Shrinking mudflat ecosystem of Kerala’s Kadalundi keeps shorebirds away
Ecology and Environment
27th Nov, 2023
The inter-tidal mudflats are one of the richest foraging grounds for migrant shorebirds along India’s west coast, and now, they are in danger of disappearing, because of both natural and anthropogenic factors
- Kadalundi, on the south-west coast, had about 8 hectares of nutrient-rich inter-tidal mudflats in the early 2000s.
- Today, the expanse of mudflats in the estuary of the Kadalundipuzha river has reduced to just about 1 hectare.
- This too is gradually being covered with sand, depriving prey to thousands of shorebirds that migrate from colder climes in winter to Kadalundi village in Kozhikode district.
Mudflats, or otherwise known as tidal flats, are coastal wetlands that form when mud is left behind by tides or rivers. They’re found in sheltered regions such as bayous, lagoons, estuaries, and bays. Mudflats might be seen geologically as exposed layers of bay mud, a result from :
- the deposition of estuarine silts
- marine animal detritus
The majority of the sediment in a mudflat is within the intertidal zone, therefore the flat is submerged and exposed about twice per day.
Need for Mudflats conservation:
- Vanishing of Mudflats: If the mudflats are not protected and restored, Kadalundi will vanish from the global map as a prominent destination of migrant shorebirds in a few years.
- Biodiversity conservation: It is the abundance of prey such as polychaetes and crustaceans in the mudflats that attract a wide variety of migrant shorebirds to Kadalundi from places such as Siberia, Ladakh, Mongolia, and Scotland.
Efforts to conserve mudflats:
- Ecotourism: Efforts are on to popularise ecotourism in the Kadalundi-Vallikunnu Community Reserve (KVCR) by widening the expanse of mangroves.
- Encroaching mangroves: The 154-hectare KVCR had less than 50 hectares of mangroves until a few years ago, but these trees that thrive in salt water have proliferated so fast that they currently occupy more than 60 hectares.
- Decline in prey: The sedimentation of sand on mudflats not only brings down the amount of prey there, but also helps mangroves easily proliferate.
- Invasive Characteristics: The viviparous mangroves of Kadalundi, according to researchers, have been displaying an aggressively invasive behaviour.
- Mangrove vs Mudflat in carbon sequestration: The mangrove lobby has been raising carbon sequestration as the key environmental factor for its promotion. But people often underestimate the significance of soil and mud in carbon sequestration. Soil contains nearly twice the amount of carbon compared to the combination of the atmosphere, vegetation, and animals.
- Wetlands and grasslands: Studies show that wetlands and grasslands have the capacity to sequester more carbon than many types of forests.
Importance of Kadalundi:
- The mangroves of Kadalundi never attract shorebirds coming from colder regions.
- They prefer open mudflats where they are safe from predators.
- When the research was started in 2005, there were large congregations of migrant species such as the lesser sand plover, greater sand plover, common sandpiper, whimbrel, Eurasian curlew, common redshank, common greenshank, Kentish plover, Terek sandpiper, dunlin, and sanderling foraging voraciously during low tide.
- But now the prey depletion, because of sandbanks and mangrove proliferation, is forcing them to stay away from the mudflats.
- Tree plantation: Haphazard tree planting without proper understanding is never advisable.
- Holistic approach: It is crucial to adopt a holistic approach that prioritises the protection of intact ecosystems and focuses on restoring the functionality of degraded ecosystems.