Long Island Sound is an estuary (a place where fresh river water mixes with salty ocean water). It is extremely productive in that it abounds with plant life, finfish, shellfish and waterfowl. It provides feeding breeding, nesting and nursery areas for many animals.
According to Living Treasures: The Plants and Animals of Long Island Sound, the Sound is 110 miles long from end to end, from East River to the “Race.” At its widest point, it is 21 miles and ranges from 60 - 300 feet at its deepest points; average depth - 65 feet. While most estuaries orient from North to South, the Sound orients from East to West. Its watershed, which is a place that receives the run-off and drainage of other bodies of water, reaches into five states and part of Canada.
Some rivers that drain into Long Island Sound are the Thames, Connecticut, Quinnipiac, and the Housatonic. There are more than 1,200 species of invertebrates and 170 species of fish. It is an essential food stop for dozens of species of migratory birds. There are salt marshes and tidal wetlands that provide sheltered nursery areas for many species of fish. In the tidal flats, sandy, muddy areas, we find gastropods and bivalve mollusks, horseshoe crabs and others. In the subtidal zone, there are benthic (of the sea floor) and pelagic (open water) communities. Included in the benthic animals are sponges, cnidarians like sea anemones, and coral. There are channeled whelks (conchs) and lobsters, which molt, often; and the blue crab, fiddler crabs, spider crabs, sea stars and sea urchins; skates, which lay eggs in purse-like pouches called a “Mermaid’s Purse.” In the pelagic zone or open water areas, things bloom bountifully; perhaps too bountifully because even algae blooms, which are not toxic, can cause havoc. The algae blooms result from excess nutrients in the form of Nitrogen discharged to Long Island Sound from treated sewage. The blooms multiply and die, using up tremendous amounts of Oxygen. This causes drops in Oxygen to dangerous levels for the other animals. There has been some attention given to this problem.
There are many groups protecting the watershed. In the Resource Directory of Agencies and Organizations focused on Long Island Sound and its watershed, organizations are listed by Environmental Organization: Connecticut National Region, New York etc.; Land Conservation Trust, Local Government; Museum/Nature Center; Regional Planning Organizations; and State and United States Government. Each also lists a mission statement, contact telephone numbers, E-mail; web sites, available resources and fees.
The Sound Book
, these organizations, recognizing the need for watershed protection, have identified significant issues and devised a plan to address them, involving local, state, and federal resources. The task is a difficult one because of these danger signs to watershed health: 1) Erosion from development sites of stream banks that carry nutrients and sediments, clog rivers and wetlands, and damage fish habitats. 2) Landscape trash ends up in the
3) Fallen trees block streams, causing flooding. 4) Algal blooms cause nutrient problems in natural waters. 5) Dead fish and wild life indicate low oxygen levels or polluted water. 6) Pipes (illegal pollution sources) spill into natural waters. 7) Failed septic systems. 8) Intrusion on watershed wetlands needed to purify storm water runoff. 9) Closed beaches and shellfish beds indicate pathogen contamination.
There are also many Living Resources and Habitats of the Lower Connecticut River listed in the Connecticut College Arboretum, bulletin #37. One can find information on the geology, hydrology and Ecology of the lower Connecticut River. The bulletin lists birds, fisheries, and human uses of Aquatic Resources. Students would find this book useful for doing research, but on an upper grade level.
Aquaculture Depends on the Health of the Ocean
Aquaculture (the farming of the sea) depends on the health of the ocean. According to Dr. Hank Trapido-Rosenthal of the Bermuda Biological Station for Research, Incorporated (BBSR); and his key partners: Dr. Stephen Giovannoni of Oregon State University; and Dr. Craig Carlson of the University of California, Santa Barbara (Partnership with Diversa); “This diversity has existed for three billion years and less than 1% of these marine animals have been classified and domesticated.” The staggering potential of extracting beneficial chemicals pharmaceutically is today greatly enhanced by such advanced technology as “cloning.” However, pollution has always been a threat to the health of the sea and to our fresh water.
There is always the threat of pollution. Our ground water, which is fresh water is very easily contaminated by pesticides, while other water lends itself to microbes, heavy metal in anti-fouling paints, waterborne diseases and chemical contamination.
