India needs to protect its wetland flora

Wetlands in India are facing an ecological imbalance. Uncontrolled siltation; discharge of waste water and industrial effluents; denudation of aquatic vegetation; aquaculture; construction of dykes, dams and seawalls; discharge of pesticides, herbicides, etc; and filling for solid waste disposal — these are some of the major threats to wetlands.

Wetlands are a distinct ecosystem flooded by water. Its aquatic vegetation makes it different from other aquatic bodies.

Aquatic system flora helps maintain ecological balance by interacting with their environment in numerous ways, and therefore, their management is crucial. So far, only 68 wetlands are protected in India. Thousands of other wetlands that are biologically and economically Olympian have no legal status.

Flora vegetation

Aquatic (fresh-water) vegetation — which grows around streams, rivers, lakes, etc — has more ecological significance than sea-water vegetation. The former maintains water quality by filtering out nutrients and sediments.

They also play a role in the food web. Seeds or tubers found in fresh-water ecosystem are consumed by waterfowl species. Many plants enter the food chain as detritus, which are small plant particles formed after decomposition of plants and are subsequently consumed by invertebrates. 

Fresh-water vegetation, thereby, serves as a breeding ground for aquatic and terrestrial fauna. It provides nesting areas to migratory birds. They help prevent erosion and stabilise soil.

Wetlands flora can broadly be classified into submerged water plants, floating water plants, emergent water plants and riparian water plants.

Submerged water plants are 100 per cent under water, and provide food source for native fauna and habitat for invertebrates. They also possess filtration capabilities.

Floating water plants are found in slow-moving water and have small roots. They are a source of food for avian species. Emergent water plants grow above water with their roots submerged in marsh localities. Surrounding trees and shrubs found along the edges of wetlands or other water bodies are called riparian water plants.

The marine ecosystem comprises deltas, coral reefs, mangrove forest, lagoons, sea grass beds, etc. Seaweeds and seagrass are the major plants found in sea-water.

While seaweeds are primitive, marine non-flowering plants (algae) without roots, stem and leaves, seagrass are flowering plants that grow in shallow coastal waters and estuaries.

Urchins and fishes feed on seaweed, which also provide shelter to fishes, invertebrates and mammals. Large seaweeds can form dense underwater forests, called ‘Kelp forests’ and act as underwater nurseries for marine animals such as snails and sea urchins.

Seagrass, on the other hand, require sunlight for photosynthesis. Less than 60 species globally, they help maintain water clarity by trapping fine sediments and particles with their leaves and help prevent soil erosion. They provide habitat for many fishes and invertebrates. Seagrass and other organisms that grow on them are a food source for many marine animals.

Mangroves, which are part of marine ecosystem, serve as breeding, feeding and hiding place for fishes, crabs, oysters, prawns, etc. Apart from protecting the coastline from erosion, they control floods also. Halophytes act as salt extractors and reduce soil salinity.

The road ahead

To maintain ecological equilibrium, it is crucial to maintain wetlands. The problem, however, is that India’s wetlands have not been delineated properly so far.

The Ministry of Environment, Forests and Climate Change, is primarily responsible for the management of wetlands. Effective coordination between the different ministries such as energy, industry, fisheries, revenue, agriculture, transport and water resources is essential for protecting these ecosystems.

Only the wetlands that come under the Protected Area Network have management plans. Their active monitoring over a period of time is essential. Comprehensive inventory of all wetlands involving the flora, fauna and biodiversity, along with direct and indirect values, should be prepared. There is no special legislation to protect these ecosystems.

 An environmental impact assessment plan needs to be highlighting threats to these ecosystems and formulating corrective measures. As wetlands are common property with multi-purpose utility, their protection and management need to be a common responsibility.

An appropriate forum to resolve exisiting issues needs to be set up. All relevant ministries need to allocate sufficient funds for conserving these ecosystems. Awareness among the general public, educational and corporate institutions must be encouraged to achieve sustainable success in protection of these wetlands.

Microwave remote sensing tools play an important role in applications relating to wetland monitoring and vegetation assessment. Microwave sensors are highly sensitive to moisture content and textural properties of vegetative cover. They can be used to discriminate between grasses, aquatic vegetation, forest and crop cover.

Encroachments can be identified. Unmanned Aerial Vehicle (UAV) technology can be tried for monitoring wetlands. Remote sensing data in combination with GIS methods are effective tools that have been used to delineate the open water habitat with aquatic vegetation in Keoladeo Ghana National Park in Bharatpur.

It is high time that earnest efforts are taken on scientific basis for better management of flora of wetlands.