Thames River

A recent study indicates that climate change is set to increase algal blooms in Thames River, despite a significant reduction in phosphorus levels over the past decades.

• About Thames River: Total Length is 346 km, making it the longest river in England and the second longest in the UK (after River Severn).
• Flows Through: Southern England, passing major cities like London, Reading, Windsor, and Oxford (where it is also called the Isis River).
• Course:

o Origin: Thames Head, Cotswold Hills, Gloucestershire.

o Mouth: North Sea, via the Thames Estuary.

o Nore Sandbank: Marks the meeting point of the Thames and North Sea.

o Basin Area: Covers approximately 16,130 sq. km.

• Major Tributaries: Lea, Leach, Churn, Coln, Windrush, Kennet, Evenlode, Ock, and Loddon.
• About Algal Blooms: Rapid increase in algae population in aquatic systems, often visible as green scum on water surfaces.
• Role of Phosphorus:

o Primary Nutrient: Phosphorus is a key nutrient that promotes algal growth.

o Sources: Commonly enters water bodies through agricultural runoff containing fertilizers and effluent discharge.

• Impact of Elevated Phosphorus Levels:

o Eutrophication: Excess phosphorus leads to nutrient-rich conditions, causing dense algal blooms.

o Oxygen Depletion: Decomposition of abundant algae consumes dissolved oxygen, potentially resulting in fish kills and biodiversity loss.

• Case Studies: Bengaluru Lakes & Ukkadam Lake