Mosquitos

Nobody really enjoys having those itchy, swollen spots from getting bitten by a mosquito. During the height of summer, almost everyone finds them cursing the fact mosquito exist at least once. Many people may even entertain the idea of getting rid of them so they wouldn't go around biting people. But as any biologist knows, eliminating one species can have a dire ripple effect on the rest of their ecosystem. However, writers for Nature** recently asked scientists how big the ripple effect would be if we were to get rid of mosquitoes from the world.

Like many things, this hypothetical really depends on where you are looking at. The importance of mosquitoes varies from ecosystem to ecosystem, something that is fairly intuitive. One prime example provided in the article is that of the Arctic tundra. In the Arctic, mosquitoes have an annual hatching where there are massive numbers of adults for a short span of time. These mosquito swarms not only act as a food base for many birds and fish, but also they have a direct effect of the paths that caribou take on their migrations, in order to avoid these choking swarms of bloodsuckers. The removal of these mosquitoes may serve to devastate the stability of the Arctic tundra biome.

However, there aren't especially many people for mosquitoes to annoy up in the Arctic tundras, suppose that we eradicated them in a less far-removed location. What would be the consequences of that? Studies showed that many species rely on mosquitoes as a food base. This ranged from spiders, fish, other insects, and many birds that simply had a diet of which mosquitoes are fraction to very specialized predators like the mosquitofish, which (as the name implies) is a predator that predates almost exclusively on mosquitoes. An experiment done with house martins revealed that the birds averaged one more egg per nesting in areas where mosquitoes were present. However, other species such as bats have a very small gut content of mosquitoes and would not be disturbed by their removal. Many ecologists speculated that the mosquitoes were filling an easily replaceable niche that would not be particularly crippling in the larger picture when they were removed. Mosquito larvae also have a notable role in the environments they inhabit. They help decompose decaying organic matter back into nutrients which are released back into the environment. However, they are just one among many species that perform this task, and in most areas don't make up an abundant amount of the biodiversity. It is only in, again, very specific areas and ecosystems that the removal of mosquitoes would be felt with some significant gravity.

This is just the ecological part of the picture. What sort of humanitarian reasons could we have for exterminating a species entirely beyond that they are just plain annoying? Mosquitoes are what is referred to as disease vectors, that is, mosquitoes spread diseases through sucking one organisms blood then depositing in their next meal. This transfer of bodily fluids spreads all sorts of nasty contagions. Mosquitoes spread malaria, which is one of the leading causes in death in many underdeveloped countries. It claims approximately one million a year, and infects 247 million. Other diseases born on the wings of mosquitoes are dengue fever, yellow fever, Japanese encephalitis, Rift Valley fever, Chikungunya virus, and West Nile virus. Exterminating mosquitoes could potentially cripple the virulence of these diseases and save millions of lives each year, not to mention extortionate amounts of money in the department of healthcare and disease prevention. The drawback for this, of course, is having more people alive in a world that is already considered to be over carrying capacity. But it is something of a tough call to make by saying that the issue of overcrowding is worse than the horrific effects that these mosquito-borne diseases have on the world. In that respect, the article concludes with the statement that it is probably our limitations on the ability to exterminate these pesky bugs that stops us from doing so more than the dilemma of whether it will have devastating effects on the world that stops us from getting rid of mosquitoes all together.

LINK: http://www.nature.com/news/2010/100721/full/466432a.html

Posted by Reed Allen (1)