Introduction to Marine Pollution

Abstract

The ocean plays a key role in cycles of carbon, nitrogen, phosphorus and a variety of other important chemicals. Ocean chemistry has been changing due to human activities, both regionally in coastal waters and in the open ocean. Some of the greatest impacts are on carbon, nitrogen, and dissolved oxygen, which affect biological productivity. The rate of primary production is determined primarily by light and nutrients. Decades of pollution of marine waters, along with coastal habitat destruction, overfishing and bottom trawling have had devastating impacts on biodiversity and habitats. The increasing demand for seafood worldwide has depleted fish populations and devastated the economic well-being of coastal communities. At the same time, climate change is altering the oceans in major ways that we are only beginning to understand.

Land-based sources pollute estuaries and coastal waters with nutrients, sediments, pathogens as well as many thousands of toxic chemicals, including metals, pesticides, industrial products, pharmaceuticals and more. Following the industrial revolution, increasing amounts of materials have been discharged into the environment from chemical industries, sewage treatment plants, and agriculture, eventually reaching marine ecosystems. Highly visible events such as the Exxon Valdez, and the Gulf of Mexico “gusher” have raised public awareness of marine pollution in recent decades. There is growing scientific evidence demonstrating serious, sometimes disastrous, impacts of pollution in the marine environment. Pollutants of major concern are those that are widespread and persistent in the environment, accumulate in biota, and induce effects at low concentrations. Toxic chemicals are varied and often difficult to detect. In recent years, attention is being devoted to new or newly recognized threats to the environment – contaminants of emerging concern (CEC), ocean acidification, and noise pollution.