The variability in marine salinity between habitats does not impact the fish living there.

The statement is false: differences in salinity affect the amount of water and salt moving into or out of a fish’s body. Fish must regulate their internal salt and water balance, and species are adapted to particular salinity conditions. Therefore, marine salinity variability can impact the fish living in different habitats; the false choice is B.

AI-written and checked against the verified answer.