Bioindicators of Pollution in Marine Environments

Abstract

World marine ecosystems are constantly impacted by anthropogenic activities, accumulating pollutants from the tropics to the poles. Physical, chemical, and biological stressors produced by industrial processes, intensive agriculture and urban development, have the potential to alter the balance of ecosystems by triggering changes in the biotic communities, including the marine environment. Traditionally, the pollution assessment at these ecosystems has been based on the analysis of specific xenobiotics levels in selected matrices. However, the present challenges require an integrated assessment of contamination levels along with their possible adverse effects on organisms, even if they are found in concentrations below to the permitted limits. Then, it is essential to develop consistent tools for biomonitoring, while also assessing their potential impacts on human health. Essentially, bioindicators are organisms, populations, or communities that undergo through a certain change when exposed to contamination; these changes are based on thecomplexities of the ecosystem and provide representative responses which allow the assessment of the environmental health from a dynamic perspective. A suitable bioindicator should have a wide range of properties; however, the selection in marine environments should be based on specific criteria considering the different habitats (from coastal areas to offshore, from benthic environments to pelagic waters) and the sensitivity degree of organisms to diverse pollutants (or pollutants complex) to which they are exposed. This chapter summarizes numerous marine species from different taxonomic groups that have been tagged in the last 20 years to be used as bioindicators of diverse physicochemical pollutants in marine environments; it will address their suitability according to the different habitats and life habits, ranging from microorganisms to marine mammals. Besides, this chapter presents the most important challenges and advances in the field of marine bioindicators in recent years, which could be relevant for integrative monitoring purposes and the development of new approaches and technologies in marine pollution monitoring.