Arctic charr (Salvelinus alpinus) squeezed in a complex fish community dominated by perch (Perca fluviatilis)

Sandlund, Odd Terje; Haugerud, Eivind; Rognerud, Sigurd; Borgstrøm, Reidar

doi:10.5324/fn.v33i0.1579

Cited by 12 publications

(13 citation statements)

References 42 publications

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“…Consequently, all three species investigated in this study feed on a mixture of pelagic and profundal diet, also confirmed by the stomach analyses. A. charr appeared to consume most profundal prey, as it was previously found to be the weaker competitor against whitefish [58,59], thus forced to occupy the less energetically favourable profundal niche [60][61][62]. This was also reflected in the highest δ 15 N ratios measured for A. charr (Table 1), as profundal primary consumers produce higher baseline δ 15 N than pelagic zooplankton [39].…”

Section: Age Size and Weight Distributions Stable Isotope Ratios Ansupporting

confidence: 54%

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Seasonal Variations in the Use of Profundal Habitat among Freshwater Fishes in Lake Norsjø, Southern Norway, and Subsequent Effects on Fish Mercury Concentrations

et al. 2016

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This study is based on monthly sampling of fish from grates mounted at an industrial water intake, located at a depth of 50 m in Lake Norsjø (Southern Norway) during the year 2014, to investigate seasonal variations in the use of the profundal habitat and subsequent variations in total Hg-concentrations in profundal fish. Data on various fish present in a cold and dark hypolimnion of a large, deep, dimictic lake within the upper temperate zone of the Northern Hemisphere are rare. While predominant species such as A. charr (Salvelinus alpinus) and E. smelt (Osmerus eperlanus) were continuously present in this habitat, whitefish (Coregonus lavaretus) occupied this habitat primarily during wintertime, while other common species like brown trout (Salmo trutta), perch (Perca fluviatilis) and northern pike (Esox lucius) were almost absent. Besides stomach analyses (diet) and biometry, stable isotope analyses (δ 15 N and δ 13 C) and total mercury (Tot-Hg) analyses were carried out on the caught fish. The δ 13 C signature and stomach analyses revealed a combined profundal-pelagic diet for all three species, A. charr with the most profundal-based diet. Length was the strongest predictor for Hg in whitefish and A. charr, while age was the strongest explanatory variable for Hg in E. smelt. A. charr was the only species exhibiting seasonal variation in Hg, highest during winter and spring.

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Section: Age Size and Weight Distributions Stable Isotope Ratios Ansupporting

confidence: 54%

“…A. charr was caught all year, with the highest presence in autumn, as they are likely forced to occupy the profundal niche by competition with whitefish [58,59,61,62]. E. smelt was also caught in the profundal zone all year, but fewer individuals were caught in summer.…”

Section: Use Of the Profundal Habitatmentioning

confidence: 99%

Seasonal Variations in the Use of Profundal Habitat among Freshwater Fishes in Lake Norsjø, Southern Norway, and Subsequent Effects on Fish Mercury Concentrations

et al. 2016

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“…Typical effects of eutrophication are increased primary productivity with decreased dissolved oxygen (Smith & Schindler, ; Vonlanthen et al ., ). Therefore, it is expected that eutrophication and species introductions currently pose a greater threat to southern S. alpinus populations than predicted increases in temperature, as S. alpinus typically occur in deep lakes that provide a thermal refuge from negative interspecific interactions (Jensen et al ., ; Sandlund et al ., ).…”

Section: Introductionmentioning

confidence: 97%

Non‐native species and lake warming negatively affect Arctic charSalvelinus alpinusabundance; deep thermal refugia facilitate co‐existence

