The Earth’s oceans, vast and enigmatic, have long captivated human imaginations with their depths teeming with life. Since the Industrial Revolution, anthropogenic impacts on natural systems have constantly intensified, especially on marine systems. Although most stressors have an anthropogenic origin and occur worldwide, they present different characteristics on which they may be managed. Yet, beneath ocean surfaces lies a profound and intricate crisis – a convergence of challenges that threaten all biological realms and associated marine and coastal environments. This chapter embarks on the intensities and effects of ocean warming, acidification, and plastic pollution-induced water quality deterioration, revealing their interconnectedness and underscoring the urgency of our response. Due to increasing atmospheric CO2, the world’s oceans are warming and slowly becoming more acidic (ocean acidification), and profound changes in marine ecosystems are certain. Calcification is one of the primary targets for studies of the impact of CO2-driven climate change in the oceans. Plastic pollution is ubiquitous in the ocean but causes the most serious harm near coastlines and during its journey toward open waters. The formation of oxygen-depleted dead zones and toxic algal blooms narrate the threats of a compromised aquatic realm due to ocean water quality deterioration. Managing waste and litter streams better, eliminating unnecessary products, ensuring adequate waste management systems are in place, setting up a circular economy for plastic products and waste where possible, boosting recycling, and incinerating unrecyclable plastic waste for energy in conjunction with the development of carbon capture and storage technology help balancing the trade-off with greenhouse gas emissions. Ocean-based renewable energy sources like wave and tidal power can reduce greenhouse gas emissions, combating ocean warming. Carbon capture and storage systems can alleviate acidification by capturing CO 2 emissions from various sources. Advanced waste-removal technologies, including ocean cleanup vessels and AI-powered monitoring systems, aid in tackling plastic pollution. More stress ecology research is needed at the frontier between ecotoxicology and ecology, going beyond standardized tests using model marine species to address multiple water quality factors (pH, temperature, toxicants, etc.) and organisms’ health. These technologies, combined with global collaborations, blue economic strategies, and building awareness, can play a pivotal role in preserving the health and sustainability of Earth’s oceans.
Dayananda N. R., Wijesinghe J., Botheju S. M., Perera W. P. R. T. & Liyanage J. A., 2025. Chapter 6 – Ocean warming, acidification, plastic pollution, and water quality deterioration: a multifaceted crisis unveiled. In: Vithanage M., Samarasekara S. M., James B. D. & Reddy C. M. (Eds.), Coastal and Marine Pollution: Source to Sink, Mitigation and Management, pp 111-138. John Wiley & Sons. Chapter (restricted access).
