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Aquatic and Man-Made Ecosystem
(Module Notes) After studying this module, you should be able to: ♦ describe what an ecosystem is; ♦ discuss the characteristics of and identify organisms found in marine and freshwater ecosystems; and ♦ describe some man-made ecosystems. Let’s See What You Already Know Before you proceed, find out first how much you already know the topics to be discussed by taking the following test. Answer the questions below by writing your answers on the lines. 1.Define ecosystem.
- Give three characteristics that make aquatic ecosystems different from terrestrial ecosystems.
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- Give three differences between a marine and a freshwater ecosystem.
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- List five examples of man-made ecosystems.
The Ecosystem An ecosystem is a complex made up of living things, their physical environment and all their interrelationships in a particular unit of space.
characteristics of an ecosystem:
♦ Living things and their physical
environment
An ecosystem is made up of not just living things but of nonliving things as well. Example: Garden/Park It is an ecosystem because it is made up not just of plants, butterflies, earthworms and other living things, but of soil, water and air as well. It is the combination of living things and nonliving things that make a particular space an ecosystem. The components of an ecosystem are grouped into two—the biotic or living components and the abiotic or nonliving components. ♦ Interrelationships
You saw how living things and
nonliving things in your yard are
related to one another. There are
different kinds of relationships in
an ecosystem. Some may be
beneficial; others may be harmful
to one party. Because of these
interrelationships, whatever
happens to one component will
definitely affect all the other
components of the ecosystem.
♦ A particular unit of space Keep in mind that each ecosystem can be found in a particular space. Different kinds of ecosystems can be found in different kinds of places. Each type of ecosystem is occupied by a specific group of organisms interacting with a physical environment that differs from other types of environments. Generally, there are two kinds of ecosystems—terrestrial and aquatic ecosystems. Terrestrial ecosystems are those that can be found on land; aquaticecosystems are those that can be found in water. LECTURE 1
Because of this major difference in environmental conditions, the two aquatic ecosystems are distinct from each other. This distinction is based on the physical and chemical differences in the water environments that influence the communities of organisms. Life Under the Sea
Have you ever imagined how it would be like to
live under the sea? What are the exciting things
that you can discover and do in an environment
surrounded by water? Imagine the creatures you
will meet! Wouldn’t life be exciting under the
sea?
there are many organisms that have developed special capabilities that let them survive underwater. The biggest water environment is the marine environment. It is the largest ecosystem in the world. Aquatic environments are specialized environments. There are two major forms of aquatic environments. Freshwater ecosystems contain water that is not salty. In contrast, marine or oceanic ecosystems contain salty water. Freshwater environments contain only 1% of the saltiness that characterizes oceans and seas. Let’s Try This The figures that follow show some organisms or biotic components found in marine ecosystems. Name each organism and describe what you know about it in the space provided.
LECTURE 2
Aquatic animals need oxygen, just like terrestrial animals do. They have developed special body parts that enable them to extract oxygen from water. Fishes, for instance, have gills for this purpose. Other animals have similar parts that help them survive underwater. The Marine Ecosystem Oceans cover 75% of the earth’s surface. Seas and oceans are important because they supply most of the water that evaporates which in turn forms into clouds and fall on land as rain. Ocean temperatures affect the global climate. Most of the oxygen present in the air and breathed by land animals comes from the plants found in seas. A marine ecosystem is special because it has a high salt content. Oceanic creatures are able to survive under these conditions while human beings and other land-based animals will find these unsuitable. Plankton are critical components of food chains in all marine environments because they provide nutrition for organisms such as crustaceans, fish and squid. Some phytoplankton are also important sources of oxygen which they release as a byproduct of photosynthesis, the food- making process in plants. The word plankton comes from the Greek word planktos, meaning “wandering” or “drifting.” This is how most plankton move, floating with the ocean’s currents. There are some plankton, however, that can control their movements. Such plankton include the jellyfish.. Plankton actually include a wide variety of organisms— bacteria, algae, the larvae of some animals, protozoans. Most plankton, however, are protists (single-celled organisms that have a nucleus). They are grouped into phytoplankton, which are plants or plantlike protists; zooplankton, which are animals or animal-like protists; and microbes such as bacteria. Phytoplankton carry out photosynthesis and are the producers of the marine ecosystem.
