Investigating the surface of the sea

Float a needle on the surface of a glass of water. Add a drop of detergent to the water and observe what happens. How could detergents harm the delicate skin of the sea?
Observe calm water from an overlook or a boat to see windrows on the surface of the sea or a lake. In a protected area, like a marina, look to see what pollutants you might find on the surface of the water. Are there oil slicks? Floating trash? Discuss how these might harm the skin of the sea.
Get some wide clear sticky tape (the kind used in packing). Find smooth surfaces (glass, metal, automobiles, tiles) in different indoor and outdoor environments. The surfaces should not have been cleaned or washed recently. If you can, find out how long it has been since the surface was washed or wiped. Cut a strip of sticky tape about 70-mm long and fold over one end about 5-mm to form a tab. Place the tape over the surface and smooth it down, then lift it off again along with the dust, dirt and "fallout" from the surface. Write down the time and exact location of the sample on a piece of paper and stick the tape onto the paper. Collect samples from vertical and horizontal surfaces, upwind and downwind of urban areas (perhaps students living in different parts of the community can sample near their homes to get a wider sample range).
In the classroom, begin a "fallout" loose-leaf notebook of the samples. Compare samples. Where does the heaviest fallout come from? What colour is it? Can you guess where the material came from (a farm, a fire, an industrial activity, heavy motor vehicle traffic, construction).
Discuss how chemicals put onto farms and gardens to kill unwanted plants or insects could become bound up in dust particles during dry periods. How would these effect the plants and animals that live at the sea's surface when the dust blows out onto the ocean?
Collect some fall-out with a rubber or plastic blade. Place some in a glass of water and observe what happens to it. Does it float? Does it form an oil slick? Is it easily soluble in water? If not, will it dissolve easily when detergent is added to the water? (Form 6 and 7 students might investigate other physical parameters such as pH, toxicity to micro-organisms, or even heavy metal content).
Place a clean white, uncovered plastic container (an ice-cream container works fine) in an out of the way place in the classroom, and in an open, but covered, shed where air, but not rain, and pass the container. Write "Science Experiment do not clean or move" on the outside with a felt-tip pen. After four weeks, examine the inside of the container. Using a plastic or rubber blade, scrape any dust or fall out into a single pile (be careful not to blow on it). Place the sample on a piece of paper and seal it in place with clear sticky tape. Record the time and place the container was set out and collected. Note if the weather was dry or wet during the experiment. Repeat the experiment at a later time, perhaps when the weather has been different.
Design a rotating drum to sample the surface film from a boat. Dr. Hardy's surface film collector has a Teflon-coated drum towed alongside the research vessel. Organic film adheres to the drum and is continuously scraped by a squeegee into a large glass jar.
Design a special plankton net with pontoons that can skim just the top few centimetres of the skin of the ocean to collect surface-dwelling crustaceans, fish eggs and larvae.
Make (or buy) a plankton net and collect some plankton from the surface of the water in a protected embayment (or from a boat). During algal blooms, the phytoplankton is so thick one can simply collect some by scooping them up in a jar. Use a microscope to examine the plankton and record what you find. Look for larvae and fish eggs. Discuss the specialisation's of these organisms that enable them to survive in the upper zone of the sea. Consider the impact of various environmental pollutants on these creatures and what this might do to the ability of the creatures to maintain their populations.