As long as scientists have been studying the ocean, and because of biodiversity, they have only been able to identify, classify and domesticate less than one percent of the ocean’s many inhabitants. Little is known today about the pharmaceutical value of these plants and animals. My source for the following sections is DiscoveryWorks.
Let us consider two water ecosystems: freshwater and saltwater. Only 3% of the water on earth is freshwater. Our streams, ponds, lakes, rivers, swamps, bogs, marshes are considered to be freshwater even though they too, have some dissolved salts. Two percent of this total is locked in polar ice. The rest of the “freshwater” is in the ground or surface water.
Biomes are ecosystems that cover large areas of land. The major biomes are: the deciduous forest, desert, grassland, taiga, tropical rain forest, and tundra. Have students create a model of the biome in which they live and how it may have changed. Then have them create one that might have been before people inhabited it.
Living things in the freshwater community owe their survival to some abiotic factors such as: Is the water still or flowing?; Is it slow-moving or flowing rapidly?; What is the water temperature?; Is the water clear or cloudy?; and How much oxygen does the water contain? This is important because cold water holds more oxygen than warm water and fast-moving water holds more oxygen than slow-moving water. A river can be defined as running water. Rivers empty into lakes, oceans and other rivers. Rivers support freshwater fish, plants, birds and other forms of life. Lakes on the other hand are large standing bodies of water. Lakes provide many habitats for perch, bass, frogs, insects etc.
A wetland is an area where land and water meet. The soil of a wetland is watery and the oxygen is less than in a river or lake. Wetlands include marshes, which have mostly grasses and cattails; swamps, which mostly have trees and shrubs; and bogs, which consist mostly of mosses.
Ninety-seven percent of earth’s water is salty. One could consider the ocean as one continuous body of water. Its vastness makes it easy to support many forms of life, such as tiny, one-celled organisms to the highest mammals. Different organisms are found at different depths. Ocean water contains about 3 1/2 % salt, but this amount can vary. One of the projects, I plan for my students is to find out what % the “Sound” around us is salt? Ocean organisms are affected by water pressure, temperature and light.
The shoreline, where the ocean meets the land, has tides and waves that affect the organisms as well as rocks, sand and pebbles. Coastal ocean is home to kelp, jellyfish, whales. It also includes sponges, coral crabs, starfish. Coastal Ocean is shallow enough to allow sunlight to shine all the way to the coastal floor. Here is where Plankton, the basis of our food chain is plentiful.
Layers of the Open (Pelagic) Ocean
The pelagic (open) ocean covers most of the globe. Plankton abound in the upper layer while others swim in the next layer. Some live on the ocean floor without light or they make their own. Mid-water organisms include sharks, whales, manta rays, sunfish, and squid. Bottom dwellers are angelfish, viperfish and lantern fish.
There are other dissolved substances in ocean water besides salts. Six substances make up about 99% of these dissolved substances. Large amounts of dissolved gases, such as Nitrogen, Carbon Dioxide and Oxygen are also found in ocean water. The dissolved Oxygen is in addition to the Oxygen in the water molecule itself. Amounts of the Oxygen vary according to water depth and temperature. Near the surface, sunlight helps plantlike organisms grow. They release Oxygen into the water. So, surface water has more Oxygen. Gases dissolve easily in cold water so cold water areas in the world have more plants and animals. Plankton drifts with the current near the surface of the water. Phytoplankton, plant-like plankton, can only survive if there is Oxygen, Carbon Dioxide and other dissolved gases. Zooplankton, animal-like plankton, feed on phytoplankton. If the water cannot support phytoplankton, the zooplankton cannot survive either.
Sediments containing sand particles, bits of shells and decaying organisms pollute the other because they do not dissolve in water. Pollution caused by humans wreaks havoc in our oceans, especially when wastes from coastal communities are carried out to sea and dumped. These affect the quality of the water. Ocean water is a carefully balanced mixture that provides oxygen and food and support for living things in the ocean, which in turn support organisms on land - including us.
The Ocean- Resource for Life
The oceans of the world are a vast resource for life. Yet the exploration has barely begun. There is a CD-ROM (“Hello Down There”) which will allow students to take an imaginary trip 4,000 meters down. As they descend, they measure water pressure and temperature. They enter this data on a spreadsheet. Students identify the thermocline and click to learn about deep ocean organisms in the thermal vent. In (“Final Frontier”), students consider why oceans are an important resource. They “probe” to measure the ocean’s surface area, and try to determine the benefits to the marine life found there. They write their findings in a spreadsheet and analyze the data.
