GREAT LAKES

New invader found in Great Lakes

Dan Egan, Milwaukee Journal Sentinel

In 2008, the U.S. government followed Canada's lead and began requiring overseas ships sailing up the St. Lawrence Seaway to flush their ship-steadying ballast tanks with mid-ocean saltwater to prevent new species invasions of the Great Lakes.

Non-native female Thermocyclops crassus , native Mesocyclops edax,  a new invasive species found in the Great Lakes.

The shipping industry has hailed the program as a remarkable success, pointing out that no new invasive species have been discovered in the lakes since that time. That can no longer be said. 

The U.S. Environmental Protection Agency said last week a new species has been discovered in the Great Lakes — the first since 2006 — bringing the tally of non-native organisms in the lakes to at least 186.

Biologists aren't sure what type of effect the new zooplankton, which can be found throughout Europe, Asia and Africa, will have on the lakes. But conservation groups say the find of Thermocyclops crassus in western Lake Erie highlights the need to do more to protect the lakes that have been ravaged by biological invasions launched by overseas ships discharging contaminated ballast water.

Biologists aren't sure how this species colonized in the lakes, but contaminated ballast is a likely possibility. 

The discovery, made by a team of researchers from Cornell University and the EPA, comes at a time when the agency is under court order to require stiffer ballast treatment requirements for ships sailing in the Great Lakes and other U.S. waters in order to meet provisions of the Clean Water Act. 

In 2013, the EPA established a set of discharge standards that will eventually require the shipping industry to phase-in onboard ballast disinfection systems. Conservation groups sued, contending those standards still kept the door open to more invasions. A federal court agreed.

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The EPA is in the process of developing more stringent regulations. The shipping industry, meanwhile, has been pushing for legislation that would take ballast water enforcement out of the hands of the EPA, which could roll back those court-ordered Clean Water Act protections.

This week's news adds urgency to toughening ballast regulations, said Joel Brammeier of the Alliance for the Great Lakes.

“It’s a good reminder of why it’s such a bad idea to carve the shipping industry out of basic clean water protections that all other industries have to comply with,” he said.

The species has been detected at low levels in Vermont's Lake Champlain since 1991, though there is no deep-draft navigation connection between Champlain and the Great Lakes. A single specimen also was pulled from a ballast tank of an overseas ship on the Great Lakes during a 2001 study. 

It is not known if the species arrived prior to the saltwater flushing requirements and had been lurking at numbers too low to be noticed until now, or if it is a recent arrival. If it is a recent arrival, conservationists say it is evidence that existing ballast water regulations aren't adequate.

"This new discovery is serious and troubling and underscores how U.S. waters, communities and businesses remain vulnerable to harmful aquatic invasive species dumped here by foreign ships," the National Wildlife Federation's Marc Smith said. 

Ballast water is believed to be the pathway for some of the lakes' most notorious invaders, including zebra and quagga mussels that fundamentally rewired the way energy flows through the lakes, with devastating consequences for some of the lakes’ most popular fish species.