Biomes are classified by their climate, which is determined by precipitation and temperature, and by the community of organisms that live there. Tropical rain forests have higher temperatures and more rainfall annually than do tropical dry forests.

The biome concept organizes large-scale ecological variation. Terrestrial biomes are distinguished primarily by their predominant vegetation, and are mainly determined by temperature and rainfall. Differences in temperature or precipitation determine the types of plants that grow in a given area (Figure 1).

The aquatic biome is divided into freshwater and marine regions. Freshwater regions, such as lakes and rivers, have a low salt concentration. Marine regions, such as estuaries and the ocean, have higher salt concentrations.

Underwater landforms

• Continental shelf. Starting from land, a trip across an ocean basin along the seafloor would begin with crossing the continental shelf.
• Abyssal plains. Continuing your journey across the ocean basin, you would descend the steep continental slope to the abyssal plain.
• Mid-ocean ridge.
• Ocean trenches.

With maximum depth exceeding 17,000 feet (5,200 m), the seafloor’s most distinctive feature is the Tasman Basin.

The deep-sea is defined as the part of the ocean below 200 meters depth. This environment Is considered extremely harsh with temperatures of below 5 degrees Celsius, extreme pressure (2,000 meters equals about 200 times the atmospheric pressure at sea level), and no sunlight.

The simple answer is that not all of the ocean floor is made of sand. The ocean floor consists of many materials, and it varies by location and depth. In shallow areas along coastlines, you’ll mainly find sand on the ocean floor. Over 70 percent of Earth’s surface is covered by oceans.