What is in the Water?
What is in the water? Salt! However, when the oceans formed billions of years ago, they were not salty. The two most common elements in salt are sodium and chlorine. In nature, sodium chloride, potassium chloride and magnesium chloride are present in rocks and soils. Rainwater flowing over these lands carries away traces of this salt as well as other elements and compounds. Rainwater drains into rivers and streams that let out into the ocean. The ocean keeps some of them. Those that come out of solutions form sediments and settle on the ocean floor. Even freshwater rivers and streams deposit dissolved salts in the oceans. On the average, 1 kilogram of ocean water contains 35 grams of salt. So, 3.5% of ocean water is made up of dissolved salts. My students will determine the percent of salinity in the “Sound” around us.
One suggestion is that students follow a drop of rainwater as it falls into a river and flows toward the ocean. They can also estimate the distance it would travel from the beginning of the river system to the ocean. Another mathematics challenge would be, to have students compare the amounts of water available from these sources: oceans, glaciers, granddaughter, lakes, rivers and the atmosphere. Oceans contain 97% of Earth’s water, glaciers - 2%, granddaughter - 0.6 %, lakes and rivers - 0.02%, atmosphere - 0.001%. If l mL = 1% and 5 drops of water =1 mL, ask students to calculate how many mL or drops of water they would have to put in jars representing each source? Results: Oceans - 97 mL, glaciers - 2 mL, granddaughter - 5 drops, lakes/rivers - 0.1 drop and atmosphere - 0.005 drop.
As we know, pollution (the contamination of the environment by waste), is a great threat to water. There are freshwater pollutants as well as ocean water pollutants. The lesson in
Science Horizons- Grade 5
, suggests a warm-up exercise. Water may not be as safe to drink today as it was 100 years ago. Ask students why. Divide students into groups and give each group a set of eight cards labeled: lake water, ocean water, pond water, tap water, water from the sink drain, melted snow, river water and melted icicles. Have each group classify these as suitable or unsuitable for drinking. Students can also identify the key contaminants of fresh water and their sources. Discuss the answers.
Three fourths of the earth is covered with salty water, which is unsuitable for drinking, industry and farming. Less than one percent of fresh water is usable and most of that is locked up in the polar caps and glaciers. This small percent of usable freshwater, found in lakes and rivers can easily be polluted by sewage (raw and treated), chemicals and heat. This sewage, material that passes down drains in sinks and is flushed down toilets has microbes in it that cause disease in humans and animals. It is therefore unsafe to drink. Chemicals such as pesticides, (including fungicides, hubicides, rodenticides, algaecides, and all biocides) can also pollute water supplies. Fertilizers are chemicals that add minerals to the soil, but are often carried away by runoff. The runoff carries fertilizers to streams and lakes. Laundry detergents can also pollute water. It is a substance used for cleaning, but contains phosphorous, which can help some living things to grow and others to die.
Simple algae plants may grow quickly in water containing phosphorus. When the algae die, microbes break down their remains, which uses up great amounts of Oxygen needed by fish. Heat can also pollute water. Heat from nuclear power plants raises the temperature of the ponds and rivers near these plants. Warm water holds less Oxygen than the same amount of cool water. Adding heat reduces the amount of Oxygen available to the living things in water. If the fish are very active, they will need more Oxygen, which is already scarce. However, wastewater can be purified by filtering it through several tanks of sludge and charcoal (which removes color from water). The sludge may also be burned or used as landfill. Chemicals are added to kill bacteria. The clean water is then tested for purity before being released into a river or lake.
