Question

The eggs and larvae of marine animals tend to require water with more dissolved oxygen in it than the adults do. If water flows from a freshwater source into a salt water bay, what effect would this have on the population of marine animals?

Answer 1

The information you have given would indicate the population will increase since saltier water has less oxygen dissolved in it than fresh water.

Answer 2

Marine animals (unless they're brackish water animals) would not necessarily tolerate the change in osmolarity even if the water has more oxygen. For example larval shrimp cannot survive at salinities less than 30 ppt, even though less salinity may have more dissolved oxygen