Environmental monitoring approaches for the detection of organic contaminants in marine environments: A critical review

•Mass spec. techniques as the most reported approach for marine water monitoring.•Combining passive sampling and effect-based analysis to pollutant exposure insights.•Biomonitoring to determine bioavailability and bioaccumulation of pollutants.•Promissive sensor developments needs further validation prior to field application. This review reports different approaches for monitoring the presence of organic contaminants in marine environments. From the traditional standard chromatographic methodologies coupled to different detectors to the recent advances in sensor technology, different strategies have been adopted by researchers aiming to provide more comprehensive, realistic and accurate environmental monitoring data sets. Reports on chemical analysis by different techniques of marine water and sediments, using grab and passive sampling techniques, are the most abundant in literature, showing relevant developments. Analysis of the marine biota (biomonitoring) has also been widely used as a proxy for the detection of organic chemicals in seawater, with bivalves being the most used as sentinel specie. Such biomonitoring can provide insights on bioavailability and bioaccumulation of organic pollutants, which is not possible to obtain by water and sediment analysis solely. Furthermore, effect-based methods are also presented as an important approach when it comes to obtain environmental meaningful data, such as potential toxicity and hazards posed by the complex chemical mixtures to local biota. This approach is reported to be a useful tool for screening areas without any previous knowledge on chemical composition, with subsequential qualitative and quantitative characterization being performed by chemical analysis. Finally, some of the most recent developments in sensor and biosensor technology for environmental purposes are also discussed, with some proof-of-concept studies showing promising results. However, further development and validations work is strongly advised prior to the use of those sensing platforms in real field trials.