Morrissey‐McCaffrey

Shephard

Kelly

et al. 2018

Journal of Fish Biology

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This study finds that non-native species and warming temperatures have significant negative effects on Arctic char Salvelinus alpinus abundance in Irish lakes. Eutrophication was not important at the range of total phosphorus tested (0.005-0.023 mg l −1 ). Model results predict that S. alpinus occur across the temperature range sampled (8.2-19.7 C) when non-natives are absent, but S. alpinus catch is predicted to be close to zero irrespective of temperature when non-native catch is high. This result indicates that to persist, S. alpinus may require a habitat where non-natives are at low abundance or absent. Salvelinus alpinus segregated from other species along the thermal axis, inhabiting significantly colder water and actively avoided non-native species, which appeared to limit their distribution. The thermal niche realized by S. alpinus in non-native dominated lakes was thus compressed relative to native dominated lakes and S. alpinus population density was significantly lower. These findings were consistent even when the only non-native present was Perca fluviatilis. Temperature appeared to limit the distribution of non-native species, such that the presence of deep thermal refugia is currently facilitating S. alpinus co-existence with non-natives in associated lakes. Diet analysis identified P. fluviatilis as potential predators and competitors. This study provides strong evidence that non-native species are a key driver of low S. alpinus abundance in Irish lakes. Temperature increases associated with climate change are identified as a secondary concern, as they could erode S. alpinus' thermal niche and lead to their extirpation. The lower thermal buffering capacity of shallow lakes identifies these as higher risk systems. Salvelinus alpinus conservation in Ireland should focus on preventing future illegal non-native species introductions because unlike other stressors (e.g., eutrophication etc.), species introductions are rarely reversible.

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“…Sandlund, Haugerud, Rognerud and Borgstrøm () showed that there was a marked segregation in habitat use, with Arctic char observed in the profundal and deep areas of the pelagic zone, and perch and roach captured in the littoral and upper part of the pelagic zone. The observed narrow trophic niche of Arctic char, compared with perch and roach, is also a limiting factor for this species (Sandlund et al., ). European whitefish Coregonus lavaretus L .…”

Section: Introductionmentioning

confidence: 99%

“…Sandlund, Haugerud, Rognerud and Borgstrøm (2013) showed that there was a marked segregation in habitat use, with Arctic char observed in the profundal and deep areas of the pelagic zone, and perch and roach captured in the littoral and upper part of the pelagic zone. The observed narrow trophic niche of Arctic char, compared with perch and roach, is also a limiting factor for this species (Sandlund et al, 2013). European whitefish Coregonus lavaretus L. is one of the most widely introduced fish species in northern Europe and although it has the ability to co-exist, the species has partially or completely displaced many native Arctic char populations (Nilsson & Pejler, 1973;Sandlund et al, 2010Sandlund et al, , 2016Svardson, 1976).…”

mentioning

confidence: 99%

Potential climate change impacts on Arctic char Salvelinus alpinus L. in Ireland

Connor

Shephard

Rocks

et al. 2019

Fisheries Management Eco

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Climate change has been identified as a global threat to Arctic char Salvelinus alpinus L. populations. Bayesian statistical models were used to identify important physical and ecological factors explaining Arctic char presence and persistence in Irish lakes. Maximum lake depth and the presence of mixed fish communities (i.e. including non‐salmonid fish species) were the most important drivers of Arctic char presence. There was a 75% probability that an Irish lake would contain Arctic char when maximum depth exceeded 40 m, if only a salmonid community was present. However, the required depth increased to 57 m when a mixed fish community (e.g. pike, perch or roach) was present. Similar variables explained char persistence, with surviving Arctic char populations being more likely in lakes with greater maximum depth and fewer non‐salmonid fish species. Tested temperature covariates were not important in explaining Arctic char presence or persistence in Irish lakes. A risk analysis was undertaken to identify which Arctic char lakes are vulnerable to colonisation by thermally plastic mixed fish communities due to flooding. Results indicated that 32 out of 45 lakes were not at any risk from the colonisation of thermally plastic mixed fish communities and 13 lakes had some level of risk.

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Arctic charr (Salvelinus alpinus) squeezed in a complex fish community dominated by perch (Perca fluviatilis)

Cited by 12 publications

References 42 publications

Seasonal Variations in the Use of Profundal Habitat among Freshwater Fishes in Lake Norsjø, Southern Norway, and Subsequent Effects on Fish Mercury Concentrations

Seasonal Variations in the Use of Profundal Habitat among Freshwater Fishes in Lake Norsjø, Southern Norway, and Subsequent Effects on Fish Mercury Concentrations

Non‐native species and lake warming negatively affect Arctic charSalvelinus alpinusabundance; deep thermal refugia facilitate co‐existence

Potential climate change impacts on Arctic char Salvelinus alpinus L. in Ireland

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