Numerous contemporary environmental concerns jeopardizing the health and sustainability of coastal and marine ecosystems are induced or intensified by a multitude of anthropogenic stressors, further aggravated by climate and oceanic changes. Since the public became aware of the growing contamination of water supplies, deterioration of the atmosphere, and poisoning of soils by industrial toxicants, environmental pollution issues have grown to be global issues. The use of biomonitoring techniques in assessing and controlling strategies for the marine environment has several advantages (precise, responsive, and feasible) over any other technique method. Nuclear techniques have opened up new perspectives on the pathways and rates of uptake. This chapter focuses on clarifying the function of radiological marine biomonitoring. This paper highlights the application of radiotracers, illustrates the advancement of existing radioecological tracing techniques for contemporary environmental challenges, and presents insights on forthcoming difficulties that could benefit from both current and novel radiotracer methodologies.