Continental‐scale patterns of nutrient and fish effects on shallow lakes: introduction to a pan‐European mesocosm experiment

Abstract

Summary 1. Shallow lake ecosystems are normally dominated by submerged and emergent plants. Biological stabilising mechanisms help preserve this dominance. The systems may switch to dominance by phytoplankton, however, with loss of submerged plants. This process usually takes place against a background of increasing nutrient loadings but also requires additional switch mechanisms, which damage the plants or interfere with their stabilising mechanisms. 2. The extent to which the details or even major features of this general model may change with geographical location are not clear. Manipulation of the fish community (biomanipulation) has often been used to clear the water of algae and restore the aquatic plants in northerly locations, but it is again not clear whether this is equally appropriate at lower latitudes. 3. Eleven parallel experiments (collectively the International Mesocosm Experiment, IME) were carried out in six lakes in Finland, Sweden, England, the Netherlands and Spain in 1998 and 1999 to investigate the between‐year and large‐scale spatial variation in relationships between nutrient loading and zooplanktivorous fish on submerged plant and plankton communities in shallow lakes. 4. Comparability of experiments in different locations was achieved to a high degree. Cross‐laboratory comparisons of chemical analyses revealed some systematic differences between laboratories. These are unlikely to lead to major misinterpretations. 5. Nutrient addition, overall, had its greatest effect on water chemistry then substantial effects on phytoplankton and zooplankton. Fish addition had its major effect on zooplankton and did not systematically change the water chemistry. There was no trend in the relative importance of fish effects with latitude, but nutrient addition affected more variables with decreasing latitude. 6. The relative importance of top‐down and bottom‐up influences on the plankton differed in different locations and between years at the same location. The outcome of the experiments in different years was more predictable with decreasing latitude and this was attributed to more variable weather at higher latitudes that created more variable starting conditions for the experiments.

Synergistic control of CO2 emissions by fish and nutrients in a humic tropical lake

“…These N and P levels were chosen to simulate the nutrient levels typically found in Brazilian lakes while avoiding toxic levels (Moss et al 2004). The final N and P concentrations in the nutrient-enriched mesocosms were within the range used in other studies that have assessed the effects of fish and eutrophication on community structure (e.g., Stephen et al 2004). We added P in the form of KH 2 PO 4 and K 2 HPO 4 to attenuate the changes in pH, and N was added as NH 4 NO 3 to reduce the possible negative influence of ammonium on the fish.…”

Mesocosm Experiments as a Tool for Ecological Climate-Change Research

“…(1) Finkel et al (2006), (2) Ward et al (2012), (15) Blanchard et al (2012), (16) Poloczanska et al (2008), (17) Cheung et al (2009), (18) Sheldon et al (2011), (19) Henry and Molau (1997), (20) Perkins et al (2012), (21) Stephen et al (2004), (22) Meerhoff et al (2007), (23) Friberg et al (2009), (24) Woodward et al (2010a), and (25) Gudmundsdottir et al (2011a). Reference numbers are the same as in the text and Table 1.…”

“…McQueen et al, 1986;Williams and Moss, 2003;Williams et al, 2002). More recently, an ambitious programme that spanned a latitudinal gradient in Europe combined space-for-time surveys with mesocosm approaches (Bécares et al, 2008;Gyllström et al, 2005;Moss et al, 2004;Romo et al, 2004;Stephen et al, 2004).…”

Sources and causes of water pollution in Bangladesh: A technical overview

“…It along these lines incorporates ranger service, trim culture, biomass creation for fuel and creature farming. Effects on freshwater and marine frameworks may incorporate consequences for water science [30][31][32][33][34][35][36] with resulting eutrophication and nourishment web adjustment [37][38][39], biocide filtering [40][41][42][43][44][45], suspended burdens from soil disintegration [46], change of the hydrological cycles [47], impacts of unusual species utilized, especially in fish and shellfish culture, and physical alteration of the living space (channelization, station change, bank and seepage) [48]. It is difficult to isolate impacts of horticulture from those of urbanization.…”