WASHINGTON – “Attention boaters: Help stop zebra mussels from coming into Maryland.”
State officials are posting that message at every boat ramp in the state to warn boaters that zebra mussels, a harmful invasive species that has caused billions in damages in the Great Lakes region, is now an imminent threat to Maryland.
Environmental officials have had their eyes on the zebra mussels for years, but became alarmed after the shellfish were found recently in remote parts of the Chesapeake Bay watershed in New York, as well as in other areas in Pennsylvania, Virginia and West Virginia.
“We’re desperately trying to keep them out of Maryland,” said Jonathon McKnight, the director of habitat conservation for the state Department of Natural Resources.
“Once they get here it’s very difficult to eradicate them. And once they become established they’re almost impossible to get rid of,” he said.
The state will spend $8,000 to $10,000 this year alerting boaters, in an attempt to prevent an incursion into Maryland. That price tag is nothing compared to what the state could lose, McKnight said: By one estimate, mussels cost businesses and industries in the country as much as $5 billion between 1993 and 1999.
“This (the zebra mussel) is one that everybody should pay attention to because this is going to hit people in their pocketbook,” McKnight said.
The mussels are extremely fertile and can quickly encrust boats, pilings, any hard surface they can find. They often ruin the water-intake systems of power plants and water-treatment facilities when their small shells get sucked in and stuck.
They are extremely durable — zebra mussel larvae can survive even a week out of water — and are ravenous filter feeders. That coupled, with their huge numbers, robs other animals living in and around invaded waters of the nutrients they need to live.
One saving grace for the bay is the fact that the zebra mussel, a native to the Caspian Sea, is mainly a freshwater mollusk. It can survive only in saline concentrations of 10 parts per thousand or less, while bay salinity is generally much higher, McKnight said.
But a big enough portion of the bay — particularly the waters above the Bay Bridge — has salinity low-enough to raise concern, he said. Freshwater is also at high risk this spring, when people from other states might be bringing in boats that are tainted with the mussels or their larvae.
“Our biggest fear is for Deep Creek Lake. We’re really afraid that that could be ground zero for this thing,” McKnight said.
While spots like Garrett County’s Deep Creek do not connect to any known infested waters, it is relatively easy for boaters to transport zebra mussels. Bilge water, vegetation lingering on boats and live bait are all ways that the microscopic, free-swimming larvae can move from place to place. Even scuba divers with water leftover in their suits and goggles can spread the species, McKnight said.
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