Lake St. Francis is situated on the St. Lawrence River, bordering south-east Ontario, south-east Quebec, and northern New York State. A great number of fish species are found in the St. Lawrence River, with many of them also present in varying numbers in Lake St. Francis.
Due to a high aquatic plant abundance, the waters of Lake St. Francis are clear and alkaline. As well as supporting a diverse range of fish species, the area is home to a variety of waterfowl, reptiles, and amphibians.
The south shore of the lake feeds into wetlands, which comprise a national wildlife area. Shallow waters transition to a steep drop-off, meaning that the lake is not easily accessible for fishing. Smallmouth bass, northern pike, walleye, and largemouth bass are considered to be the four top species to catch in Lake St. Francis.
Lake St. Francis Fish Species
1) Smallmouth bass (Micropterus dolomieu)
The smallmouth bass is the most important game fish in Lake St. Francis. Reaching lengths of around 70 cm (28 in), it prefers shallow, rocky areas with clear water, especially for spawning, during which time the male builds a nest and guards it. The nest is usually within a similar location each year.
Juvenile smallmouth bass feed on plankton and aquatic insects, while adults feed on crayfish, fish, and insects. This species is also occasionally cannibalistic: research has shown that this can happen due to fluctuations in food availability.
2) Northern pike (Esox lucius)
Female northern pike are generally much larger than males, capable of reaching 150 cm (59 in), whereas the maximum length recorded in males is 137 cm (54 in). This species prefers clear water with plenty of vegetation, heading to shallower, marshier regions of the lake for spawning.
Adults will feed on frogs and crayfish; however, their predominant food source is other fish, including those of the same species. The feces of northern pike contain an alarm pheromone, which causes their conspecifics to avoid the area. Research has shown that other fish species, such as fathead minnows, will also avoid the feces of northern pike.
While northern pike are popular table fish, they often carry tapeworms, which can infect humans if the fish is improperly cooked. The increasing popularity of eating raw fish has boosted the prevalence of tapeworm infection in Canada.
3) Walleye (Sander vitreus)
The walleye is a popular game fish and can be cooked in a variety of styles. Walleye fishing tournaments have been run on Lake St. Francis in the past. Walleye can attain lengths of over 100 cm (39 in), although they are more commonly 55 cm (22 in) in length.
They are nocturnal feeders, preying on insects and fishes, and prefer clear water with vegetation. Interestingly, a study on walleye showed that poor water clarity inhibits their productivity, but that increases in water clarity beyond a certain point can do the same – the optimal conditions for walleye lie somewhere in between.
4) Largemouth bass (Micropterus salmoides)
Largemouth bass have a preference for shallow, vegetated habitats with a muddy substrate. An important gamefish, they can reach lengths of 97 cm (38 in), although they are more commonly found at lengths of 40 cm (16 in). This species preys on a variety of other aquatic animals including crayfish, frogs, fish, and insects. Feeding stops during spawning, at which time the male becomes highly aggressive towards conspecifics as he guards his nest.
Productivity of the largemouth bass can fluctuate throughout the year: a study on the growth of largemouth bass discovered that while they are largely unaffected by the changes in temperature or the weight loss resulting from the lack of food during spawning, they are influenced by changes in prey availability across the seasons. Water temperature does affect largemouth bass, however; in waters that are above the optimum temperature, largemouth bass will behaviorally thermoregulate, seeking out refuges to cool down.
5) Brook trout (Salvelinus fontinalis)
Brook trout can occasionally be found in Lake St. Francis. These fish can reach lengths of 86 cm (34 in), although they are more commonly around 30 cm (12 in). They have a preference for clear, well-oxygenated water and have a highly varied diet of worms, crustaceans, leeches, insects, mollusks, amphibians, and other fish.
During spawning, the female digs a nest in gravelly substrate while the male guards her. After spawning, she sweeps gravel over the top of the eggs and moves on to build another nest. Brook trout aren’t a hugely popular table fish but are reported to have a light, delicate taste.
