Wildlife indicators Biomarkers

Several candidate wildlife indicators are suggested and discussed in this chapter. In addition, we recognize that valuable sources of data on residue-effect relationships are available to assist in the selection of habitat-specific indicators (Jarvinen and Ankley 1999 USCOE and USEPA 2005). Although this chapter emphasizes animals, similar considerations and literature exist for plants and microorganisms as bioindicators and biomarkers (National Research Council 1989 USEPA 1997 Gawel et al. 2001 Citterio et al. 2002 Yuska et al. 2003). 

Metabolomics has made remarkable inroads into the environmental research community. Here, a major emphasis is to understand the impact that environmental stress, such as pollution and climate change, has on wildlife. Indeed, many government organizations monitor the prevalence of pollutants in certain species of wildlife as indicators of the exposure risk within the environment. Studies of Japanese medaka have been conducted to investigate the effects of trichloroethylene, a common environmental pollutant, and the pesticide dinoseb, on the development of fish embryos (44, 45). Similarly, cadmium toxicity has been examined in the bank vole and rat and has revealed changes in lipid metabolism that preceded classical nephrotoxicity (46, 47). Another study investigated the effects of environmental toxins on earthworms (48). In particular, the analysis of earthworm tissue extracts by NMR spectroscopy identified maltose as a potential biomarker for ecotoxicity within a metal-contaminated site. 

Human health biomonitoring may also use animal surrogates in the environment to assess potential health hazards to humans - the proverbial canary in the coal mine . For example, chemical and biomarker analysis of bodily fluids or tissue biopsies from family pets, especially dogs, are sometimes used to assess potential chemical exposure and effects in children. This is because dogs often accompany children in the outdoor environment, and both have a tendency to (accidentally or intentionally) consume environmental media such as soil and surface water There has also been an increasing trend to use native animals as sentinel species, that is, fish, wildlife, or invertebrates that are indicators of possible human health risks from environmental hazards. For example, increased incidences of tumors or endocrine disruption in fish may indicate the presence of compounds in the water that may cause cancer or reproductive dysfunction in humans. Concern has also been raised over the increased incidence of deformities in frogs, because these may indicate an increased level of chemicals in the environment, which can cause birth defects in humans. 

Endpoints like mortality, growth, reproduction, etc., are regarded as important indicators to decide about possible effects on the sustainability of populations which is in general the main protection goal. Especially when using data from mammalian toxicology for wildlife assessments but, also in connection with endocrine disruption, the relevance of data for biomarkers is difficult to evaluate. 

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