Read on here: http://www.grandforksherald.com/news/re ... s-10-yearsNo new confirmed aquatic invasive species in Great Lakes for 10 years
The first saltwater ship of the 2016 season is expected to enter the Twin Ports within the next week or two, likely to pick up some grain.
But it’s what that oceangoing freighter won’t be dropping off that has spurred excitement among scientists and regulators.
After a decades-long stream of foreign invaders that hitchhiked across the oceans in the ballast of salties, the Great Lakes haven’t seen a confirmed new aquatic invasive species since 2006. That’s either a string of good luck or some evidence that a U.S. Coast Guard-enforced program requiring ships to flush their ballast at sea is working.
“It’s really remarkable considering what had been happening,” said Doug Jensen, aquatic invasive species expert for Minnesota Sea Grant in Duluth. “I don’t think it’s luck. There are a lot of (scientists for multiple agencies) out looking, especially in the Duluth-Superior harbor, that I’m pretty confident that if something new was established here, they would have found it.”
It’s a startling reversal of fortune for the Great Lakes, which saw 185 foreign species invade over the last century. Since the St. Lawrence Seaway opened in 1959, allowing unfettered access to the Great Lakes by oceangoing ships, more than half of the new species are believed to have arrived in ships’ ballasts.
Those species have cost hundreds of millions of dollars in expenses, especially zebra mussels, and caused untold damage to ecosystems, including extinctions of native species and altering natural food chains. Ruffe from Europe have been the most numerous fish caught in test nets in the Duluth-Superior harbor for nearly three decades. In Lake Michigan, quagga mussels and spiny water fleas are shocking the food chain, causing a crash in small baitfish like alewives that are the primary food source for salmon and trout.
With the rise of global trading and travel, it's opened up a pathway for invasives to spread around the world. The Great Lakes here in the US have been hit very hard by this; it's really a sad sight to see.
It's great to hear though that we've been able to pinpoint where some of these aquatic invasives are coming from, and that having ships flush their ballast is probably working! It also looks like more measures are in the works to help further clear ballast tanks of foreign organisms. It may take some time, but at least these talks are being had.