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by
Grayce P. Storey
An ecosystem is defined by the ecologist who is studying it. A fresh water ecosystem may include all wild life in the system, microorganisms, plants in and around the system, pollutants in and around the system, and many things associated with system while keeping in mind that ecosystems overlap and affect one another.
My unit will deal primarily with habitat of marine organisms, three types of symbiosis; commensalism, mutualism, and parasitism, to the atmosphere and back to the earth, water pollution which is cause by water runoff and debris, hypoxia in the Long Island Sound which is in most oxygen depleted areas. The organisms will suffer stress and will eventually suffocate. This can result in fish and other mobile animals leaving the area. Which results in oxygen depletion, toxic contamination, pathogen contamination, floatable debris, and education vocabulary. The students will also develop mini ecosystems using a square meter garden. The students will study microscopic organisms from various systems study how they react to toxins (i.e. gasoline, oil, soap, etc.) and will affect organisms. My unit will also include resources, lessons plans, bibliographies for teachers and students, a vocabulary list. A suggested field trip with Quinnipiac Schooner Inc., around the Long Island Sound, lots of hands on activities are recommended, and the garden ecosystem may be used year round. This unit will be used in the 7th and 8th grades science class for two weeks and the ecosystems study will be ongoing.
An ecosystem is not difficult to find, they are all around you.
When we think of interdependency the term symbiotic comes to mind. A symbiotic relationship occurs when two species of organisms live in close physical contact with each other. There major types of symbiosis are commensalism, mutualism and, and parasitism .
In a commensalism relationship one species obtains food or shelter from another species without seriously harming that organism or providing any benefits in return.
A mutualistic relationship in which two different species live in a symbiotic way where both species benefit in a symbiotic way where both species benefit and are dependent upon the relationship.
Parasitism relationship is a relationship between two species in which the parasite species is nourished at the expense of the host species.
Habitat provides shelter and a place to reproduce. A habitat can be small or very large. The entire ocean is the habitat of the whale. In the habitat of animals they have a role to perform in that community. The job or role is called the organism’s niche. Even though organisms may share the same habitat, their niches may and does differ.
Succession describes the ever changing environment and the gradual process by which one habitat replaces another. Changes in an environment trigger changes in plant and animal population. A pond may be transformed into a marsh, then a forest over a thousand years. Environments are not static but ever changing.
Extinction is a natural process. Excessive and intensive human activity can cause an acceleration in an environment extension of various forms of life.
Most precipitation falls back into the ocean, lakes, rivers, and streams. Some water falls on land and runs off into the aquatic systems, and the cycle repeats itself.
Not all water goes back into the various systems of water but taken in by living things and later returned to the nonliving part of the environment. For example, plants take in water through their roots and release some water vapor through their leaves, this process is called transpiration.
Past the low tide line you can find microscopic plants (phytoplankton), living near the surface in order to receive sunlight which aids in food production. Almost all the animals in the ocean depend either directly or indirectly on phytoplankton for food.
Fresh water serves as a habitat for organisms such as the water lilies, cattails, algae, fish, water snakes, frogs, and microscopic plants to mention a few. Freshwater biomes may receive visits from ducks, raccoons, and other animals to feed or nest.
The Chesapeake Bay, situated on the eastern coast of the United States, is the largest estuary in the United States. An estuary is the boundary between a freshwater biome and a maine biome. Estuaries include salt marshes, lagoons, mangrove swamps, and that mouth of rivers that empty into an ocean. This area contains both freshwater and saltwater.
Because of the shallowness of estuarians, sunlight can reach all levels of the water. Organisms found growing in estuaries are marsh grass, algae, and all kinds of plant life that provide food for a variety of fish, crabs, oysters, and shrimp (scavengers). It also serves as nurseries for many different types of fish before heading to the open ocean. Many birds can be found nesting there.
The Chesapeake Bay estuary has benefitted man tremendously by producing many crabs, oysters, and fish. It has enhanced the economy of Virginia and Maryland.
Sometimes the impacts of environmental pollution can be difficult to see, where as at other times they are obvious. A major oil spill causes a potential impact to wild life. Feathers of birds are damaged, embryos are killed because oil seeps into eggs, fish suffocate when gills are clogged, and death comes to marine and terrestrial animals by ingesting food and water contaminated by the oil.
