First overfishing, then hydro dams. Lake sturgeon, Ontario’s largest and longest-lived fish, now belongs to one of the most beleaguered groups of animals on the planet.
By Peter Christie
Tim Haxton shifts his chair to allow his visitor a better view of the photograph on the computer screen. The dark image of a fossilized fish makes a subtle “S” in the lighter brown mud-stone that surrounds the shape. It is as if the creature suddenly turned to stone during a lazy swim through murky water. The petrified details – even the fine rays of fins – are crystal clear, and the identity of the fish is unmistakeable. “Sturgeon,” confirms Haxton, a fisheries specialist with the Ontario Ministry of Natural Resources (MNR). “This one is probably about 200 million years old, from the Jurassic period. They really haven’t changed much in form or function since.”
The soft-spoken biologist has collected hundreds of photos during his 15 years of studying lake sturgeon, Ontario’s largest and longest-lived fish. His picture of the fossil, however, adds an almost mind-boggling historical view to our discussion of sturgeon conservation: close ancestors of this formerly indomitable animal were swimming the world’s waters before the Atlantic Ocean was born, before birds flew and about 200,000 millennia before humans first appeared. They swam right through the great extinction of the dinosaurs and, despite volcanic eruptions, ice ages and other climatic calamities, have overcome every threat they encountered – until now.
Sturgeon today confront a higher risk of extinction than any other non-insect animal in the world, says Haxton, citing the conclusions of a 2010 workshop of the International Union for Conservation of Nature (IUCN). Decimated by periods of overfishing and prized for their eggs, which are sold as expensive caviar, many sturgeon populations around the globe have been in free fall for decades. All 27 sturgeon species – including lake sturgeon – are on the IUCN’s Red List of Threatened Species. Two-thirds of these are considered “critically endangered” because their plummeting numbers or shrinking, fragmented ranges mean that the odds of this fish disappearing for good are “extremely high.” Four sturgeon species may already be gone forever.