phytoplankton blooms

03.06.2025

phytoplankton blooms

Context

In the last few years, satellite images have revealed frequent and large-scale phytoplankton blooms in the Indian Ocean and Arabian Sea. These developments are closely studied due to their impact on ocean health, fisheries, and climate balance.

About the News :

• Phytoplankton blooms observed in Arabian Sea and Southern Ocean.
• Blooms linked to desert dust carrying iron into ocean water.
• Studies highlight role of phytoplankton in carbon absorption.
• Impact on oxygen levels and marine food chains under review.
   

Plankton:

Plankton are microscopic drifting organisms that rely on water currents for movement.These organisms are incapable of resisting oceanic flow, which distinguishes them from swimming marine life.

Broad Categories :

Plankton are grouped based on their function in the ecosystem:

• Producers (Phytoplankton): These light-dependent organisms act like oceanic plants, generating energy through photosynthesis.
• Consumers (Zooplankton): These tiny animal species feed on phytoplankton and contribute to nutrient cycling.
   

Ecological Value

1. Oxygen Generation: Phytoplankton are responsible for producing more than half of the Earth's oxygen supply.
    
2. Food Web Foundation: They serve as the primary source of energy for fish, marine mammals, and other aquatic organisms.
3. Climate Regulation: By capturing carbon dioxide, plankton reduce the impact of greenhouse gases.
4. Environmental Indicators: Their population patterns offer insight into ocean health, pollution, and climate shifts.
    

Challenges

• Overgrowth causes Dead Zones, like in the Gulf of Mexico.
• Decomposition of blooms depletes oxygen, harming fish life.
• Some blooms release biotoxins, harming humans and marine life.
• Iron-induced blooms can exhaust other nutrients, as seen in the Southern Ocean.

Way Forward

• Monitor blooms through satellite mapping, like by Indian National Centre for Ocean Information Services.
• Study dust fertilization impacts from deserts like Kalahari and Namib.
• Support ocean health policies under the United Nations Ocean Decade Programme.
• Regulate nutrient runoff from agriculture, as in coastal Andhra Pradesh.
   

Conclusion

Phytoplankton blooms are both an environmental opportunity and a challenge. While they support marine ecosystems and help in climate regulation by absorbing carbon dioxide, unchecked blooms can damage marine biodiversity. Understanding and managing these blooms is essential for sustainable ocean governance and food security.