Simplify the following text for a Grade 7 native English-speaking person.
Original: The Red Sea is generally saltier and more nutrient-poor than the Atlantic , so the Red Sea species have advantages over Atlantic species in the less salty and nutrient-rich Eastern Mediterranean . Accordingly , most invasions are of Red Sea species into the Mediterranean , and only few in the opposite way .
Simplified: The waters of the Red Sea are saltier than that of the Mediterranean .