DOI: 10.5061/dryad.cp45ht6
title: Data from: Predictability of the impact of multiple stressors on the keystone species Daphnia

description: Eutrophication and climate change are two of the most pressing
 environmental issues affecting up to 50% of aquatic ecosystems worldwide.
 Mitigation strategies to reduce the impact of environmental change are
 complicated by inherent difficulties of predicting the long-term impact of
 multiple stressors on natural populations. Here, we investigated the
 impact of temperature, food levels and carbamate insecticides, in
 isolation and in combination, on current and historical populations of the
 freshwater grazer Daphnia. We used common garden and competition
 experiments on historical and modern populations of D. magna ‘resurrected’
 from a lake with known history of anthropogenic eutrophication and
 documented increase in ambient temperature over time. We found that these
 populations response dramatically differed between single and multiple
 stressors. Whereas warming alone induced similar responses among
 populations, warming combined with insecticides or food limitation
 resulted in significantly lower fitness in the population historically
 exposed to pesticides. These results suggest that the negative effect of
 historical pesticide exposure is magnified in the presence of warming,
 supporting the hypothesis of synergism between chemical pollution and
 other stressors.
description: Cambronero_etal_Environmental metadataPaleolimnological and historical data are shown for the sedimentary archive of Lake Ring. For each radiometrically dated year, Daphnia magna ephippia count, Cladocera assemblage, carbamate insecticides, Loss on Ignition (LOI), transparency measured as Secchi disk depth, total Nitrates (TN) and total Phosphates (TP) are shown. Na = missing data. Data for transparency, TN and TP are available between 1971 and 1999Cambronero_etal_pesticidesList of insecticides sold in Denmark according to the Danish county authority between 1955 and 2010 (www.middeldatabasen.dk). The total amount of each insecticide is show in tons. Yellow lines highlight carbamate insecticides, of which the commercial brand Carbaryl was used in this study.Cambronero_etal_life history traitsIndividualID, populationID, experimental exposure and life history traits (mortality, size at maturity, age at maturity and fecundity) measured after controlling for maternal effect in the three common garden experiments are shown. CGE1: temperature; CGE2: temperature and food levels; CGE3: temperature and insecticide Carbaryl concentrations. Temperatures used are: 18C and 24C; food levels are 0.2 mg Carbon/L and 2.4 mg Carbon/L; Carbaryl concentrations are 4 μg/L and 10 μg/L. Experimental exposures are as follows: T18 – Temperature 18C; T24 - Temperature 24C; TFH18 - Temperature 18C and high food levels; TFL18 - Temperature 18C and low food levels; TFH24 - Temperature 24C and high food levels; TFL24 - Temperature 24C and low food levels; TIH18 - Temperature 18C and high insecticide levels; TIL18 - Temperature 18C and low insecticide levels; TIH24 - Temperature 24C and high insecticide levels; TIL24 - Temperature 24C and low insecticide levels.