National Environmental Research Institute Department of Freshwater Ecology Pesticides in Danish streams and lakes: Concentrations, loss and ecological effects Brian Kronvang, NERI

National Environmental Research Institute Department of Freshwater Ecology Introduction kg active ingredients was applied in Danish agriculture during the year 2000 Following spraying pesticides can reach surface water due to wind drift, leaching, runoff and bad handling Our knowledge about the presence of pesticides in surface waters have been very limited

National Environmental Research Institute Department of Freshwater Ecology Pesticide pathways to streams

National Environmental Research Institute Department of Freshwater Ecology NOVA-2003 Analysed for 68 pesticides i 5 larger streams and 48 pesticides i 25 small streams in agricultural catchments during 2000 og 2001 In total measured 43 pesticides and metabolites above the detection limit Detection limit normally ug/l

National Environmental Research Institute Department of Freshwater Ecology Pesticide detection frequencies and maximum concentrations measured in streams in the Danish Aquatic Monitoring Programme 2000

National Environmental Research Institute Department of Freshwater Ecology Is there any ecological effects of pesticides in streams? Fyns amt (2002)

National Environmental Research Institute Department of Freshwater Ecology Lakes and ponds

National Environmental Research Institute Department of Freshwater Ecology NOVA-2003 Measured for 48 pesticides in 8 lakes in 2001 In total measured 42 pesticides or metabolites Maximum concentration was 0,22 µg/l (diuron) Maximum median concentration was 0,03 µg/l

National Environmental Research Institute Department of Freshwater Ecology Maximum concentrations in NOVA streams and lakes

National Environmental Research Institute Department of Freshwater Ecology Concentrations of pesticides in 69 lakes and 47 ponds sampled in regional programs

National Environmental Research Institute Department of Freshwater Ecology Intensive study in 2 catchments

National Environmental Research Institute Department of Freshwater Ecology Study catchments

National Environmental Research Institute Department of Freshwater Ecology Number of samples taken in the two catchments during Lillebæk (culverted sub-catchment) Water 104 Suspended sediment 8 Streambed sediment 6 Lillebæk (entire catchment) Water 96 Suspended sediment 8 Streambed sediment 6 Odderbæk Water 68 Suspended sediment 10 Streambed sediment 6

National Environmental Research Institute Department of Freshwater Ecology Pesticides in Stream Water

National Environmental Research Institute Department of Freshwater Ecology Pesticides in Suspended Sediment

National Environmental Research Institute Department of Freshwater Ecology Applied amount of pesticides in the 3 catchments and the detection frequency and concentration levels in streams

National Environmental Research Institute Department of Freshwater Ecology Terbuthylazine in Lillebæk, Funen

National Environmental Research Institute Department of Freshwater Ecology

Pesticide application, loss and loss ratios 18 different pesticides during 2000 ____________________________________________________ AppliedLoss Loss ratio (kg a.i.)(gram) (%) ____________________________________________________ Odderbæk Lillebæk (culverted sub-catchment) Lillebæk (Open sub-catchment ____________________________________________________

National Environmental Research Institute Department of Freshwater Ecology Transport/applications

National Environmental Research Institute Department of Freshwater Ecology Loss

National Environmental Research Institute Department of Freshwater Ecology Breakthrough curve for the Herbicide Bentazone

National Environmental Research Institute Department of Freshwater Ecology Breakthrough curve for the Insecticide Dimethoate

National Environmental Research Institute Department of Freshwater Ecology Possible Ecological Effects

National Environmental Research Institute Department of Freshwater Ecology Gammarus survival Caves installed 10 m upstream, at the tile drain outlet and 10 m downstream 6 caves each with 10 Gammarus The experiment prevailed for 8 hours only Mortality and inactivity

National Environmental Research Institute Department of Freshwater Ecology Effects – Drain experiment

National Environmental Research Institute Department of Freshwater Ecology Conclusions Under “normal” conditions the concentration of pesticides are generally low in Danish streams and lakes During storm events short lived high and ecological critical concentrations can occur The highest concentrations are detected in small streams and ponds Effects have been documented on the macroinvertebrate Gammarus pulex during an experiment