Chesapeake Bay News

On July 6th, a team of biologists from the Maryland Department of Natural Resources’ (DNR) Monitoring and Non-tidal Assessment Division spotted several suspected zebra mussel adults for the first time in the lower Susquehanna River below the Conowingo Dam.

These recent findings indicate that a population of this non-native, invasive mussel is established in this part of the Susquehanna. The first-ever sightings of zebra mussels in Maryland occurred in the lower Susquehanna River upstream of the Conowingo in November 2008.

“Most of the specimens were the largest I’ve ever seen, ranging up to 38 mm (almost 1-1/2 inches) in shell length, and they were probably three to four years old,” said DNR Biologist Ron Klauda.

Zebra mussels (Dreissena polymorpha) have caused over five billion dollars in damages and economic losses in North America since they were introduced into the Great Lakes during the 1980s. Based on studies conducted in the Hudson River Estuary, New York, the potential impacts of zebra mussels on the freshwater to slightly brackish portions of Maryland’s aquatic ecosystem could be substantial, with effects on all aspects of the food web from plankton to fish by outcompeting native species, filtering all available plankton and rapidly colonizing large areas.

“The good news is that, at least for now, the density of zebra mussels appears to be low,” said DNR Natural Resource Biologist Jay Kilian.

Boaters, anglers and other recreational water users who enjoy the lower Susquehanna River can help stop the spread of harmful zebra mussels to other Maryland waters by taking these simple precautions before launching and before leaving:

(1) Remove all aquatic plants and mud from boats, motors, and trailers, and put the debris in the trash.

(2) Drain river water from boat motors, bilges, live wells, bait buckets and coolers before leaving to prevent aquatic hitchhikers from riding along.

(3) Dispose of unused live bait on shore far from the water body or in the trash.

(4) Rinse boats, motors, trailers, live wells, bait buckets, coolers and scuba gear with high pressure or hot water between trips to different water bodies.

(5) Dry everything at least two days (preferably five days) between outings.

DNR urges boaters to do their part to stop the introduction and spread of zebra mussels and other invasive species in Maryland. Citizens who find what look like zebra mussels should seal them in a zip lock bag, put the bag in the freezer, record where and when they were found and report the find to DNR at 410-260-8615.

For more information about zebra mussels and other invasive species in Maryland, call 1-877-620-8DNR or visit www.dnr.maryland.gov/invasives.

source: DNR press release

The Maryland Department of Natural Resources (DNR) has launched an education and outreach campaign to inform the public about the threats posed by zebra mussels. More than 20 years ago zebra mussels were introduced into the Great Lakes in ship ballast water. Now this non-native, invasive mussel has found its way into Maryland. The mussels were discovered last fall in the Susquehanna River, at and upstream from the Conowingo Dam.

“We want boaters and anglers who use the lower Susquehanna to know that zebra mussels likely now live there,” said Ron Klauda, a biologist with DNR. “We’re again asking everyone to take a few precautionary steps now to hopefully head off the potentially devastating environmental and economic impacts in Maryland that this small, invasive mussel has had in other parts of the country.”

DNR convened a Zebra Mussel Information Exchange in Annapolis in January 2009, where it formed the Mid-Atlantic Zebra Mussel Working Group to continue the discussion on zebra mussel ecology, distribution, monitoring and control technology and to develop a response plan.

The agency recently posted STOP AQUATIC HITCHHIKERS signs at boat ramps and marinas along the Harford and Cecil county sides of the Susquehanna between the Pennsylvania-Maryland border and the river mouth as a part of the response plan.

The large “hot pink” signs ask boaters and anglers to follow these five simple steps before launching and leaving:

(1) REMOVE aquatic plants and mud from your boat, motor and trailer, and put the debris in a trash can (or at least on shore, far from the water).
(2) DRAIN river water from your boat, motor, bilge, bait buckets, live wells and coolers.
(3) DISPOSE of unused live bait on shore far from the water or in a trash can.
(4) RINSE your boat, motor, trailer, live wells, bait buckets, coolers and SCUBA gear with high pressure or hot water.
(5) DRY everything for at least 5 days between outings.

For personal watercraft, impeller areas can harbor zebra mussels and aquatic plants with attached mussels.

When your watercraft is on the trailer, run the engine for 5-10 seconds to blow out excess water and any associated mussels and plants.

Before leaving the area, inspect and REMOVE any zebra mussels, plants, mud, and other debris from the intake, steering nozzle, hull and trailer.

