News Excerpt:

Zebra mussels have been discovered in Clear Lake, Riding Mountain National Park, Canada.

• On July 17, snorkellers found a partial shell and a live, adult-sized Zebra mussel attached to a rock during a visual survey.

More About Zebra mussels

• Zebra mussels are small, invasive mollusks about the size of a fingernail, originally from Eurasian freshwater habitats.
• Their name comes from the dark, zigzag stripes on their shells. 
• Its scientific name is Dreissena polymorph.
• These mussels likely arrived in the Great Lakes in the 1980s through ballast water discharged by large ships from Europe.
• Since then, they have rapidly spread throughout the Great Lakes region and into major rivers of the eastern Mississippi drainage.
• They have also been discovered in Texas, Colorado, Utah, Nevada, and California.

Life cycle of Zebra Mussels

• On average, zebra mussels live for 2 to 5 years and can start reproducing by their second year.
• Each year, a mature female zebra mussel can release up to one million eggs, while a male can release over two hundred million sperm into the water, where fertilization occurs.
• Within about two days, the fertilized eggs develop into free-swimming larvae known as veligers, which can be carried over long distances by water currents.
• After 2 to 3 weeks, the veligers begin to settle in the water as their shells form, attaching to firm underwater surfaces.

Impact on ecosystem:

• Zebra mussels have several negative effects on ecosystems. They filter out algae that native species rely on for food and can attach to and harm native mussels.
• Zebra mussels compete with native species for food and space and can quickly overwhelm a water system due to their rapid reproduction.
• This change can disrupt local food webs by depriving native species of plankton-based food and by increasing water clarity, which makes it easier for visual predators to hunt.

Treatment measures:

• Managing zebra mussels involves measures such as chemical treatments, biological control using predators or pathogens, and physical removal. 
• Preventative measures, like cleaning boats and equipment, are crucial to prevent their spread.