We are quite familiar with invasive species on land: plants like milfoil and lupines, for example, take over fields and ponds and cause changes that lead to the extinction of local species. However, since the 1980s, it has also been recognized that there are numerous aquatic species transmitted far from their original homes via ships’ ballast waters.
Among the most problematic of these is the Chinese mitten crab. It is officially listed as one of the world’s 100 worst invasive species because during its migrations, it damages riverbanks by causing erosion, contributes to temporary local extinction of native invertebrates, and damages or destroys fishing and aquaculture gear.
A recent study conducted by Plymouth University of England focused on invasive species in the northeastern and southwestern Atlantic—a common trade route—and found that there are 44 unique invasive species in the northeastern Atlantic—near England and Wales—and 15 in the southwest, near Brazil, which is not as well studied.
This research comes in time to put extra emphasis on the importance of signing the IMO Ballast Water Convention, a United Nations initiative to prevent further spread of invasive species. The regulations will go into effect in September of 2017, but have only been signed by enough countries to cover 53 percent of the world’s shipping. The United Kingdom, for example, still hasn’t signed on.
But it’s in the nation’s interest to do so, because these regulations can literally save lives.
“An estimated 10,000 marine species are transported around the world in ballast water every day,” writes study co-author Prof. Jason Hall-Spencer. “This sometimes causes outbreaks of diseases such as cholera, in which thousands of people die, and commonly introduces toxic algae which can cause massive kills of aquatic life.”
Unfortunately, since aquatic invasive species aren’t as visible as land-based ones, many people are unaware that such problems even exist. The research being done at the University of Plymouth, however, can help promote knowledge about the problem and help find ways to undo the damage done and prevent more damage in the future.