Q.Write notes on the following:
a. Eutrophication
b. Algal Bloom

Eichhornia crassipes (water hyacinth) earns the name "Terror of Bengal."

Eichhornia crassipes, a free-floating aquatic invasive weed introduced from South America, reproduces extremely fast by vegetative propagation (stolons) and doubles its population in a couple of weeks under favourable conditions. It formed dense mats on ponds, lakes and canals of West Bengal, blocking sunlight and oxygen exchange, choking navigation and fisheries, and outcompeting native aquatic flora — earning it the popular name "Terror of Beng …

Cultural eutrophication is nutrient over-enrichment of a lake/pond caused by human discharge of nitrate- and phosphate-rich waste.

Eutrophication is the natural nutrient-enrichment of an ageing lake or pond that occurs slowly over geological time as part of aquatic (hydrarch) ecological succession. When this process is drastically speeded up by human activities — discharge of domestic sewage, detergents and agricultural fertiliser runoff, all rich in nitrates and phosphates, into a water body — it is called cultural or accelerated eutrophication. The excess nutrients trigger explosive growth of algae ('algal blooms'), and when these algae die and are decomposed by bacteria, dissolved oxygen in the water is depleted, kil …

Water hyacinth is the problematic aquatic weed.

Water hyacinth (Eichhornia crassipes), called the 'terror of Bengal', is an introduced (alien) aquatic plant that grows extremely fast and forms dense mats over ponds and lakes. It causes eutrophication problems, blocks waterways, depletes dissolved oxygen and threatens native aquatic life. …

Fertilizer in a pond causes eutrophication.

Fertilizers are rich in nitrogen and phosphorus. When they run into a freshwater pond, the excess nutrients cause rapid overgrowth of algae (algal bloom). When the algae die, their decomposition by microbes consumes dissolved oxygen, so fish and other a …

An algal bloom is a sudden, dense growth of algae triggered by nutrient enrichment (eutrophication) of a water body, which chokes off oxygen and light for other aquatic organisms.

When large quantities of nutrients -- mainly nitrates and phosphates from fertiliser run-off, detergents, or untreated sewage -- enter a lake, pond or river, the water becomes nutrient-enriched. This process is called eutrophication. The excess nutrients cause explosive, dense growth of planktonic algae and cyanobacteria on the water's surface, which is called an algal bloom; it often gives the water a green, blue-green or reddish colour. The bloom blocks sunlight from reaching submerged plants, and when the algae die and are decomposed by b …