The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden

The correlation between water chemistry and fish species distribution was examined in forty small, coastal lakes in northern Sweden. Lakes were fished in summer and water chemistry sampled mainly in late winter. Twenty out of the forty lakes were isolated from other water bodies and twenty had a dir...

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Autor principal: Öhman, Johanna
Formato: L3
Lenguaje:Inglés
sueco
Publicado: SLU/Dept. of Forest Ecology and Management 2004
Materias:
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author Öhman, Johanna
author_browse Öhman, Johanna
author_facet Öhman, Johanna
author_sort Öhman, Johanna
collection Epsilon Archive for Student Projects
description The correlation between water chemistry and fish species distribution was examined in forty small, coastal lakes in northern Sweden. Lakes were fished in summer and water chemistry sampled mainly in late winter. Twenty out of the forty lakes were isolated from other water bodies and twenty had a direct connection to the sea. The central question of the study was whether water chemical variables play a greater role in isolated lakes, since these cannot be recolonized if a species once has become extinct. As much as 48 % of the variation in fish species distribution in isolated lakes was explained by methane and acidity. Methane is an indicator of anoxia and not a controlling factor in itself. In connected lakes, lake area was the only significantly contributing factor, explaining 12 % of the variation. Different fish species were controlled in their distribution by different chemical variables. Methane indicated that the distribution of pike and perch was controlled by anoxia in isolated lakes. The distribution of the anoxia-tolerant crucian carp and sticklebacks was instead controlled by predation and acidity. In connected lakes, the possibility of migration decreased the effect of anoxia radically making pike and perch common, depressing the distribution of crucian carp. A third group of fish containing roach, ruffe, bream, bleak and ide was rarely found in isolated lakes and no clear distribution pattern of that group was seen.
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institution Swedish University of Agricultural Sciences
language Inglés
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publishDate 2004
publishDateSort 2004
publisher SLU/Dept. of Forest Ecology and Management
publisherStr SLU/Dept. of Forest Ecology and Management
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spelling RepoSLU114222024-07-10T11:06:55Z The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden Öhman, Johanna fish water chemistry isolation anoxia dissolved oxygen DO acidity pH pike perch roach crucian carp stickleback bream bleak ide ruffe Västerbotten northern Sweden ice winter lake The correlation between water chemistry and fish species distribution was examined in forty small, coastal lakes in northern Sweden. Lakes were fished in summer and water chemistry sampled mainly in late winter. Twenty out of the forty lakes were isolated from other water bodies and twenty had a direct connection to the sea. The central question of the study was whether water chemical variables play a greater role in isolated lakes, since these cannot be recolonized if a species once has become extinct. As much as 48 % of the variation in fish species distribution in isolated lakes was explained by methane and acidity. Methane is an indicator of anoxia and not a controlling factor in itself. In connected lakes, lake area was the only significantly contributing factor, explaining 12 % of the variation. Different fish species were controlled in their distribution by different chemical variables. Methane indicated that the distribution of pike and perch was controlled by anoxia in isolated lakes. The distribution of the anoxia-tolerant crucian carp and sticklebacks was instead controlled by predation and acidity. In connected lakes, the possibility of migration decreased the effect of anoxia radically making pike and perch common, depressing the distribution of crucian carp. A third group of fish containing roach, ruffe, bream, bleak and ide was rarely found in isolated lakes and no clear distribution pattern of that group was seen. Den här studien behandlar sambandet mellan vattenkemi och fiskarters spridning i fyrtio små kustnära sjöar i Västerbotten. Sjöarna provfiskades sommartid och vattenproverna togs främst under vintern. Tjugo av sjöarna var isolerade och saknade därmed till- och frånflöden medan de andra tjugo hade ett vattendrag som ledde direkt till havet. Den centrala frågan för studien var ifall kemiska variabler bidrar starkare till fiskarters utbredning i isolerade sjöar eftersom de inte kan återkoloniseras när en art har dött ut. Så mycket som 48 % av variationen i fiskarternas utbredning i isolerade sjöar kunde förklaras av metanförekomst och aciditet. Metan är inte toxiskt i sig utan indikerar syrefri miljö. I sjöar med länk till havet var sjöarea den enda faktor som bidrog signifikant till fiskarternas utbredning och förklarade där 12 % av variationen. Vilka faktorer som styr utbredningen varierar med fiskart. Metan indikerade att utbredningen av gädda och abborre i isolerade sjöar styrs av syrebrist. Utbredningen av ruda och spigg styrs i stället av predation och aciditet. I sjöar som kunde återkoloniseras var effekten av syrebrist inte lika stor. Gädda och abborre var vanliga även i sjöar som var syrefattiga under vintern och som en följd var utbredningen av ruda och spigg lägre i återkoloniserbara sjöar. Mört, gärs, braxen, löja och id förekom endast sparsamt i isolerade sjöar och det gick inte att hitta någon gemensam faktor som styrde utbredningen. SLU/Dept. of Forest Ecology and Management 2004 L3 eng swe https://stud.epsilon.slu.se/11422/
spellingShingle fish
water chemistry
isolation
anoxia
dissolved oxygen
DO
acidity
pH
pike
perch
roach
crucian carp
stickleback
bream
bleak
ide
ruffe
Västerbotten
northern Sweden
ice
winter
lake
Öhman, Johanna
The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden
title The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden
title_full The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden
title_fullStr The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden
title_full_unstemmed The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden
title_short The effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern Sweden
title_sort effects of water chemistry on fish species distribution : a comparison between isolated and connected lakes in northern sweden
topic fish
water chemistry
isolation
anoxia
dissolved oxygen
DO
acidity
pH
pike
perch
roach
crucian carp
stickleback
bream
bleak
ide
ruffe
Västerbotten
northern Sweden
ice
winter
lake