Cleanups are not always successful. The detergents used to clean up the spill and remove the oil from the birds wings can cause damage to the structure and arrangement and water proofing of the feathers. Birds may also be more susceptible to disease during this time of stress, and weakened to the point that it is difficult to secure necessary food and water. Because of the pollution, food and water sources may be affected quality wise.
Animals are threatened when crowded by humans and their discomfort may be displayed by fleeing, grinding of teeth, coiling, hissing, stomping feet, snarling, coughing or woofing. However, flight is the usual way of showing stress. Many animals have certain distances they keep from their own kind. An example is the wolf. The wolf may demand a large range which no other wolf outside their pack may enter.
Tributaries of freshwater entering the Long Island Sound include 70 percent from the Connecticut River, 12 percent from the Housatonic River and 9 percent from the Thames River. Both points and non-point sources of pollution of these rivers occur upstream from Massachusetts and Northern New England. A major source of non-point pollution is runoff form roads.
Studies have revealed that the biological foundation is threatened by the by products of human activity. All flora and fauna, such as fin fish and shell fish are subject to the effects of eutrophication, industrial or municipal discharges toxic pollutants in water and sediments, steam flow diversion, thermal pollution, siltation, and habitat destruction. Also filter feeding shellfish grown in water with high concentration of human sewage may bioaccumulate infectious microorganisms that can be passed on to the human consumers. Sometimes the ingestion of these infectious microorganisms can result in a tragedy (death).
Protecting the Long Island Sound fisheries from pollution will enhance the quality of life in Connecticut’s residents and bring about more tourism which will provide strength to the boating and fishing industries. All of the above will add to Connecticut’s economy because shell fishing and fin fishing are contributors. The winter flounder, lobster, and oyster are the most economically important species in Connecticut. Others are tacetoy, striped bass, blue fish, cod, fluke, shad, salmon, lobster, blue crab, clams, oysters, and scallops.
Connecticut’s State Department of Health Services has issued human health advisories regarding consumption of both striped bass and large blue fish, because of the concentrations of PCB’s in their tissues. PCB is a cancer causing agent. In the past four years there has not been any new data indicating whether the PCB problem is improving or worsening.
Shell fish obtain food by filtering seawater through their tissues, they can obtain infectious bacteria, viruses, parasites, and toxic chemicals that are present in the seawater. These harmful pathogens may be passed on to the consumer. Biological toxins from marine algae (saraytic, shell fish poison) when consumed may cause illness to humans or death.
It is believed that in the Long Island Sound the problem is intensified by excess nutrients entering the Sound via sewage treatment plants, runoff, and the atmosphere. In 1987 the Long Island Sound’s studies determined that hypoxia is more of a problem in the western half of the Sound. In 1988 the hypoxia conditions were slightly less severe while west of Bridgeport and Port Jefferson showed evidence of oxygen being below acceptable levels.
Microscopic plants (phytoplankton) growth is stimulated by the nutrients nitrogen and phosphorus in order to live. If there is an excess supply of nutrients phytoplankton grows in large quantities.
They produce oxygen during the day and at night they require oxygen for respiration especially when the phy to plankton dies it sinks and uses up still more oxygen from the water.
Hypoxia can occur naturally, especially in summer. This occurs when the sun warms the surface of the water forming a lighter layer that the water below. “This stratification reduces mixing between surface and bottom waters, so oxygen added to the upper part of the water column, through interface with the atmosphere and the photo synthesis of marine plants, is largely prevented from replenishing the oxygen in deeper waters.”
Computer models are being developed to betted understand the cause of hypoxia.
Hypoxia plays a role in animal reproduction. Studies indicate that the population of some animals (lobsters, window pane flounder) was affected by the presence of hypoxia.
The atmosphere deposited large amounts of copper and lead to the sediments in Central Long Island Sound.
The NS and T Program showed four elements and four classes of organic compounds having average concentration over three years. These concentrations differed among the nine Long Island Sound sites. The elements are silver (Ag), chromin (Cr), mercury (Hg), and lead (Pb). The organic classes are polychlorinated biphenyl (PCB’s), polynuclear aromatic hydrocarbons (PAH’s), and pesticides (DDT) and chlordane. Mussels and sediments in the Throgs Neck area show a general wester enhancement of contamination.
