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<p>Arctic freshwater ecosystems are characterized by low temperatures, a short ice-free period, low productivity, and low biodiversity. There is only fragmented knowledge about High Arctic benthic communities and no information about their functional relationships. The environmental characteristics and food resources of five contrasting High Arctic stream reaches near Ny-Ålesund, Svalbard, were investigated. The streams represented a gradient in environmental harshness. In addition to hydrological, chemical, and physical characteristics, food resources, algal biomass, and benthic invertebrate assemblages were determined. Food web structure was investigated using stable isotope signatures of δ<sup>13</sup>C and δ<sup>15</sup>N. The streams varied significantly in their hydrology, water temperature, and water chemistry. There was a clear distinction of these characteristics between streams fed by glacial meltwater, snowmelt and groundwater, as well lake outflows. Zoobenthos abundance was significantly lower in the glacier-fed stream and was highest in the groundwater-fed stream, enriched with nutrients, flowing below a bird cliff. Chironomidae dominated in all streams, although the dominance and relative abundance of the subfamily Diamesinae varied between streams. Stable isotope ratios (δ<sup>13</sup>C, δ<sup>15</sup>N) of food sources (autochthonous – allochthonous matter) varied considerably within and between streams. Most of the benthic invertebrates were heterotrophic consumers, although the food source differed between streams, with some relying mainly on autochthonous resources (glacial stream), others on allochthonous resources (most other streams), and a combination of both food sources in the stream near the bird cliff. Based on the research data, which were at characterizing the actual ecosystem structure and function, the accelerated rate of climate change in the Arctic, coupled with glacial retreat and permafrost thaw, is expected to significantly alter catchment characteristics. These changes will, in turn, affect benthic communities, food resources, and food webs. The classification of stream types according to their water source and catchment properties offers a robust framework for future monitoring efforts.</p>

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Contrasting benthic communities and food webs in different stream types on high arctic Svalbard

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2025年9月13日

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  • Leopold Füreder,
  • John E. Brittain

摘要

Arctic freshwater ecosystems are characterized by low temperatures, a short ice-free period, low productivity, and low biodiversity. There is only fragmented knowledge about High Arctic benthic communities and no information about their functional relationships. The environmental characteristics and food resources of five contrasting High Arctic stream reaches near Ny-Ålesund, Svalbard, were investigated. The streams represented a gradient in environmental harshness. In addition to hydrological, chemical, and physical characteristics, food resources, algal biomass, and benthic invertebrate assemblages were determined. Food web structure was investigated using stable isotope signatures of δ13C and δ15N. The streams varied significantly in their hydrology, water temperature, and water chemistry. There was a clear distinction of these characteristics between streams fed by glacial meltwater, snowmelt and groundwater, as well lake outflows. Zoobenthos abundance was significantly lower in the glacier-fed stream and was highest in the groundwater-fed stream, enriched with nutrients, flowing below a bird cliff. Chironomidae dominated in all streams, although the dominance and relative abundance of the subfamily Diamesinae varied between streams. Stable isotope ratios (δ13C, δ15N) of food sources (autochthonous – allochthonous matter) varied considerably within and between streams. Most of the benthic invertebrates were heterotrophic consumers, although the food source differed between streams, with some relying mainly on autochthonous resources (glacial stream), others on allochthonous resources (most other streams), and a combination of both food sources in the stream near the bird cliff. Based on the research data, which were at characterizing the actual ecosystem structure and function, the accelerated rate of climate change in the Arctic, coupled with glacial retreat and permafrost thaw, is expected to significantly alter catchment characteristics. These changes will, in turn, affect benthic communities, food resources, and food webs. The classification of stream types according to their water source and catchment properties offers a robust framework for future monitoring efforts.