Book 30, Question 129
How did tiny mussels change the Great Lakes?
They multiply quickly, stick to every hard surface, and filter huge amounts of water.
Zebra and quagga mussels are small striped shellfish from Europe that arrived in ships' ballast water in the 1980s. This makes lakes much clearer, but it takes away food that tiny native animals need. They also clog pipes and cover beaches with sharp shells, so wear water shoes.