Contamination in Long Island Sound changes overtime. This change is brought about due to the condition in surrounding water. It is believed that mussel analysis is the best source to determine contamination trends over time.
Damage to DNA, the basic genetic material of an organism, may not affect the health of an animal but it is considered a necessary preclude of the kind of abnormal cell growth that cause tumors. Only one fish in the Sound was found to have liver tumors which was believed to have been contributed to contamination.
There is no test for determining the number of pathogenic organisms, but there is a test that counts indicator organisms. The indicator organisms are coliform bacteria which is commonly found in the intestinal track of humans and other warm blooded animals. These organisms can be found in water runoff. These bacterias are not harmful to humans but their presence indicates other pathogenic organisms may also be present.
Floatable debris presents a problem to marine environment, fish, birds, marine mammals, and turtles. These animals can be fatally entangled, especially in six pack rings, and they can ingest floatable debris which can cause suffocation or starvation.
In the past, medical waste was found on beaches all over the country. Although Long Island Sound has been exempted from that type of waste litter there is still a problem of litter washing upon beaches and shorelines.
Marine debris can cause beaches to close because of health hazards.
There is an effort to educate the public in keeping our beaches, waterways and shoreline clean of all pollution and litter.
| Habitat | Symbiosis | Commensalism | Mutualism | |
| Parasitism | Niche | Succession | Extinction | |
| Pollution | Precipitation | Phytoplankton | Biome | |
| Estuary | Ecosystem | Sediment | Tributary | |
| Flora | Fauna | Silt | PCB | |
| Hypoxia | Photosynthesis | Interface | Pathogen |
Performance Objective The students will be able to discuss what takes place in a symbiotic relationship and describe the three major forms in a symbiotic relationship with 100% accuracy.
| I. | ICE BREAKER: |
| A. | With the medicine dropper drop a drop of water on to the wax paper. |
| B. | Have the students write their description of the drop of water and everything that they know about water. |
| C. | Have the class share their information verbally and record on the board. |
| II. | VOCABULARY |
| Symbiotic | Mutation | Environment |
| Habitat | Parasitism | Succession |
| Commensalism | Niche | Extinction |
| III. | THREE MAJOR FORMS IN A SYMBIOTIC RELATIONSHIP |
| A. | Commensalism |
| B. | Mutualism |
| C. | Parasitism |
| IV. | REVIEW QUESTIONS |
| (symbiotic) | 1. A ____________ relationship occurs when two species live in close physical contact with each other. |
| (one) | 2. In a Commensalism relationship none of the species obtain food or shelter from the other species. |
| (does) | 3. A mutualistic relationship does not involve a reciprocal relationship where both species benefit. |
| (true) | 4. Habitat provides shelter and a place to reproduce. |
| (ever changing) | 5. Succession describes the stationary environment and the gradual process by which one habitat replaces the other. |
| (false (is)) | 6. Extinction is not a natural process. |
| V. | PLAN A FIELD TRIP TO THE WHITNEY WATER CENTER |
Performance Objective The students will be able to draw the water cycle and describe what takes place in each phase of the cycle.
