Description

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Context:

Recently, INCOIS has identified nine key algal bloom hotspots along India’s east and west coasts.

About Harmful Algal Blooms

Category	Details
Algal Blooms	Excessive algae growth in water bodies, visible in green, blue-green, red, or brown shades.
Causes	Favorable environmental conditions like nutrient enrichment, warm temperatures, and stagnant water.
Types of Water Bodies	Occur in fresh, marine (salt), and brackish (mix of fresh & salt) water.
Harmful vs. Beneficial Blooms	Most are beneficial as they serve as food for marine life. Some, called Harmful Algal Blooms (HABs), can negatively impact human health and aquatic ecosystems.

Algal bloom hotspots

Coast	Key Areas
East Coast
Gujarat Coast	Gulf of Khambhat, Gulf of Kutch
Maharashtra Coast	Mumbai and surrounding coastal areas
Goa Coast	Goa beaches and estuaries
Karnataka Coast	Mangaluru and surrounding areas
Kerala Coast	Kochi and other coastal areas
West Coast
Tamil Nadu Coast	Chennai and surrounding coastal areas
Andhra Pradesh Coast	Visakhapatnam and Kakinada areas
Odisha Coast	Puri and Gopalpur coastal areas
West Bengal Coast	Sunderbans and other coastal areas

Why they occur?

Cause	Explanation
Nutrient Overload	Excess nitrate and phosphate from agriculture and industry enter seawater through rivers, providing ideal conditions for algae growth.
Coastal Upwelling	Deep, nutrient-rich cold water rises to the surface, fostering rapid algal growth and increasing bloom occurrences.
Monsoon Effect	Heavy rainfall carries nutrients from land to sea, enhancing algae growth, especially during monsoon season.
Climate Change	Rising sea temperatures accelerate algae growth, leading to more frequent and intense algal blooms, disrupting marine ecosystems.

Impacts

HABs can produce toxins that may result in acute or chronic disease in most vertebrates depending on the type of toxin and the amount of toxin absorbed.
HABs can damage the environment by exhausting oxygen in water which can kill fish and other living creatures.
HABs, which bloom near the water surface, can also block sunlight in achieving organisms deeper in water.

About the Indian National Centre for Ocean Information Services (INCOIS)

Aspect	Details
Parent Organization	Ministry of Earth Sciences (MoES)
Location	Hyderabad, India
Established	1999
Affiliation	Unit of Earth System Science Organization (ESSO), New Delhi
Mandate	To provide the best possible ocean information and advisory services to society, industry, government agencies, and the scientific community through ocean observation and research.

Source:

THE HINDU

PRACTICE QUESTION

Q. Discuss the causes and ecological impacts of harmful algal blooms (HABs) in marine and freshwater ecosystems. How do they affect human health and the economy? Suggest effective measures to control and mitigate the occurrence of HABs. (250 WORDS)