Ocean pollution is caused by natural means and humans. People dump waste materials into the ocean and eventually, it washes up on the beach. It often consists of non-biodegradables (substances that do not decay) such as plastics. It is dangerous for sea life. Sea life and birds strangle, choke and suffocate on plastic. Cans, bottles, and wood are other harmful pollutants that should be recycled. Oil is another pollutant. Most spills leave an oil slick. The Exxon Valdez oil spill in Prince William Sound in 1989 was one that spilled 10 million gallons of oil into the bay. The oil slick covered everything. It killed many sea otters, birds, and even deer that fed near the shore. However, there are several ways to clean up an oil spill: it can be soaked up by absorbent materials, sprayed with detergents (a process called emulsifying) that break up the oil into droplets; skimmers can be used to remove the oil from the water’s surface; it can be burned by spraying it with laser beams from helicopters; add bacteria that digests oil, to the water and to the beach.
Water polluted with industrial waste can cause cancer in humans. Cancer is a condition in which some cells grow faster than others and gobble up good, healthy cells. They can form lumps and tumors. Cancerous cells can spread throughout the body.
An extension of the water pollution lesson would be to have each student measure the amount of water used from one tap in his/her home for a period of time. They should record whether each use was a legitimate use or a wasteful use of clean water. One more activity would be to make a charcoal filter to show how it helps to purify water.
In exploring our tap water, there is a kit that each student can use. It prepares the students, by having them work in groups. There is a vocabulary list that students will learn as they tour the “tap water route.” Distilled, “hard water,” and indicator are a few which are defined as we tour. Each group will do some record keeping, testing and cleanup. Students will test for iron, pH levels of purity, copper etc. Each should be made to understand, however, that failed experiments can also be a learning experience. For instance, if a student with an orange stain in the bathtub tests negative for iron, he needs to know that iron is unstable in solution and that it probably settled out of solution before testing began. Tests can also be done on pool water, puddles, fish tanks and rainwater.
In the kit, there is a list of water words, all defined: acid, algae, bacteria, base, calcium, Carbon Dioxide, chlorine, corrosion, disinfect, magnesium, monitoring, pH, scale and water conditioners. As an introduction, students will bring in a tap water sample in an appropriate container. The students will know that 3/4 of the earth is covered with water and less then 0.4% is fit for consumption; and that the average family uses 300 gallons of water per day.
Unit 1 - pH Testing
The kit comes with all the testing materials. For pH testing, there are pH tablets, sample bags, baking soda, aspirin, vinegar, tap water, straws, 4 quarts of distilled water, 3-quart containers, a data sheet, a prepared poster for class results and, color chart paper. A pH scale is used. The definition of pH is a scale that tests for the acidity or baseness of water. The scale ranges from 0 - 14, with 7.0 (middle of the scale) being neutral. Students will discover that lemon juice, cola, and vinegar are highly acidic, while household bleach is very basic. Each will use his/her 3 water samples to test for color and pH. Put in a tablet, close the bag and shake so that the tablet dissolves. Do this with Carbon Dioxide and baking soda. Compare the resulting color with the chart. Ask students to journal about what they learned.
Students will also want to know how our water is purified. A trip to the Water Purification Plant is in order. Some students may use well water. That being the case, they will need to know that rocks and soil act as filters for our drinking water. The same rocks and soil that septic tanks drain into help to purify our drinking water. There is a Water Pipe Diagram which shows how corrosive water with a low pH of 5.0 can be to pipes, virtually destroying them. Water with a neutral pH of 7.0 will not harm pipes. Water with a high pH will “clog” pipes.
Unit 2 - The Chlorine Test
The chlorine test follows the same procedure. Using DPD #4 tablets, students will test each sample and chart the results. Chlorine will kill bacteria and control algae. It is added to city water supplies. When this activity is completed, charts are filled in and students will be asked to journal about the results. Students should know that chlorine bleach has some residual effects and lasts beyond its first use.
Unit 3 - Testing for Iron
Testing for “iron” follows the same procedure. In the five steps of sample #1, we fill a quart container with distilled water, and leave one empty. One supplement tablet is put in a cup to which 3 teaspoons of distilled water is added. Swirl to dissolve the tablet coating because the coating will interfere with the color development. Mix the uncoated tablet in one quart of distilled water for 30 seconds. Put the water into the empty container. What happened to the tablet? It probably will look the same. Some forms of iron do not react with the tablet. Iron bacteria causes rust and has a foul odor, but will not give a positive test. In sample #2, measure out 1/2 cup of sample #1 and put it in an empty, clean, one-quart container. Fill the container with distilled water. Avoid handling the iron tablets with wet hands. It is a skin irritant.
