Describe ecological and regulatory implications of Zebra mussel invasion on freshwater systems.

Describe ecological and regulatory implications of Zebra mussel invasion on freshwater systems.

• A. They increase phytoplankton and reduce water clarity; no regulatory actions.
• B. They reduce phytoplankton and increase water clarity, disrupt native species, alter nutrient cycling, and clog infrastructure; ballast water and transport pathways are typical regulatory targets.
• C. They have no impact on nutrient cycling or native species.
• D. Regulations focus solely on fishing quotas.

Answer: (B)

Zebra mussels are prolific filter feeders that remove phytoplankton and other suspended particles from the water, which lowers phytoplankton abundance and increases water clarity. This change in the food web can disrupt native species by altering competitive dynamics and predator–prey relationships, and it shifts nutrient cycling because nutrients are taken up into mussel biomass and then released back as inorganic nutrients, while clearer water can promote growth of aquatic plants in the littoral zone. They also attach to hard surfaces and foul infrastructure like pipes and intake structures, causing economic and operational problems. Because they spread mainly through ballast water and other transport pathways, regulatory efforts focus on preventing introductions and secondary spread via ballast water discharge, hull fouling, and related transport-pathway controls. This combination of ecological effects and regulatory targets accurately captures the invasion's impacts.

Zebra mussels are prolific filter feeders that remove phytoplankton and other suspended particles from the water, which lowers phytoplankton abundance and increases water clarity. This change in the food web can disrupt native species by altering competitive dynamics and predator–prey relationships, and it shifts nutrient cycling because nutrients are taken up into mussel biomass and then released back as inorganic nutrients, while clearer water can promote growth of aquatic plants in the littoral zone. They also attach to hard surfaces and foul infrastructure like pipes and intake structures, causing economic and operational problems. Because they spread mainly through ballast water and other transport pathways, regulatory efforts focus on preventing introductions and secondary spread via ballast water discharge, hull fouling, and related transport-pathway controls. This combination of ecological effects and regulatory targets accurately captures the invasion's impacts.