Question: How do ocean currents and water masses impacts marine life and coastal environment? Give suitable examples.
Answer:Ocean currents are one of the major condition that affects climate and weather of a region including the ecosystem of coast. The effects are felt on economic as well as geographical front.
Ocean currents and water masses’ impact on coastal environment and marine life
- Marine productivity
Ocean currents have great impact on the biomass production in a region. The currents are responsible for increasing or decreasing marine organisms on the coast. 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 region in terms of fishing activities.
Ex: The Japanese coast is suitable for large-scale fishing due to mixing of Oyashio and Kuroshio currents.
- Rainfall patterns
The ocean currents have ability to influence rainfall patterns owing to their ability to attract or repel warm winds. The coast having presence of cold currents usually inhibit onshore winds, resulting in creating desert like conditions.
Ex: The North-western coast of Africa is flanked by cold currents called Canary currents. These currents prevent warm air from ascending near the coast leading to formation of Sahara desert.
- Sea ice formation
Ocean currents and masses are responsible for formation of sea ices 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 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 presence of cold Labrador current. Whereas the ports of Norway and United Kingdom do not experience sea ice inspite of them located in higher latitudes than Canadian ports. This is due to warm gulf stream.
- Local climate
Some coastal regions on the globe experience higher and lower temperatures mainly due to warm and cold currents. This will have a large impact on locally observable climatic conditions.
Ex: Cities of New York and Lisbon are located on the same latitudes but both experience different weather conditions. This is because New York is flanked by cold current and Lisbon by warm current.
Thus, ocean currents and masses play an important role in defining climatic conditions of a region other than features like altitude, Latitude, Distance from sea etc.