Q. What are the forces that influence ocean currents? Describe their role in the fishing industry of the world. [250 Words, 15 Marks]
Why the Question?
UPSC PYQ – CSE Mains – 2022
Keywords of the Question
- Forces
- Influence ocean currents
- Fishing industry of the world
Directive Word
Describe – Provide a detailed explanation as to how and why something happens
How to approach this Question?
Introduction
- Define Ocean Currents: Briefly define what ocean currents are.
- Mention Importance: Highlight the significance of ocean currents in global climate and marine ecosystems.
Body
- Forces Influencing Ocean Currents:
- Primary Forces: Solar heating, wind, gravity, Coriolis effect.
- Secondary Forces: Temperature differences, salinity differences, Earth’s rotation.
- Role in Fishing Industry:
- Nutrient Distribution: How currents bring nutrient-rich waters to the surface, supporting marine life.
- Fishing Grounds: Influence on the location of rich fishing grounds.
- Fish Migration: Impact on the migration patterns of fish.
- Upwelling Zones: Importance of upwelling zones in supporting fisheries.
Conclusion
- Summarize Key Points: Recap the main forces influencing ocean currents and their role in the fishing industry.
- Highlight Importance: Emphasize the critical role of understanding ocean currents for sustainable fishing practices and marine conservation.
Note: Please note that the following ‘answers’ are not ‘model answers’ nor are they synopses in the strictest sense. Instead, they are content designed to meet the demands of the question while providing comprehensive coverage of the topic.
Answer Key
Introduction
Ocean currents are continuous, directed movements of seawater generated by various forces acting upon the water. They play a crucial role in regulating the Earth’s climate, distributing heat, and supporting marine life.
Body
Forces Influencing Ocean Currents
- Solar Heating:
- The Sun heats the water at the equator more than at the poles, causing the water to expand and creating a slope.
- Example: This differential heating drives the equatorial currents like the Gulf Stream.
- Wind:
- Winds blowing across the surface of the ocean push the water, creating surface currents.
- Example: Trade winds drive the equatorial currents, while westerlies influence the mid-latitude currents.
- Gravity:
- Gravity pulls water down the slope created by solar heating, contributing to the movement of currents.
- Example: Gravity helps maintain the flow of the thermohaline circulation.
- Coriolis Effect:
- The Earth’s rotation causes moving water to turn and twist, influencing the direction of currents.
- Example: The Coriolis effect causes currents to turn right in the Northern Hemisphere and left in the Southern Hemisphere.
- Temperature and Salinity Differences:
- Variations in water temperature and salinity create density differences, driving deep ocean currents.
- Example: The thermohaline circulation, also known as the “global conveyor belt,” is driven by these differences.
Role in the Fishing Industry
- Nutrient Distribution:
- Ocean currents bring nutrient-rich waters to the surface, supporting the growth of phytoplankton, the base of the marine food web.
- Example: The upwelling along the coast of Peru supports one of the world’s richest fisheries.
- Fishing Grounds:
- Currents influence the location of productive fishing grounds by creating areas of high biological productivity.
- Example: The Grand Banks off Newfoundland are rich fishing grounds due to the meeting of the cold Labrador Current and the warm Gulf Stream.
- Fish Migration:
- Currents affect the migration patterns of fish, which follow nutrient-rich waters.
- Example: The migration of sardines along the coast of South Africa is influenced by the Benguela Current.
- Upwelling Zones:
- Upwelling brings cold, nutrient-rich water to the surface, supporting large populations of fish.
- Example: The California Current system supports a significant portion of the U.S. fishing industry due to upwelling.
Conclusion
Understanding the forces that drive ocean currents and their impact on the fishing industry is essential for sustainable management and conservation of marine resources. Ocean currents not only regulate climate but also create nutrient-rich environments that support thriving marine ecosystems, crucial for global fisheries.
Mind Map
