Atlantic Whitefish Research Articles

The fish population of small water bodies in Lake Onego catchment, and their prospective uses

The results of the surveys of two small lakes located in the western and southern parts of the Republic of Karelia (Sukkozero and Kedrozero) are reported. Hydrological and hydrochemical indices were analyzed. The water bodies are of glacial genesis, and belong to the catchment of Lake Onego. Human population in the catchments of the lakes is scarce, there are no large industrial enterprises, fish farms, etc. The lakes are classified as β-oligotrophic on the trophicity scale. Some bays and sites of Lake Kedrozero have acquired mesotrophic traits. Hydrobiological data, including the fish population of the lakes, are presented in detail for the first time. The fish species composition, length-weight growth and diet of the prevalent species were studied. The fish population of Lake Sukkozero is represented by 10 species, of Lake Kedrozero – by 14 species. Smelt, perch, roach and bream are the most abundant in both lakes. Atlantic salmon, brown trout, whitefish and vendace are valuable fish. Salmon and trout are included in the Red Data Book of Karelia. A higher growth rate is observed in fish from Kedrozero, obviously due to the richer food resources. A comparative analysis of the data shows that the investigated water bodies have remained practically unchanged over a long time. This situation is now very rare, not only in the region, but also in Russia at large. Water bodies can serve as benchmarks for assessing the state of aquatic ecosystems under a significantly increased human impact. Small lakes, due to the lack of industrial-scope fishing, are promising for amateur, sport fishing and tourism development.

Hydroacoustic tracking of the endangered Atlantic whitefish (Coregonus huntsmani); comparative analysis from wild and hatchery reared populations

Atlantic whitefish (Coregonus huntsmani) are an endangered species located in only three lakes in Nova Scotia, Canada. Conservation efforts are directed toward increasing their range and number of viable populations. Current stocking programs use hatchery reared fish. The goal of the study was to determine the survival and distribution of hatchery reared Atlantic whitefish after release. Comparative hydroacoustic tracking experiments were performed to examine the survival, depth preferences and movements of hatchery reared and wild Atlantic whitefish. Hatchery reared fish were released to a non native lake whereas wild fish were released back to their native lake. Hatchery reared fish were ‘lost’ from the study lakes through presumed predation at a much higher rate (67 %) than wild released (6.5 %). Mortality rate in wild released fish was higher (50 %) than hatchery reared fish (20 %) and were likely due to the increased stress associated with handling or tagging. Movements were tracked over 248 and 342 days for wild captured and hatchery reared fish respectively. Hatchery reared fish were slow to disperse from the release site (mean ± standard error; 12 ± 3.2 days) and swam at the surface of the water for extended periods, which could have led to the unknown losses of these fish. After dispersal throughout the lake, however, the hatchery-reared fish were distributed in depths similar to those of the wild released fish, an important finding for the use of hatchery-reared fish in conservation. Results are discussed to improve hatchery practices for fish destined for stocking.

Establishing past environmental conditions and tracking long-term environmental change in the Canadian Maritime provinces using lake sediments

Freshwater lakes in the Canadian Maritime provinces have been detrimentally influenced by multiple, often synergistic, anthropogenically-sourced environmental stressors. These include surface-water acidification (and a subsequent decrease in calcium loading to lakes); increased nutrient inputs; watershed development; invasive species; and climate change. While detailed studies of these stressors are often hindered by a lack of predisturbance monitoring information; in many cases, these missing data can be determined using paleolimnological techniques, along with inferences on the full extent of environmental change (and natural variability), the timing of changes, and linkages to probable causes for change. As freshwater resources are important for fisheries, agriculture, municipal drinking water, and recreational activities, among others, understanding long-term ecological changes in response to anthropogenic stressors is critical. To assess the impacts of the major water-quality issues facing freshwater resources in this ecologically significant region, a large number of paleolimnological studies have recently been conducted in Nova Scotia and southern New Brunswick. These studies showed that several lakes in southwestern Nova Scotia, especially those in Kejimkujik National Park, have undergone surface-water acidification (mean decline of 0.5 pH units) in response to local-source SO2emissions and the long-range transport of airborne pollutants. There has been no measureable chemical or biological recovery since emission restrictions were enacted. Lakewater calcium (Ca) decline, a recently recognized environmental stressor that is inextricably linked to acidification, has negatively affected the keystone zooplankter Daphnia in at least two lakes in Nova Scotia (and likely more), with critical implications for aquatic food webs. A consistent pattern of increasing planktonic diatoms and scaled chrysophytes was observed in lakes across Nova Scotia and New Brunswick, suggesting that the strength and duration of lake thermal stratification has increased since pre-industrial times in response to warming temperatures (∼1.5 °C since 1870). These include three lakes near Bridgewater, Nova Scotia, that are among the last known habitat for critically endangered Atlantic whitefish (Coregonus huntsmani). Overall, these studies suggest that aquatic ecosystems in the Maritime Provinces are being affected by multiple anthropogenic stressors and paleolimnology can be effective for inferring the ecological implications of these stressors.

