Recent trends in marine toxicological assessment emphasize the integration of advanced technologies and methodologies to enhance accuracy and efficiency. This book is divided into four sections. Section 1 provides an introduction to the topic. Section 2 covers the sampling methods used for pollution assessment in marine ecosystems, detailing the monitoring techniques for studying marine benthic community structures, primary producers, invertebrates, and fish, as well as the migration and transformation of chemicals in marine environments. Section 3 delves into the molecular pathways of pollutants at various biological levels. Finally, Section 4 explores the latest high-throughput screening methods, including predictive Tox-21 tools such as QSAR models, DNA barcoding, and omics techniques, which are extensively used in marine toxicological assessments. Collectively, these advancements drive more comprehensive and precise evaluations of the impacts of pollutants on marine ecosystems, contributing to sustainability efforts.