Team members

Names / Roles:

• Gary Tan            (Leader)
• Megan Soh         (Writer)
• Teh Le Sze         (Research)
• Valerie Chang     (Research)
• Samuel Ng         (Research) 

Overview

Brief description of the ecosystem:

Where can it be found? Level of human activity? etc

Physical Factors

Light, temperature, water, air, pH, mineral salts and salinity

Physical factors of ecosystem (deep sea)

1) Light

2) Temperature

3) Water depth

4) Air

5) Availability of nutrients and food

6) Salinity

Link: http://www.mnstate.edu/leonard/G305life.html

1) Light

-Photic zone

It extends from the atmosphere-water interface downwards to a depth where light intensity falls to 1% of that at the surface (also called euphotic depth), so its thickness depends on the extent of light attenuation in the water column. Typical euphotic depths vary from only a few centimeters in highly turbid eutrophic lakes, to around 200 meters in the open ocean.

Since the photic zone is the only zone of water where primary productivity occurs, an exception being the productivity connected with abyssal hydrothermal vents along mid-oceanic ridges, the depth of the photic zone is generally proportional to the level of primary productivity that occurs in that area of the ocean. About 90% of all marine life lives in this region.

-Aphotic zone

It is formally defined as the depths beyond which less than 1% of sunlight penetrates. Consequently, bioluminescence is essentially the only light found in this zone. Most food comes from dead organisms sinking to the bottom of the lake or ocean from overlying waters.

The depth of the aphotic zone can be greatly affected by such things as turbidity and the season of the year. The aphotic zone underlies the photic zone, which is that portion of a lake or ocean directly affected by sunlight.

2) Temperature

-         The temperature of the seawater cannot be too hot or cold. Some aquatic animals cannot adapt to the surrounding temperature and will thus, die.

3) Water depth

-Pressure of water

Water pressure is dependent on depth and density of the liquid, it is dependent on depth because if you are in deep that means there is more water on top of you. Similarly atmospheric pressure is also about height, we can say this because pressure near sea surface is more than that of on top of the Himalayas. This is because there is more air above you when you are nears the sea surface.

4) Air

-Types of air

·        Noble Gases

-Helium, Neon, Argon, Krypton

-Their concentrations in seawater result from a number of physical factors. Studies of noble gases in seawater show the importance of a process called air injection. When waves at the sea surface break or form whitecaps, small bubbles of air are forced into the water and can be mixed downward where the hydrostatic pressure causes their gases to dissolve and become supersaturated when compared with their solubility at atmospheric pressure. Surface seawater can be about 104 percent saturated with atmospheric gases owing to air injection.

·        Oxygen

-         Marine plants such as phytoplankton, seaweed, and other types of algae produce organic matter from carbon dioxide and nutrients through photosynthesis, the process that produces oxygen. The upper 10 to 50 meters (33 to 164 feet) of the ocean can be highly supersaturated with oxygen owing to photosynthesis.

-         Photosynthesis by plants is restricted to the upper sunlit areas of the ocean, but organic matter settles from the surface layer to deeper waters where oxygen consumption by animals and bacteria is a major process. A process called thermohaline circulation renews the oxygen content of deep ocean waters. When surface waters either cool or become more saline (salty), their density increases and they sink to greater depths in the ocean where they can spread over vast distances.

·        Nitrogen

-Nitrogen is an essential nutrient required in the photosynthetic production of organic matter by marine plants. Many types of plants cannot use nitrogen gas in the atmosphere and dissolved in seawater, however. Nitrogen must be converted into forms such as nitrate (NO₃⁻) or ammonia (NH₃) before it becomes a useful nutrient for most photosynthetic organisms. While the biological cycling of nitrogen is very important in the ocean, it has only a slight effect on the amount of nitrogen gas in seawater. Nitrogen in ocean waters is within 5 percent of equilibrium with the atmosphere.

5) Availability of nutrients and food

The animals in the sea either eat other living creatures of the sea. Or they eat plants/algae grown in the deep sea.

6) Salinity

-Water salinity

 Fresh water  Brackish water  Saline water  Brine

  < 0.05 %       0.05 – 3 %        3 – 5 %     > 5 %

  < 0.5 ppt       0.5 – 30 ppt    30 – 50 ppt  > 50 ppt

-Salinity is an ecological factor of considerable importance, influencing the types of organisms that live in a body of water. As well, salinity influences the kinds of plants that will grow either in a water body, or on land fed by a water (or by a groundwater). A plant adapted to saline conditions is called a halophyte. Organisms (mostly bacteria) that can live in very salty conditions are classified as extremophiles, halophiles specifically. An organism that can withstand a wide range of salinities is euryhaline.

Salt is difficult to remove from water, and salt content is an important factor in water use (such as potability).

LESZE(:

Classification of Living Organisms

Producers

Consumers

Decomposers

Food Web 

Please use Microsoft PowerPoint to create and upload picture. 

Interrelationship in Ecosystem

Predator-prey relationship

Parasitism

Mutualism

Useful Links

Include the links of websites you took information from. 

For example:

Wild World @ nationalgeographic.com ( http://www.nationalgeographic.com/wildworld/terrestrial.html )

• [Name of website] (website address)
• [Name of website] (website address)
• [Name of website] (website address)
• [Name of website] (website address)