A fetus is especially at risk because they are under developed and easily susceptible to sicknesses or radiation
Somone sections of ocean get more rain than others, the salinity is affected when the freshwater from rain adds to the sea water and dilutes it
More abilities and can adapt to it's area.
A habitat is useful to animal because it is a place where they can easily adapt or wouldn't have to adapt. They could have as many right to food as they need, and they could easily find shelter.
