In the North Atlantic Ocean wind-driven surface currents head poleward from the equator, cooling all the while and eventually sinking at high latitudes into the ocean basins (thermohaline circulation). Extensive mixing takes place across ocean basins, reducing differences between them and making the Earth's ocean a global system. On their journey, the water masses transport heat, gas and matter around the globe. This circulation has a large impact on the climate of our planet.
Phytoplankton carry out nearly 50% of primary production in the open ocean. Also it support the greatest biodiversity in the planet.
It is important to the carbon cycle because it represents a major reservoir for carbon – dissolved carbon, organic and inorganic.
Major source of food. About 1 billion people rely on fish as their main source of protein.
About half of the world population lives by the coast or work within 100 kilometers of the sea.
International seaborne trade relies on regular and safe routes for freight and passengers. World seaborne trade is estimated at approximately 28,000bn tonne miles1. 90% of EU external trade and 40% of EU internal trade is carried by sea and in the UK the shipping sector employs over 30,000 people2.
Marine habitats such as coral reefs and salt marshes provide natural coastal defenses and nursery grounds for fisheries as well as diverse ecosystems. Changes in marine species distribution, disruption to life cycles.
You have already had a couple of lectures on climate change – climate change has an impact on the ocean, ocean acidification, sea rise, this affects ecosystems and biological processes.