Stowaways
On a small island in the middle of the ocean, there is little we can do to say “no” to visitors; wanted or unwanted, somehow, someone or something is going to give them a warm welcome. Sometimes, they stay for a short while and leave, like most responsible visitors on vacation. But others for some reason choose to stay just because they found it easy and readily available to survive in. Living spaces that can accommodate their needs, an abundance of their favorite foods, a fairly untouched market with no competitors, it is the perfect place to start a new life. Now, to draw the line between humans and nonhuman organisms, there must be a definition as to what part of the island community they are visiting. But fortunately, instead of delving into the politics of immigration, this narrative will delve into some subjects of introduced and invasive species.
As I have stated above, introduced species following that analogy as “permanent visitors” find their way into the island ecosystem, brought onto the island by various means. Fortunately, not all introduced species share the same habits as invasive pests. Some species, like the catfish on the Talofofo River, saw an open niche and took it, sticking to it and not encroaching onto other species as far as we can tell. The classic, local examples would be the brown tree snake and the coconut rhinoceros beetle serve as the unfortunate models of a takeover of an ecosystem. They have been the basis of many of the ecological problems on Guam. The introduction of the brown tree snake saw the expiration of many of the local bird species, threatening numerous other avian and nonavian species as well. When the coconut rhinoceros beetle was discovered on Guam, a certain species of coconut palm was already being threatened. These examples of aggressive behaviors disturbing ecological equilibrium from these species give conservationists and biologists a further problem, would complete extermination of these invasive pests disturb the ecosystems further, or would we see change for the better.
It would not be as simple as hunt-to-kill expeditions for these pests, they are small, nocturnal, and definitely quite difficult to find and catch. Instead, conservation scientists and biologists devoted to this field should consider every aspect of the pests’ biology and find some loophole, some “Achilles heel”, that they can use to remove them from affecting Guam’s habitats. For example, acetaminophen has an adverse effect on brown tree snake biology, effectively killing them in the process of digesting anything with the drug. By inhibiting a large food source for the pests and interfering with the biology and behaviors of the pests, scientists can hope to see their populations decline.
In order to test for the effectiveness of the eradication techniques, scientists would have to survey the different species affected by the controls. Would they see more avian species immediately due to the effects of eradicating the snakes? Would the coconut trees affected by the beetle see an immediate recovery? The recovery signs will not be that obvious; if anything they would be more subtle like a countable decline in the population of the pests. Biologists in the field would need to survey areas of high pest activity to count live specimen, and possibly dispatch them immediately to prevent more destruction. When we see the birds come back, then we will know that the snakes have gone. When the coconut trees show no signs of damage, then we will know that the beetles have left. In the long run, this is what the island community would like to see.
BI100L-02 | R. Kim
November 26, 2017
Comments
Post a Comment