In a blog on the Stormwater magazine site a couple of years ago, I mentioned a battle taking place in the Great Lakes; invasive lampreys destroy about 100 million pounds of fish each year, and the Great Lakes Fishery Commission has been spending $20 million a year to try to control them. Researchers had begun using synthesized pheromones to attract the lampreys to specific areas and poisoning them.
Lampreys are just one of the non-native species—albeit one of the more destructive ones—to affect the Great Lakes; others include the Asian carp and the zebra mussel. But other places in the world also suffer from invasive species, and they have different ways of dealing with them. Sometimes, they eat them.
In Berlin, the local waterways have become overrun with North American crawfish. Officials’ best guess is that aquarium owners released the freshwater invaders. The crawfish are now thriving in the wild, taking over habitat from local shellfish and other animals. Even worse, many of them carry a fungus that we in North America consider fairly harmless, but which is killing the more susceptible European species of crawfish.
Under Germany’s poaching laws, it has until now been illegal to catch the North American crawfish, but that just changed. The city has awarded a single fishing license to a family-owned company, allowing it—encouraging it—to catch as many of the crawfish as it can by the end of the year. Hoping to maximize profits, the company’s 64-year-old owner is trying to convince local restaurants to purchase his catch and add Cajun dishes like gumbo and étouffée to their menus.
The city’s goal is to eliminate the North American crawfish within a few months. There’s a danger, I suppose, that if the new menu items become popular enough, restaurant owners might try to import more of them.
I haven’t been able to find much information on how the lamprey experiment is going; presumably, research is still underway. But as we’ve discussed in Erosion Control, the fight against invasive plants and animals has had a mixed history of success.