Consequences of Fish Kills for Long-Term Trophic Structure in Shallow Lakes: Implications for Theory and Restoration

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• 作者：Carl D. Sayer ; Thomas A. Davidson ; Ruth Rawcliffe ; Peter G. Langdon…
• 关键词：fish kills ; shallow lakes ; palaeolimnology ; trophic cascades ; macrofossils ; eutrophication ; biomanipulation
• 刊名：Ecosystems
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：19
• 期：7
• 页码：1289-1309
• 全文大小：1,043 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Ecology
  Plant Sciences
  Zoology
  Environmental Management
  Geoecology and Natural Processes
  Nature Conservation
  
• 出版者：Springer New York
• ISSN：1435-0629
• 卷排序：19

文摘

Fish kills are a common occurrence in shallow, eutrophic lakes, but their ecological consequences, especially in the long term, are poorly understood. We studied the decadal-scale response of two UK shallow lakes to fish kills using a palaeolimnological approach. Eutrophic and turbid Barningham Lake experienced two fish kills in the early 1950s and late 1970s with fish recovering after both events, whereas less eutrophic, macrophyte-dominated Wolterton Lake experienced one kill event in the early 1970s from which fish failed to recover. Our palaeo-data show fish-driven trophic cascade effects across all trophic levels (covering benthic and pelagic species) in both lakes regardless of pre-kill macrophyte coverage and trophic status. In turbid Barningham Lake, similar to long-term studies of biomanipulations in other eutrophic lakes, effects at the macrophyte level are shown to be temporary after the first kill (c. 20 years) and non-existent after the second kill. In plant-dominated Wolterton Lake, permanent fish disappearance failed to halt a long-term pattern of macrophyte community change (for example, loss of charophytes and over-wintering macrophyte species) symptomatic of eutrophication. Important implications for theory and restoration ecology arise from our study. Firstly, our data support ideas of slow eutrophication-driven change in shallow lakes where perturbations are not necessary prerequisites for macrophyte loss. Secondly, the study emphasises a key need for lake managers to reduce external nutrient loading if sustainable and long-term lake restoration is to be achieved. Our research highlights the enormous potential of multi-indicator palaeolimnology and alludes to an important need to consider potential fish kill signatures when interpreting results.