Last month, the spiny water flea, a tiny shrimp-like organism native to Europe and Asia, was discovered on the “doorstep” of Lake Champlain. Researchers found it in a canal that connects Lake Champlain to the Hudson River, and then a fisherman found it in Lake George, an Adirondack lake located about a half-mile upstream from Lake Champlain.
The findings confirmed everyone’s worst fears: another invasive species made the leap from the Great Lakes and Hudson River watersheds. If it hasn’t already, it won’t be long before it reaches Lake Champlain, which straddles Vermont and New York and is the sixth largest natural lake in the U.S.
The news made me recall the day I stood on the lakeshore with reporters to announce the arrival of zebra mussels in the summer of 1993. I worked as Vermont’s Lake Champlain coordinator in the 1990s, and we had chosen the site where a 13-year-old boy found the first ones while snorkeling near his family’s dock. I felt defeated. It had been five years since they were first discovered in the Great Lakes, and there seemed to be little we could do to keep them out. Once the invasive mollusk becomes established, there’s no way to eradicate it. It was a sad day for the lake.
Fast-forwarding almost 20 years, this most recent news must come as a real blow to those involved with Lake Champlain’s ongoing clean-up and restoration efforts. New York State officials’ announcement about the finding in Lake George on August 1 coincided with the release by the Lake Champlain Basin Program (LCBP) of a four-year status report called State of the Lake 2012. The report identifies the spiny water flea, along with two other species, round goby and Asian clam, as the lake’s most immediate threats, and advises anglers, boaters and other recreational users “to remain diligent in preventing the spread of invasive species.”
The spiny water flea (Bythotrephes longimanus) derives its common name from its thorn-like barbed tail. At less than one-half inch in length, the crustacean earns its bad reputation by feeding on other tiny organisms, including species of Daphnia (other tiny crustaceans) favored by native fish for food. It disrupts the food chain and according to the LCBP website, “can have a dramatic impact on the overall productivity of a fishery.” A recent special issue of the journal Biological Invasions, edited by Norman D. Yan et al., states that spiny water flea “has proven to be a serious threat to pelagic biodiversity in both large and small lakes” in North America.
Riding in Ballast and Bait Buckets
Many of the invasive plants and animals that plague North American waters arrived in the ballast water of ships. The problem is not unique: the same ships fill their holds with water from the Great Lakes and coastal estuaries, such as the Chesapeake Bay, and return to ports in Europe and Asia. Aquatic species invasions aren’t new phenomena. According to researchers William Ryan and Walter Pitman in their book Noah’s Flood, a species of algae first entered the Black Sea as a stowaway in the bilge water of ancient Greek row galleys. Non-native, nuisance aquatic species pose a threat to lakes, seas, and estuaries all over the world. They have made their way inland to places such as Lake Balaton in Hungary, where zebra mussels arrived in the 1930s through the lake’s connection to the Danube River via a constructed canal.
Residents of the Lake Champlain region appreciate the rich history of the area and are well aware of the important role the lake has played in the history of the United States, due in large part to its strategic position between the St. Lawrence and Hudson Rivers. It is for this reason – its connection to major waterways – that the lake is so vulnerable to the introduction of invasive species like the zebra mussel and spiny water flea.
Experts on Lake Champlain figured it was just a matter of time before the spiny water flea would reach the lake after it was discovered in the Hudson River watershed in 2008. What’s amazing to me is that it was held at bay for so long. Unlike the zebra mussel invasion, the spiny water flea, first discovered in the Great Lakes in 1984, took 28 years to reach the Champlain basin. Although nothing can be done to stop this latest species from establishing itself as part of an ecosystem once it has already invaded, the delay offers a glimmer of hope that a quick response could help delay or prevent it from spreading to other nearby lakes.
Finding the spiny water flea in both the canal and Lake George shines light on the main pathways for spreading this and other non-native plants and animals. It seems clear that in addition to passing through the canal, the latest invader hitchhiked a ride on a recreational boat, in a fisherman’s bait bucket or attached to fishing gear.
