Orcas, or killer whales, are most commonly found in coastal waters less than 200 meters deep. The top 200 meters of ocean are known as the epipelagic, or sunlight, zone because the sun's light is able to penetrate into this zone.
The depths of the ocean are commonly divided into zones. The top layer is the epipelagic zone, and it has daylight. Most marine life lives in this area. Immediately underneath this layer is the mesopelagic zone, which has twilight. Underneath these two rather shallow layers is the bathypelagic zone, which goes down 4,000 meters, is completely devoid of light and has crushing pressures from the water; despite these features, many creatures live in the bathypelagic zone. Sometimes whales, particularly sperm whales, dive down into the bathypelagic zone. Underneath that is "the abyss," or the abyssopelagic zone. The abyss is close to freezing, has no light, has crushing water pressure and is virtually free of life.
Orcas hunt fish and marine mammals close to the surface of the ocean. They are most commonly found in cold areas of the world but have been spotted in tropical waters at times, according to Marine Bio. Orcas are a species of large predatory dolphin.