Assessment of ecosystem health and ecotoxicology through chemical analysis and modeling

Abstract

The industrialization and urbanization in China over the past 30 years have resulted in serious deterioration and contamination of the natural ecosystems in terms of air, soil, water and also the biota as evidenced by chemical and toxicological data reported widely (Ford and Cheng 2009; Ford et al. 2011; Gu and Wang 2012, 2013; Zhao et al. 2013). As chemical analysis can show the concentrations of specific contaminants at the time and locations of sampling, it serves as a direct indication on the extent of contamination, but it also has its own limitations by the entities of the sampled and the analytical methods used. Such data are only relevant to the specific compartments of the ecological niche under the specific conditions at the time of sampling and the methods used (Zhao et al. 2012a, b). Collection of environmental data that can yield historical events is hardly possible with routine chemical analysis alone except for a few cases, e.g., lead isotopic ratio for the sources of the contamination in sediment cores and nitrogen isotope ratio for the sources of pollution. As such, alternative approaches in understanding the environmental impact from pollution and toxic chemicals can be ecological based by using indicators that can stand the test of time to reflect the historical events of the past or pollution. In general, ecological investigations have not been given the importance and uniqueness as they deserve mainly due to the high variability and also the long duration of the study for collection of meaningful data to reach a more convincing conclusion (Shen et al. 2010). However, it is undeniable that ecological analysis coupling with chemical data can provide more insights to the environmental status of the ecosystems and the changes that have been taking place. In a similar but different approach, microbial community structure composition of selective biochemical process can be used as reliable environmental quality indicators, anammox bacteria as one has been proposed as selective species of this group are only detected in contaminated environments while others are only in pristine ecosystems (Cao et al. 2011, 2012, 2013; Li et al. 2011a, b). Since PCR-based amplification of specific DNA templates extracted from sediments/soils is highly specific and sensitive, this approach has been successful in confirming the anthropogenic pollution sources. All of these new advances are important in further scientific understanding of the living environment and in preventing against detrimental changes due to anthropogenic impacts. We believe that the research field of ecotoxicology can be advanced by more in-depth research and fundamental investigations of environmental chemistry, ecotoxicology and environmental/pollution toxicology, applied biology and molecular biology to provide the essential basic information and key data for a better understanding of the environmental issues and also protection of the environment. It is non-disputable that many scientists in China have actively engaged in research on pollution sources, types of the pollutants, toxic effects of chemicals on target and non-target organisms at a wide range of response levels including molecular, enzymatic, and organismic levels, especially many studies carried out in laboratory under simulated and controlled conditions (Han et al. 2011; Wu et al. 2009; Zhao et al. 2009, 2013). The information from such hypothetical studies must serve the needs for problem solving in the real world, which is community and ecosystem based. Here an integration of studies on ecosystem ecology and computer modeling with toxicology and analytical chemistry has been collected from selective papers J.-D. Gu (&) School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China e-mail: jdgu@hku.hk