Let’s See What You Have Learned 1.Enumerate the different marine zones and give the characteristics of each.
2.Describe the kinds of organisms found in marine ecosystems.
Compare your answers with those in the Answer Key on page 40. Did you get a perfect score? If you did, that’s very good. If you didn’t, that’s okay. Just review the parts of the lesson that you did not understand very well before you move on to Lesson 3. Let’s Remember ♦ Aquatic ecosystems are divided into marine ecosystems and freshwater ecosystems. ♦ Oceans cover 75% of the earth’s surface and are important for the maintenance of global climate. ♦ Plankton are the major producers in marine environments. Consumers such as fish eat these plankton as a source of energy. ♦ The marine environment can be characterized as pelagic environment and benthic environment. ♦ Marine organisms can be classified into those that live in the pelagic environment (plankton and nekton) and those that live in the benthic environment (benthos).
LECTURE 3
Freshwater
Ecosystems
Seas and oceans occupy a big portion of the biosphere, the part of the planet where life can be found. About 75% of the surface of the earth is covered with water and only about 2% is covered with freshwater. Freshwater refers to water that has low salinity (salt content). The salinity of freshwater bodies such as ponds, rivers and lakes contain 1% of that found in sea or saltwater. Freshwater is precious to human life. Water comprises roughly 80% of the human adult body weight. Without freshwater, we would have no drinking water. There are four major bodies of freshwater namely, streams, rivers, ponds and lakes. They are created from runoffs from mountains and other highlands. Rainwater travels downward due to gravity and collects in streams and rivers, which generally move fast as they travel toward the oceans. Because of their nature, streams and rivers have long, winding routes. Streams emerge to form rivers. Streams and rivers are bodies of water that travel toward the sea. Ponds and lakes, on the other hand, are formed when runoff water accumulates in a landlocked basin. Therefore, the water is not fast flowing because it does not rush toward the sea. Both ponds and lakes contain standing water. Ponds are smaller versions of lakes. Whether moving or not, long or wide, fast or slow, bodies of freshwater contain life. The relationship between living and nonliving things in these bodies of water is referred to as freshwater ecosystem. Since you have learned that ecosystems differ when physical conditions differ, there are two general types of freshwater ecosystems—the standing freshwater ecosystem of the ponds and lakes and the running water ecosystem of streams and rivers
Let’s Learn
Underwater creatures are adapted not only to life under water in general but to the particular conditions of their water environment. An example of such condition is salinity or salt content. A freshwater fish like tilapia, for example, cannot survive in the sea. Sharks would also die if they were placed in rivers. Although there are some organisms that can tolerate both environments to a certain extent, generally, organisms prefer to live in the environment to which they are most adapted. Adaptation may be physical or behavioral.
Man-Made Ecosystems
LECTURE 4
Human beings have proven themselves to be the most successful species on the planet. Because of the special abilities of human beings to change their environment, nature never looked the same ever since humans first walked on the face of the earth. ♦ An ecosystem is made up of all the living and nonliving things found in a particular area. The living creatures found in an ecosystem are called the biotic components. The nonliving things are referred to as the abiotic components. ♦ Ecosystems found on land are called terrestial ecosystems while ecosystems found underwater are called aquatic ecosystems. ♦ There are two major forms of aquatic environments, namely, freshwater ecosystems, which contain water that is not salty and marine or oceanic ecosystems that contain salty water. ♦ Phytoplankton are the major producers in marine environments. ♦ The seas and oceans occupy a bigger portion of the biosphere. About 75% of the surface of the earth is covered with water and only 2% is covered with freshwater. ♦ There are two major types of freshwater ecosystems—standing freshwater (ponds and lakes) and flowing freshwater (streams and rivers). Each ecosystem has distinct characteristics and qualities. ♦ A man-made ecosystem is an ecosystem which was developed by human beings by changing or altering the structure or form of a natural ecosystem. Examples of man-made ecosystems are terrariums, aquariums, parks, gardens, dams and farms.
