13 Fish Species in Bear Lake (Updated)

Fish Species in Bear Lake

1) Bonneville cisco (Prosopium gemmifer)

Endemic to Bear Lake, the Bonneville cisco can be found in the pelagic zone, where it feeds on zooplankton. While these fish reach maturity at three years of age, at which point they may measure over 7 inches in length, it is not until they are older that they can attain the larger sizes, with some adults measuring 12 inches. As water temperatures increase, the Bonneville cisco will descend deeper into the lake to access cooler waters.

These fish only ever enter the benthic regions of Bear Lake for spawning, which takes place in January. The Bonneville cisco prefers a rocky substrate for laying its eggs, generally found in the shallow borders of the lake. The eggs are laid in tightly packed clumps, and upon hatching at around the start of May, the young Bonneville cisco travel to the surface water. This provides them with ample food and sufficient warmth to fuel swift growth.

Adult Bonneville cisco are consumed by cutthroat trout and lake trout. Eggs of the Bonneville cisco are targeted by the Bear Lake sculpin: one study found that one individual had 230 eggs in its stomach! Whitefish are also suspected to consume Bonneville cisco eggs: conservation concerns over endemic fish populations affected by egg predation have prompted the provision of protection for Bonneville cisco and have also inspired further research into the species’ life history.

2) Bear Lake whitefish (Prosopium abyssicola)

Not generally caught for sport, the Bear Lake whitefish reaches a maximum length of around 12 inches. This species is endemic to Bear Lake, and in contrast to the Bonneville whitefish (see below), it inhabits cooler waters and is rarely seen near shore. This has both benefits and drawbacks: lower temperatures mean slower growth, however there are fewer predators found in this region, so fish are more likely to survive. The Bear Lake whitefish spawns in February and feeds benthically on ostracod populations.

Interestingly, the Bear Lake whitefish has become reproductively isolated from the Bonneville whitefish, because of a dissimilarity in when each species spawns and the regions of the lake each occupies. The speciation of these two species is thought to be relatively recent, and both species still spawn on the rock pile near Gus Rich Point, to the east of the lake. Additionally, the two species show subtle morphological differences, with the Bear Lake whitefish having fewer scales above the lateral line than the Bonneville whitefish.

3) Bonneville whitefish (Prosopium spilonotus)

In contrast to the Bear Lake whitefish, the Bonneville whitefish occupies the mid and upper benthic regions of the lake: these areas are warmer, thus the Bonneville whitefish grows rapidly and can reach lengths of over 20 inches. The Bear Lake whitefish was first described in 1919 at the same time that the Bear Lake whitefish and Bonneville cisco were discovered. At the time, these fish were frequently caught by local fishermen, but the number caught has dwindled over the years and now they are only occasionally captured.

This species also spawns on the rock pile near Gus Rich Point, however spawning takes place in December, which is thought to be the leading cause of speciation between this and the Bear Lake whitefish. The Bonneville whitefish will also spawn on rocky substrate at the lake margins.

Bonneville whitefish are piscivorous. Once they have attained a length of around 10 inches, they begin to feed on smaller fish species such as Bear Lake sculpin. In turn, this species of whitefish is predated on by trout: the introduction of lake trout to the lake has caused concern for populations of Bonneville whitefish, which is endemic to Bear Lake.

4) Bear Lake sculpin (Cottus extensus)

The last of the endemic species, the Bear Lake sculpin is benthic and consumes aquatic macro-invertebrates and zooplankton. This small species (4 inches maximum) spawns in late spring in shallow, rocky regions of the lake. The eggs hatch towards the end of May, with the larval fish traveling to surface waters to capitalize on warmer temperatures and an abundance of food.

Water currents at the surface also distribute the larval fish around the lake. These young fish continue to migrate from the bottom of the lake and the surface each night: this allows fast growth while providing protection from predators that are less active at night, such as the cutthroat trout and lake trout. Predation of Bear Lake sculpin is especially prevalent in winter and spring.

Studies have suggested that the daily vertical migration of the Bear Lake sculpin also enables them to track the movements of zooplankton, specifically Epischura nevadensis, which display similar migratory behavior. However, there is contrasting evidence to imply that the majority of the Bear Lake sculpin’s stomach contents were harvested benthically; more research is therefore required to fully understand the life cycle and behavior of this species.

5) Cutthroat trout (Oncorhynchus clarkii)

The cutthroat trout is native to Bear Lake, although it is also widespread across the eastern Pacific. A commonly caught sport fish, it can reach lengths of 40 inches. The dietary requirements of the cutthroat trout vary with age: when small it feeds on macroinvertebrates and zooplankton, progressing to Bear Lake sculpin and other small fish species as it grows. At its largest, it predates Bonneville cisco, and until lake trout were introduced, the cutthroat trout was the dominant predator in Bear Lake.