6) Lake trout (Salvelinus namaycush)
The lake trout is an important game fish and is a popular catch in Lake St. Francis. Lake trout may reach 150 cm (59 in), although they are more commonly found at lengths around 50 cm (20 in). This species shows enormous variability in its diet, consuming freshwater sponges, crustaceans, insects, fish, and small mammals, although some populations subsist entirely on plankton. Lake trout that only consume plankton show slower growth rates and decreased life spans compared to those with varied diets.
Prior to spawning, male lake trout clean the rocks and await the arrival of females. Spawning takes place at night and can be a highly competitive activity, with as many as seven males and three females attempting to spawn together at one time!
7) Rainbow trout (Oncorhynchus mykiss)
The rainbow trout is a large gamefish, with a maximum length of 120 cm (47 in). This species feeds on a variety of invertebrates and small fishes. Despite its preference for cold water, it is highly adaptable to different environments, although it does not do well in poorly oxygenated waters.
Rainbow trout can be cooked in a wide variety of styles, and the color of this fish’s flesh is dependent on its diet: a study found that adding carotenoids to the diet of the rainbow trout produced pink/red flesh, whereas naturally, the flesh would be white.
During spawning, rainbow trout dig nests in gravel, where they deposit their eggs. The fry are attached to a large yolk-sac, which provides them with the sustenance and nutrients they need to survive the early life stage. Once they have used up the yolk-sac, they emerge from the gravel, and due to the precise timing of spawning, food is then abundant in the environment, boosting their chances of survival.
8) Brown trout (Salmo trutta)
Also known as sea trout, the brown trout can attain lengths of 140 cm (55 in), although they are more commonly found to be around 70 cm (28 in). They spend some of their time (between 1 and 5 years) in freshwater, and the rest (between 6 months and 5 years) in saltwater. Spawning takes place in freshwater, usually utilizing tributaries where the water is fast-flowing and well-oxygenated.
Adult brown trout feed on mollusks, crustaceans, and small fish, whereas juveniles subsist on a diet of aquatic and terrestrial insects. A study has shown that brown trout compete with brook trout for resources such as food and habitat, with the presence of brown trout resulting in weight loss in the brook trout. The presence of brown trout in Lake St. Francis could possibly explain the low abundance of brook trout.
9) Chinook salmon (Oncorhynchus tshawytscha)
Chinook salmon are popular game fish, capable of reaching 150 cm (59 in) in length. Despite their large size, they feed predominantly on insects and small crustaceans when in freshwater. This species migrates from marine to freshwater environments (such as Lake St. Francis) to spawn; the young may then remain in the freshwater areas for up to three years before making the journey to the sea.
10) Muskellunge (Esox masquinongy)
A highly revered trophy fish, the muskellunge isn’t hugely common in Lake St. Francis, although large individuals can be found at the ‘Muskellunge Hotspot’, where the water suddenly drops away to depths of 30 feet. Trophy-length individuals may attain lengths of 180 cm (71 in).
This species prefers clear water with plenty of vegetation. It is solitary, preying on other fish, ducklings, muskrats, and snakes. Muskellunge are at risk of declining due to loss or damage to their habitat, however various conservation methods are in place, such as encouraging people to release the fish again after catching.
11) Lake sturgeon (Acipenser fulvescens)
Capable of reaching lengths of 275 cm (108 in), lake sturgeon are considered trophy fish, however overfishing in pursuit of caviar and meat has led to their decline. In an effort to help populations recover, state-funded research has focused on the conditions required for their reproductive success.
Lake sturgeon feed benthically over muddy, sandy, or gravelly substrates. Sensory barbels allow them to detect anything edible, and they are omnivorous, consuming any suitable food source that they come across. Spawning, the onset of which is influenced by rises in water temperature, takes place in rocky areas of the lake.
12) American eel (Anguilla rostrata)
The American eel can reach lengths of 150 cm (59 in), with the females generally being much larger than the males. This species prefers a muddy or silty substrate and is nocturnal: during the daytime these fish hide underneath sunken debris such as logs or boulders. It has a varied diet, including but not limited to insect larvae, gastropods, and other fish.
A catadromous species, eggs are laid and larvae hatch and develop in marine environments, before metamorphosing into elvers and returning to freshwater to mature. The American eel is endangered due to loss of habitat, overfishing, and pollution. Removal of dams or provision for the migration of eels past dams is an example of a conservation measure that could help aid the recovery of eel populations.
