What affect would the freshwater zebra mussels have on the shipping industry?

Question

Please help and explain

Answer 1

the zebra mussels are a tremendous problem in the Great Lakes of North America, as they attach themselves to the bottom of ships, hold on very tightly, grow very fast and to a large size..........this creates tremendous drag on the ship, slowing it down, causing it to burn more fuel and reducing its steering at slow speeds.....

zebra mussels can also then be carried by ships to anywhere in the world, infecting other harbors and rivers.