• Ashtamudi Lake, a backwater lake in Kerala, was the site of a concerning environmental incident, as hundreds of dead fish were found floating in the water, triggering panic among local residents. 

• Although isolated reports of fish deaths had occurred in the area previously, this marks the first instance of such a massive die-off in the lake's history.

Causes of mass fish mortality: 

• Local residents suspect that leachate contamination is to blame for the fish mortality, citing the potential dumping of large volumes of waste into the lake. 

• The recent mass die-off of fish in Ashtamudi Lake has been linked to the discharge of toxic substances into the water. These pollutants have significantly reduced the oxygen levels in the lake, leading to the death of a large number of fish downstream.

• The contamination has also resulted in the production of harmful gases and elevated levels of hazardous compounds, including hydrogen sulfide, ammonia, and heavy metals.

Ashtamudi Lake

• Ashtamudi Lake is a prominent backwater lake located in the Kollam district of Kerala, and is one of the most visited in the state.

• The lake’s surroundings were pivotal in the 14th century as a major port area, connecting the ancient city of Quilon (Kollam) to international trade routes.

• This made Quilon an important trading hub in Kerala during the medieval period. Ibn Battuta, the Moroccan traveler and explorer, mentioned Quilon as one of the key trading centers, emphasizing the strategic and economic importance of the city and the lake.

• Ashtamudi Lake is the second largest estuary ecosystem in Kerala, after the Vembanad Lake.

• Its name, derived from the Malayalam word “Ashtamudi”, meaning “eight braids”, reflects the lake’s octopus-shaped topography, with multiple interconnected branches.

• Ashtamudi boasts a unique wetland ecosystem, supporting rich biodiversity, including numerous species of fish and shellfish.

• The lake is part of Kerala’s backwaters, renowned for its houseboats and resorts that attract thousands of tourists each year. The Kallada River serves as the primary water source for Ashtamudi Lake, contributing to its brackish water ecosystem.

• Ashtamudi Wetland was designated a Ramsar site in 2002, recognising its international importance for wetland conservation and sustainable utilization, particularly for fishing and tourism.

• In 2014, the Clam Governing Council of Ashtamudi became the first Marine Stewardship Council (MSC) certified fishery in India for its sustainable clam fishing practices, a significant achievement for responsible resource management.

• Ashtamudi Lake is home to various mangrove species, including two endangered species, Syzygium travancoricum and Calamus rotang, highlighting its ecological value in preserving rare and vulnerable flora. These species thrive in the marshy regions of the lake, contributing to the unique biodiversity of the wetland.

UPSC Civil Services Examination, Previous Year Questions (PYQs):

Q. With reference to the Indus river system, of the following four rivers, three of them pour into one of them which joins the Indus directly. Among the following, which one is such a river that joins the Indus direct?

a) Chenab

b) Jhelum

c) Ravi

d) Sutlej

Ans: (d).

(The author is a trainer for Civil Services aspirants.)