Coregonus Artedii Research Articles

Predicting the effects of rainbow smelt on native fishes in small lakes: evidence from long-term research on two lakes

We assessed predictability of negative interactions between native fishes and exotic rainbow smelt (Osmerus mordax) through field experiments and long-term data analysis for two lakes in Wisconsin. Predictions were made based on thermal preferences, diet characteristics, and published accounts of interactions between smelt and yellow perch (Perca flavescens) and smelt and cisco (Coregonus artedii). Our results indicate predation is the most likely cause for the extirpation of cisco from Sparkling Lake in 1990. In Crystal Lake, native yellow perch experienced significant overlap in distribution and diet with smelt. The condition of adult perch was negatively correlated with smelt abundance indicating competition was occurring. Smelt feed on a wide size range of prey items making this species a threat to native fishes, especially when spatial overlap is high. Information on spatial and temporal overlap and diet enable useful predictions about the effect of smelt invasions on native fishes.

Comparative toxicity of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin to seven freshwater fish species during early life‐stage development

AbstractThe toxic effects of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) to fathead minnow (Pimephales promelas), channel catfish (Ictalurus punctatus), lake herring (Coregonus artedii), medaka (Oryzias latipes), white sucker (Catastomus commersoni), northern pike (Esox lucius), and zebrafish (Danio danio) were observed during early life‐stage development after waterborne exposure of fertilized eggs. Species sensitivity based on TCDD‐Cegg (TCDD concentration in eggs) was determined by effects observed over a 32‐d period for all species except lake herring in which a 100‐d period was used. Signs of TCDD toxicity, including edema, hemorrhaging, and craniofacial malformations were essentially identical to those observed in salmonids following TCDD egg exposure and preceded or accompanied mortality most often during the period from hatch through swim‐up. The no‐observed‐effect concentrations and lowest‐observed‐effect concentrations, based on significant decreases in survival and growth as compared to the controls, ranged from 175 and 270 pg/g for lake herring to 424 and 2,000 pg/g for zebrafish, respectively. Shapes of concentration–response curves, expressed as TCDD‐Cegg versus percent mortality, were similar for all species and were consistently steep suggesting that the mechanism of action of TCDD is the same among these species. The LCegg50s (concentrations in eggs causing 50% lethality to fish at test termination) ranged from 539 pg/g for the fathead minnow to 2,610 pg/g for zebrafish. Comparisons of LCegg50s indicate that the tested species were approximately 8 to 38 times less sensitive to TCDD than lake trout, the most sensitive species evaluated to date. When LCegg50s are normalized to the fraction lipid in eggs (LCegg,l50s), the risk to early life stage survival for the species tested ranges from 16‐ to 180‐fold less than for lake trout.

Predation by Ruffe ( Gymnocephalus cernuus) on Fish Eggs in Lake Superior

Ruffe ( Gymnocephalus cernuus) were introduced to North America in the Duluth, Minnesota—Superior, Wisconsin harbor, which is the westernmost point on the Laurentian Great Lakes. The species proliferated in the harbor and became the subject of research which has gradually revealed certain characteristics of the biology and population growth of the ruffe. In this study ruffe in Southwestern Lake Superior were found to have eaten benthic organisms and eggs of lake herring ( Coregonus artedii). Overwinter predation by ruffe on eggs of lake herring and of other fall spawning Great Lakes fishes might pose a substantial new source of overwinter mortality.

Radium-226 in water, sediments, and fish from lakes near the city of Elliot Lake, Ontario, Canada

