Viruses Can Travel the Great Lakes by Ship

By Kevin Bunch, IJC

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Recent studies suggest that viral communities are able to travel far from home by hitching a lift in ballast water aboard ships. Credit: Yiseul Kim

Ships moving within the Great Lakes could be carrying viral passengers inside ballast tanks from one port to another.

These viruses are seemingly entering the Great Lakes from a variety of potential pathways: they may be spread by waterfowl, infected fish migrating from the Atlantic coast, bait transport or aquaculture. They also could be hitchhiking along in ballast water tanks that ships use to maintain balance, according to a 2015 study published in the American Chemical Society journal. What’s more, a followup study published since then suggests some viruses can make it to marine ports around the globe.

State and provincial governments around the Great Lakes have issued an advisory for an invasive virus called viral hemorrhagic septicemia (VHS) in fish in the Great Lakes, first detected in Lake Ontario in 2005. The disease has led to major fish die-offs in all Great Lakes, Lake St. Clair and the St. Lawrence River. Although researchers aren’t sure how VHS entered the Great Lakes, it has proven to be a challenge to fisheries management.

Ballast water is used to fill these ballast tanks when a ship has less cargo to keep a ship stable. As more cargo is loaded onto the ship, ballast water is discharged to balance out the weight. Aquatic and marine life can get sucked up in that ballast water and discharged in completely different parts of the world, which accounts for the bulk of the invasive species in the Great Lakes. Canada and the United States have taken steps to prevent new invasive species from getting a lift from ballast water, by instituting one of the most stringent ballast water management regimes in the world, halting new aquatic invasive species from entering the basin from ballast water since 2006. This largely constitutes exchanging freshwater for seawater.

The 2015 study sampled ballast water from ships in a variety of locations on the lakes, including harbors like Toledo on Lake Erie, Essexville on Lake Huron, Burns Harbor on Lake Superior, and Hamilton on Lake Ontario. The ships were heading to Duluth on Lake Superior, one of the busiest harbors on the Great Lakes, and the ballast water was compared against the waters there as well, according to researcher Dr.  Yiseul Kim, a recent graduate from the Michigan State University Department of Microbiology and Molecular Genetics studying under Dr. Joan Rose (a member of the IJC’s Health Professionals Advisory Board).

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Michigan State University researchers Yiseul Kim and Tiong Gim Aw add water samples from Duluth to plastic containers for study. Credit: Yiseul Kim

The ballast waters contained virus communities, Kim said, corresponding to the harbors from where the ships had picked up their ballast water. By comparing the virus’ genetic sequences against those in a database for Duluth’s harbor, she was able to determine whether they were local to the area or unwanted passengers. These viral communities targeted life in a variety of scientific kingdoms, including algae, plants, invertebrates (like insects), and vertebrates (like fish).  More than half of these sampled viral communities target bacteria, the study said.

“Viruses influence microbial communities because they require a host to replicate,” according to Rose.  “When you consider the ecological, economic and public health problems associated with taking up and discharging ballast water, we’re talking about potentially a large impact if waterborne viruses and diseases are spread over these long distances.”

The study didn’t investigate viruses coming into the Great Lakes from other parts of the world, but Kim said a study she worked on that was published in 2016 looked at virus communities in ballast water traveling around the world to marine ports. She had similar findings in that study, with seemingly nonnative viruses riding along to different parts of the globe. Limiting the spread of these viruses by shipping would require ballast water treatment technology that Kim said is still in the research phase, as well as more information about virus types and their impact. Ballast water treatment systems are going to be required for ships entering the Great Lakes in the coming years, however, as regulations include new discharge limits for microbes for human health concerns.

A virus not native to a particular region does not necessarily mean it’s invasive. An invasive species is a nonnative species that is having a detrimental impact on its new environment and disrupts the ecosystem.

“I found that ballast water contains viruses,” Kim said. “It can potentially bring viruses (to new areas) but to confirm if they are invasive species I need to investigate the impact of the viruses on the new water system.”

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A researcher heads down into the ballast tank of a ship to collect water samples for the study. Credit: Yiseul Kim

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Upcoming Progress Report on Great Lakes Expected to Generate Widespread Interest

By Frank Bevacqua, IJC

The first progress report under the 2012 Great Lakes Water Quality Agreement will cover familiar topics from earlier versions of the Agreement such as nutrients, chemicals and Areas of Concern and also bring an increased focus to newer topics including climate change impacts, groundwater, habitat and invasive species.

The Progress Report of the Parties (PROP) will be released in the near future by the governments of Canada and the United States, the parties that signed the Agreement. It will document actions to restore and protect the Great Lakes as well as work by the two countries to set binational targets and coordinate domestic actions.

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The report is known as the PROP, or Progress Report of the Parties. Credit: Gilly Walker

Excessive nutrients in the water contribute to toxic and nuisance algal blooms, and experts identified the nutrient phosphorus as a major factor. In February 2016, the governments adopted several new targets to reduce phosphorus entering Lake Erie that were largely consistent with 2014 recommendations from the IJC.

These reductions are necessary to minimize oxygen-depleted “dead zones,” maintain algal species consistent with a healthy ecosystem and prevent cyanobacteria levels that threaten human or ecosystem health. The governments are working to develop domestic action plans by 2018 to achieve the reductions.

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Fishing in Lake Erie. Credit: Ohio Sea Grant

Pollution and other human activities can prevent the normal use of Great Lakes waters and result in beneficial use impairments such as restrictions on eating the fish, beach closings and habitat loss. Work to restore beneficial water uses in Great Lakes Areas of Concern (AOCs) has been sufficient to formally remove seven areas from the list of 43 AOCs designated nearly 30 years ago. Efforts are underway to restore water uses in remaining AOCs and the PROP is expected to report on the status of efforts in each of the locations.

Chemicals of mutual concern such as mercury, polychlorinated biphenyls (PCBs) and flame retardants known as PBDEs can damage aquatic ecosystems and threaten human health when people eat contaminated fish. Binational actions to date include designating the first eight chemicals of mutual concern. Strategies to reduce the release of these chemicals will be developed to fulfill Agreement objectives and protect human health and the environment.

The Agreement calls on the two countries to develop lake ecosystem objectives and Lakewide Action and Management Plans (LAMPs) for each of the Great Lakes and their connecting channels. In response to these commitments, a draft Lake Superior LAMP was released in November 2015 and a draft Nearshore Framework was released in May 2016.

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A Lake Superior wetland. Credit: USFWS Midwest

The 2012 Agreement recognizes that groundwater quality can impact the Great Lakes. In May 2016, the governments released a report on Great Lakes groundwater science that examines connections to surface water quality, delivery of contaminants and nutrients, role in aquatic habitats and impacts to groundwater from urban development and climate change.

The PROP is expected to report on actions to address issues such as climate change impacts, habitat conservation and discharges from ships. Both countries have implemented regulations to reduce the risk of introducing aquatic invasive species from discharges of ships’ ballast water, including stringent binational enforcement of ballast water exchange requirements. No new aquatic invasive species from ballast water have been reported in the Great Lakes since 2006.

The IJC wants to hear your views on progress by the governments to fulfill their commitments under the Agreement and whether the PROP is a useful report. There are many opportunities to join the discussion and provide comments during the IJC’s upcoming public engagement period.

Frank Bevacqua is the public information officer at the IJC’s US Section Office in Washington, D.C.