Many people in the scuba world are familiar with invasive species; perhaps the most renown of all is the lionfish. The truth is, there are more harmful invasive species in US waters, some of whom have a catastrophic impact.
But there is hope: In areas where invasive species have moved in, there are programs in place where you can participate in their population control. Let’s take a look at just a few of the most harmful invasive species we deal with here in the US.
Asian Carp
Decrying the Asian carp as an invasive species of US waters presents a bit of a challenge, as there are eight different carp species referred to under the umbrella term “Asian carp” that are invasive to the US. Four of them are establishing themselves with such a vengeance that the fight to diminish, or at least manage, their populations caught the attention of the federal government.
Asian carp pose a threat to both aquatic ecosystems and humans. Their quick reproduction allows their populations to quickly overtake native species, reducing food and habitat. The threat to humans comes in the form of an unexpected blast to the head as this fish leaps from the water, startled by noise created on the surface.
Lionfish
Hailing from the subtropical and tropical waters of the Indo-Pacific, lionfish populations have surged in Atlantic and Caribbean waters, from the northeastern US down through the Bahamas and South America. Although ornate and beautiful to observe, this species reproduces at incredible speeds and adults will eat anything in their path, even fish much larger than themselves!
Local fishermen, divers, and authorities of the regions where lion fish have invaded are becoming desperate, as all measures to control population growth have proven futile. The future of Atlantic and Caribbean reefs under the lionfish invasion remains to be seen.
Zebra Mussels
If you’ve ever been to a wharf, pier, or jetty, chances are pretty good you’ve seen a zebra mussel. These seemingly innocuous bivalves cause much more damage than you might think. Without constant maintenance, rapidly reproducing zebra mussels can jam up propellors and overtake hulls. Their real threat lies in their ability to overtake native species, weakening species biodiversity and therefore ecological health.
European Green Crab
The European green crab seems harmless enough, but its taste for mollusks and other crustaceans has had a dire impact on fisheries of both US coasts. A prolific breeder, the female European green crab lays up to 185,000 eggs over her lifetime, many of which survive to adulthood to complete the cycle. This species is so widespread that it’s on the list of the world’s worst invasive species.
Sea Lamprey
Besides looking like something straight out of your nightmares, sea lampreys pose a great threat to native species of the Great Lakes for their parasitic nature. Those unfortunate to suffer a bite from the sea lamprey are doomed to death by infection or blood loss, as the lamprey’s teeth secrete an anti-coagulant. The Great Lakes’ apex predators, like the lake trout, are taking a substantial hit from this bloodsucker.
Northern Snakehead
The northern snakehead is a very harmful invasive species of US waters, primarily for its ability to adapt to any water temperature and environmental conditions. Its aggressive dominance over a large area and insatiable appetite for native fish populations make it a serious problem. Perhaps most fascinating is the northern snakehead’s ability to survive up to four days out of water on dry land — even longer if burrowed in wet mud. A lack of natural predators just adds to this villain’s superpowers.