Discrimination of the Endangered Atlantic Whitefish from Lake Whitefish and Round Whitefish by Use of External Characters

AbstractThe scope of phenetic variation exhibited by populations of lake whitefish Coregonus clupeaformis in the Canadian Maritime Provinces is not known, which complicates the task of accurately identifying specimens of the endangered Atlantic whitefish C. huntsmani. We developed criteria for accurate (≥95% correct classification) species discrimination using morphological data acquired from archival and recent coregonid collections from the Maritime Provinces. We used discriminant function analyses to assess (1) the usefulness of Atlantic whitefish external typological characters in accurately identifying species, (2) the temporal stability of reportedly diagnostic characters, and (3) which morphological characters could be used to accurately identify these coregonids to species. Not all external typological characters were robust in the discrimination of recent Atlantic whitefish and lake whitefish collections. Several previously identified diagnostic characters exhibited significant temporal variation but remained robust in species discrimination. Species‐specific differences for the number of lateral line scales, mouth position, and proportional pectoral fin length could be used concomitantly for accurate (≥95% correct classification) identification of coregonid species in the Canadian Maritime Provinces. Atlantic whitefish possessed a significantly (P < 0.001) greater number of lateral line scales (range = 90–102; mean ± SD = 93.79 ± 2.70) than lake whitefish (range = 66–91; mean = 77.18 ± 4.21), a significantly (P < 0.01) shorter pectoral fin than lake whitefish (11% and 16% of fork length, respectively), and a significantly (P < 0.001) more terminal mouth than lake whitefish (ratio of upper jaw to lower jaw: mean ± SD = 0.98 ± 0.07 and 0.82 ± 0.06, respectively). These characters can also be used to distinguish between Atlantic whitefish and round whitefish Prosopium cylindraceum collected in the Maritime Provinces.

National values for regional aquatic species at risk in Canada

The goal of the present analysis was to assess the geographic scope and magnitude of non-market values for 6 regional aquatic species listed, or being considered for listing, as endan- gered under the Canadian Species at Risk Act. I used latent class analysis to partition responses from a national Internet-based survey that asked respondents about their preferred conservation program from amongst scenarios that varied according to target species (Atlantic salmon Salmo salar, Atlantic whitefish Coregonus huntsmani, leatherback turtle Dermochelys coriacea, North Atlantic right whale Eubalaena glacialis, porbeagle shark Lamna nasus, and white sturgeon Acipenser transmontanus), program performance, cost, and method of payment. The large sample of the Canadian public (n = 2761) cleaved into 9 distinct segments that varied significantly in their patterns of preferences. Mean implicit prices, calculated using regression coefficients, ranged as high as CAD $85.99 annually for Atlantic salmon Salmo salar. There was strong support for programs that had a high probability of success even though increases in population abundance and improvements in listing status were each only significant for 4 of the 9 segments. I also found evidence that members of 1 segment were unwilling or unable to make tradeoffs between the program attributes (i.e. they exhibited 'lexico- graphic preferences'). Members from all 9 segments were distributed across Canada, implying that the proper geographic scope of benefits assessments should be expanded beyond the regions in which regional aquatic species at risk actually occur. These findings should help ensure that the broad societal benefits of conservation are captured when making endangered species listing and investment decisions in Canada in the future.

