The marine environments are directly or indirectly connected with the total environmental conditions including bio-geo-hydro and atmospheres. The marine areas especially marginal marine areas including aquatic organisms were recently facing a lot of environmental crises. The discharge of large volumes of nitrogen and phosphorus is generally considered a common source of pollution in the marine environment, with inputs derived from various point and diffuse sources. The negative impact of these issues is most probably eutrophication and increases in the occurrence and severity of marine diseases (Strain et al. 2022). Pollutants such as pesticides, toxic elements, microplastic, and other persistent organic chemicals are previously unknown for their adverse environmental and health effects. Recent research has demonstrated that microplastic materials (MPs) taken up from the water column and sediments especially plastic particles between 1 µm and 5 mm can have physical, chemical, and biological impacts on organisms. These MPs can occur directly through ingestion or dermal uptake, especially through respiratory surfaces (gills). Exposure to MPs caused elevated mortality, increased inter-brood period, and decreased reproduction and physiological alterations such as decreased food consumption, weight loss, decreased growth rate, and fecundity and energy depletion (Zhang et al. 2021). The leachate materials such as catalysts, solvents, and additives leaching from plastic materials are possible to generate negative effects on biological systems.

Similarly, Pesticides and polycyclic aromatic hydrocarbons(PAHs) are toxic, teratogenic, carcinogenic, and mutagenic and they are still commonly detected in different environmental media these chemicals have an extremely long half-life and are also found from coastal beaches to the deepest ocean trenches (Jamieson et al. 2017., Zhao et al. 2017; Pradhap et al. 2021). Due to the extensive residues and the occurrences of these pollutants in the environment especially in marine matrixes and their direct or indirect health risks to humans, they have become global environmental pollutants that cannot be ignored (Qian et al. 2020, Radhakrishnan et al. 2023).

The recent updates in this field are increasing scientific interest in the presence of newly identified POPs such as perfluoroalkyl and poly-fluoroalkyl substances, polychlorinated naphthalenes, flame retardants, and paraffins in in the marine environment. The eco-friendly and cost-effective method studies for marine pollution are more important to environmental sustainability and biodiversity health. To meet the objective of the SI, we have conducted the national seminar on “Marine Pollution and Ecological Degradation”—MPAED 2022 from the 27th to the 29th July 2022. The topic of the special issue includes the Source, fate, and distribution of environmental contaminants in the aquatic environment including marine, estuaries, and brackish water environments, eco-toxicological and risk assessment studies on the marine environment, climatic change-related impact on the marine environment including extreme events and the introduction of novel contaminants and the national and International policies and Regulations for marine environmental pollution. The scientific meeting had 6 keynote presentations and 36 presentations. The special issue was invited for this scientific meeting to publish marine pollution and its impact on the ecological environment. Over nine research articles and one review article were included in this special issue. For example, Selvaraj et al. (2023) investigated the trace element concentration and environmental risk of Arasalar River Estuary sediments Tamil Nadu, India; Padmachandran et al. (2023) studied the microplastics in estuarine environment from Kavvayi and Kumbla backwaters of Malabar Coast, Kerala, India; Priyadharshini et al. (2023) discussed the baseline human health risk assessment due to consumption of dried fish in Chennai, Tamil Nadu, India: a baseline report; and Nyambar et al. (2023) carried out the hydrochemistry, water quality, and pollution risk studies on urban lakes along the coastal region of Miri, NW Borneo. The outcome of the published research work in the conference proceedings and special issue perhaps promotes awareness about marine environmental pollution. The conducting of continuous awareness programs and scientific campaign movements along the coastal areas and common public is helpful and provides a good solution to these efforts. Further, we feel that the research papers of these SI probably create awareness about the marine pollution-related ecological impact and fulfill the scientific knowledge gap around research communities.

We, the guest editors, would like to thank the Editor-in-Chief of the ESPR Journal, the editorial assistant, and all the supporting staff for giving us this opportunity. We convey our special thanks to the Management of Malankara Catholic College, Mariagiri, Kaliyakkavilai, Kanyakumari District, for providing all the necessary facilities and moral support for this national seminar and during the progress of the special issue.