Deep Sea
The deep sea is too deep for light to penetrate that plants need
to make their food. Plants get their energy from sunlight and
through a process called photosynthesis, turn this sunlight into
food for the plant. Since there is not any usable light available
for plants to photosynthesize in the deep sea plants cannot live
there.
There are bacteria that can live as deep as 1500m to 3200m near deep sea hot vents. These bacteria use a compound called hydrogen sulfide, instead of sunlight, to make their food. The bacteria get the hydrogen sulfide from deep sea hot water geysers that release this compound. In fact, because of these tiny bacteria an entire community of animals can survive and thrive in these hot vent areas!