The continuous growth in the amount of solid waste that humans produce, and the very slow rate at which that waste degrades, are together leading to a gradual increase in the amount litter found at sea, on the seafloor and along coastlines around the world.
Human activities on land are the biggest sources of marine pollution—an estimated 8 million tonnes of plastic waste enter the world’s oceans each year. These include solid waste dumped along coastlines, scattered litter on beaches, and pieces of broken down ships. Floods and other storm-related events flush this waste into the sea, where it sinks or is carried away by currents. The major sea-based sources of marine pollution include discarded fishing gear, shipping activities, and legal and illegal dumping.
All of this pollution causes serious economic losses. Coastal communities face increased expenditures on beach cleaning, public health and waste disposal. The shipping industry is impacted by higher costs associated with fouled propellers, damaged engines and managing waste in harbours. The fishing industry faces damaged gear and reduced and contaminated catch.
Marine pollution also causes biodiversity loss and hampers ecosystem functions and services. Discarded fishing gear can entangle and kill marine life and smother wildlife habitats. Pesticides and other toxins adhere to tiny particles of discarded plastics (microplastics), which can be accidentally ingested by small aquatic life. Once ingested, the toxins move up the food chain, accumulating in birds, sea life and possibly humans.
UNEP’s Global Programme of Action for the Protection of the Marine Environment from Land-Based Activities, which has been active since 1995, aims to provide guidance to national and regional authorities on how to prevent, reduce, control and eliminate marine degradation from land-based activities. Launched in 2017, UNEP’s #CleanSeas campaign urges governments to enact policies to reduce the use of plastic, targeting industry to minimize plastic packaging and redesign products, and calling on consumers to change their throwaway habits before irreversible damage is done to our seas. UNEP also works through the Regional Seas programme to strengthen marine protections around the world.