Aquaculture production is an important industry in many countries and there has been a growth in the use of medicines to ensure the health and cost effectiveness of the industry. This study focussed in the inputs of sea lice medication to the marine environment. Diflubenzuron, teflubenzuron, emamectin benzoate, cypermethrin and deltamethrin were measured in water, sediment and biota samples in the vicinity of 5 aquaculture locations along the Norwegian coast. Deltamethrin and cypermethrin were not detected above the limits of detection in any samples. Diflubenzuron, teflubenzuron and emamectin benzoate were detected, and the data was compared the UK Environmental Quality Standards. The concentrations of emamectin benzoate detected in sediments exceed the environmental quality standard (EQS) on 5 occasions in this study. The EQS for teflubenzuron in sediment was exceeded in 67% of the samples and exceeded for diflubenzuron in 40% of the water samples collected. A crude assessment of the levels detected in the shrimp collected from one location and the levels at which chronic effects are seen in shrimp would suggest that there is a potential risk to shrimp. It would also be reasonable to extrapolate this to any species that undergoes moulting during its life cycle.
Via John Bostock