Ra-226 was measured by α-emission spectroscopy in water, sediments, and fish (tissues and gut contents), from five lakes in a watershed containing U mining and milling operations at Elliot Lake, Ontario, and from control lakes in an adjacent non-industrialized watershed. Ra-226 transfer parameters from lake water and sediments to fish tissues, and annual intakes by humans consuming fish, were estimated. Mean dissolved 226Ra levels ranged from ∼76 mBq litre −1 in water of the most affected lake, to < 10 mBq litre −1 in control lakes. Levels in summer were consistently higher than in fall or winter; no consistent variation with depth was noted. Sediment levels ranged from ∼3000 mBq g −1 dry wt in one study lake to < 100 mBq g −1 dry wt of sediment in control lakes. Bone 226Ra concentrations were higher than in muscle. The lake trout ( Salvelinus namaycush), a predatory secondary consumer, had bone 226Ra levels (< 20 mBq g −1 dry wt) that did not show significant site variation. In contrast, bottom feeding whitefish had significantly more 226Ra in bone tissue (to 38 mBq g −1 dry wt in the lake whitefish, Coregonus clupeaformis, and 76 mBq g −1 in round whitefish, Prosopium cylindraceum) in study lakes than in controls (< 20 mBq g −1 dry wt). Ra-226 levels in lake trout muscle were low and showed erratic variation among lakes whereas levels in whitefish muscle did not vary significantly among study and control sites. Lake herring (= cisco, Coregonus artedii), a planktivorous fish taken only from Quirke Lake, had mean 226Ra levels of 18 and 1.4 mBq g −1 dry wt in bone and muscle, respectively. Gut 226Ra levels, highest in lake trout from McCabe and Quirke Lakes (126 ± 53, 64 ± 44 mBq g −1 dry wt, respectively), and just detectable in McCabe and Elliot Lake whitefish (24 ± 2, 36 ± 14 mBq g −1 dry wt, respectively), were below detection in lake trout and whitefish from other lakes. Concentration ratios (CRs) of 226Ra from water to muscle ranged from 8 to 14 in lake trout, 7 to 14 in whitefish, and 4 to 6 in lake herring. The water to bone CRs varied from 81 to 142, 314 to 548, and 126 to 272 in the same species. CRs were always < 1 between sediments and fish tissues. Annual intake of 226Ra by human consumers of these fish was estimated to provide an effective dose of 0.003 mSv year −1. This represents a small fraction of both natural background (> 2 mSv year −1) and the public dose limit (5 mSv year −1).

Spring Distribution and Abundance of Larval Fishes in the St. Marys River, With a Note on Potential Effects of Freighter Traffic on Survival of Eggs and Larvae

Larval fishes were collected at seven transects in the St. Marys River from late April to late May, 1985, to determine potential effects of extending the winter navigation season on spawning success and survival. Larval lake herring ( Coregonus artedii) 8 to 25 mm occurred in densities of 0 to 1,450 larvae/1,000 m 3 and were most commonly found in shallow water (1 to 2 m). Most lake herring hatching occurred during late April to early May, the first 3 wk after ice break-up, but there was no distinct hatching peak. Lake whitefish ( C. clupeaformis) larvae, 12 to 23 mm, with densities of 0 to 600/1,000 m 3, were most common at 1 m being collected at all transects, except the transect in the Edison Hydropower Canal which passes Lake Superior water into the river. Densities of the two coregonine species were similar to densities observed in important nursery areas of Lake Huron. However, the contribution of lake herring to the river population is not known. Burbot ( Lota lota) larvae were common temporally and spatially, with higher abundances in the channel. Yellow perch ( Perca flavescens) and rainbow smelt ( Osmerus mordax) larvae were absent in April and early May, and abundant in late May. Lake herring, lake white-fish, and burbot have the greatest probability of being affected by the proposed extension of the navigation season through resuspension of sediments, dislodgment of eggs, and premature emergence of larvae.

Radium-226 equilibrium between water and lake herring, Coregonus artedii, tissues attained within fish lifetime: Confirmation in this species of one assumption in the simple linear concentration factor model

Equilibrium conditions are assumed in the simple linear concentration factor model commonly used in simulations of contaminant flow through ecosystems and in dose and risk calculations. Predictions derived from a power function model have suggested that if the time scale of the food-chain transfer is less than six years in fish, radium-226 equilibrium will not be achieved in nature, thereby violating the equilibrium requirement in the concentration factor model. Our results indicate 226Ra equilibrium is achieved in a natural population of lake herring ( Coregonus artedii), contrary to predictions of the power function model.

The linkage among ecosystem perturbations, remediation, and the success of the Nipigon Bay fishery

Since the inception of the commercial fishery in Nipigon Bay of Lake Superior, walleye (Stizostedion vitreum) and lake sturgeon (Acipenser fulvescens) have been extirpated and the abundance of lake trout (Salvelinus namaycush), brook trout (Salvelinus fontinalis), and northern pike (Esox lucius) has declined significantly while the abundance of lake whitefish (Coregonus clupeaformis ) and lake herring (Coregonus artedii) has increased. Systemic stresses including eutrophication, airborne contribution of contaminants, and exploitation (reduced by closure of the commercial fishery in 1988) remain but may not impair populations of lake whitefish and herring, which interact less with tributaries and nearshore waters. Improvements in habitat, through water flow management in the Nipigon River, removal of logs in the nearshore, shoreline and stream restoration, cessation of log drives, as well as artificially increasing adult abundance have resulted in resumption of some limited reproduction by walleye and increased egg deposition and early life survival by brook trout. Multiple stresses are still ubiquitous in the Nipigon ecosystem, but relief of several stresses in tributaries and nearshore environments at least appears to have resulted in an initially encouraging response by two species dependent upon these areas.

