CHILL MAGAZINE

 

Scientists at Cave Hill Campus are currently involved in significant research work and hemispheric cooperation aimed at helping Barbados and the rest of the region cope with the invasion of the Giant African Snail.

 

Dr. Angela Fields, a lecturer in Biology at UWI, Cave Hill, is leading the University’s involvement, which has so far seen graduate and undergraduate students benefit from major opportunities to be part of groundbreaking work. The projects have so far also involved CARICOM, United Nations Food and Agriculture Organisation (FAO), Inter-American Institute for Cooperation in Agriculture (IICA), the United States Department of Agriculture (USDA) and a number of regional governments.

 

Additionally, Fields has already conducted a “gully survey” for local agricultural authorities that looked at, among other things, the prevalence of the pest in gullies in Barbados. Despite all the work of the past seven years, she noted, there were still significant questions to be answered about how the island and region should respond to the introduction and explosion of the populations of Giant African Snails.

 

“I would say that the Giant African Snail right now is established in Barbados,” Fields said. “It is now a part of our landscape, our environment. We have now to talk about control as opposed to eradication, unless something new emerges.

 

We have to look to see how to manage the population of Giant African Snails, and how to do that without hurting other aspects of the environment. We certainly cannot give serious consideration to dumping large volumes of molluscicides (bait) in our gullies, or turning them into finely manicured areas just to get rid of the snails... There is still a lot of research to be done.”

 

Managing the use of bait in gullies and other virgin areas is also of extreme importance, since in addition to killing the invasive variety, it will also kill native snails which play a key role in the local ecosystem in the breakdown of decaying vegetation.

 

“In Barbados I was interested in finding out what was happening, so I involved students in collecting snails and recording data on them, including places of prevalence, the sizes in which eggs were present, and the possible impact of molluscicides on native snails.

 

It appeared to me that in some places I could see the evidence of molluscicide use in terms of the number of dead Giant African Snails. But we also saw our local snails dead, and whereas we saw evidence of recovery among the African snails, we did not see that evidence with the local snails.”

 

Fields’ work with the snail dates back to 2002, when as part of her PhD programme she collected data on land snail fauna in four Caribbean islands, which in part influenced FAO, IICA and USDA to take a closer look at the migration of the snail from the French to the English-speaking Caribbean.

 

“As a result of my surveying for snails generally, I was invited to give a presentation at a workshop in St. Lucia in 2002 on our work, where I met some USDA personnel, and then FAO wanted to lend their assistance to the education of people involved in pest control … and they brought me on as a consultant for their technical assistance programme… I did workshops across the region as well as additional surveys… . The USDA was also interested in what was taking place in the region and that started an informal relationship.”

 

Dr. Fields’ research into the growth of Giant African Snail populations in Barbados, which has also involved significant input by graduate student Anton Norville, has turned up two developments that are now the focus of on-going study that could potentially assist in managing the problem. One is the discovery of a mite that was usually found on native snails being present on the Giant African Snail, while the second is the appearance of a deformed variety of the Giant African Snail.

 

“We are interested in finding out if the mite has anything to do with the deformity, and if the mite has any value as a native biological control agent to help us deal with the snail,” she added.

 

She explained further: “During the time we were collecting snails, we came across some deformed snails but we could not find much on what could have caused the deformity. Anton started work on the distorted snail and that has turned into a major undertaking right now”.

 

In addition to the practical scientific research, Fields revealed she is now representing UWI on a technical working group that forms part of a network of plant health directors set up by the CARICOM Secretariat to help member governments cope with plant pests. This also involves IICA, FAO and USDA and at the first meeting it was determined that the Giant African Snail should be treated as a priority.

 

Another offshoot of all this work is that the region’s capacity to check Giant African Snails for the presence of the nematode that is found in rats and which causes meningitis in humans is also likely to be developed.

 

“We need to know if we have the nematode in the snails here that can cause meningitis,” Fields said. “This also has implications for how we deal with rats because the nematode lives in rats … the Giant African Snail is one of the snails that can house the larvae … . It is important for us to develop the capability to check for this here… . Rats will eat the Giant African Snail, and in some places where the snail has emerged there has also been an increase in the rat population. So if you are interested in cutting down the instances of leptospirosis then you have to look at the snail as well.”

 

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