November 20, 2014 by Adam Peters

Dean and I attended SETAC North America in Vancouver last week. This is the first time for quite a few years that wca have been represented at this event, and as regular attendees of SETAC Europe we were a little surprised to find it to be of a similar size to the European events. Dean presented on the Tuesday afternoon on the ‘Implementation of Biota Standards under the WFD’, and I presented 3 posters, on a variety of metals related issues, and a platform on deriving an EQS for iron. I also had the opportunity to attend a small meeting prior to SETAC on the mechanisms of nickel toxicity, where Chris Woods and Mike McLaughlin gave particularly interesting talks about aquatic and terrestrial ecosystems, respectively.

There were numerous sessions dealing with metals and metal toxicity, including broader application of biotic ligand models. There has also been quite a lot of interest in, and research on, the effects of ionic salts and their mixtures on aquatic organisms and ecosystems in North America. The important industrial sources of effluents of this type are produced waters from oil and gas extraction. Mesocosm studies on benthic macroinvertebrates indicate that these organisms may be appreciably more sensitive than standard laboratory test organisms.

There has also been considerable progress in the implementation of the copper BLM in the USA, with increasing numbers of states now considering its application, and approaches towards simplifying the data requirements in a manner more similar to the approaches being considered in Europe. There has also been considerable development in the modelling of mixtures of metals. This can be an important issue as metals are almost always found as mixtures in the environment. It would appear that there will be some challenges in modelling the interactions in terms of competitive binding at a “biotic ligand”, and an improved understanding of the internal mechanisms of toxicity might be required. Some very interesting studies have been performed on mixtures of cadmium and zinc, which are typically present at a relatively consistent ratio, on mesocosms containing benthic macroinvertebrates by Chris Mebane and researchers at the USGS.

Other sessions of interest covered EDs, marine ecotoxicology, effects of pharmaceuticals, nano-materials, biota standards and measurement of contaminant concentrations in biota, and wildlife ecotoxicology. Our favourites were talks dealing with the monitoring of mercury and cortisol in polar bear hair, assessment of pesticide bioaccumulation in America mink as a surrogate for marine mammals, anti-sea lice pesticides used in salmon aquaculture and toxicity to non-target topical organisms, endangered species toxicity extrapolation using Interspecies Correlation Extrapolation (ICE), and disposal of fracking water in giant evaporation ponds which attract migrating birds.