Investigating the effects of organic pollutants on amphibian populations in the UK

Amphibians are undergoing dramatic population declines, with environmental pollution reported as a significant factor in such declines. Technologies are required that are able to monitor populations at risk of deteriorating environmental quality in a rapid, high-throughput and low-cost manner. The application of biospectroscopy in environmental monitoring represents such a scenario. Biospectroscopy is based on the vibrations of functional groups within biological samples and may be used to signature effects induced by chemicals in cells and tissues. Here, attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy in conjunction with multivariate analysis was implemented in order to distinguish between embryos, whole tadpoles at an early stage of development and individual tissues of late-stage tadpoles of the common frog collected from ponds in the UK with varying levels of water quality, due to contamination from both urban and agricultural sources. In addition, a Xenopus laevis cell line was exposed to low-levels of fungicides used in agriculture and assessed with ATR-FTIR spectroscopy. Embryos, in general did not represent a sensitive life stage for discriminating between ponds based on their infrared spectra. In contrast, tadpoles exposed to agricultural and urban pollutants, both at early and late stages of development were readily distinguished on the basis of their infrared spectra. ATR-FTIR spectroscopy also readily detected fungicideinduced changes in X.laevis cells, both as single-agent and binary mixture effects. Data reported in this study confirm the use of ATR-FTIR spectroscopy as a sensitive technique capable of detecting small changes in cellular groups, and as such represents a valuable starting point for its use in the monitoring of amphibian populations. However further research is needed in order to overcome confounding factors existent in natural populations of complex organisms