This latest news has triggered renewed debate about how to prevent other species from invading the lake. “I fear that the spiny water flea is just another one of many invasive species threatening Lake Champlain,” the manager of the LCBP, Bill Howland, told me. “It’s cousin, the fishhook water flea, uses the same mode of travel, so it could well be next.” I share his fear.
The round goby, a small bottom-dwelling fish, is moving east in the Erie Canal and south through the St. Lawrence and Richelieu Rivers. Zebra mussel’s cousin, the quagga mussel, is also making its way east through the Erie Canal. The Asian carp probably isn’t far behind.
The LCBP State of the Lake 2012 report states that “waterways in the regions surrounding the Lake Champlain Basin are home to many invasive species that are not found in Lake Champlain.” A telling figure (see below) on page 28 shows 184 invasive species in the Great Lakes, 122 in the Hudson River, and 87 in the St. Lawrence River – all with waterways connecting to Lake Champlain, which currently has 49 invasive species. “There are some vectors we cannot control,” said Howland, “but I’m worried about the remaining 135 species that potentially could be introduced to Lake Champlain.”
“The spiny water flea is one more lost battle in a long war against invasive species,” said Howland. But ever optimistic, he and his Lake Champlain partners are already laying “battle plans” to prevent future critters from invading the watershed and to slow the spread of ones that are already there. But as Howland is quick to point out, the war analogy ends there. The LCBP has learned from experience to employ a collaborative approach to solving difficult problems such as this. “Our role is to bring the various interests to the table and find solutions,” he reminded me. This is the way it’s done on a lake shared by two states, two countries and hundreds of local jurisdictions.
In addition to the ongoing public education efforts and regulatory programs, one option on the table is creating a physical barrier on the Champlain Canal, one of the main pathways for nuisance species entering the lake. Shortly after zebra mussels arrived in Lake Champlain, researchers conducted a feasibility study for creating an electronic barrier dam in the canal, but the idea never gained much traction because it was not considered cost-effective at the time. A 2005 feasibility study by Lake Champlain Sea Grant concluded that physical or mechanical modification of the canal and/or locks would be “the most effective at stemming the flow of canal-borne invasives.”
In a press release on July 30, the Lake Champlain Basin Program’s Aquatic Invasive Species Rapid Response Task Force called for “immediate action to prevent the spread of spiny water flea into Lake Champlain by slowing the movement of spiny water flea through the canal systems, and development of a long term solution to address the Champlain Canal as a vector for all aquatic invasive species moving in and out of the Lake Champlain Basin.” They also recommended “pursuing a hydrologic barrier on the Champlain Canal that will address the other aquatic invasive species that are threatening to invade Lake Champlain.”
Revisiting the idea of creating a barrier on the canal seems prudent, especially when considering the very real threat that other species pose to the lake. Lake Champlain International (LCI), a nonprofit focused on water quality and fisheries, has already started a petition to disconnect the canal from the lake.
Although this and other issues on Lake Champlain are inherently local in nature, they have global implications. The LCBP partners have become a role model for others tackling similar problems in lake watersheds around the world. The arrival of spiny water flea is a real wake-up call and not-so-gentle reminder of the need to act quickly in order to prevent other species from entering the lake before it’s too late. Like the zebra mussel before, the quagga mussel, round goby and Asian carp will soon be knocking at the door.
Links to more information:
- Global Invasive Species Database
- USDA National Invasive Species Information Center
- ANS Task Force, Stop Aquatic Hitchhikers, Protect Your Waters Campaign
- Spiny Water Flea Fact Sheet and Distribution Map (USGS)
Lisa Borre is an Annapolis-based freelance writer, lake conservationist and sailor. With her husband, she co-founded LakeNet, a world lakes network that was active from 1998 to 2008, and co-authored a cruising guide called The Black Sea based on their sailing voyage around the sea in 2010. Lisa also served as the Vermont Coordinator of the Lake Champlain Basin Program from 1990 to 1997.