Life would not be able to evolve. Organisms able to survive the lower salt concentrations (of which there would be some in the ocean) would survive, organisms not able to survive the lower salt concentrations (which would be most of the organisms in the ocean) would go extinct.

This disruption to the food chain would cause even more organisms to die out, such as predators dependent upon the animals which went extinct, and this would turn into a major mass extinction event.

Life would not be able to evolve in this short amount of time. Organisms able to survive the lower salt concentrations (of which there would be some in the ocean) would survive, organisms not able to survive the lower salt concentrations (which would be most of the organisms in the ocean) would go extinct.

This disruption to the food chain would cause even more organisms to die out, such as predators dependent upon the animals which went extinct, and this would turn into a major mass extinction event.