‘Short term relief with a long term problem’- Ecologist bemoans increased invasive species in Dominica since Hurricane Maria

Invasive species which have the potential to completely wipe out some of Dominica’s endemic wildlife continue to be a threat to the island, as officials are reporting a 50 percent increase in non-native land animals since the passage of Hurricane Maria in 2017.

Without deliberate and swift action to curtail their populations, there could be consequences for the environment, tourism industry, economy and the overall health of Dominica’s population. That is according to Jeanelle Brisbane, a Conservation Ecologist and Founder of Wild Dominique – a non-profit conservation organization, and Environmental Education Coordinator at the Forestry, Wildlife and Parks Division.

She revealed that since the 1500s and up until Hurricane Maria, Dominica had about 10 invasive land animals, but that figure has gone up by 50 percent since the major hurricane.

In an interview with Dominica News Online (DNO), Brisbane said that two of the invasive species which have caused concern over the last three years are the Cuban tree frog – an extensive breeder which came in through the Portsmouth Port, and the stripped-tail iguana – a larger and more aggressive reptile than Dominica’s native iguana.

The Cuban tree frog affects humans through toxic mucus in its skin and is a cannibal which consumes any animal that fits inside its mouth. Dominica’s endemic snakes, frogs, and lizards are among a long list of animals falling prey to the invasive species. It will even eat its own kind, Brisbane warned, adding that all 60 endemic beetles in Dominica can also be consumed by the invasive species. One female can lay up to 3000 eggs per year, she noted.

Since its first sighting at the Portsmouth Port in July 2018, the Cuban tree frog has bred in the thousands. A year after the species was introduced to the island, Wild Dominique, through a donor-sponsored program, was able to hire individuals to try to control and monitor the frogs, Brisbane said.

In October 2019,l a second population of the species was discovered at the Cabrits Resort & Spa Kempinski Dominica in Portsmouth, Brisbane stated. The Wild Dominique’s team was then split to facilitate both the port and hotel locations. This, she said, posed a challenge, as it left inadequate manpower to effectively deal with the frogs on each site.

“We had a confirmed population at the Kempinski Resort. The frogs were brought in with their landscaping plants and with that, actually, additional invasive species were brought in. We have a new species of geckos in Dominica…” she said.

Brisbane continued, “We had done an assessment. At the time, I wasn’t employed by Forestry, but I was assisting their team… We gave them (the resort) a list of recommendations with all the background information on the invasive species we had confirmed on their property at the time, and a list of recommendations as to how to deal with it.”

DNO’s efforts to obtain comments from the hotel have been futile thus far.

At present, the Wild Dominique team captures over 1000 Cuban tree frogs per week from missions which usually have a span of three hours for five nights a week in the north. However, lack of manpower is still a prevailing concern. These efforts have cost way over $200,000 and Brisbane fears that Dominica could lose ground in the fight against the species if more support is not received. The frogs are now being spotted in various other communities on the island.

Noting that most of Dominica’s new invasive species were inadvertently imported with relief supplies following Hurricane Maria, Brisbane underscored the importance of biosecurity and the need for it to be a major consideration during disaster planning to prevent such occurrences in the future.

“All the relief we got was short term relief with a long term problem because the Cuban tree frog – we’re just controlling it – it’s not even eradicated. Just to control it has cost us over $200,000 in one year…It’s breeding in the thousands [and] we’re the only organization tackling this issue right now.  There’s not enough man power… It’s going to take other key players to come in and to be able to do something about it,” she said.

Another invasive frog – the Venezuelan snouted tree frog – also reached Dominican shores after Hurricane Maria. It was sighted in Stowe, Grand Bay and its population has been successfully controlled, according to forestry division officials.

Meanwhile, the stripped-tail iguana (iguana iguana) has been spotted in areas such as Fond Cole, Canefield and surrounding communities. These reptiles compete with the native iguanas for food and shelter. Brisbane fears that extinction is possible since these invasive iguanas have already killed off the native species in other Caribbean countries. Dominica’s native iguanas were found in islands from Anguilla down to Martinique but at present, Dominica is the last country with a “healthy population” of the species, Brisbane revealed.

The conservation ecologist stated that the “very aggressive” foreign iguanas which are “not afraid of people at all,” have already been hybridizing with the natives and creating new interbreeds which look and act like the invasive species.

“The babies are no longer ours and that’s where the issue lies,” she said, noting that natives lay on average 26 eggs while the stripped-tail iguana will produce 71.  “One was found with as many as 105 eggs,” she informed.

Despite the uneven reproductive odds against the native iguana, Brisbane was optimistic as she reported a visible reduction in the population of the stripped-tail iguanas due to Wild Dominique’s efforts thus far. She is adamant that for native species to be preserved, invasive populations must be restricted and where possible, eradicated.

“We’re finding less and less iguanas but that doesn’t mean that we should stop, she said, warning that letting their guard down would just allow the population to grow.

Apart from animals, Dominica has also been home to other invasive species in the past including the chytrid fungus, which caused the devastation of Dominica’s native mountain chicken population in 2002 and the black sigatoka fungus which has affected bananas and plantains. Various vines which now invade local forests and the mimosa plants which “are taking over Macoucherie right now” are also invasive species, Brisbane pointed out.

“That’s why prevention is always better than cure. It doesn’t only apply to diseases. It applies to everything in conservation. It’s a lot less expensive to just prevent invasive species from coming to the island because once they’re here [then] its long term management and even if they’re gone we still have to hire people to survey for a few years until we can actually say it’s no longer here,” the environmental education coordinator said.

“So a lot of time and effort has to go into these things. It’s definitely worth it because that’s what makes Dominica so unique and so special – our nature and what I am telling people is that if we allow all these invasive to take over the island we’re essentially becoming basic and nobody wants to be basic,” she lamented.

Brisbane emphasized the importance of preserving Dominica’s biodiversity and identity as the “Nature Isle” as it is commonly referred to because of its pristine and unique flora and fauna.  She believes that if native species are wiped out, the tourism industry stands to suffer as Dominica could lose its ability to attract visitors if it can no longer boast of unique features.

“Tourists who come from Florida or wherever else – the same animals would be in their back yard. Florida is the hub of all invasive species. What they’re seeing in their backyard, they will come to Dominica and see that same thing,” she pointed out. “That’s not going to attract people here. We attract people here with our unique features and our unique plants… and wildlife. And if we don’t protect those things then we don’t deserve to be the nature island anymore. It’s our product.”

Furthermore, Brisbane said that there are also implications for the environment.

“It’s not just our [tourism] product. Our native iguanas actually help to grow trees faster. So after a major hurricane, [like] Hurricane Maria, we didn’t go in and plant all those millions of trees that are all about now. I mean, yes, we have a reforestation program but the birds and the iguanas and the likes are doing most of the work for us,” she said, adding that if the iguanas would go extinct, some of Dominica’s birds would in turn go extinct.

“What would be the ripple effects if another hurricane hits?” she asked.

“How is the island going to bounce back? Our forests affect our water; it affects our air, our soil. So it’s very important to maintain the biodiversity that we have for our health, for our livelihood,” she stated adding, “A lot of people think that we’re protecting these animals just because, but it goes beyond that. It’s for our health too. It’s for your children’s health. Some of these things (plants and animals) are the reason why we have clean water, clean air and fertile soil and you have to be thankful for that. In saying that, we [should] act like the nature isle and give back to nature and help maintain nature so we can continue to see the benefits that we get from all natural resources.”

One of the sponsors of the invasive species work undertaken by Wild Dominique is the GEF Small Grants Program.