Tools and techniques in aquatic sciences. From fish models to environmental approaches

Two thirds of the Earth is covered by water, and oceans, lakes and rivers are a crucial source of food and jobs. On a global scale, it is increasingly important to utilise marine and freshwater ecosystems in a sustainable way, to maintain their biodiversity and to reduce the negative impact of human activities. New test systems have to be developed for the security of both, human health and aquatic ecosystem health. These might use new materials, new devices, new measurements or new model organisms. During the last years, significant progress has been made in the development of new tools and techniques that could be used in and for Aquatic Science. Is it the development of small passive intebrated transponders to track small fishes [Roussel et al.2009], the increasing research activities on fish models as tools for medicine or the improvements on fish ecotoxicology, there are plenty of new concepts in Aquatic Sciences that have been established. Aquatic ecosystems around the world face serious threats from anthropogenic contaminants [Ostrach et al., 2008].The increasing worldwide contamination of freshwater systems and oceans with thousands of industrial and natural chemical compounds is one of the key environmental problems facing humanity. Although most of these compounds (such as metals) are present at low concentrations and much is known about their concentration effects, many of them raise considerable toxicological concerns, particularly when present as components of complex mixtures. And still little or nothing is known about the majority of the chemical compounds. Therefore, tools to assess the impact of these pollutants on aquatic life and human health must be further developed and refined. Most aquatic organisms will be exposed, to varying degrees, to the contaminations. The number of species exposed could be thousands, and quite possibly tens of thousands. Little is known about whether or not these species are adversely affected by the chemicals present in their environment. Often it is not even known what species are present, let alone whether they are affected by the chemicals present. Examples of tributyl tin causing imposex in molluscs and oestrogens 'feminizing' male fish showed that chemicals have undoubtedly adversely affected aquatic species, occasionally leading to population crashes. That is why cost-effective and appropriate remediation and water-treatment technologies must be explored and implemented and the introduction of critical pollutants into the aquatic environment should be minimized [Schwarzenbach et al. 2011]. Here, the aquatic ecosystem health is strongly dependend on new tools and techniques.