If you had to guess, what would you say is the greatest threat to the economy of Hawaii? Go ahead, take a moment. Labor rates? Nope. Expensive petroleum imports? Try again. Or not, I don’t want you all to get bored and leave! You may be surprised to learn that, according to Gov. Neil Abercrombie, “invasive species are the single greatest threat to Hawaii’s economy and the state’s cultural resources, affecting agriculture, health and our island lifestyle.”
The National Invasive Species Council defines exotic organisms as: “an alien (or non-native) species whose introduction does, or is likely to cause economic or environmental harm or harm to human health.” For those unfamiliar with the issues surrounding invasive species, or more simply, “invasives”, you may wonder, what harm could come from bringing some fish to the US from Asia to control populations of algae, weeds and snails in aquaculture ponds? While that may sound innocuous, some of these fish escaped, and established breeding populations in the Mississippi in the mid 1970’s. Of course, I’m writing about Asian carp, which are considered a noxious invasive species, and responsible for serious aquatic ecosystem disruption. These carp have pushed inexorably northward over the past couple of decades, displacing native species as they go. If the carp were to reach the Great Lakes, it would likely prove devastating to the $7 billion dollar fishing industry there. This is not to mention the serious injuries that boaters have sustained as a result of silver carp. These fish have a habit of leaping up to 10 feet out of the water when startled by passing boats; this presents a real threat as they can grow to weigh over 100 pounds.
Or consider the case of brown tree snakes on Guam. This invasive species is responsible for nine of the 12 species of native forest birds that have been drive extinct on the island. Economically speaking, several million dollars worth of damage occurs annually as a result of these snakes damaging electrical equipment, while they cause, on average, one power outage every three days. It is estimated that if brown tree snakes were to stow away on a boat or plane and colonize Hawaii, the economic damage “would range from $593 million to $2.14 billion annually.” The snake infestation on Guam is so bad that officials have resorted to dropping dead mice laced with snake poison from helicopters.
One of the reasons that invasive species are so successful, and also why they can be so hard to dislodge once a population has been established, is that they tend not to have any natural predators in their new surroundings. Enter the top predator: humans.
While I’m not suggesting we hunt any additional species into extinction, we could use our status at the pinnacle of the food chain to reduce or eliminate invasives from areas where they are causing ecological and economic harm. This strategy for combating invasives has already proven successful in at least one case. Residents in Wisconsin have trapped and eaten enough of the invasive Rusty Crayfish in Sparkling Lake that over several years, the population of this environmentally destructive critter has dropped to 1% of its peak. Lionfish can reduce the population of native Caribbean reef fish by 95%. In response locals have developed incredibly tasty means of dealing with this swimming environmental calamity.
I believe it is time that we humans reassert our position as the dominant predator, and use that position to eat our way through the population of harmful invasive species, and achieve greater ecological and economic health for all.