About this Research Topic
Marine pollution monitoring programs aim to guide the conservation, protection and sustainable management of marine ecosystems. International institutions with competence in environmental management currently call for a strategy based not only on the concentration of chemicals in different environmental compartments, but also on evaluating their effects in ecosystems. Thus, standardization and application of biological techniques to develop quantitative parameters to link the available information on inputs and quantities of pollutants to harmful effects on marine ecosystems has long been considered a crucial knowledge gap. Within the framework of environmental legislation there is furthermore a need to develop internationally agreed assessment criteria for environmental pollutants, as well as sensitive biological responses for pollution surveillance. This research topic will consider contributions concerning the new challenges in marine pollution monitoring, including the development of new relevant techniques or technology.
Although the use of biological effects techniques in marine pollution monitoring has been repeatedly encouraged, the alteration of biological responses caused by pollutants seems to be commonly masked by the interference of natural intrinsic and environmental variables (‘confounding factors’), which have an effect on the organ-ism’s response to pollutant exposure. This constitutes one of the main limitations of current monitoring pro-grams, especially those of large geographical scale covering heterogeneous environmental scenarios. Further-more, recent laboratory studies have demonstrated that bioaccumulation can also be affected strongly by ‘con-founding factors’, such as those related to the condition of the organism (food availability, food quality, reproductive status).
International monitoring programs generally comprise the analysis, in representative matrices, of a limited group of pollutants, selected due to their persistence and/or toxicity such as trace metals, organochlorinated com-pounds or polycyclic aromatic hydrocarbons. Many other organic contaminants such as current-use pesticides, antifouling substances, personal care products, pharmaceuticals or surfactants might however represent poten-tial threats to the environment or to the human health. Such substances, which are not adequately covered by current environmental regulations, are considered as pollutants of emerging concern, or emerging pollutants, due to their continuous input into the marine environment. Urgent information is needed about these pollutants, including environmental distribution, bioaccumulation potential and ecotoxicity.
Among the emerging pollutants, there has recently been increasing environmental concern about ‘microplastics’, defined as plastic particles smaller than 5 mm in diameter. Recent studies have demonstrated that microplastic pollution is widespread and ubiquitous within the marine environment, with the potential to cause harm to bio-ta. However, due to methodological difficulties in their quantification, the impact of microplastics in marine organisms is not well known. Plastics are considered chemically inert, but the organic compounds used as additives to modify the properties of the original polymers can be harmful to living organisms. In addition, plastics have the capacity to concentrate organic contaminants and it has been speculated about the possible pathway of environmental pollutants into the marine food chain by plastic ingestion.
The widespread occurrence of toxicants in coastal waters has prompted the development of environmental quality criteria for single compounds. However, aquatic organisms are typically exposed to a wide range of toxicants in the environment rather than to individual substances. The inclusion of the combined effects of toxicants resulting from multiple exposures in the water quality regulations to develop appropriate regulatory strategies may be taken into account.
Keywords: Marine pollution, ecotoxicology, biomonitoring, water quality, bioaccumulation
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