What two changes would decrease the density of ocean water

the temperature of the water and the salinity of the water

There are two main factors that make ocean water more or less dense than about 1027 kg/m3: the temperature of the water and the salinity of the water.

Explanation:

kelp are large brown algae that live in cool, relatively shallow waters close to the shore. they grow in dense groupings much like a forest on land. these underwater towers of kelp provide food and shelter for thousands of fish, invertebrates, and marine mammal species.

e) all of the above