13) Silver lamprey (Ichthyomyzon unicuspis)
The silver lamprey can reach lengths of around 40 cm (16 in), although it is more commonly around 20 cm (8 in). This species is parasitic, attaching itself using its circular toothed mouth to suckers or sturgeon, to feed on blood or flesh. Although they’re not the most popular table fish, silver lampreys are edible – although they must be thoroughly washed and cooked prior to eating.
Silver lampreys undergo metamorphosis as they age: the larvae burrow down into soft substrate, where they may remain for up to seven years before transitioning into the juvenile phase and migrating into the lake. Populations of silver lamprey are threatened by habitat alterations such as the installation of dams, pollution from herbicides, and lampricide treatments. These lampricide treatments were created to target invasive sea lamprey, however silver lamprey are also affected by them.
14) American shad (Alosa sapidissima)
With a maximum length of 76 cm (30 in), the American shad is a popular game fish with a delicate flavor. While adults migrate into rivers and lakes to spawn, and larvae begin their lives in the lake, this species is predominantly marine. They consume copepods, plankton, and occasionally other small fishes.
The best time to fish for American shad is during their breeding migration, usually in May or June. These fish are susceptible to parasites, including nematodes, which can have serious implications for human health if consumed.
15) Spotfin shiner (Cyprinella spiloptera)
The spotfin shiner is a small fish, reaching just 12 cm (5 in) in length. It prefers a sandy or gravelly substrate and feeds on surface insects as well as immature aquatic insects. These fish spawn in crevices in rocks; research has shown that fallen trees are also frequently used for spawning. Once the eggs are laid, the male remains to defend them. Spotfin shiners are rarely caught in Lake St. Francis, due to them only being present in small numbers.
16) Bridle shiner (Notropis bifrenatus)
The bridle shiner is a very small fish, with a maximum length of just 6.5 cm (3 in). It prefers to inhabit areas with a muddy substrate and dense aquatic vegetation, where it consumes small crustaceans and insects. Bridle shiners are important forage fish for juvenile pike in Lake St. Francis.
During spawning, bridle shiners change color, with males becoming yellow or gold along their sides, and females being the same color as non-breeding males, but with a yellow anal fin. Females also have deeper bodies. Interestingly, males commonly court females larger than themselves; it is rare for males to pursue females that are the same size or smaller than them.
17) Common carp (Cyprinus carpio)
With a maximum length of 120 cm (47 in), the common carp is a popular game fish. It is an adaptable species, capable of surviving in a variety of environmental conditions, however it prefers shallow, well-vegetated areas over a soft substrate. It is crepuscular, feeding on benthic organisms and plant matter. An introduced species, it originated in Europe and Asia but became widespread across North America due to demand for angling and its use as a food source. Being a fast-growing species that reaches maturity at a comparatively low age, it makes an ideal game fish.
The common carp exerts great influence over the ecology of lakes: its presence may affect nutrient composition, phytoplankton abundance, and biodiversity. In some areas, the common carp may have detrimental effects on lake ecosystems, and it has been suggested that the removal of the species results in an improvement in water quality. In Lake St. Francis, however, the common carp is an abundant game fish; thus, it is there to stay.
18) Yellow perch (Perca flavescens)
Yellow perch are abundant in Lake St. Francis. They have a maximum length of around 50 cm (20 in) and feed on immature insects, fish, and fish eggs. Due to being diurnal, they are often predated on themselves by larger fish and birds. Research has found that yellow perch from Lake St. Francis contain high levels of mercury, which raises concerns around its consumption, as it is a popular sport and table fish. The yellow perch lays its eggs on aquatic plants, where they adhere to each other.
19) Channel darter (Percina copelandi)
The channel darter is a small fish, reaching just 7.2 cm (3 in) in length. This species has a preference for a sandy or gravelly substrate, where it feeds on the larvae of various insects, including midges, mayflies, and caddisflies. It migrates from deeper waters during the day to shallower waters at night. During spawning, male channel darters establish a territory and await the arrival of a female. The eggs are slightly adhesive and are subsequently buried in the sandy substrate by the female.
