New study finds significant ecological degradation in the Veli-Akkulam lake

Study reveals ecological degradation in Veli-Akkulam lake due to bioinvasion, invasive species, impacting native species and local livelihoods.

A new study has revealed significant ecological degradation in the Veli-Akkulam lake, primarily driven by bioinvasion.

The study led by researchers of the University of Kerala and presented at the International Conference on Coastal Resilience (ECSA 60) in Hangzhou, China, highlighted dramatic shifts in the lake’s trophic status and food web over the past three decades.

The research, which employed the Ecopath Model to assess ecological efficiency and food web structure, revealed a decline in the Veli-Akkulam lake’s indigenous aquatic species and an increase in invasive species.

C.M. Aravindan of the University of Kerala first mapped the ecosystem in the 1990s, revealing a rich presence of native species such as prawns, indigenous cichlids, barbs, and catfishes.

However, the current study reveals a stark decline in the biomass of these species. For instance, the biomass of prawns dropped from 57.60 tonnes per sq km to a mere 0.110 t/sq. km, while indigenous cichlids have diminished from 41.6 tonnes per sq km to 0.350 tonnes. The study was carried out by A. Biju Kumar, S.R. Regi, and Smrithy Raj of the Department of Aquatic Biology and Fisheries, University of Kerala, and G.B. Sreekanth of

ICAR-Central Coastal Agricultural Research Institute, Goa. The research was supported by the University of Kerala and the Ecomarine Project of the European Union.

It found that by the 2000s, the native species were replaced by the exotic and invasive Mozambique tilapia (Oreochromis mossambicus), which has now been overtaken by the Nile tilapia (Oreochromis niloticus). Further complicating the ecosystem are other invasive species like the Amazon African catfish (Clarias gariepinus) and Amazon sailfin catfish (Pterygoplichthys pardalis).