Temperate oceans feature a plethora of living organisms. You can find life at any depth of the temperate oceans, from the sunlit surface to the inky black depths of the deepest trenches where no light reaches. Outside of the abundance of fish that you might have guessed inhabit these waters, numerous marine mammals, invertebrates, birds and even reptiles rely on these oceans for survival.

​Temperate oceans​, or oceans found in the temperate climate zone, lie between the Arctic regions and the warmer subtropical and tropical regions. Two areas of temperate oceans exist, one in the Northern Hemisphere and one in the Southern Hemisphere.

Temperate oceans contain a mixture of different oceanic currents. Warm water from the tropics moves toward the cold water at the poles. Conversely, the cold water from the poles moves towards the equator, pushing upwards as it warms and bringing nutrients with it. This process is known as ​upwelling​. These nutrients from upwelling allow the entire food chain to flourish in temperate oceans.

Plenty of green, plant-like organisms live in the ocean, including seaweeds and kelp of all kinds. However, these creatures are not true plants! Instead, scientists classify them as ​algae​. One of the only types of true plants that grows in the temperate ocean is seagrass. Seagrasses grow true roots like any other plant, whereas algae use a root-like ​holdfast​ to fix themselves to objects or the seafloor.

Because temperate oceans are so dense with nutrients and microorganisms, you can find an immense variety of animal life that thrives in these regions. Fish, invertebrates, marine mammals, reptiles and birds are some of the different types of animals in temperate oceans.

Temperate oceans are home to many different types of fish. The jawless fishes, lamprey and hagfish, range throughout temperate and tropical oceans. Many different species of cartilaginous fishes, the group containing sharks and rays, also live in temperate oceans. Some notable species include the great white shark, sawfish and whale shark. The bony fishes, or those with skeletons of bone rather than cartilage, comprise the widest range of species in temperate oceans. Some examples include salmon, tuna, anglerfish, sturgeon and halibut.

You can also find invertebrates of all kinds in temperate oceans. A number of different mollusks, including snails, squid, octopus, clams and much more, inhabit these regions. Cnidarians such as jellyfish and sea anemones also live in temperate seas. Other invertebrate animals that live in these regions include sponges, sea urchins and sea cucumbers.

Diving into the next group, you find marine mammals that prey on the wide range of fish and invertebrates in temperate oceans. The cetaceans, also known as the whales and dolphins, make up a large number of marine mammals in this region. This includes the largest animal on Earth, the blue whale. The other group of marine mammals in temperate oceans are the pinnipeds, or the seals and sea lions.

Though cold-blooded and generally restricted to warmer regions, a few types of marine reptiles inhabit temperate oceans throughout various times of year. Two species of sea turtles, the green turtle and the leatherback turtle, range into temperate oceans while making lengthy migrations.

Many marine birds either migrate through or spend potions of the year fishing in temperate oceans. Though some float and sleep on the waves over long migrations, many seabirds live in coastal regions of temperate seas. These birds commonly nest along the shoreline as well, making beaches or cliffs their home. Some types of seabirds in these regions include albatross, gannet, puffin, seagull and tern.