Chloride and sulphate toxicity to Hydropsyche exocellata (Trichoptera, Hydropsychidae): Exploring intraspecific variation and sub-lethal endpoints.
The rivers and streams of the world are becoming saltier due to human activities. In spite of the potential damage that salt pollution can cause on freshwater ecosystems, this is an issue that is currently poorly managed. Here we explored intraspecific differences in the sensitivity of freshwater fauna to two major ions (Cl(-) and SO4(2-)) using the net-spinning caddisfly Hydropsyche exocellata Dufour 1841 (Trichoptera, Hydropsychidae) as a model organism. We exposed H. exocellata to saline solutions (reaching a conductivity of 2.5mScm(-1)) with Cl(-):SO4(2-) ratios similar to those occurring in effluents coming from the meat, mining and paper industries, which release dissolved salts to rivers and streams in Spain. We used two different populations, coming from low and high conductivity streams. To assess toxicity, we measured sub-lethal endpoints: locomotion, symmetry of the food-capturing nets and oxidative stress biomarkers. According to biomarkers and net building, the population historically exposed to lower conductivities (B10) showed higher levels of stress than the population historically exposed to higher conductivities (L102). However, the differences between populations were not strong. For example, net symmetry was lower in the B10 than in the L102 only 48h after treatment was applied, and biomarkers showed a variety of responses, with no discernable pattern. Also, treatment effects were rather weak, i.e. only some endpoints, and in most cases only in the B10 population, showed a significant response to treatment. The lack of consistent differences between populations and treatments could be related to the high salt tolerance of H. exocellata, since both populations were collected from streams with relatively high conductivities. The sub-lethal effects tested in this study can offer an interesting and promising tool to monitor freshwater salinization by combining physiological and behavioural bioindicators.
Centre Tecnològic Forestal de Catalunya - CTFC, Solsona, Catalunya, Spain.
Miquel
M
Sala
CESAM, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
Melissa
M
Faria
Technische Universität München, Munich, Bayern, Germany.
Ignacio
I
Sarasúa
Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain.
Carlos
C
Barata
Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia, Spain; Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia, Spain.
Núria
N
Bonada
Aquatic Ecology Group, BETA Tecnio Centre, University of Vic - Central University of Catalonia, Vic, Catalonia, Spain; Catalan Institution for Research and Advanced Studies, ICREA, Barcelona 08010, Spain.
Sandra
S
Brucet
Aquatic Ecology Group, BETA Tecnio Centre, University of Vic - Central University of Catalonia, Vic, Catalonia, Spain.
Laia
L
Llenas
Aquatic Ecology Group, BETA Tecnio Centre, University of Vic - Central University of Catalonia, Vic, Catalonia, Spain.
Sergio
S
Ponsá
Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia, Spain.
Narcís
N
Prat
CESAM, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
Amadeu M V M
AMVM
Soares
Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia, Spain; Aquatic Ecology Group, BETA Tecnio Centre, University of Vic - Central University of Catalonia, Vic, Catalonia, Spain. Electronic address: mcanedo.fem@gmail.com.
Miguel
M
Cañedo-Arguelles
D000818:Animals; D002712:Chlorides / Q000633:toxicity*; D004784:Environmental Monitoring; D007220:Industrial Waste / Q000032:analysis; D007313:Insecta / Q000187:drug effects* / Q000254:growth & development; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D013030:Spain; D013431:Sulfates / Q000633:toxicity*; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D002712:Chlorides; D007220:Industrial Waste; D013431:Sulfates; D014874:Water Pollutants, Chemical
Biomarkers; Freshwater salinization; Image processing; Ion toxicity; Mining; Sub-lethal effects