The Effect of Water Temperature Regime on Benthic Macroinvertebrates
Total Page：16
File Type：pdf, Size：1020Kb
The effect of water temperature regime on benthic macroinvertebrates A contribution to the ecological assessment of rivers Inaugural-Dissertation zur Erlangung des Doktorgrades Dr. rer. nat. des Fachbereichs Biologie und Geografie an der Universität Duisburg-Essen, CE vorgelegt von Alexandra Haidekker aus Hamburg Oktober 2004 Die der vorliegenden Arbeit zugrunde liegenden Experimente wurden in der Abteilung Hydrobiologie des Instituts für Ökologie der Universität Duisburg-Essen durchgeführt. 1. Gutachter: PD Dr. Hering (Universität Duisburg-Essen) 2. Gutachter: Prof. Dr. Greven (Universität Düsseldorf) Vorsitzender des Prüfungsausschusses: Prof. Dr. Schuhmacher (Universität Duisburg-Essen) Tag der mündlichen Prüfung: 22.02.2005 πάντα ρει̃ Table of Contents 1. General introduction ...................................................................................................... 1 2. The temperature characteristics in two river-types in the Lower Mountain Range of Western Germany ........................................................................................................ 6 2.1. Introduction............................................................................................................. 6 2.2. Materials and methods ............................................................................................ 7 2.2.1. Study area and study sites ................................................................................ 7 2.2.2. Recording of temperature data, assessment of environmental variables ....... 11 2.2.3. Weather data................................................................................................... 14 2.2.4. Temperature data processing.......................................................................... 14 2.2.5. Temperature parameters used for the analysis ............................................... 15 2.2.6. Data analysis .................................................................................................. 16 2.3. Results................................................................................................................... 18 2.3.1. Thermal parameters – ecological significance............................................... 18 2.3.2. Thermal parameters – typological significance ............................................. 21 2.3.3. Small- and mid-sized rivers – are they thermally homogeneous? ................. 23 2.3.4. Thermal pattern in relation to environmental conditions............................... 25 2.3.5. Classification with other river-types .............................................................. 27 2.4. Discussion............................................................................................................. 32 2.4.1. Temperature parameters of typological and ecological importance .............. 32 2.4.2. Thermal pattern of the river-types and environmental influence................... 35 2.4.3. Classification with other river-types .............................................................. 38 3. Influence of a modified temperature regime on the development of two Hydropsyche species........................................................................................................................ 40 3.1. Introduction........................................................................................................... 40 3.2. Materials and methods .......................................................................................... 42 3.2.1. Study area and sampling sites ........................................................................ 42 3.2.2. Assessment of environmental data................................................................. 43 3.2.3. Invertebrate data: sampling and determination .............................................. 46 3.2.4. Statistical tests................................................................................................ 47 3.3. Results................................................................................................................... 48 3.3.1. Thermal changes downstream from the Bigge confluence and the power station............................................................................................................. 48 3.3.2. Comparison of the thermal changes by hypolimnic and cooling water ......... 50 3.3.3. Development of two Hydropsyche spp. in different thermal regimes ........... 52 3.4. Discussion ............................................................................................................. 58 3.4.1. Environmental situation ................................................................................. 58 3.4.2. Longitudinal influence of thermal changes.................................................... 59 3.4.3. Development of Hydropsyche larvae ............................................................. 60 4. The influence of water temperature on the macroinvertebrate community................. 65 4.1. Introduction........................................................................................................... 65 4.2. Materials and methods .......................................................................................... 66 4.2.1. Study area and sites........................................................................................ 66 4.2.2. Sampling ........................................................................................................ 67 4.2.3. Data processing .............................................................................................. 69 4.2.4. Data analysis .................................................................................................. 70 4.3. Results................................................................................................................... 71 4.3.1. Variation of environmental and thermal characteristics ................................ 71 4.3.2. The EPTC-community ................................................................................... 73 4.3.3. Community pattern and habitat...................................................................... 74 4.3.4. Explanatory power of the environmental variables........................................ 75 4.4. Discussion............................................................................................................. 81 4.4.1. Temperature and community pattern ............................................................. 81 4.4.2. Temperature parameters in comparison ......................................................... 81 4.4.3. Other environmental variables and their effects on community .................... 82 4.4.4. Temperature-sensitive species: do they reflect strategies for different thermal environments?................................................................................................ 84 5. Summary and conclusion............................................................................................. 90 6. Zusammenfassung ....................................................................................................... 93 7. References.................................................................................................................. 104 8. Appendices ................................................................................................................ 122 1. General introduction 1. General introduction One early reason for intensifying research in running waters was the rising pollution level in the beginning of the 20th century (Schönborn 2003). Kolkwitz & Marsson (1908, 1909) developed the first saprobic index to assess the organic pollution in rivers. In the following years several other saprobic systems (e.g. Liebmann 1962, Pantle & Buck 1955, Zelinka & Marvan 1961) and biotic indices (e.g. Woodiwiss 1964, Beak 1965) were developed in different regions and countries in Europe in order to assess the water quality. With increasing knowledge and the attention paid to the ecological state of rivers the focus turned also to other stressors apart from organic pollution, since rivers have been modified in many ways: in particular anthropogenic influence caused further changes in stream-water physico-chemistry, i.e. acidification, eutrophication, input of toxic sub- stances, modifications of the thermal regime, as well as changes in river morphology, hydrology, and habitat diversity. An increasing number of assessment systems have been developed to measure the state of degradation for most of the stressors mentioned above, using mainly benthic inverte- brates, but also fish, phytobenthos, phytoplankton, or macrophytes as indicators. The majority of methods has been developed to detect the degree of organic pollution and general degradation in rivers (e.g. Kokes et al. 2001, Schöll & Haybach 2001), followed by assessment methods for hydromorphological degradations (e.g. Buhmann & Hutter 1996, LAWA 2001, Lorenz et al. 2004), eutrophication (e.g. Institut für Wassergüte 2002, Bayerisches Landesamt für Wasserwirtschaft 1998), acidification (e.g. Braukmann 1999, Rutt et al. 1990) and toxic substances (e.g.Wogram & Liess 2001) (for a review on assessment methods see Birk & Hering 2002, Knoben et al. 1995). Recently, the EU Water Framework Directive (WFD; Directive 2000/60/EC – Establish- ing a Framework for Community Action in the Field of Water Policy) sets uniform stan- dards in water management practices for Europe with the focus on biotic indicators to survey the