The black sturgeon, Acipenser oxyrinchus, is a fascinating fish from Quebec, prized by anglers for its impressive size and ancient history. Although it is not the most combative fish, catching it represents a technical challenge due to its size and strength. It is primarily found in the large rivers and estuaries of Quebec, notably in the St. Lawrence River. Its distribution covers a wide area, but it is more common in regions where the water is rich in nutrients. Its fishing is often regulated, as its population is vulnerable due to overfishing and habitat degradation. Sport fishermen appreciate the challenge of catching it but must be aware of the strict rules surrounding its fishing and release.

The black sturgeon is easily recognizable by its elongated, fusiform body, lacking true scales. Instead, it has five rows of bony scutes: two lateral, two ventral, and one dorsal. Its skin is rough, with coloration ranging from dark gray to brown, sometimes almost black, hence its name. Its mouth is sub-terminal, located under a pointed snout, and is surrounded by four sensory barbels that help it detect food on the bottom. Its fins are well developed, with a heterocercal caudal fin typical of sturgeons, where the upper lobe is longer than the lower lobe. Young sturgeons have lighter patterns and more pronounced scutes, while adults tend to have a more uniform appearance. Males and females are difficult to distinguish with the naked eye, except during the spawning period when females may have a swollen abdomen due to the presence of eggs.

In Quebec, the black sturgeon is particularly present in the St. Lawrence River, from Montreal to the estuary, as well as in the large rivers that flow into this river. It is also found in some estuaries and bays of the Gulf of St. Lawrence. The species is rarer in the inland waters of remote areas of the river and is absent from small lakes and rivers. Its abundance varies by area, being more frequent in waters rich in nutrients and where pollution is lower. Conservation efforts aim to protect critical habitats for its survival, especially spawning and feeding areas.

The black sturgeon prefers large waterways and estuaries where the water is deep and rich in nutrients. It is often found at depths ranging from 10 to 30 meters but can go deeper to feed. It favors sandy or muddy bottoms where it can use its barbels to detect prey. Calm waters and areas with little current are also favored habitats, especially for young sturgeons. In summer, they may approach the shores to feed but move to deeper, cooler waters as temperatures rise.

The black sturgeon has a long and complex life cycle. Spawning occurs in spring when the water temperature reaches about 10 to 15 °C. Females lay thousands of adhesive eggs on rocky or gravel substrates, often in areas of moderate current. The eggs hatch within a few days, releasing larvae that move to calmer habitats to grow. Young sturgeons spend several years in fresh or brackish waters before migrating to estuaries. They reach sexual maturity between 12 and 18 years, depending on environmental conditions. The longevity of the black sturgeon is remarkable, with some individuals living up to 60 years. In spring, they spawn and actively feed; in summer, they move to cooler waters; in autumn, they prepare for winter; and in winter, their activity decreases significantly.

The black sturgeon is generally a solitary fish, but it can group in small numbers during spawning or in food-rich areas. It is not particularly territorial and tolerates the presence of other fish well. Sensitive to changes in temperature and pressure, it can modify its habitat depth in response to these variations. Sturgeons are also influenced by light, being more active at night or on cloudy days. They respond little to noise and surface movements, making them relatively indifferent to human disturbances.

The black sturgeon has a varied diet adapted to its benthic lifestyle. Young sturgeons primarily feed on small aquatic invertebrates such as insect larvae, worms, and small crustaceans. As they grow, their diet expands to include mollusks, dead fish, and other organic matter. Adults can consume larger prey but continue to primarily feed on the bottom. Their diet varies little by season, although they may feed more intensively in spring and summer to build reserves.

Fishing for black sturgeon is particularly productive in spring and summer, when the fish are more active and moving to feed and spawn. In spring, the best times are early morning and late evening, while in summer, night fishing can be very effective. In autumn, activity slows down, but catches are possible during mild weather. In winter, sturgeon fishing is rare, as they become lethargic and move to deeper waters. Weather conditions have little influence on their fishing behavior, although stable atmospheric pressures and overcast skies may favor fishing activity.

For black sturgeon, lures are not as important as natural baits. However, if you use lures, prefer natural colors like brown, green, or black that mimic their natural environment. In murky waters, lures with metallic reflections can help attract attention. In clear water and sunny weather, more subdued colors are preferable.

To fish for black sturgeon, a sturdy rod of 2.4 to 3.6 meters is recommended, with heavy power and moderate action. A large-capacity spinning or baitcasting reel is ideal, spooled with 30 to 50 lb line. Use circle hooks sized 5/0 to 8/0, which promote release. A fluorocarbon leader of 60 to 80 lb is recommended to resist abrasion.

The black sturgeon should be handled with care. Always support its weight with both hands, one under the head and the other under the tail. Avoid taking it completely out of the water if possible. For a successful release, let it recover in the water before releasing it. For a photo, keep the fish low above the water to minimize stress.

Predators of the black sturgeon primarily include humans due to fishing. Young sturgeons can fall prey to carnivorous fish like pike or walleye. Birds like herons may also target young sturgeons in shallow waters.

The black sturgeon is a vulnerable species in Quebec, primarily due to overfishing and habitat loss. It is subject to strict regulations, including catch limits and closed seasons. Release is often mandatory to help maintain populations. Conservation efforts aim to protect critical habitats and restore populations in certain areas.