Marine Water Ecosystem

• The Marine Environment• The Marine Biota• Zonation of the Sea• Quantitative Study of Plankton• Communities of the Marine Environment• Mangroves and Coral Reefs• Communities of Oceanic Region• And Estuary

Topics Included

Marine Ecology is the scientific study of marine-life habitat, populations, and interactions among organisms and the surrounding environment including their abiotic and biotic factors.

Living(Biotic) Non- Living(Abiotic)

Fish Phytoplankton Dinoflagellates Coral Bacteria Mangroves

etc..

Sunlight Water Temperature Currents Sediments/sand Substrate Water pressure

etc..

For centuries man Regarded the sea as a restless surface which first hindered, then aided his efforts to explore the world. He also learned that the sea was a source of food which could be harvested, by dint of great effort, to supplement the products of

land and fresh water.

HMS Challenger – One of the first ship specifically equipped for the study of the sea

“He must consider the oceans as an integral part of his “total life-support system” and not as

an inert “supply depot” that is merely there for the taking”

The Oceans, seas, bays, estuaries and other major water bodies including their surface interface and interaction with the atmosphere and with the land seaward of the mean high water marks.

Features of the Sea1. The sea is big: it covers 70 percent of the earth surface.

2. The sea is deep and all life extends to its depth.

Pressure in the ocean increases by about 1 atmosphere for every 10 meters of depth, the amount of pressure experienced by many marine organisms is extreme.

Marine Environment

3. The sea is continuous, not separated as are land and freshwater habitats. Temperature Salinity Depth

Marine Environment

4. The sea is dominated by waves of many kinds and by tides produced by the pull of moon and sun. Spring tides Neap tides

Marine Environment

5. The concentration of dissolved nutrients is low and constitutes an important limiting factor in determining the size of marine population. oxygen

4. The sea is in continuous circulation air temperature difference between poles and equator.(Ocean Conveyor Belt or “thermohaline circulation”) Upwelling Outwelling

7. The sea is salty. salinity is remarkably constant throughout the deep sea, at about 35 parts per thousand. There are some minor differences in salinity, but none that is ecologically significant, except in the Mediterranean and Red Seas. Stenohaline describes an organism, usually fish that cannot tolerate a wide

fluctuation in the salinityof water. Stenohaline is derived from the words: "steno" meaning narrow, and "haline" meaning salt.

Euryhaline organisms are able to adapt to a wide range of salinities.

Marine Environment

Life in the Sea

The Marine Biota

The five major kingdoms in the ocean are:

Monera:single-celled organisms without nucleus (Prokaryotes) Protista:single-celled organisms with nucleus (Eukaryotes)

Fungi : important in decomposition and recycling.

Metaphyta: plants that grow attached to the sea floor.

Metazoa: all multicellular animals in the ocean.

The sea or ocean of the sea is divided into various divisions which is called zonation of seaThe marine environment can be divided into two zones:

Pelagic zone Benthic zone

Pelagic from the greek word pelages which means open sea .The pelagic zone occupies 1330 million cubic miles. Fish that live in pelagic area called pelagic fish

Neritic zone this is the part of the ocean extending frim low tide mark to the edge of continental shelf. neritic zone has generally well

oxygenated water . low water pressure and stable

water temperature. Zooplankton ,free floating

foraminifera are to small fish and shrimp live in this zone.

Oceanic zone The oceanic zone begins in the area off shore where the water measures 200meters deep or deeper .It is the region of open sea beyond the edge of continental shelf and includes 65% of the oceans completely open water shelf break deep open water.

Zonation of the Sea

Oceanic Zone Subdivision

Zonation of the Sea

1. Epipelagic (sunlit) This zone stars from the surface down to 200m. this is illuminated zone at the

surface of the sea ,where there is light for photosynthesis .

Nearly all primary production in the ocean occurs here.

with the light heat comes and this heat is responsible for the wide range if temperature.

organism found in this zone are planktons, seaweeds , jellyfish etc.

2. Mesopelagic (twilit) Zone stars from 200meters down to 1000 meters ,sometimes referred from mid water zone.

although light penetrate this second layer ,it is sufficient for photosynthesis.

sometimes creature live in this zone are bioluminescent .

organisms that available here are squid ,cuttlefish ,wolfish ,swordfish etc.

a great diversity of strange and bizarre fishes can be found here.

Zonation of the Sea

3. Bathypelagic (Midnight) From 100 meters down to 400m. from ancient Greek Bathys means deep.

at this depth the ocean is pitch black apart from occasional bioluminescent organisms such as lantern fish.

there is no living plant life. most species depends on prey

for food ex. Giant squid.

most of the animals that live at this depth are black or red in color due to lack of light.

Zonation of the Sea

4. Abyssopelagic (lower midnight) The name is derived from the Greek abyssos means bottomless and from 400m down to 600m .

the water temperature us near freezing and there is no light at all.

this zone is mostly unknown and very few species are known to live here.

the abyssal plain is covered with soft sludge composed of dead organism from above.

Zonation of the Sea

Benthic zone The zone of the ocean bottom is called benthic zone the zone can be divide as follows. Intertidal zone the zone

between high tide and low tide .Most of the area of this zone is exposed to air during low tide.

