They only hunt and travel in water. They do need fresh water to drink, but it doesn't matter to otters if their prey lives in fresh or salty water. Our North American otter is just as much at home along seacoasts as riverbanks. Here, where I see otters, they actually much prefer the seacoast. Lots more fish there than in our rivers.
Giant otters are terrestrial animals.
They only hunt and travel in water. They do need fresh water to drink, but it doesn't matter to otters if their prey lives in fresh or salty water. Our North American otter is just as much at home along seacoasts as riverbanks. Here, where I see otters, they actually much prefer the seacoast. Lots more fish there than in our rivers.