Tracking anthropogenic‐ and climatic‐related environmental changes in the remaining habitat lakes of the endangered Atlantic whitefish (Coregonus huntsmani) using palaeolimnological techniques

Abstract Atlantic whitefish (Coregonus huntsmani) is a critically endangered species whose remaining habitat is restricted to three lakes near Bridgewater, Nova Scotia, Canada. Other lakes in this region have been affected by a variety of environmental changes over the past 150 years (e.g. acidic deposition, eutrophication, and climatic changes); however, the extent of the impact on these remaining Atlantic whitefish lakes, and how the current limnological conditions compare with pre‐industrial conditions, is not known. Given the lack of long‐term monitoring data, palaeolimnological techniques were used to track environmental changes in these three lakes to infer historic limnological conditions. Results of this study show that acidic deposition has had no significant impact on these lakes (diatom‐inferred lakewater pH has changed little over time), nor has the nutrient status of these lakes changed as the sediment profiles have been consistently dominated by oligotrophic diatom taxa. Changes in the dominance of diatom assemblages since ∼1850, from Aulacoseira distans to Cyclotella stelligera, are correlated with climatic warming (r = 0.48–0.89, P<0.05). Contrary to initial concerns, these only remaining habitats of the Atlantic whitefish have not yet been affected by acidic precipitation. However, other potential stressors, such as climatic warming and associated limnological changes, may now be affecting the habitat of this endangered species. Copyright © 2008 John Wiley & Sons, Ltd.

Ontogenetic development of the endangered Atlantic whitefish (Coregonus huntsmaniScott, 1987) eggs, embryos, larvae, and juveniles

Atlantic whitefish ( Coregonus huntsmani Scott, 1987 ) are an endangered species endemic to Canada and are known only from Nova Scotia. Information concerning their early life-history stages — not previously described — is required to support several recovery actions under the federal Species at Risk Act (SARA). We describe the ontogenetic development of Atlantic whitefish eggs, larvae, and juveniles acquired through captive-mating of wild-caught adults, following criteria established for fishes in general and for other North American coregonine species where possible. We then conduct interspecific comparisons between Atlantic whitefish and the two most closely phylogenetically related species (i.e., lake whitefish ( Coregonus clupeaformis (Mitchill, 1818)) and cisco ( Coregonus artedii Lesueur, 1818)) to (i) identify ontogenetic differences that may facilitate field identification, (ii) determine whether differences at common ontogenetic milestones reinforce the recognition of Atlantic whitefish at the species level, and (iii) comment on whether these differences are consistent with the putative ancestral status of Atlantic whitefish. Interspecific differences were observed at all ontogenetic stages, several of which may serve as field identification criteria. Evidence for heterochrony during embryogenesis, as well as interspecific differences in egg size, myomere counts, and pigmentation patterns, substantiate the recognition of Atlantic whitefish as a valid species and support its putative ancestral status.

First Record of Age 0+ Atlantic Whitefish, <em>Coregonus huntsmani</em>, from the Wild

A small school of juvenile Atlantic Whitefish (~20-30 individuals) were observed in the littoral zone of Hebb Lake (Petite Rivière watershed), Nova Scotia in June 2000. Of these, a single individual was captured with a beach seine, and confirmed to be a young-of-the-year specimen. This is the first documented report of the occurrence of wild Atlantic Whitefish juveniles. Occupation of the littoral zone into early summer by young-of-the-year Atlantic Whitefish may have implications for predation by invasive Smallmouth Bass.

