The smallest and the largest forms of life on Earth are found in the ocean. As on land, the number of individuals is greater for smaller organisms than for larger ones.
Ocean life adapts to water motion and the patterns of physical and chemical properties.
Other non-living factors that influence the patterns of ocean life include large scale circulation, local tides, and storm events. Knowing this, scientists try to create order out of all the observations about plants and animals that they have made. They can then look them up in field identification guides. Correct identification of members in a habitat is important because it allows scientists to describe and monitor changes within and between species. Moreover, changes in a species' population might indicate a change in the physical environment.