The only place zebra mussels are currently found in Maryland is the lower Susquehanna. Zebra mussels threaten fish and other aquatic life by consuming available food and smothering native mussels. They can ruin boat motors by clogging their cooling systems and jamming steering components. A single female mussel can release up to a million eggs each season, quickly increasing the population. They can encrust walls of intake structures and clog pipes at drinking water facilities and power plants. The U.S. Army Corps of Engineers calculated economic losses related to zebra mussel infestations at more than $5 billion between 1993 and 1999, not including the costs of ecological damages.

“Nobody can say for sure how zebra mussels found their way into the lower Susquehanna, but experiences with them in other parts of the country have taught us they are effective hitchhikers on boats and trailers,” said Klauda. “We also don’t know how long zebra mussels have been there or if they’ll become established and start to reproduce in great numbers this summer. We are concerned that the mussel population in the lower Susquehanna could take off like they did in the Hudson River back in the early to mid-1990s and we could be dealing with billions by the end of 2010.”

In addition to taking preventive measures to stop the spread, DNR is also asking boaters and anglers to be vigilant and contact the agency if they find anything that they suspect to be zebra mussels in the lower Susquehanna or elsewhere in the state. While young mussels are too small to see, newly settled young feel like fine sand paper on boat hulls and other smooth surfaces. Adult mussels are usually about the size of a fingernail and commonly have alternating dark and light stripes. Anyone spotting a suspected zebra mussel should put it into a zip-lock bag, place a paper label inside containing the collection site and date written in pencil, freeze the bag and its contents and report the finding to DNR toll free at 1-877-6208-DNR extension 8615 or 410-260-8615.

For more information on zebra mussels and other invasive species, visit DNR’s website: www.dnr.maryland.gov/invasives.

DNR Calls on Boaters to Help Prevent Spread of Harmful Zebra Mussels

The Maryland Department of Natural Resources recently confirmed the presence of zebra mussels in the lower Susquehanna River. The latest zebra mussels found in Maryland were recovered from a boat docked in Harford County. Biologists are calling for vigilance and assistance from boaters and anglers to prevent spread of harmful zebra mussels.

“Maryland’s freshwater reservoirs have a lot to lose if zebra mussels get in,” said Dr. Ron Klauda, a biologist with the Maryland Department of Natural Resources. “By taking a few simple precautionary steps now, boater and anglers can help prevent the devastating economic impact and ecological havoc caused by this invasive species.”

The zebra mussel, a small freshwater mollusk from the Caspian Sea, has already infested much of the Great Lakes region, causing economic and ecological damage. Free-swimming zebra mussel larvae will stick to any hard surface and begin to grow. As the mussels grow, they physically clog water systems, coat boat bottoms and any structures in water. Zebra mussels have encrusted boats, ruined power plant intakes, and changed the way municipal water systems must operate. Ecologically, zebra mussels are killing native mussels, including endangered species. Their presence been connected with widespread ecological impacts from increasing toxic microorganisms to declining duck populations.

Since inadvertent introduction into the Great Lakes in the mid-1980s, the zebra mussel has spread rapidly into freshwater habitats from Louisiana to New Hampshire. While the species free-swimming larvae move rapidly with natural currents, the main mechanism for its transport up rivers and to inland lakes is hitchhiking with people.

“Recreational boaters can unknowingly carry zebra mussels around in their bilge, minnow buckets or aquatic vegetation on their trailer.” explained Klauda. “In Minnesota and a number of other states, fishermen and boaters have been very effective in halting the spread of this serious pest by a little preventative maintenance. We hope that Maryland boaters will help us by washing down hulls, cleaning bilges, removing aquatic vegetation from props and trailers, and limiting movement from place to place, particularly from the Susquehanna River to other waterbodies.”

Boaters and anglers who use the Susquehanna, the only water body in MD where zebra mussels have been found, should be particularly careful to avoid spreading these invasive species to other state waters.

DNR has teamed up with the Chesapeake Bay Trust to post signs at all Maryland Boat ramps to inform Maryland boaters about the problem and how they can avoid being carriers. For the past few years, owners of recreational craft of trailer-able size received brochures from DNR by mail informing them how to prevent zebra mussels’ spread.

“The rate of spread of this species is nothing short of astounding,” said Klauda. “We’ve been watching for it and trying to prevent its arrival, but here it is. Time will tell if this species will become established in the Susquehanna, but its record elsewhere is pretty grim.”

source: Maryland Department of Natural Resources press release