There’s more going on in Vegas than just the gambling. Mosquitoes carrying the deadly West Nile virus have been discovered, with six cases of the virus reported in Clark County already this year.
Each year, for the last three years, Clark County has seen the West Nile virus kill someone; but, the number of cases overall has declined from 11 in 2011 to eight in 2012. The reason for the decline may have something to do with a cheaper, more environmentally friendly way to attack the problem. When it comes to West Nile virus, the water reclamation district and the county public works department could say there is something fishy happening in Vegas.
Gambusia affinis, a small, unassuming freshwater fish, has a big appetite, especially for mosquitoes. Commonly called mosquitofish, one tiny fish can consume over 100 mosquito larvae each day. The fish live two to three years, giving birth to three or four broods per year. The fry or baby fish are born alive (not from eggs) and unless they have plenty of vegetation to hide in can be eaten by larger fish. They prefer sunlit ponds and lakes and dislike shaded areas which make them suitable to the Nevada climate.
The flood channels and washes on the outskirts of Las Vegas are proving to be the most beneficial way to spread the fish population, which swim downstream to reach as many bodies of water where the mosquitoes breed as possible. By dumping a large amount of the fish at once, it helps provide the widest coverage. But, there’s promise in even depositing small amounts of fish, which means this fishy phenomenon can prevent many cases of West Nile virus from happening all over Vegas.
Shallow, stagnant pools are where the fish do their best, according to Christopher Bramley, vector control supervisor for the Clark County Department of Public Works. He recently deposited 300 mosquitofish into small pools of water on the Desert Rose Golf Course. Mostly the fish are placed on county properties, which allow the Department of Public Works to “recycle” the fish by catching them downstream and putting them back in the district’s system again upstream.
The Water Reclamation District began using the fish by first catching them in minnow traps in the water overflow basins at their plants. Now, to save time, they breed their own mosquitofish at the wastewater treatment plant. The fish are bred in barrels in a space once used as a water quality lab. Currently, they have four barrels of fish.
The future plans for these tiny, mosquito-eating machines, is to one day be able to suspend the chemical and bacterial treatments the county now uses to control the mosquito population. The Water Reclamation District says it would be able to lower costs to around $4,000 per year, if it only used the mosquitofish and stopped the other forms of treatment for which they now pay approximately $30,000 per year.
Is there something fishy going in in Vegas to prevent the Wet Nile Virus? There sure is and as Virginia Figuero-Mayer, a member of the Desert Rose Golf Course security staff says, “The mosquitoes here are really, really bad. I hope those little fish will help.” She mentioned she was having some trouble with raccoons, but there’s not a fish for that problem, yet.
By: Lisa Nance