The waters of the Columbia River is occupied by a varied of fish, one of the more ancient ones is the white sturgeon, a fish that has remained unchanged for millions of years. Incredibly, they can live to be 100 and grow to 19 feet long. These bottom feeders spend most of their lives in the dark murky waters of river beds.
Sturgeon are covered in five rows of bony “scutes” that give them their unique “armoured” appearance. The sturgeon have no bones; relying on cartilage to give their bodies structure and support. A popular myth is that sturgeon are blind, however, they have small eyes that allow them to see just a little bit. They get around by using four rows of “whisker” at the front of their mouth that feel around for food. Sturgeon are “broadcast spawners”, meaning that both male and females release sperm and egg indiscriminately into the water
For quite a while, sturgeon numbers have been on the decline. The decline in the Columbia River is something biologists call “recruitment failure.” Adults are producing a lot of young but young sturgeon are not surviving long enough to reach reproductive maturity. A ban on commercial and sport harvest has been in effect since the mid-nineties, First Nations groups have also voluntarily given up their sustenance harvesting, and currently, upper Columbia sturgeon are listed as endangered. Due to the lack of knowledge of these animals, researchers were slow to pick up on the decline.
The question as to why wild stocks aren’t successfully reproducing remains unanswered, but experts note a few factors. First, the Columbia River system has seen massive changes within the last 100 years. This is mostly due to the string of hydroelectric dam projects on the river. Dams have affected water temperature and clarity that have likely contributed to the struggles of young sturgeon. Predation by invasive fish species could also be a factor in the lack of sturgeon reproductive success.
After spending some decades in decline, White Sturgeon numbers are finally seeing some positive change. A BC hydro initiative has successfully increased the number of white sturgeon in the Upper Columbia basin by approximately 10 fold in the span of 15 years. This has led to more than 33,000 white sturgeon swimming in our waters.
Hatchery staff use special mats laid in the river during spawning time. These large mats collect wild fertilized eggs, which are kept in a temperature-controlled environment and brought to the hatchery. Here they complete development, hatch, and grow large enough to be released into the wild. This method of intercepting fertilized eggs versus other methods previously used ensures that hatcheries staff raise a genetically diverse cohort of sturgeon to release into the wild.
At one level, the recovery efforts have been very successful. Where there was just over 3,000 sturgeon in the Upper Columbia river 15 years ago, there are 10X that now. Although recovery initiatives have increased the total number of fish in the water, the mystery regarding the root of their failure still remains unanswered. An advanced age of sexual maturity (about 20 years) means that the success of BC Hyrdo recovery efforts won’t be known for some years. The hatchery fish, making up over 90% of the population, have yet to reach sexual maturity and therefore have yet to prove the sustainability of recovery efforts.
The high survival rates of hatchery fish in the Columbia give hope to researchers and the members of the recovery initiative, though many questions remain to be answered. Time will tell if the initiatives have been successful to conserve and protect these unique and incredible fish.
Julien Gullo and Vickie Gould are second-year Recreation, Fish and Wildlife students at Selkirk College in Castlegar.