“Water and air, the two essential fluids on which all life depends, have become global garbage cans.”
Jacques Yves Cousteau
Populations in coastal regions are growing and placing increasing pressure on coastal and marine ecosystems. Marine pollution of many kinds threatens the health of the ocean and its living resources. While the past decades have seen efforts at the local, national, and international levels to address the problems of marine pollution, more needs to be done.
Numerous forms of pollution from a variety of land, sea, and air-based sources undermine the health of the ocean. Of these sources, it is estimated that 80 percent of marine pollution originates on land. Two of the most prevalent types of marine pollution are nutrient pollution and marine debris.
Nutrient pollution emanates from diverse sources including agricultural runoff and sewage and wastewater discharges. It overloads marine environments with high concentrations of nitrogen, phosphorous, and other nutrients, which can produce large algal blooms. The decomposition of these algae after they die consumes oxygen, which in turn creates hypoxic, or oxygen depleted “dead zones” where fish and other marine life cannot thrive. An estimated 500 dead zones now exist in the world and many more areas suffer adverse effects of high nutrient pollution. Toxic algal blooms also harm economies as they can severely disrupt the fisheries and tourism upon which many communities depend.
Marine debris – trash and other solid material that enters the ocean – threatens wildlife and marine habitats and presents health and safety concerns for humans. Trash and debris in coastal and ocean ecosystems also pose safety hazards and impose significant direct and indirect costs to society. Packaging and plastics consistently make up a significant percent of all marine trash. Preventing trash from entering the ocean presents a huge challenge due to the many sources, including municipal storm sewers, poor trash management by industrial and waste management facilities, disposal from vessels and offshore platforms, and littering by individuals in coastal and inland areas. The challenge is heightened by the fact that effective trash and litter prevention strategies require significant changes in the behavior of businesses, government entities, and individual citizens.