Updated status report on the endangered Atlantic Whitefish, Coregonus huntsmani

Updated status report on the endangered Atlantic Whitefish, Coregonus huntsmani

The Role of Pollution and External Refugia in Structuring the Onondaga Lake Fish Community

ABSTRACT Historical accounts of Onondaga Lake dating to the 1600's indicate that the lake once supported a coldwater fishery. By the late 1800's, severe degradation of the lake and adjacent tributary environments was accompanied by declines in the American eel (Anguilla rostrata), and extirpation of Atlantic salmon (Salmo salar) and whitefish (Coregonus sp.). Nine faunal surveys were conducted from 1927 to 1994. We used rarefaction analyses to standardize survey results by computing expected species richness values (E(Sm)) relative to the 1946 gill net catch (7 species, m=164 individuals). Linear regression applied to the expected richness values (E (S164)) over time showed a significant increase in richness from 1946 (YEAR=0) to 1994 (YEAR=47) for fish caught in gill nets [E(S164) = 0.153*YEAR + 6.785, r2=0.79, P<0.005] and trap nets [E(S164) = 0.226*YEAR + 3.723, r2=0.89, P<0.01]. Although species richness has increased, almost half of the species captured since 1989 show no evidence of juvenile recruit...

Meristic and Morphometric Variation between the Endangered Acadian Whitefish, Coregonus huntsmani, and the Lake Whitefish, Coregonus clupeaformis, in the Canadian Maritime Provinces and the State of Maine, USA

Principal component and discriminant function analyses of morphological variation between whitefish populations from the Canadian Maritime Provinces and the State of Maine, USA, clearly distinguished the Acadian whitefish, Coregonus huntsmani, from the lake whitefish species complex, Coregonus clupeaformis. Ten meristic and 44 morphometric characters were examined and the species were best discriminated by number of vertebrae (&gt;97% separation) and mouth shape. Acadian whitefish had a terminal mouth and 64–67 [Formula: see text] vertebrae, while lake whitefish had a subterminal mouth and 58–64 [Formula: see text] vertebrae. Acadian whitefish were also characterized by having more lateral line scales (88–100, [Formula: see text] than lake whitefish (63–95, [Formula: see text], a shorter adipose to caudal fin length, a smaller adipose fin, and a longer pelvic axillary process than lake whitefish. Considerable morphological variation was found between lake whitefish populations examined although there was no morphological basis to recognize any lake whitefish population as taxonomically distinct. The Acadian whitefish has morphological characteristics of both subgenera Leucichthys and Coregonus; it could be important for understanding the evolution of coregonine fishes and its imminent extinction would represent a serious loss of genetic diversity.

Mitochondrial DNA and isozyme electrophoretic analyses of the endangered Acadian whitefish, Coregonus huntsmani Scott, 1987

Electrophoretic analysis of isozymes and mitochondrial DNA (mtDNA) restriction analysis were used to study the genetic divergence between the Acadian whitefish, Coregonus huntsmani, and members of the subgenera Coregonus (lake whitefish, C. clupeaformis) and Leucichthys (Arctic cisco, C. autumnalis, and lake cisco, C. artedii). Results obtained from both studies demonstrated that the Acadian whitefish is genetically highly distinct from the other coregonines examined. mtDNA restriction analysis revealed that the Acadian whitefish possesses a unique mitochondrial genotype which is divergent from that of the two cisco species or lake whitefish. Twelve of 13 restriction enzymes used were informative in distinguishing the Acadian whitefish from the other species, and species-specific fragment patterns were observed for 10 enzymes. In isozyme analysis of five loci, the Acadian whitefish was monomorphic at two loci for alleles not found in lake whitefish. Acadian whitefish also possessed an additional isozyme at another locus that was not found in lake whitefish and Arctic cisco specimens. This isozyme is unknown from the genetic model for lake whitefish at this locus. These results provided useful genetic markers to identify the Acadian whitefish. They emphasize that the extinction of the species would represent a major loss of both genetic diversity and potential information concerning the contentious phylogeny of coregonine fishes.

A new name for the Atlantic whitefish: Coregonus huntsmani to replace Coregonus canadensis

The Atlantic whitefish, indigenous to Nova Scotia, was originally described as Conegonus canadensis. The name canadensis is shown to be unavailable and a new name, Coregonus huntsmani, is proposed. The holotype is a mature male from Tusket River, Nova Scotia (Royal Ontario Museum no. 16674). Counts and measurements of the holotype are given.