Zonation of the Sea

The continental shelf ,rise and slope together are called continental margin. Continental Shelf is shallow ,near horizontal

seafloor extension from the shoreline to the upper continental slope .

this shelf forms the shallow margin of each deep basin.

it is one of the most productive zone of the ocean .

this area is commercially very important. The bottom is composed of fume sediments like sand and silt.

Continental Margin

Zonation of the Sea

Continental slope begins at the shelf break and plunge downward to great depths of the ocean basin proper.

Continental Rise many continental slopes end in gently sloping smooth surfaced features called continental rise.

Zonation of the Sea

PLANKTON Not only does plankton occupy the key role in the ocean ecosystem ,but it lends itself to quantitative sampling.. 1830 J, Vaughan Thompson and 1845 Johannes Muller used the now called plankton. Plankton was not proposed until Muller was studying the life history of starfish. Plankton net are generally made of bolting silk or nylon ,the strands if

which are held firmly by binding it. Clark Bumpus -a closing net equipped with a metering device that

measures the amount of water filtered and use to the given depth can be sampled without contamination while the nerves being lowered and raise. -Net plankton and nannoplankton also called macro and micro plankton. >the most important photosynthetic organisms are not relatively large netpankton,but the nannoplankton, especially tiny green flagellates 2 to 25 microns in size.

Net plankton and nannoplankton also called macro and micro plankton. the most important

photosynthetic organisms are not relatively large net pankton,but the nannoplankton,especially tiny green flagellates 2 to 25 microns in size.

Ex. Nanno plankton -may also dominate the metabolism of coastal coast. Tiny flagellates- most of them colorless but some containing chlorophyll ,have also been found in abundance in the aphotic zone at depth of 1000 meters or more. And these presume to live heterotrophically at least of the time dissolved organic matter originating in the photic zone. These flagellates may be one of the jey of food chain links.

Quantitative Study of Plankton

phytoplankton diatoms and dinoflagellates.

micro flagellates Green algae(Chlorophyta) Brown algae(Phaeophyta) Red algae (Rhodophyta)

Producer

Some of fixed algae are economic importance as a source of agar and other products on Northern rocky coasts "seaweed "harvest is a regular industry and in Japan certain species are culture food .

Giant crustaceans Large copepods Small copepod Chaetognaths Medusae Salp

Consumer

Composition of Communities of the Continental Shelf Region

Zooplankton Play vital role in marine ecosystems. Variation in the zooplankton species composition ,biomass and secondary production will change the structure and function of the ecosystem.

Mangroves and Coral Reefs

MangrovesMangroves are among the few emergent land plants that tolerate the salinities of the open sea.Mangroves are not only important in extending coasts and building islands, but also in protecting coasts from excessive erosion which might otherwise be produced by fierce tropical storms.

Mangroves and Coral Reefs

Coral Reefs Coral reefs are widely distributed in shallow waters of warm seas. Coral reefs is not a heterotrophic community, but a complete ecosystem

with a tropic structure that includes a large biomass of green plants. Corals produce large amounts of mucus protects the delicate animals

from siltation, while perhaps also providing the reef community with another means of trapping particulate nutrients.

Mangroves and Coral Reefs

Three types or reefs

1. Barriers reefs among continents.2. Fringing reefs around islands3. Atolls, which are horseshoe-shaped edges of

reefs and islands with a lagoon in the center.

All in all mangroves and coral reefs are both important as “land builders” which help form islands and extend

shores.

Mangroves and Coral Reefs

Communities of the oceanic region.

Oceanic phytoplankton predominantly as “micro plankton”.

Zooplankton or “zooplankton” Oceanic birds whales

An estuary is a semi-enclosed coastal body of water with freshwater flowing into it and a connection to the open sea.

Estuaries—areas where fresh and saltwater mix—are made up of many different types of habitats. These habitats can include oyster reefs, coral reefs, rocky shores, submerged aquatic vegetation, marshes, and mangroves. There are also different animals that live in each of these different habitats. Fish, shellfish, and migratory birds are just a few of the animals that can live in an estuary.

Estuaries are often associated with high rates of biological productivity. They are among the most productive ecosystems in the world and are home to unique plant and animal communities. Many animal species rely on estuaries for food and as places to nest and breed. An estuary has very little wave action, so it provides a calm refuge from the open sea. Some of the animals, such as flounder, eels, and striped bass are temporary residents, while fishes such as sticklebacks, silversides, as well as mud snails, fiddler crabs, ribbed mussels, and oysters may spend their entire lives there. In almost all estuaries the salinity of the water changes over the tidal cycle. To survive in these conditions, plants and animals must be able to respond quickly to these changes and tolerate a wide range of salinities. Relatively few organisms have evolved adaptations to such stressful conditions, so estuaries tend to have lower biodiversity than other coastal habitats in the same region. Some organisms have evolved special physical structures to cope with changing salinity. The smooth cord grass in salt marshes, for example, has special filters on its roots to remove salts from the water it absorbs and salt glands on its leaves that expel excess salt.