Composition of Fish Consumed by the James Bay Cree

Five species of adult female fish were harvested in Autumn from coastal and inland reservoir areas within the territory of the James Bay Crees of Quebec, Canada. Whitefish (Coregonus clupeaformis), cisco (Coregonus artedii), brook trout (Salvelinus fontinalis), lake trout (Salvelinus namaycush), and pike (Exos lucius) were harvested, portioned, and analyzed for proximate composition, heavy metals (Hg, Cd, As, Pb), nutritional minerals (Ca, Fe, Zn, Cu), and a complete profile of fatty acids. Liver of pike and lake trout and eggs of whitefish, cisco, and lake trout were also analyzed. Although liver and eggs are important traditional cultural food resources, nutrient data in liver and eggs have not been previously reported, except for whitefish eggs. Pike and lake trout flesh and liver and eggs of lake trout had Hg levels exceeding 0.5 μg/g. All samples had greater amounts of unsaturated fatty acids (mono- and polyunsaturates) than saturated fatty acids. Fe and Zn were low (<0.5 mg/100 g) in flesh, but were higher in portions of liver and eggs, thus providing dietary complement.

A process model for food competition

A model for food competition that describes competition between two predator species consuming the same array of prey species was developed and applied to give equations for estimation of competition coefficients from observable data, and to examine the historical lake herring ( Coregonus artedii) and chub ( Coregonus hoyi) fisheries of Lake Superior. If the two species consume the same foods, and if food consumption and mortality are functions of size, the two species coexist. The analyses indicate three types of differences between species that could lead to competitive exclusion: different proportions of prey eaten, different efficiencies of food utilization, and different mortalities. Lake herring and chubs consumed similar foods, but lake herring were larger than chubs, and a difference in body size could result in exclusion of chubs from areas occupied by lake herring and lake trout because of the relation of mortality to size for pelagic species.

Energy Density of Three Fishes from Minnesota Waters of Lake Superior

Energy densities of three salmonine prey species in Lake Superior were determined by bomb calorimetry to examine seasonal trends, differences due to gender and to establish a relation with percent dry weight. These results from April through October for 1992 and 1993 were compared with other studies from the Great Lakes region. Across the 2-year sampling period rainbow smelt Osmerus mordax energy density decreased from April to June and July then significantly increased into September. Lake herring Coregonus artedii energy density was highest in June, decreased significantly by August, and remained stable through October. Bloater C. hoyi energy density was lowest in July, then increased in August and early September before decreasing in late September. There were no significant differences in energy density between males and females for rainbow smelt and lake herring collected on the same date across sampling dates. However, bloater energy density was significantly higher for females than for males on two dates. Energy density estimates for bloater in Lake Superior were lower than those reported from Lake Michigan. Energy density values of rainbow smelt and lake herring fell within the range reported in Lake Michigan and Lake Ontario (rainbow smelt), and from two inland lakes in Minnesota and Lake Mendota, Wisconsin (lake herring). Percent dry weight was a good predictor of energy density (P < 0.001, r 2 = 0.92–0.99) for all three species for both years. Percent dry weight vs energy density was significantly different between years for bloater and lake herring, and was significantly different for all three species compared with populations in other lakes in the Great Lakes Region.

Changes in fish populations affected by the construction of the La Grande complex (Phase I), James Bay region, Quebec

Catches per unit of effort (CPUE) with experimental gill nets, recruitment, growth, and condition were monitored between 1977 and 1992 to evaluate the impact of impoundment on the main fish species of La Grande 2, Opinaca, and Caniapiscau reservoirs and the Boyd–Sakami diversion. CPUE and recruitment of northern pike (Esox lucius) and lake whitefish (Coregonus clupeaformis) increased markedly at most stations after impoundment and decreased at the end of the series. The lake whitefish and cisco (Coregonus artedii) showed their most striking rise in CPUE at two bay stations of La Grande 2 and Opinaca reservoirs. CPUE and recruitment of the longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), and lake trout (Salvelinus namaycush) (Caniapiscau) showed a general decrease following impoundment. CPUE for the walleye (Stizostedion vitreum) also decreased at several stations; however, the two most southerly stations in La Grande 2 reservoir and the Boyd–Sakami station showed high CPUE during the series. Concentration–redistribution phenomena explain part of the observed variations in CPUE. Correlation analyses showed that walleyes and white suckers were attracted to the warmer, more turbid stations, and that the high primary and secondary productivity of bay stations attracted the coregonines. Growth and condition of the main species increased during variable time intervals after impoundment and decreased at the end of the series.