During the iron activity, group students and have someone on the team fill a bag to line “C” with sample #1 and sample #2. Add a LR iron tablet to each. Close the bag and shake. Compare the resulting color with the color chart and record the data on the data sheet. Compare the two tests. Which one is darker? (#1) because it has more iron. Then have the students test their tap water samples for iron. Ask the question, “Do you have iron? How concentrated is it?” Compare the color to the reaction with the color chart poster. Record the answer on the data sheet. The data sheets are a good tool for the students to use. The activity engages them and keeps them focused on the task.
Unit 4 - The Copper Test
Next is the copper test. Small amounts of copper are found in natural water. Sometimes people put copper in water to control algae. Copper can also dissolve in your water from copper pipes and fittings. Only acidic water dissolves copper from inside the surface of pipes. Students should be reminded of the pipe diagram on the pH section. They will learn that people use copper solutions to treat fish with bacterial disease. The copper kills bacteria. They should answer question like, “Was your water acidic?, Do you have copper in your water?” Bathtubs and sinks have a blue-green stain if copper is present. Students should use the data sheets. Teams will fill a clean bag to line “C” with tap water and add a Copper HR tablet. Close the bag and shake. Compare the color with the color reaction chart. Record the copper concentration on the data sheet.
Another experiment is to have students place a penny in vinegar. The acidic vinegar will dissolve some of the copper. If enough of it is dissolved, the solution will become blue. Try to get the students to see the connection that acidic waters can dissolve metals out of pipes. There is a Word Search to go with these activities. The students will keep their data sheets and Science Journals.
Unit 5 - Checking for Hardness
There is an activity to check for hardness. Not all liquid hand soaps will produce bubbles. Students will use a liquid hand soap in deionized water to attempt to get bubbles. It probably will not work with soaps that have a lot of additives. These tend to overcome the affects of calcium and magnesium. They might also try the soap in the classroom. One drop of ideal soap in deionized water should give a rich lather. Several drops of this soap in hard water should give no bubbles, and make cloudy, bathtub water. Hard water has a lot of calcium and magnesium minerals dissolved in it. It is responsible for the spots on your drinking glasses, the white crusty scale on the showerhead, and even the ring in your bathtub.
One experiment that dealt, not specifically with hard water, but with the detergent that gave more bubbles or washed the most dishes for the money, is one that could be used here as well. Use one cup of water, add one drop of glycerin and 1/2 ounce of detergent. After mixing the solution, spill one teaspoon on a smooth counter or one covered with a taped down garbage bag. Have each student blow through a straw at counter level until a bubble starts. Blow the bubble as large as you can. When it pops, measure the footprint and chart the information.
In the hardness activity, a clean bag is filled to line “A” with tap water; add a T hardness tablet; close the bag and shake. Compare the results to the color chart. The ring in your bathtub is formed when your soap reacts with the calcium and magnesium in the water. In doing so, it gets all used up and cannot remove dirt. So, in washing clothes, dishes, cars, and pets, you should use more soap if you have hard water.
Do the bubble test. Use 2 bags, filling one with a hard water sample and one with distilled water. Ask, “Which one has more calcium and magnesium?” The hard water does, of course, because the distilled water is pure.
The activity includes using a cardboard strip to add one drop of soap at a time to your water. Keep adding until you get bubbles. Record which sample needed more soap to bubble. There is a bubble gram game for this activity.
At the end of all of these activities, is a summary. The tour can be summarized. The Water Quality Report is a wrap-up in itself. The report should generate discussions on actual results. Water Quality Reports and Crossword Puzzles are handed out. Some summary topics that we should be concerned about are (the presence of); pH, corrosion, scale; chlorine, taste, smell, bacteria; iron, stains; copper, taste, stains; hardness, crusty deposits, uses too much soap.
There is a concept map on Ocean Water found in a grade 6 Houghton Mifflin
, which I think will benefit my students. A discussion starter might be to ask what a marine biologist would use to monitor whether or not a pollution problem is getting better or worse. Some things would include the amount of garbage in the water; cloudy water, fewer living things and changes in their behavior or health. These chapters abound in vocabulary words. Some could be made into a puzzle: plankton, zooplankton, salinity, photosynthesis benthos, phytoplankton, and nekton.