The ocean's zones
There are three ocean zones: the sunlight zone, the twilight zone, and the midnight zone. They all vary in pressure, light, temperature, and the amount of marine life that inhabits each zone.
The sunlight zone is the zone with the most light. It is the top zone of the ocean. Ninety percent of all marine life live in the sunlight zone, mostly because it is an easy place for plants to flourish and has the least pressure. Some of examples of life that live in the sunlight zone are clownfish, sharks, stingrays, jellyfish, sea-turtles, coral, plankton, and seals. The sunlight zone goes down about 600 ft. into the ocean. Plankton thrives in this zone. The sunlight zone is also called the euphotic zone.
The twilight zone is the zone beneath the sunlight zone. This zone extends from about 600 ft. to around 3000 ft. Little life lives in this zone. There is not very much sunlight at all, and plants cannot grow. There is more pressure, less sunlight, less life, and the temperature drops down. Only animals that have adapted to the small amount of life can survive here. Examples of these animals are lantern fish, rattalk fish, hatchet fish, viperfish, and mid-water jellyfish. Some squids and fish use their bodies to make light in this dark zone. The twilight zone is also called the disphotic zone.
The midnight zone is the last zone of the ocean. High pressure, density, freezing or below freezing temperatures, almost no life, and no light exist in this zone. The living things that survive in the midnight zone live close to cracks in the Earth's crust that give off materials full of minerals from the actual Earth. Forms of bacteria utilize hydrogen sulfide from the cracks for the sustaining energy to make food. This bacteria feeds all other life in the midnight zone, which includes angler fish, tripod fish, sea cucumbers, snipe eels, opposom shrimp, black swallowers, and vampire squid. The midnight zone is also called the aphotic zone.
The sunlight zone is the zone with the most light. It is the top zone of the ocean. Ninety percent of all marine life live in the sunlight zone, mostly because it is an easy place for plants to flourish and has the least pressure. Some of examples of life that live in the sunlight zone are clownfish, sharks, stingrays, jellyfish, sea-turtles, coral, plankton, and seals. The sunlight zone goes down about 600 ft. into the ocean. Plankton thrives in this zone. The sunlight zone is also called the euphotic zone.
The twilight zone is the zone beneath the sunlight zone. This zone extends from about 600 ft. to around 3000 ft. Little life lives in this zone. There is not very much sunlight at all, and plants cannot grow. There is more pressure, less sunlight, less life, and the temperature drops down. Only animals that have adapted to the small amount of life can survive here. Examples of these animals are lantern fish, rattalk fish, hatchet fish, viperfish, and mid-water jellyfish. Some squids and fish use their bodies to make light in this dark zone. The twilight zone is also called the disphotic zone.
The midnight zone is the last zone of the ocean. High pressure, density, freezing or below freezing temperatures, almost no life, and no light exist in this zone. The living things that survive in the midnight zone live close to cracks in the Earth's crust that give off materials full of minerals from the actual Earth. Forms of bacteria utilize hydrogen sulfide from the cracks for the sustaining energy to make food. This bacteria feeds all other life in the midnight zone, which includes angler fish, tripod fish, sea cucumbers, snipe eels, opposom shrimp, black swallowers, and vampire squid. The midnight zone is also called the aphotic zone.
Zooplankton and phytoplankton
Plankton is the base of the ocean food chain. The zooplankton (the animal-type plankton) feed off of the phytoplankton (the plant-type plankton). Small fish then eat the zooplankton, while the bigger fish consume the smaller fish. Plankton lives in the sunlight zone where there is not much pressure, the temperature is moderate to warm, and there is plenty of sunlight for photosynthesis to exist. Plankton is the base of the ocean food chain. Without plankton, the whole ocean population would eventually die out.
Benthos
Benthos are the sea animals that live directly on the ocean floor. This can mean the ocean floor of the midnight zone or the shallow, sloping ocean floor of the continental shelf, slope, and rise in the sunlight zone. Some benthos even live on the shore, in small tide pools! Benthos can be microscopic, like plankton, or large like nekton. Some benthos are nekton as well, such as flounder or the sandfish. Benthos eat jellyfish and organic matter such as algae that drifts down from higher zones to the ocean floor. Occasionally they will eat each other. Some common examples of benthos are hermit crabs, lobsters, oysters, sea-sponges, and clams.
Nekton
Nekton are the animals that can move by themselves in the ocean waters. Nekton live in all zones of the ocean. However, just like benthos and plankton, most live in the sunlight zone or shallow twilight zone since there is the most sunlight and it is easy to feed on smaller organisms such as krill and minnows. Some nekton move faster or slower than others depending on which zone they live in (sunlight zone less density and pressure, midnight zone most density and pressure) and how they're built. What nekton eat also depends on where they live and how they're built. Whales eat plankton because that's the only thing that can go through their teeth (baleen plates).