An analysis of the distribution of fish species in a large prairie lake

The distribution of fishes in Dauphin Lake, a large, shallow, turbid, prairie lake in west‐central Manitoba, was examined using gillnets. Catch per unit effort was used to assess differences in distribution thai may be attributed lo year, season, lake zone (inshore, offshore), substratum, water depth, water temperature, turbidity and presence of other fish species. Although 13 species were caught, only the distributions of the six most abundant was analysed. Variation in number of species caught was attributed mainly to lake zone, water depth and water temperature. White sucker (Catastomus commersoni) distribution can be explained by zone and temperature. Shorthead redhorse (Moxostoma macrolepidotum) catches were related to depth and temperature. Cisco (Coregonus artedii) catches varied with year, zone and temperature. Variances in northern pike (Esox Indus) distribution reflected year and zone. Walleye (Stizostedkm vitreum) varied with year, depth and temperature and differences in the catches of yellow perch (Pertaflurescens) were attributed to year, depth, temperature and turbidity. They were also positively correlated to the numbers of northern pike caught.

An analysis of the distribution of fish species in a large prairie lake

The distribution of fishes in Dauphin Lake, a large, shallow, turbid, prairie lake in west-central Manitoba, was examined using gillnets. Catch per unit effort was used to assess differences in distribution thai may be attributed lo year, season, lake zone (inshore, offshore), substratum, water depth, water temperature, turbidity and presence of other fish species. Although 13 species were caught, only the distributions of the six most abundant was analysed. Variation in number of species caught was attributed mainly to lake zone, water depth and water temperature. White sucker (Catastomus commersoni) distribution can be explained by zone and temperature. Shorthead redhorse (Moxostoma macrolepidotum) catches were related to depth and temperature. Cisco (Coregonus artedii) catches varied with year, zone and temperature. Variances in northern pike (Esox Indus) distribution reflected year and zone. Walleye (Stizostedkm vitreum) varied with year, depth and temperature and differences in the catches of yellow perch (Pertaflurescens) were attributed to year, depth, temperature and turbidity. They were also positively correlated to the numbers of northern pike caught.

Factors Influencing Bald Eagle Densities in Northcentral Saskatchewan

Bald eagle (Haliaeetus leucocephalus) densities vary througbout North America, but reasons for these differences are poorly understood and may be important for directing management practices. Thus, we evaluated the influence of forest nesting habitat and food abundance on the densities of bald eagles on 2 lakes in northcentral Saskatchewan, Canada. We found no evidence that nest-site availability influenced the number of eagles on either lake. Differences in the food supply were investigated both directly by netting fish, and indirectly, through information obtained from biological surveys at Besnard and Nemeiben Lakes. Cisco (Coregonus artedii), a key prey species for eagles, were more common and larger (P < 0.05) in Besnard Lake

Phenotypic plasticity of a transplanted population of dwarf cisco,Coregonus artedii

A population of dwarf cisco in Minnesota was studied in native and transplant environments. Life history characters were recorded and the stability of meristics and morphometrics of the population over a two year period in three different environments was assessed with univariate and multivariate statistics. Transplanted cisco lived longer and grew larger than they did in their native lake, yet retained distinctive pigmentation patterns and an unusually early spawning season. Meristic characters of dwarf fish remained within ranges reported forCoregonus artedii during the lifetimes of individuals in their new environments, but morphometric measures underwent significant size- and shape-related changes. Incubation and rearing studies show egg incubation time and behavior of larvae were identical of those of non-dwarf cisco. Comparisons with non-dwarf cisco populations illustrate the ecophenotypic plasticity of adult fish of this population of North American cisco.

Environmental influences on seasonal distribution of coastal and estuarine fish assemblages at Wemindji, eastern James Bay

The coastal fish assemblages of Wemindji, eastern James Bay, were studied in 1987 and 1988 to describe seasonal utilization of the Maquatua River estuary and the adjacent coastal waters by marine and anadromous fishes. Fish diversity was low (11 sp.) and experimental gill net catches were highly variable between sites in the estuary and coastal waters, and also seasonally at a given site. During summer, the estuarine fishes were numerically dominated by two marine species, the fourhorn sculpin,Myoxocephalus quadricornis, and the slender eelblenny,Lumpenus fabricii, and also by juvenile cisco,Coregonus artedii, and juvenile lake whitefish,C. clupeaformis. In coastal waters, three marine species were abundant: the shorthorn sculpin,M. scorpius, the arctic sculpin,M. scorpioides and the Greenland cod.Gadus ogac. In contrast with the estuary, large (> 270 mm) cisco and lake whitefish were abundant in coastal waters indicating extensive movements of these species in James Bay during the summer. Distribution patterns were influenced by a combination of physical conditions (salinity and temperature) and biological characteristics (habitat choice, migration and reproduction) depending on the season.