Let’s See What You Have Learned Explain the similarities and differences between the following ecosystems. Write your answers in the spaces provided.
- terrarium and garden
- aquarium and dam
- forest and farm
What Have You Learned? Fill in the blanks with the correct words. Choose the answers from the box. dam biotic abiotic ecosystem phytoplankton photic rivers aquarium extinction salinity marine detritus
- Oceanic ecosystems are also called _____________ ecosystems.
- Sediments falling to the bottom of a lake are called __________________.
- An ______________________________ is an example of a small man-made aquatic ecosystem.
- The ___________________ components are the nonliving components of an ecosystem.
- The disappearance of a species is referred to as _____________________.
- The _______________________ zone receives sunlight and has plants that can perform photosynthesis.
- A ________________ is a man-made lake.
- __________refers to the saltiness of a body of water.
- Fast-flowing aquatic ecosystems include _________________________.
- An _________________________has interrelated biotic and abiotic components.
- _________________________include plantlike protists.
- The ___________________ components of an ecosystem refer to plants and animals.
D. Lesson 3 Let’s See What You Have Learned (page 25)
- The shallower areas of bodies of freshwater receive adequate sunlight. This allows for more plants to thrive in the upper photic zone. Plants are food sources for organisms. This rich food supply promotes a greater variety of organisms in that zone.
- Organisms in the aphotic regions are able to create energy even without sunlight. Giant worms in these regions are able to utilize sulfur and other gases from the ocean floor to create energy. Some fishes can change color to match their environment. This is called camouflage. E. Lesson 4 Let’s See What You Have Learned (pages 34–35)
- terrarium and garden Similarity Both are man-made or terrestrial ecosystems. Difference A garden is bigger than a terrarium.
- aquarium and dam Similarity Both are aquatic freshwater ecosystems. Difference An aquarium is smaller than a dam. An aquarium is usually constructed for display while a dam is constructed to provide hydroelectric power.
- forest and farm Similarity Both are terrestrial ecosystems. Difference Forests have a great diversity of species. Farms, on the other hand, are planted with a single crop that does not promote diversity in the ecosystem. Farms cannot renew themselves while forests can. F. What Have You Learned? (page 37)
- marine 7. dam
- detritus 8. salinity
- aquarium 9. rivers/streams
- abiotic 10. ecosystem
- extinction 11. Phytoplankton
- photic 12. biotic
Abiotic Nonliving.
Aphotic zone Refers to the deeper area in a sea or ocean where sunlight
cannot penetrate.
Aquatic ecosystem Ecosystem found in water.
Aquarium A glass tank or bowl that is filled with water; represents a
smallscale aquatic ecosystem.
Biosphere A portion of the planet where life can be found.
Biotic Living.
Ecosystem A complex of interrelated living and nonliving things found in a
particular area.
Endangered Under threat of being extinct.
Freshwater environment Contains water that is not salty.
Habitat The place where an organism lives.
Hydroelectric power Electricity from water.
Intertidal zone The area where land meets water, also commonly referred to
as the beach.
Landscaping The practice of changing the environment to suit one’s own needs
or preferences such as in a garden.
Neritic zone The area farther out in the sea.
Oceanic zone The deepest area of the ocean.
Photic zone Refers to the shallower part of the big marine or oceanic
ecosystem where plants such as algae, seaweeds and phytoplankton that can
manufacture food are found.
Phytoplankton Plants or plantlike protists in the pelagic environment.
Salinity Salt content.
Terrarium A container usually made of glass that houses a collection of plants
and other organisms.
Terrestrial ecosystem Ecosystem found on land.
Zooplankton Animal or animal-like protists in the pelagic environment.
GLOSSARY
