What are the forces that influence ocean currents? Describe their role in the fishing industry of the world. (250 words) [2022]

Introduction

Ocean currents are continuous movements of water in the ocean that follow set paths, kind of like rivers in the ocean. They play a crucial role in maintaining the Earth’s climate, distributing heat, and supporting marine life. The primary forces that influence ocean currents include wind, temperature and salinity gradients, Earth’s rotation, and gravity.

Forces Influencing Ocean Currents

Wind: Surface currents are driven by global wind systems fueled by energy from the Sun. Wind direction, Coriolis forces from Earth’s rotation, and the position of landforms interact with the currents.
Temperature and Salinity Gradients: Density differences in water masses due to temperature (thermo) and salinity (haline) variations cause thermohaline circulation. These currents move water masses through the deep ocean, taking nutrients, oxygen, and heat with them.
Earth’s Rotation and Coriolis Force: The Coriolis force acts to the right in the northern hemisphere and to the left in the southern hemisphere, influencing the circulation of ocean currents.
Gravity: Gravity plays a role in driving deep water currents, which are influenced by density differences caused by temperature and salinity variations.

Ocean Currents and the Fishing Industry

Ocean currents play a significant role in the fishing industry by affecting the growth and distribution of marine life:

Nutrient Availability: Currents affect the availability of nutrients for plant growth, which in turn influences the availability of food for marine animals. Example – The Benguela Current system off the west coast of South Africa supports the growth of plankton, which in turn provides food for the sardines during the Natal Sardine Run.
Rich Fishing Grounds: Rich fisheries often occur where different currents meet and mix in ocean fronts, creating fertile feeding grounds for marine life. Example – The meeting of the cold Labrador Current and the warm Gulf Stream creates the ideal breeding ground for fish in the Grand Banks area, one of the world’s richest fishing grounds.
Fish Migration: Ocean currents determine fish movements along coastal areas, affecting the distribution of fish species and the location of fishing grounds.
Upwelling: Surface wind-driven currents generate upwelling currents in conjunction with landforms, creating deepwater currents that bring cold, nutrient-rich waters to the surface, supporting the growth of phytoplankton and providing energy for fish. Example – Upwelling currents along the west coast of Africa and America bring cold, nutrient-rich waters to the surface, supporting the growth of phytoplankton and providing energy for fish.

Conclusion

Ocean currents play a vital role in the fishing industry by influencing the growth, distribution, and migration of marine life. Understanding the forces that drive ocean currents and their impact on the fishing industry is essential for sustainable management and conservation of marine resources.