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

Since water is generally shallow, photosynthetic processes are possible for marine life which attracts more organisms to their primary food sources. Since the land is near shallow waters, discharges of nutrients from the soil are brought into the sea for the consumption of organisms. Aside from these reasons, periodic upwellings in the sea also provide cool and nutrient rich waters for different species.

If you remove all the lions from the savanna it will lead to a increase of gazelle and a increase of cheetahs becasue of no competition