Effect of heat inactivation of lipoxygenase on lipid oxidation in lake herring (coregonus artedii)

AbstractThe role of lipoxygenase in causing lipid oxidation in lake herring was studied. Lipid oxidation was measured by assaying for 2‐thiobarbituric acid‐reactive substances (TBARS), and lipoxygenase activity was measured by a spectrophotometric (470 nm) method. Lipoxygenase activity was highest in light muscle, lowest in skin and intermediate in dark muscle. Light muscle contained the highest percentage of phospholipids (PL) and the least total lipid. The percentage of PL was lowest and total lipids were highest in the skin. Eicosapentaenoic acid and docosahexaenoic acid were found in larger amounts in PL than in triglycerides. Heat treatment rapidly inactivated lipoxygenase. After a 5‐min heating period, lipoxygenase was totally inactivated in most cases. TBARS data indicated that samples heated at 80°C for 1.5–2.0 min were more stable than samples heated at 80°C for 2.5–5.0 min, suggesting that heat accelerated nonenzymatic oxidation.

Density-Dependent Maturation, Growth, and Female Dominance in Lake Superior Lake Herring (Coregonus artedii)

Density-related changes in age at maturation, sex ratio of recruits, growth, and fecundity at very low density result in spawning populations which comprise many older females and few young males and in which egg production per lake herring (Coregonus artedii) is increased by a factor of five. Age of maturation is delayed at low density for females, but not for males. Thus, males dominate the youngest age classes but females become increasingly more abundant from age 2 + through age 6 +. A model of lake herring population structure showed that although delayed maturation accounts for many characteristics of depressed populations, it does not explain overall population femaleness. The model was used to evaluate effects of differential adult mortality, recruitment failure, and changes in the sex ratio of recruits, and only the latter provided an adequate explanation for overall femaleness. Despite the apparently compensatory nature of these responses, the slow and unsteady recovery of depressed Lake Superior populations during the last two decades indicates that one or more additional factors play important roles in determination of year class strength.

Seasonal regulation of Daphnia populations by planktivorous fish: Implications for the spring clear‐water phase

The ability of planktivorous fish to regulate the population dynamics of Daphnia galeata in Lake Mendota, Wisconsin, was examined during spring and summer 1987. Low rates of consumption by yellow perch (Perca flavescens) and cisco (Coregonus artedii) allowed populations of D. galeata to expand rapidly during spring, resulting in a distinct clear‐water period that lasted from mid‐May until early June. A subsequent decline in D. galeata abundance resulted from low food availability brought about by its exploitation of algal resources. Once populations of D. galeata were reduced, predation by perch and cisco was sufficient to keep populations of D. galeata at low densities during July and August in spite of more abundant algal food resources. Extreme seasonal variation in the degree to which planktivorous fish can regulate daphnid population dynamics may have allowed daphnids to persist in Lake Mendota during the past century in the presence of abundant zooplanktivores.

Chromosomal and Mitochondrial DNA Characterization of a Population of Dwarf Cisco (Coregonus artedii) in Minnesota

This study compared the chromosome complement and mitochondrial DNA profile of a population of dwarf cisco in Ten Mile Lake, Cass County, Minnesota, to two populations of normal-sized Coregonus artedii in order to determine if the dwarf fish were conspecific with C. artedii. Chromosomal analysis revealed a diploid chromosome number (2n = 80) the same as reported for C. artedii. Mitochondrial DNA (mtDNA) analysis revealed unexpected levels of intrapopulational diversity in each study population, with the dwarf fish displaying the highest level of mtDNA diversity. Heteroplasmy, restriction site polymorphisms, and three size variants were documented. Each population was characterized by a unique profile of mtDNA clonal types, yet interpopulational comparisons revealed more similarities between the dwarf fish in Ten Mile Lake and the two normal populations than between the populations of normal-sized fish. Based on these data, the dwarf fish of Ten Mile Lake should be considered conspecific with Coregonus artedii.