How do ocean currents and water masses differ in their impacts on marine life and the coastal environment? Give suitable examples. (15 Marks)

Mentor’s comment:

  • The question is straightforward and asks about the difference in the impact of ocean currents and water masses on marine life and coastal environment.
  • In the intro, briefly describe the ocean currents and water masses.
  • In the body, described in the first part the impact of ocean currents on marine life and coastal environment- for example, state how ocean currents impact the temperature and humidity of coastal region and thereby affects the other inter-related aspects of the marine life and coastal environment.
  • In the second part, describe the impact of water masses-like, how water masses determine the hydrological conditions of the water which influence the production and the growth of plankton and fish species. Likewise, water masses impact the humidity and pressure of the air above its surface, which in turn impacts the circulation of winds affecting coastal environment Ex: Land breeze and Sea breeze.


Our planet is composed of 70 % of oceans and 30 % of the land. Thus oceans have a huge impact on life under it and also on the life of coastal regions. Their impact is also varied according to the location and movements of ocean water.

Impact of ocean currents and water masses on coastal environment and marine life

  • Desert formation: cold ocean currents inhibit rains and cause arid conditions to create deserts. Eg. Atacama desert of South America, Mojave desert of North America.
  • Marine productivity:
    • Sealife is concentrated in the sunlit waters near the surface, but most organic matter is far below, in deep waters and on the seafloor. When currents upwell, or flow up to the surface from beneath, they sweep vital nutrients back to where they’re needed most. 
    • The warm currents are rich in organic contents due to upwelling and cold currents are oxygen supportive. The region where these currents meet is one of the most productive regions in terms of fishing activities. Ex: The Japanese coast is suitable for large-scale fishing due to mixing of Oyashio and Kuroshio currents.
  • Rainfall: warm ocean currents bring rain to the areas adjacent to it. Eg the British type of climate is due to warm ocean currents.
  • Sea ice formation: Ocean currents and masses are responsible for the formation of sea ice at higher latitudes. The region of temperate climates will suffer from sea ice formation which affects coastal navigation leading to loss of economic activity. Warm currents prevent the formation of sea ice even though the region is close to poles.
    • Ex: Canadian ports located near Newfoundland suffer from sea ice formation due to the presence of cold Labrador current. 
    • Whereas the ports of Norway and the United Kingdom do not experience sea ice in spite of them located in higher latitudes than Canadian ports. This is due to the warm gulf stream.
  • Piling up of warm water near coasts may result in the formation of tropical cyclones.

Though the presence of water mass and ocean currents both impact coastal environments- ocean currents produce more dramatic and consistent impacts that touch the lives of people and animals than the water masses would have.

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Dakshina Moorthy
Dakshina Moorthy
2 years ago

Please review the answer

2 years ago


2 years ago