Invasive mussels: Stowaways on transported boats

Date:  June 25, 2015

Source:  EAWAG: Swiss Federal Institute of Aquatic Science and Technology

Summary: When recreational boats are transported overland, they are often accompanied by zebra mussels, attached to the hull. This alien species, which first appeared in Switzerland in 1960, can thus invade other natural waters. A new study which identified the main transport routes recommends various preventive measures that could at least slow the spread of invasive species. Meanwhile, quagga mussels have also been detected for the first time in the Rhine at Basel.

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A highly destructive, invasive, mussel threatens Britain for first time

Quagga mussels, an invasive mussel that UK scientists have identified as the number one most dangerous alien species, are threatening Britain’s wetlands.

Quagga mussels are less than 5cm long but breed prolifically, forming vast colonies on hard surfaces that can smother boat hulls, block pipes and potentially cause flooding.

And for the first time the mussels have been found in Britain at Wraysbury Reservoir near Heathrow Airport, a popular sailing, fishing and scuba diving lake that’s also a protected area for wildlife, and upstream from The Wildfowl & Wetland Trust’s London Wetland Centre.

This is extremely worrying wildlife experts are warning. Quagga mussels have been described as 'ecosystem engineers' because their vast capacity to filter water upsets the natural balance throughout the food web. They eat some pollutants, but they turn it into concentrated toxic faeces which can poison drinking water for people and wildlife.

Earlier this year the quagga mussel was unanimously identified by a group of scientists as the greatest single threat to Britain’s wildlife of any alien species. In the US the mussel is threatening to bring the Hoover dam to a standstill and cut off water to Las Vegas.

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New Methods Improve Quagga and Zebra Mussel Identification

Oct. 31, 2013 — Reports identify new sampling and testing methods that improve accuracy in the detection of quagga and zebra mussels and outline procedures used to test for them. The earliest possible detection of quagga and zebra mussels has long been a goal of biologists seeking to discover their presence in water bodies. The Bureau of Reclamation's Detection Laboratory has released two reports identifying a new sampling method to improve the accuracy of quagga and zebra mussel detection while still at the microscopic larval stage.

The reports also outline the processes and procedures used to identify invasive mussels through DNA testing.

"Improving the accuracy of testing provides Reclamation and its partners better information about the presence of quagga and zebra mussels in water bodies where our facilities are located," laboratory manager Denise Hosler said. "These sampling procedures allow for the improved detection when the mussels are in their larval stage."

For early detection, Reclamation searches samples from reservoirs, lakes, canals and other water bodies for the microscopic larval form of quagga and zebra mussels. Because they are so small, multiple testing methods are used, including cross-polarized light microscopy, scanning electron microscopy and PCR testing of the DNA of larvae in the water sample.

"Early detection of mussel larvae does not mean that the water body will necessarily become infested," Reclamation's Director of Research and Development Curt Brown said. "Early detection provides a warning for managers that a water body is being exposed to mussels through some pathway, so they can consider additional means to prevent further introduction."

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