Deep Sea Biology

A presentation for Chandler Oaks Elementary

What is the Deep Sea?

Ocean can be separated into 3 zones:

1. Photic Zone → Light Zone2. Disphotic Zone → Twilight Zone3. Aphotic Zone → Midnight Zone

Deepest part = Mariana Trench at Challenger Deep (36,037 ft)

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Light Zones

Photic Zone● 0 - 200m depth● Area with the most sunlight● Appears bright blue and well-lit● Plants/algae produce oxygen and energy● Animals are very abundant and competitive

Disphotic Zone

● 200 - 1,000m depth● Only receives some filtered sunlight● Appears deep blue and murky● No plants or photosynthesis● Animals do not have much food and tend to

migrate vertically for resources

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The Aphotic Zone, aka “The Deep Sea”

Four main characteristics

Deep

Dark

Cold

Lonely

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Deep = Pressure

Depth ranges from 1,000 - 10,070m● Average depth is 13,000 ft● Average habitat on Earth is the deep sea● Mount Everest + 1 mile!

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All animals must deal with immense pressure (1 atmosphere = 33 feet)● No spare cavities filled with air● Special microscopic proteins● Body is either very small or very large● Large animals are squishy and flexible

Dark

No eyes or very large eyes

Red or black bodies become “invisible”

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Bioluminescence● Communication● Finding mates● Luring prey● Camouflaging

Cold

Temperature ranges from -1 to 4°C (30 - 34°F)

Animal adaptations:● Antifreeze proteins keep blood from freezing● Blubber used by deep-diving mammals to stay warm● Countercurrent exchange

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Lonely

Vertical migration

Store food for months, utilize marine snow, or have extremely long migrations

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Live with others in colonies

● Hydrothermal vents● Whale fall communities● Sediment concentrations● Brine lakes

Marianas Trench (MT)

What we know about MT:

● Mostly microbial communities

● Only 2 manned trips

● Dozens of new species discovered on every dive

● Trash from 1970s has recently been found :(

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