The distribution of the cutthroat trout varies considerably: larger individuals generally inhabit cooler waters, except during spring when they travel to warmer waters to spawn. Smaller individuals are also found in warmer waters.

The Bear Lake population of cutthroat trout has been a conservation concern: over-fishing and loss of spawning habitat caused a decrease in numbers, although this has been successfully remedied using a combination of protective measures and spawning traps to assist breeding. Fishing for wild cutthroat trout in Bear Lake was severely limited by regulations introduced in 1998 and although populations have recovered significantly since then, whether fishing of this species should be permitted is still heavily debated.

6) Utah sucker (Catostomus ardens)

With a subterminal mouth designed for feeding on the bottom of the lake, the Utah sucker is benthic and native to Bear Lake. This species is found at most depths – although it prefers vegetated areas – and consumes benthic invertebrates and detritus, being able to burrow several inches into the muddy substrate to capture its prey.

Interestingly, the Utah sucker prefers to spawn in streams, however it has had great success spawning in May and June along the east shoreline of Bear Lake. The young fish remain in these shallow waters to feed and seek protection from predators present in deeper waters.

Despite reaching lengths of 25 inches, the Utah sucker is not a game fish. Research has shown that the majority of Utah suckers in Bear Lake are parasitized by tapeworms.

7) Utah chub (Gila atraria)

Similar to the Utah sucker, the Utah chub occupies benthic regions of Bear Lake and possesses a sub-terminal mouth for harvesting plant matter and benthic invertebrates from the bottom of the lake. They will also feed on the eggs of the Utah sucker. This fish is rarely found below depths of 33 ft, preferring shallower regions of the lake. Very little is known about the reproduction of the Utah chub.

8) Speckled dace (Rhinichthys osculus)

Despite speckled dace rarely being found in lakes, this species is native to Bear Lake. It is a small fish, reaching around 4 inches, and favors vegetated and rocky regions. Within Bear Lake, the speckled dace is most abundant near the Utah State Park Marina, and also resides in shallow reed beds, where it feeds on invertebrates and zooplankton. The speckled dace is not a game fish.

9) Redside shiner (Richardsonius balteatus)

Also native to Bear Lake, the redside shiner can reach 7 inches in length, although it is usually 3 inches long. It prefers vegetated habitats with a muddy or silty substrate.

The diet of the redside shiner varies according to age: small individuals feed on ostracods, small crustaceans, and diatoms, whereas larger fish predate on aquatic insects, mollusks, and fish eggs. Due to its small size, the redside shiner is not a game fish.

10) Lake trout (Salvelinus namaycush)

Lake trout are an introduced species to Bear Lake. They are found across Canada, Alaska, and eastern America and are a popular sporting fish, this being the reason they were originally introduced to Bear Lake in 1911.

This species is large, able to reach lengths of 40 inches, and once mature will feed on Bear Lake sculpin and Bonneville cisco. Smaller individuals feed on benthic and terrestrial invertebrates. The lake trout prefers deep, cold lakes; thus is slow-growing and takes a long time to reach maturity. Despite this, it is capable of becoming the apex predator and at one time began to dominate Bear Lake.

The population of lake trout in Bear Lake has been periodically added to for fishing, however this has resulted in concerns arising over the endemic fish populations, which are predated on by the lake trout. In addition, increasing competition between the native cutthroat trout and introduced lake trout has led to introductions being decreased. Sterile fish are now used as a way to prevent breeding, in order to carefully control numbers.

11) Green sunfish (Lepomis cyanellus)

The green sunfish generally prefers quiet, vegetated areas, although it is an adaptable species capable of surviving in a variety of habitats. Despite this, the productivity of the green sunfish is limited in Bear Lake: low temperatures, predation, and a lack of suitable spawning sites inhibit the species’ reproductive success. Due to this lack of productivity, green sunfish rarely reach ‘catchable lengths’ in Bear Lake, so are not often caught.

12) Yellow perch (Perca flavescens)

The yellow perch generally reaches lengths of around 7 inches, although some individuals have been recorded to attain lengths of 20 inches. This species prefers a vegetated habitat with clear water, where it predates on immature insects, invertebrates, small fish, and fish eggs.

Similar to the green sunfish, the yellow perch is an introduced species that is reproductively limited by low temperatures, predation, and insufficient spawning sites. Yellow perch are occasionally caught in Bear Lake, although this is not common.

13) Common carp (Cyprinus carpio)

The common carp is found in vegetated regions with a muddy substrate. Small, immature individuals feed on zooplankton and ostracods, while adults feed on benthic invertebrates. Due to the common carp being an introduced species, ecologically it is not best suited to Bear Lake and its reproduction is limited by the cool water temperature and insufficient spawning habitat.

As a crepuscular species, the common carp has a tapetum lucidum – usually seen in nocturnal mammals – a tissue behind the retina that reflects light, maximizing the light levels reaching the rod cells. Although it is a popular game fish elsewhere, the common carp is not generally fished for in Bear Lake.