Marine organisms exist in an ever-changing environment. The physical environment within the ocean varies with the availability of light, oxygen, food resources, pressure and temperature. This variation in the physical environment has resulted in a great diversity of organisms. To survive, these organisms need to secure food, successfully reproduce and avoid predation. Simple animals, such as anemones or worms, absorb the gases through their skin. Mobile animals use gills, or even lungs to absorb oxygen from the water and air. Some marine adaptions are those of the plankton (the drifters), nekton (the swimmers) neuston (floaters and drifters underside a film or surface of water) and the benthos (the sedentary ones). The higher density due to salt content in the ocean support the large bodies of giant squids and whales, which has allowed them to evolve without the use of strong limbs for support. Owing to the limited account of food available in the deep ocean, larger organisms chose to live in the upper ocean; the size of marine organisms decrease with depth (1) Marine adption includes symbiosis, camouflage, size, contact, communication, defensive and reproductive strategies besides, adaptions to environmental conditions like temperature, light, salinity and geography