Premium
Homogenization of fish assemblages in different lake depth strata at local and regional scales
Author(s) -
Menezes Rosemberg F.,
Borchsenius Finn,
Svenning JensChristian,
Davidson Thomas A.,
Søndergaard Martin,
Lauridsen Torben L.,
Landkildehus Frank,
Jeppesen Erik
Publication year - 2015
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/fwb.12526
Subject(s) - eutrophication , species richness , lake ecosystem , ecology , littoral zone , trophic level , environmental science , ecosystem , species diversity , biodiversity , nutrient , biology
SummaryEutrophication alters the trophic dynamics in lakes and may result in homogenisation of biotic communities. How nutrient enrichment drives patterns of homogenisation of fish species composition at within‐lake (local) and among‐lake (regional) scales is, however, not well studied. To test for homogenisation in fish communities, we analysed number, biomass and individual mean body mass of the different fish species present in 53 Danish lakes with contrasting depths, surface area and eutrophication. A combination of uni‐ and multivariate techniques revealed that eutrophication homogenises fish community composition in the littoral zone of both shallow and deep lakes at within‐ and among‐lake scales, a notable contrast being that community composition was not homogenised in the offshore in deep lakes. In addition, fish species richness and diversity converged with progressive eutrophication and mean lake depth in all lake zones. For deep lakes, surface area was positively related to increasing differences in fish species richness and diversity. Increased homogeneity of this key assemblage may have profound implications for ecosystems and their stability (such as decreased resilience to disturbance, reduced biological complexity and increased vulnerability to large‐scale and stochastic environmental events). Thus, to fully understand the impacts of eutrophication on aquatic communities at both local and regional scales, the effects of nutrient enrichment on compositional heterogeneity should be considered.