habits depend on factors like water temperature, water flow, and food abundance. These factors can contribute to low reproduction, resulting in most aging fish compared to young, more frequently spawning sturgeon. 

Hatchery-released fish are showing promising results for population growth in the Upper Columbia River. The Upper Columbia White Sturgeon Initiative, launched by BC Hydro, is an example of effective collaboration to conserve at-risk species. Sturgeon eggs and larvae are brought from the wild into protected hatcheries, where juvenile sturgeon can mature safely. 

 The initiative, begun in 2000, involves BC Hydro, U.S. and Canadian government agencies, environmental organisations, and Indigenous representatives, including the Ktunaxa Nation Council and Spokane Tribal Fisheries

Sturgeon fishing is strictly regulated in BC. Green sturgeon are endangered, and must be kept underwater and immediately released if they are caught. White sturgeon can only be fished in the Fraser River because they have a strong population that is less impacted by overfishing and dams than in other rivers. 

Sturgeon are threatened on a global scale:

Sturgeon species around the world are being impacted by climate change and poor water quality. 85% of the sturgeon family is endangered

 

The Chinese paddlefish, closely related to the sturgeon and one of only two paddlefish species, may be extinct as a result of overfishing and the construction of dams. Dams can separate fish from their spawning areas, reducing the number of offspring.

Actions you can take:

  • Read up on fishing regulations before heading out on a trip. Before going fishing, it is necessary to get both a freshwater fishing license (or an alternative license depending on where you are fishing) and a White Sturgeon Conservation tag.
  • Buy sturgeon meat, caviar, and other products from regulated sellers who are committed to conserving the species.
  • Look for local shoreline clean-ups and hatchery release events to help protect sturgeon and other large freshwater fish.