1. Open Ocean and Deep Sea

2. Ecosystems of the Open Ocean
Epipelagic
Deep Ocean
Whale falls
Hydrothermal vents
Cold seeps

3. Epipelagic Zone
The uppermost layer of the world's oceans is bathed in sunlight during the daytime.
This bright ocean layer is called the photic zone, euphotic zone (euphotic means "well lit" in Greek) or the epipelagic zone (epipelagic means "upon the sea").
The depth of this zone depends on the clarity or murkiness of the water.

4. Physical Characteristics of the Epipelagic Zone
Photosynthetic organisms live in this zone and food is abundant.
Photosynthesis in the oceans creates approximately 90% of the Earth's gaseous oxygen.
Most of the oxygen is produced by phytoplankton. These primary producers (also called autotrophs) are the first link in the food chain in the oceans.
The sea surface temperatures range from 97°F (36°C) in the Persian Gulf to 28°F (-2°C) near the north pole.

5. Epipelagic Food Chain
Primary producers – phytoplankton, green red and brown algae, and kelp
Primary consumers – zooplankton, small fish
Secondary consumers – larger fish, baleen whales, jellyfish, marine mammals
Top of the food chain – killer whales, dolphins, sharks

6. Marine Animals Terms to Know Plankton – lives floating in the water
Nekton - lives swimming in the water
Benthic - lives on the bottom of the ocean
Sessile – lives attached to a surface permanently
Plankton
Nekton
Benthic
Sessile

8. Staying afloat – most organisms are more dense than water
Staying afloat – most organisms are more dense than water. They have special adaptations to help them stay afloat.
Cranchiid (Glass squid)
* large fluid-filled chamber filled with an ammonia solution
Noctiluca (Sea Sparkle)
•large buoyant vacuoles
Flat surfaces or bodies with
appendages do not slip as
easily through the water
Janthina (violet snail)
mucous bubbles
Fish - swim bladder

9. Staying afloat – Swim!!! Pectoral fins reduce sinking.
Adaptation to remain in epipelagic
AND
allows organisms to go deep and then return to surface

10. Finding food Hunt in groups Orcas can even hunt much larger whales
BE BIG!
• You can eat almost anything you encounter
• Can swim across “ocean deserts” to find food
• High storage capacity
(longer between meals but need more food/unit time)
Build a collection device or filter
Hunt in groups
Orcas can even hunt much larger whales

11. Finding food Stay with your food - Seabirds follow schools of fish
Know where your food will be
Hunt in areas with specific properties (e.g. upwelling regions or inside gyres) likely to retain or attract prey
Cue in on timed migration of prey

12. Finding a mate Stay together
schooling fish, social marine mammals & deep
sea angler fish
Broadcast spawning
Release of millions of eggs & sperm increases chance that sperm & egg will meet
Ex. oysters, coral

13. Finding a mate Be clonal Asexual reproduction - no mate needed!
Meet at a predetermined location
If separated or too costly to stay together (e.g. competition for food), meet at a specific time & place
Ex. Colonial sea birds and Pacific salmon

14. Avoid being eaten Defend yourself Mechanical • Spines • Tough skin
Chemical
• Taste bad
• Make
predators
sick

15. Avoid being eaten • Be transparent • Be reflective Be camouflaged
• Be countershaded BE
BIG!
Big things have
fewer
predators,
especially in the
marine
environment

16. Countershading in the Epipelagic Zone
Countershading is when an animal is light on its underside and dark on its upper parts.
When a predator looks down at a countershaded animal, it blends into the darker waters; when a predator looks at a countershaded animal from below, the light underbelly disappears into the light.

17. Deep Oceans Regions of the deep ocean The Midnight Zone
Epipelagic
Mesopelagic
Bathypelagic
Abyssopelagic
Hadalpelagic
200m
1000m
4000m
6000m
The Midnight Zone
The Twilight Zone
The Abyss
The Trenches

18. Unique Stresses of The Deep
Pressure
For every 10m (33ft) pressure increases by 1atm (14.7 pounds per square foot)
Lack of Food
5% of food made at surface makes its way to deep regions
Deep sea fish do not migrate
Oxygen Minimum Layer: about 500m
Oxygen enters ocean by: gas exchange with atmosphere, by-product of photosynthesis
Respiration uses up O2
O2 can drop to practically nothing

19. Adaptations to low light
The only light is produced by bioluminescence, a chemical reaction in the creature's body that creates a low level light.
Some produce red light to lure curious prey.
Sometimes used to signal potential mates with a specific light pattern.
Fish here are often transparent, black, silvery and even red in color.
The absence of red light at these depths being red makes them invisible.
Large eyes to capture what little light exists.
Often equipped with a powerful sense of smell – to find food and mates.

20. Mating in the deep Deep sea anglerfish –reproductive adaptation.
Males are tiny in comparison to females and attach themselves to their mate using hooked teeth establishing a parasitic relationship for life.
The blood vessels of the male merges with the female's so that he receives nourishment from her.
In exchange, the female
is provided with a very
reliable sperm source.

21. Adaptations to high pressure
Deep sea creatures have adapted to pressure by developing bodies with no excess cavities, such as swim bladders, that would collapse under intense pressure.
The flesh and bones of deep sea marine creatures are soft and flabby.

22. Finding food in the deep
Corpses of large animals that sink to the bottom provide infrequent feasts for deep sea animals.
Large and expandable stomachs to hold large quantities of food.
Don't expend energy swimming in search of food, rather they remain in one place and ambush their prey
Large jaws ensure that any prey captured has little chance of escape.

24. Chemosynthesis
Most life on Earth is dependent upon photosynthesis, the process by which plants make energy from sunlight.
Cold Seep and Hydrothermal Vent communities do not rely on the Sun for energy. Organisms there derive their energy from the Earth through chemosynthesis.
Chemosynthesis is the process by which certain microbes create energy from naturally occurring inorganic chemicals.
CH4 Methane
H2S Hydrogen Sulfide

25. Hydrothermal Vents
Form in places where there is volcanic activity, such as along the Mid-Ocean Ridge.
Sunlight does not reach the hydrothermal vent communities at the bottom of the ocean.
Microbes here get their energy from different chemicals in the hydrothermal fluid like hydrogen sulfide (H2S).
Those microbes are the basis of the food chain.

27. Cold Seep Communities
Deepwater communities associated with brine and hydrocarbon seepage from the Earth’s crust.
This brine forms brine pools on the seafloor.
Microbes here use chemosynthesis and the chemical methane (CH4) to obtain energy.
Those microbes are the basis of the food chain.

29. Whale Fall Communities
Communities of organisms that form around the carcasses of dead whales.

30. Whale Fall: Scavenger Stage

31. Whale Fall: Opportunist Stage

32. Whale Fall: Sulfophilic Stage