Invertebrate community responses to pollutants in mediterranean basins : insights from ecotoxicological approaches = Respostes de la comunitat d'invertebrats als contaminants en conques mediterrànies: aproximacions ecotoxicològiques
Aquatic systems are under pressure from multiple stressors that affect the structure, the functioning, and the health of species, communities and ecosystems. One of the main human pressures affecting the Earth’s ecosystems is chemical pollution. Large-scale chemical production has led to the release...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2016 |
| Country: | España |
| Institution: | CBUC, CESCA |
| Repository: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/386400 |
| Online Access: | http://hdl.handle.net/10803/386400 |
| Access Level: | Open access |
| Keyword: | Toxicologia ambiental Toxicología ambiental Environmental toxicology Invertebrats aquàtics Invertebrados acuáticos Aquatic invertebrates Contaminació Contaminación Pollution Mediterrània (Regió) Mediterráneo (Región) Mediterranean Region Ciències Experimentals i Matemàtiques 574 |
| Summary: | Aquatic systems are under pressure from multiple stressors that affect the structure, the functioning, and the health of species, communities and ecosystems. One of the main human pressures affecting the Earth’s ecosystems is chemical pollution. Large-scale chemical production has led to the release of these compounds from agricultural, industrial, and municipal waste, into riverine, transitional, and marine waters. These pollutants can cause harmful effects on aquatic species and communities, in turn causing severe negative impacts on the structure and functioning of ecosystems, and the goods and services they provide. Chemical pollution is not only one of the most important threats to aquatic systems, it is also a complex threat due to the diversity of compounds present in these systems and the dynamics and interaction of these compounds with physical (water, sediment) and biological (amphibian, fish, invertebrate, algae) compartments. Furthermore, aquatic pollution is of special concern in Mediterranean basins, which suffer high flow variability and receive significant contaminant inputs from diffuse and point sources. Future scenarios predict that these basins will be increasingly affected by both the scarcity of water, enhanced by climate change, and high pollution. Apart from well-known pollutants, called priority substances, many studies have revealed the widespread occurrence of low level concentrations of organic micropollutants, also known as emerging contaminants (ECs), and awareness is growing with regard to the importance of mixtures of several contaminants, priority and emerging, as found in the more polluted water bodies of Europe. Different tools can be used in order to link the chemical and ecological quality of aquatic ecosystems: ecological methods (Chapter 3, 4 and 5), biomarkers of field-exposed organisms (Chapter 4 and 6), or in vitro and in vivo bioassays (Chapter 4, 5, 6 and 7). By combining these different tools, this thesis provides evidence of the effects of chemical stressors (emerging and priority pollutants) on invertebrate communities in four threatened Mediterranean rivers of the Iberian Peninsula: the Ebro, the Llobregat, the Júcar and the Guadalquivir. The ecotoxicological effects have been detected at community level, but also at the population and individual levels. It has been found that contaminants in water and also contaminants accumulated in surficial sediments affect community structure (richness and abundance). It has also been seen these contaminants affect the reproductive capacity (number of eggs), the development, the feeding, growth and the activity of antioxidative enzymes (catalase) of diferent species. The general picture obtained shows that priority and emerging pollutants represent a serious toxicity risk for invertebrates in these basins, and that the main specific drivers of this risk are pesticides, alkylphenols, and metals. Additionally, the thesis is completed with a laboratory experiment where the direct and indirect effects of two specific contaminants in the detritivorous Gammarus pulex have been tested. Research based on field studies and laboratory toxicity tests, combining experimental assays with natural community studies, is essential to understand the effects of stressors at different scales and to prevent future degradation of aquatic ecosystems. This thesis integrates observational and experimental approaches of diferent environmental disciplines (environmental chemistry, ecotoxicology and ecology) to elucidate the effects of pollution. The combination of experimental tests to study natural communities can help to understand the effects of disturbances at different scales and prevent the degradation of aquatic ecosystems and improve its management. |
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