Zebra mussels were first discovered in north america in the great lakes in 1988. this invasive species eats phytoplankton and other microscopic organisms in fresh water. what would be the most likely effect if zebra mussels are introduced into a local fresh water lake?

the ecosystem would benefit from the increased competition for food and increased diversity.
the ecosystem would be harmed as other phytoplankton-eating organisms would have less to eat.
the zebra mussels would only affect the lake if it already contained another species of mussels.
the zebra mussels would benefit the lake especially species higher up on the food chain.