• The Parrotfish Collective Co-Founder and conservationist Vinod Malwatte on tackling an expanding problem

According to the Environment Foundation (Guarantee) Limited, 27% of birds, 66% of amphibians, 56% of mammals, 49% of freshwater fish, 59% of reptiles, and 44% of flowering plant species are threatened by invasive alien species. Our biodiversity and everything that it brings us – tourism, economic advantages, agriculture, and health – are under threat because of these invasive aliens. The problem is more serious than we realise and eradicating invasive species may be the solution to keeping animals living in their safe zones without venturing into human owned properties. 

Featured on ‘Kaleidoscope’ is conservationist and The Parrotfish Collective Co-Founder Vinod Malwatte, who has just begun yet another project to clear an area demarcated in the Kumana Villu of invasive alien species in a joint collaboration with the Federation of Environmental Organisations (FEO).

Following are excerpts from the interview:

How bad is the invasive species problem in Sri Lanka? 

A: It’s actually much worse than you’d imagine. For example, when we look at our protected areas, a lot of them are overrun with invasive species. In the Udawalawe National Park, about 50% of the Park is overrun by invasive species. We’ve worked in the Lunugamvehera National Park, which is now part of Yala, and about 20% of the grassland was taken over. Also, in Minneriya, one of our premium elephant grazing habitats, about 20% of the grassland there was also taken over by invasive species at the time we had an intervention. We’ve also looked at other parks. We’re working in Wasgamuwa, which has eight main water bodies and a majority of these are covered with invasives – in fact, some were completely covered.

What’s the impact that these invasive species have on the habitat? 

It depends on the different types of species. The more terrestrial species crowd out a lot of the native species that grazers like elephants and deer will eat. They also take over large spots of grassland, not allowing animals to come through and forage. Then, there’s aquatic species like water hyacinths and salvinia, which really clog up canals. We see it in Colombo and we see it across multiple reservoirs in the country. When they clog the water body at the top, these species don’t allow sunlight to penetrate the water. So, there’s an ecosystem that’s devoid of any life at the bottom because the sunlight isn’t doing the job it’s supposed to do. These water bodies are carpeted by these invasives.

Why did you start the clean-up at Kumana Villu? 

We have noticed a reduction in the birds at Kumana over the last few years. Kumana was historically known as an avian paradise. People used to flock there every year during the migratory season to see migratory birds coming in from as far as Russia. After we started looking into it, we realised that a native creeper had taken over some of the trees that the birds were nesting in. That was causing the drop in the bird numbers. We also noticed the proliferation of water hyacinths across the open water, which meant that, again, the ecosystem wasn’t working at its optimal level. Another thing we noticed was that the river mouth had shifted. Because of that, the ecosystem has gone from a brackish water ecosystem, which is a mix of salt and freshwater, into a predominantly freshwater ecosystem. This means that the makeup of the ecosystem has changed as well. 

What we’re trying to do is actually restore Kumana to its past glory, through conservation intervention – to take off some of the creepers, cut them at the base level, let them dry and fall off. After that, we will clear some of the water hyacinths as well. We did a pilot project a while back, earlier this year. The birds have returned to their nest, which is really exciting. We’ve had life returning, so hopefully, the new section that we clear will cause more birds to return. 

There are obviously challenges when you start off initiatives like these. What are they? 

Funding is obviously a big one. Also, trying to mobilise on the ground is not easy work. It’s trial and error, trying to understand the most effective way of clearing these invasive species and then incurring maintenance costs. It’s not a one-time thing, because invasive species come back time and time again. It’s a long-term situation that we’re looking at.  

How are you planning to get funding? 

We’ve applied for grants, which is the more traditional way of doing things, but, we’ve also carried out a couple of crowdfunding campaigns. We have been fortunate in that lots of people donated towards the cause. We are also trying to reach out to corporates. Some have already come on board for certain initiatives, but there is so much work to be done. The more players we can have involved, the better. 

How do these species come into being? 

The methods are different from species to species. For example, the water hyacinth was brought by a then-governor’s wife to Sri Lanka, I think in 1906, as ornamental, because it looked nice. And gorse, which is an invasive species that we see in hawthorn plants, was brought to the Hakgala Botanical Garden. It also travels via air or on animals. So, there’s a lot of them that are of ornamental value. After that, they get into the ecosystem and just start taking over. 

Is it possible to eradicate these in the long term? 

To be honest, I’m not sure if invasive species can be 100% eradicated. They keep coming back, which is why maintenance is super important. Complete eradication is tough from within a landscape, because these are living landscapes. Animals go from one waterhole to another. Birds eat a berry, deposit it somewhere else, and the seed grows in the new area. It is tough work, but what we can do is minimise the spread of it. So, in Minneriya, the work that we’ve been doing for 20% of the grassland has resulted in a reduction to almost 0.01%, through maintenance and careful meticulous work. We’ve really seen a huge reduction, but we’ve been working on that for multiple years, diligently taking those plants out every year. Something we have been really lucky with is getting to work with the local population. It also gives them an alternate source of livelihood. There is also a deeper appreciation for the Park. Sometimes, locals have negative associations with the Park – it’s seen as somewhere that they can’t go. 

The human-elephant conflict also brings negative thoughts. So, it is nice to take them to the Park and give them the chance to reap an economic benefit through projects like this. As a plus, they get to spend time in the Park and there’s an opportunity for education. We’ve started working with neighbourhood children through some of our projects. The gateway to all of this has been invasive species removal projects, which have facilitated community engagement and led to other interesting developments. 

Are there any other particular success stories? 

Minneriya is a huge success story, as is Lunugamwehera. We had about 900 hectares (ha) that we were looking at, and we’ve almost completed about 750 ha of that, with only a little bit more to go. Our Horton Plains project is going pretty well too. The Kumana Villu pilot project has been very successful so far and we’re hoping that we’ll yield some positive results from the second stage of that as well. In Wasgamuwa, we’ve cleared out four of the eight tanks that were carpeted with invasives. Maintenance is still required, but the animals are returning, which is the main thing. The primary focus is creating optimal habitats within national parks. These State designated protected areas which we demarcate on maps are safe zones for animals to dwell in. If we can facilitate those safe zones for them to live in without invasive species to worry about, then we minimise their need to venture into human areas.  

(The writer is the host, director, and co-producer of the weekly digital programme ‘Kaleidoscope with Savithri Rodrigo’ which can be viewed on YouTube, Facebook, Instagram, and LinkedIn. She has over three decades of experience in print, electronic, and social media)