The sea lamprey is a fascinating species, although often disliked due to its parasitic lifestyle. It is found in some waterways in Quebec, notably in the Saint Lawrence River. While its sporting interest is limited, it plays an important ecological role as a regulator of fish populations. Its distribution is more common in North Atlantic waters, but it has adapted to several freshwater environments in Quebec.

The sea lamprey is distinguished by its elongated, serpent-like body, which is devoid of scales. Its color ranges from brown to gray-green, with a lighter belly. Its sucker-shaped mouth is lined with keratinized teeth arranged in concentric circles, used to attach to its hosts. The fins are reduced, and its tail is slightly spatula-shaped, facilitating its movement in the water. Young lampreys, called ammocoetes, are duller in color and live buried in the riverbed. During spawning season, males develop a more pronounced dorsal crest to attract females.

In Quebec, the sea lamprey is primarily found in the Saint Lawrence River and its tributaries. It is also found in some rivers connecting the Great Lakes, although it is less abundant in these areas. Historically, it has expanded its range due to artificial canals. It is absent from inland waters far from major waterways. Overall, it is present along the North Atlantic coasts, from North America to Europe.

The sea lamprey prefers well-oxygenated waters, whether in marine or freshwater environments. It is often found near estuaries and transitional areas between saltwater and freshwater. Adults migrate upstream in rivers to spawn, seeking gravel or sandy substrates to lay their eggs. The water depth can vary, but it is generally found in shallow areas during reproduction.

The life cycle of the sea lamprey begins with the laying of eggs in rivers, where the ammocoetes hatch and spend several years buried in sediment. They then metamorphose into adults and migrate to the sea where they live parasitically, attaching to other fish to feed on their blood. Adults return to freshwater to spawn and die shortly after reproduction. Spring → Spawning → Summer → Migration → Fall → Growth → Winter → Metamorphosis

The sea lamprey is primarily solitary, although it may gather for reproduction. It is not territorial but chooses specific spawning sites. Sensitive to changes in light, it is more active at night. Weather conditions such as wind or rain have little impact on its behavior, but it avoids overly warm waters.

Ammocoetes feed on organic matter suspended in the water. Once metamorphosed, sea lampreys become parasites that attach to other fish, feeding on their blood and bodily fluids. They prefer larger fish, such as salmon or trout, but are not selective about their hosts.

In spring, sea lampreys migrate to rivers to spawn. They are more active at dawn and dusk. In summer, adults return to the sea. Fall is a growth period for young ammocoetes. In winter, activity slows down, but ammocoetes continue to feed in the sediments. Pressure variations and weather conditions have little effect on their seasonal behavior.

The sea lamprey is not targeted by conventional lures. For scientific research or observation, no lure is necessary. However, if you are fishing in areas where it is present, choose lures suitable for host fish, such as salmon or trout.

For observation, no specific rod is necessary. If you are fishing for host fish, a rod of 7 to 9 feet, medium power, with a fast action is recommended. Use a reel size 3000-4000 with a line of 8 to 12 lb. Hooks should be strong enough to withstand the targeted fish.

If you accidentally catch a sea lamprey, handle it with care. Use gloves to avoid injuries from its teeth. Release it back into the water quickly to minimize stress. Take a quick photo if necessary, but avoid keeping it out of the water for too long.

Adult sea lampreys have few natural predators due to their parasitic lifestyle. However, young ammocoetes may be preyed upon by larger fish and aquatic birds like herons.

The sea lamprey is often considered harmful due to its impact on fish populations. However, it is an indigenous species in some regions of Quebec. Management focuses on reducing its impact in the Great Lakes, where it is invasive. Release is generally not regulated but is encouraged to preserve ecological balance.