Answer:The population will drop.
Explanation:
This is because the fresh water of high water potential will lower the solute potential of the salt water when they mixed up; to create a HYPOTONIC ENVIRONMENT for the larvae and the eggs.
Therefore, the higher water potential drives in water into the larva and egg membrane, down the water gradient by OSMOSIS. This made the cells and its organells to swell up until the elastic limit of the cell membrane is exceeded.
The products busted (eggs and larvae) once the elastic limit / stretching limit is exceeded leading to death of larvae and destrction of the egg, with eventual drop in population of the marine animals; since reproduction has been truncated( old animals are not replaced with young ones from the eggs and larvae.)
