Invasive Species Threat to Aquatic Biodiversity in Kerala

Recent studies have highlighted a significant threat to the aquatic biodiversity of Kerala, posed by an invasive species known as the North African Catfish.

This particular species was introduced globally during the 1980s for aquaculture purposes. Its unique ability to survive in oxygen-depleted and shallow muddy waters gives it a competitive edge over other fish species.

North African catfish

Defining Invasive Species

An invasive species is one that was previously absent from a specific ecosystem and has been introduced into that ecosystem from an external source, often through human intervention. Invasive species typically possess certain traits that are absent in the local fauna or flora, which allows them to outcompete native species.

Notable Instances of Invasive Species in India

Water Hyacinth covering a large portion of a waterbody

1. Degradation of Chilka Lake primarily due to siltation and the blocking of the seawater inlet channel led to the proliferation of invasive freshwater species, causing a decrease in fish productivity and a significant loss in biodiversity.
2. Invasive growth of the grass Paspalum distichum has altered the ecological character of vast areas of the Keoladeo National Park, making it less suitable for certain waterbird species, including the Siberian Crane.
3. The water hyacinth, an introduced species, is now invasive in the Kanjli Wetlands. It is periodically removed using mechanical means.
4. Invasive weeds are a significant concern at the Ropar wetlands, and management plans are currently under development.

Existing Solutions

1. A Draft National Wetland Strategy has been developed with a primary focus on controlling invasive species. Several initiatives have also been undertaken under the Convention of BioDiversiy to limit the proliferation of invasive species in wetlands and other aquatic bodies.
2. Management Action Plans (MAP) have been formulated for 30 out of 66 identified wetlands for conservation and sustainable use. These MAPs focus on biodiversity conservation and restoration of ecosystem processes and functions, including the control of alien invasive species.
3. The risk of invasive pest species entering India through imported plants or planting material is addressed under The Plant Quarantine (Regulation of Import into India) Order, 2003, under the ICAR. However, the risk analysis for invasiveness of a plant species per se is not covered under this order.
4. The Ministry of Environment and Forests issues approval along with quarantine certificates for the export of wild animals and articles under the Wildlife (Protection) Act 1972.
5. The Destructive Insects and Pests Act 1914 aims to prevent introductions into India, and the transport from one province to another, of any fungus or other pest which is, or may be destructive to crops.

Additional Measures

At present, there is no exclusive legislation or policy in India to deal with invasive alien species. Therefore, robust measures need to be implemented to address this issue. Possible actions include:

• Strengthening domestic quarantine measures to prevent the spread of invasive species to neighbouring areas.
• Developing a national database on invasive alien species reported in India.
• Creating an effective early warning and awareness system in response to new sightings of invasive alien species.
• Prioritizing funding for basic research on managing invasive species.