HOW HUMAN ACTIVITIES AFFECT MARINE ECOSYSTEM?!

Human activities are disrupting and degrading some ecological and economic services provided by marine aquatic systems, especially coastal marshes, shorelines, mangrove forests, and coral reefs. In 2008, the U. S. National Center for Ecological Analysis and Synthesis (NCEAS) used computer models to analyze and provide the first-ever comprehensive map of the effects of 17 different types of human activities on the world’s oceans. In this 4-year study, an international team of scientists found that human activity has heavily affected 41% of the world’s ocean area. No area of the oceans has been left completely untouched, according to the report. In their desire to live near a coast, some people are unwittingly destroying or degrading the aquatic biodiversity and the ecological and economic services that make coastal areas so enjoyable and valuable. In 2010, about 45% of the world’s population and more than half of the U.S. population lived along or near coasts and these percentages are increasing rapidly.


  • Major threats to marine systems from human activities include:
  • Coastal development, which destroys and pollutes coastal habitats.
  • Runoff of nonpoint sources of pollutants such as silt, fertilizers, pesticides, and livestock wastes.
  • Point-source pollution such as sewage from cruise ships and spills from oil tankers.
  • Pollution and degradation of coastal wetlands and estuaries.
  • Overfishing, which depletes populations of commercial fish species.
  • Use of fishing trawlers, which drag weighted nets across the ocean bottom, degrading and destroying  its habitats.
  • Invasive species, introduced by humans, that can deplete populations of native aquatic species and
  • cause economic damage.
  • Climate change, enhanced by human activities, which is warming the oceans and making them more acidic; this could cause a rise in sea levels during this century that would destroy coral reefs and flood coastal marshes and coastal cities.
According to a 2007 study by Ove Hoegh-Guldberg and 16 other scientists, unless we take action soon to significantly reduce carbon dioxide emissions, the oceans may be too acidic and too warm for most of the world’s coral reefs to survive this century, and the important ecological and economic services they provide will be lost.

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