| I. | ICE BREAKER: |
| Q1. (run water into a breaker) What is this? |
| II. | VOCABULARY |
| Precipitation | Percolation | Respiration |
| Evaporation | Condensation | Biome |
| III. | The water cycle (draw and explain) |
| A. | Water Sources | |
| l. Rivers |
| B. | Sun | |
| C. | Evaporation | |
| D. | Condensation | |
| E. | Precipitation | |
| F. | Transpiration |
| G. | Phytoplankton, Zooplankton |
| IV. | Film: | Toxic Waste Bullfrog films Catalogue, (organic chemistry biomagnification up the food chain, an environmentalist talk on safe environment, the role of government industry and public) 60 Minutes. |
| V. | Homework: | Students summarize what they feel the most important points were in the film Toxic Waste. |
| VI. | Activity: Building a Bottle Ecosystem. |
Performance Objective
| 1. | The students will be able to list four pollutants in the Long Island Sound. |
| 2. | the students will be able to list three ways to prevent pollution in the Long Island Sound. |
| I. | VOCABULARY: |
| Pollution | Tributary | Toxic |
| Contamination | PCB | Hypoxia |
| Phytoplankton | Zooplankton | Pathogen |
| II. | ICE BREAKER:. |
| III. | ACTUALLY TRY THE ABOVE |
| A. | Drop chemical(s) into the aquarium and plot your observations on the chart. |
| Sugar | 1 Drop | ||
| Cooking Oil | 2 Drops | ||
| Bleach | 3 Drops |
| 10 Minutes | 20 Minutes | 30 Minutes |
| B. | Observe physical change every ten minutes if the fish are still alive the following day change chemicals and report the procedure. |
| C. | Write a summary on what took place. |
| IV. | WATER POLLUTION |
| A. | What is pollution? |
| B. | Where pollution comes from? | |
| C. | The effects of pollution on plants and animals . | |
| D. | Pollution in Long Island Sound. |
| E. | Health Problems. |
Performance objective
| 1. | The students will be able to describe the cause of hypozia and relate it to problems in the Long Island Sound. |
| 2. | The students will be able to list two chemical contaminants in the Long iIsland Sound. |
| 3. | The Students will be able to list physical conditions related to water contamination. |
Questions
| 1. | How do you define water pollution? |
| 2. | Where does the pollutants come from? |
| 3. | What can be done to stop pollution? |
| 4. | What happens when you eat from polluted water? |
| I. | WATER POLLUTION | |
| A. | How pollutants get into water |
| B. | Eutrophication | |
| C. | Tributaries |
| D. | Health Advisories |
| II. | HYPOXIA |
| A. | Stress |
| B. | Nutrients and Sewage |
| C. | Microscopic Plants (Photoplankton) |
| III. | TOXIC CONTAMINATION |
| A. | PCB’s |
| B. | Atmospheric deposits |
| IV. | PATHOGEN CONTAMINATION |
| A. | Disease |
| B. | Source of Contamination |
| V. | FLOATABLE DEBRIS |
| A. | Health Hazards |
| B. | Affect on marine life |
| VI. | EDUCATION |
Activity Building a Garden Ecosystem
Select an area around the school. Section the area off with some type of marking. Observe any organic and inorganic matter. Be sure to include organisms above, on, and inside the ecosystem. Using a diary make interval recordings of your findings. Use the ecosystem year round. Do not remove any objects from your ecosystem.
Things to do... measure growth of vegetation, check for small animals (butterflies, flies, gnats, bees, etc.); check for trees, leaves, seeds, bugs, ants, worms, birds (feathers), rocks, new plants, grass, streams (life in the stream microscopic or otherwise), etc.
Maton, Anthea, Ecology Earth’s Living Resources, Prentice Hall New Jersey, 1992.
Moutran, Julia Spencer, Science Teachers Almanac, The Center for Applied Research; West Niack, New York 1992 (Practical ideas and activities).
“Water Precious Water” Book A A.I.M.S., Education Foundation, the California Department of Waer Resources, and Irvin Unified School District.
“Your Guide to Prevent Water Pollution”, The Terrence Institute, Washington D.C. 1991.
Barnes RSK. Estuariade Biology, Rusack and Co. Inc, New York p. 391, 1988.
Boremann Herbert and Likens, Gene E. Patterns and Process In a Forested Ecosysten, Springer Verlag, New York.
Odam Eugene P., Fundamentals of Ecology, W.B. Saungers Company, Philadelphia, PA.
Olmsteud, Nancy C., Plands and Animals of the Estuary, The Connecticut Arboretum, 1978.
Wiley Gosnori, Guide to Identification of Marine and Estuarine Invertebrate, Interscience 1971, p. 893.
Maton, Anthea, Ecology Earth’s Living Resources, Prentice Hall, New Jersey, 1992.
“Water Precious Water, Book A, A.I.M.S.” Education Foundation, The California Department of Water Resources, and Irvin Unified School District.
Allen, Dorothy. Hands on Science, The Center for Applied Research In Education, West Nyack, New York, 1991.
Oclum Eugene P., Fundamental of Ecology, W.B. Saunders Company, Philadelphia, PA.
Contents of 1992 Volume V | Directory of Volumes | Index | Yale-New Haven Teachers Institute
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