A mesocosm approach for detecting stream invertebrate community responses to treated wastewater effluent.
The discharge of wastewater from sewage treatment plants is one of the most common forms of pollution to river ecosystems, yet the effects on aquatic invertebrate assemblages have not been investigated in a controlled experimental setting. Here, we use a mesocosm approach to evaluate community responses to exposure to different concentrations of treated wastewater effluents over a two week period. Multivariate analysis using Principal Response Curves indicated a clear, dose-effect response to the treatments, with significant changes in macroinvertebrate assemblages after one week when exposed to 30% effluent, and after two weeks in the 15% and 30% effluent treatments. Treatments were associated with an increase in nutrient concentrations (ammonium, sulfate, and phosphate) and reduction of dissolved oxygen. These findings indicate that exposure to wastewater effluent cause significant changes in abundance and composition of macroinvertebrate taxa and that effluent concentration as low as 5% can have detectable ecological effects.
Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona (UB), Diagonal 645, 08028 Barcelona, Spain. ted.grantham@gmail.com
Theodore E
TE
Grantham
Miguel
M
Cañedo-Argüelles
Isabelle
I
Perrée
Maria
M
Rieradevall
Narcís
N
Prat
D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D007448:Invertebrates / Q000145:classification / Q000187:drug effects*; D045483:Rivers / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D012722:Sewage; D014874:Water Pollutants, Chemical