The Damaging of Veli-Akkulam Lake

A study, which was revealed by the academics from University of Kerala at ECSA 60 conference in Hangzhou, suggests that Veli-Akkulam Lake has deteriorated ecologically. The non-native species introduced in Lake Tahoe during the last 30 years have changed its biological status (trophic cascade; nutrient pathways) and unbalanced the trophic loop.

INTRODUCTION Veli-Akkulam Lake Ecosystem and Invasive Species

Historical Background:

• C.M. Aravindan had initiated the study of ecology of Veli-Akkulam in the 1990s itself.
• The lake contained a lot of native fishes like prawns, cichlids, barbs and catfish.
• Studies in the last few years have reported a significant decrease in Hoho.

Species Decline :

• Prawns: The abundance of prawns in the study area (0.110 tonnes/sq km) decreased from 57.60 to 0.
• The density of invasive cichlids: 41.6 to 0.350 tonnes per square kilometre native cichlid popn 

Rise of Invasive Species:

• In the 2000s, invasive species replaced many of these native species.
• Key invasive species include Nile Tilapia and Mozambique Tilapia.
• Other species of non-native fish include Amazon African catfish and Amazon sailfin catfish.

Invasion Meltdown:

• This is a case of what is known as an "invasion meltdown" — the combined impacts of many different invasive species turning up in one spot.

Impact on Locals:

• In the 1990s more than 100 local fishers depended on earning an income from fishing in this lake.
• There are now fewer than 20 left due to the crash of native fish populations.