M-10: Kelp Overview: Students explore a wide variety of uses of kelp and its important role in the marine ecosystem.

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1 An activity from the Environmental Volunteers M-10: Kelp Overview: Students explore a wide variety of uses of kelp and its important role in the marine ecosystem. Program Area: Marine Ecology Grade Levels: 3-6 EV Learning Objectives: 1. Seaweed s structure differs from that of soil plants due to its water environment. 2. The brown algae, or kelp, that makes up the kelp forests along the pacific coast is harvested commercially to provide a variety of useful products. 3. The kelp otter urchin relationship is a delicate balance that affects the health of the kelp forests. EV Sustainability Principals: C. Practicing responsible use of our planet s resource in sustainable, and appropriate ways, leaving them in good shape for future generations. E. Understanding the beauty of our planet, the elegance of natural systems, and the interconnectedness of all its parts. MATERIALS LIST Kelp poster Samples of kelp plants Samples of seaweed-related products i.e.: toothpaste, agar, chips, ice cream cartons CALIFORNIA EDUCATIONAL STANDARDS All standards are for science unless otherwise noted. 1 Third Grade 3a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction. 3b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands. 3c. Students know living things cause changes in the environment in which they live; some of these changes are detrimental to the organism or other organisms, and some are beneficial. EEI Learning Objectives 3a-1 Identify that plants and animals have different structures that allow them to grow, survive, and reproduce by using/consuming the goods and ecosystem services provided by natural systems. 3c-1 Identify how living things (including humans) can cause changes in the environments in which they live. 3c-3 Explain how changes to the environment, brought about by an organism may harm that organism or other organisms. Fourth Grade 2a Students know plants are the primary source of matter and energy entering most food chains. 3b. Students know that in any particular environment, some kinds of plants and animals survive well, some survive less 1 Note about EEI Learning Objectives: this learning station supports these objectives of the Education and the Environment Initiative s Environmental Principles and Concepts. As the learning objectives do not have their own numbering convention, the one used here show the number of the standard before the dash and the number after the dash is the bullet point from the list of objectives for that standard. M-10: Kelp Page 1 Last Updated 2/27/16

2 well, and some cannot survive at all. EEI Learning Objectives 2a-2 Recognize that plants are the primary source of energy for living things in an ecosystem. 2a-3 Explain how living things meet their needs and survive by using resources (e.g., matter and energy) from their environment. Sixth Grade 5e. Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition. ACTIVITY BEFORE CLASS SET UP Take a small sample of seaweed from the kit and soak it for a couple hours in water. ACTIVITY 1: Seaweed structure (Time required:5-7 minutes) Show students the dried samples of seaweed and let them feel and observe the samples. You can refer to the visual aid that shows parts of a kelp plant. Ask students what four things all plants (and living organisms) need in order to survive. Earth (nutrients), air (carbon dioxide), sun, and water. Have students identify a holdfast and ask what purpose it serves. How does the seaweed get water and nutrients? It is similar to a soil plant root in that it holds the plant in place. This is its only job, which is extremely important due to the force of currents and tides. Roots also acquire water and nutrients for the soil plant. Seaweed does not need this since both can be directly absorbed through the blades or fronds. Have students identify a stipe and ask what purpose it serves. It is similar to a soil plant stem and supports the kelp and defines its structure. However, it does not need to transport water and nutrients, so its structure is simpler. Have students identify blades and ask what purpose they serve. Blades are similar to soil plant leave. They are the primary location of photosynthesis. Have students identify air bladders and ask what purpose they serve. Air bladders help float the blades to the surface of the ocean for better access to sunlight. Ask why kelp grows where wave action is the greatest. This is where the shallow water begins and seaweed needs access to sunlight. Also, nutrients needed by seaweed are stirred up by waves and are more accessible. Show sample of seaweed that has been soaked. Let students feel it. Gives students a feel for what seaweed is like slippery, tough (especially lengthwise). M-10: Kelp Page 2 Last Updated 2/27/16

3 Identify red, green and brown algae in the samples. Ask why they are not all green, since there is photosynthesis. Note red and green are not as thick and tough as brown. Other pigments mask the green of chlorophyll. Note that only the brown algae are called kelp. Ask how each plant reproduces itself. Flowering plants produce flowers and seeds. Seaweed doesn't, but it does reproduce by gametes male/female sex cells or by regeneration from the holdfast. This is similar to mosses and ferns. ACTIVITY 2 Economic Importance (Time required:5-7 minutes) Ask if any student has eaten seaweed. Most will say No since they don t recognize seaweed in what they eat. Tell the students that communities that live near an ocean eat a lot of seaweed but it can be found in almost any culture s food. Show food product packages (soup, sushi wrap, crackers, etc.). Ask if any have eaten similar foods. Most will now realize some of what they have eaten is seaweed. Many of these samples are not kelp (see background information). Explain that kelp is harvested by barges, but that there are regulations on how much can be harvested (no deeper than 4 ). Ask students if they can tell you why such controls are necessary. Cut too much in general and you can kill the plant. Cut too deep and you can limit how much sun the plant gets and so stunt its growth. These can have a negative impact on the health of the kelp forest and thus the entire local food chain (see section 3). State that the products made from the harvested kelp are used extensively in food and other manufactured items for emulsification (blending oil and water), thickening, and texture. List some of these products by looking at the packages that are in the kit. Have them look at the ingredient lists to find kelp. Rarely does a label just list kelp or seaweed in an ingredient list. Have the children look for algin and carrageenan, both extracts from kelp. Ask students why kelp is the primary seaweed in this harvest. It grows extremely fast (up to 8 inches a day), and it is large and abundant. It renews itself easily generally it can regrow the legal 4 harvest in a week. Discuss uses of other seaweeds. Red algae looks like a delicate fern. Make agar-agar. Doctors use this for throat cultures by taking a swab of suspected bacteria & incubating it in the petri dish. Orchids are cloned in test tubes filled with sugar agar for a nutrient gel to hold delicate, growing plant. M-10: Kelp Page 3 Last Updated 2/27/16

4 ACTIVITY 3: Kelp Food Chains (Time required: 5 minutes) Using the kelp forest visual aid, give each child an animal to place on the poster to make a food chain. Discuss where the animal fits on the food chain. What are the major producers (kelp)? What are the major herbivores (urchins)? What are the major predators (otters, humans)? How do other animals fit in? Remove sea otter from the poster. Ask what would happen if sea otters were not protected from hunting. Kelp beds might disappear again due to destruction by urchins. Other animals will disappear due to lack of the kelp forest environment. Ask what dangers can be foreseen if the otter population grows too large? A herd of 2,000 otters eats 20 million pounds of invertebrates in a year! Reduce numbers of abalone; then as otters deplete abalone supply, they switch to digging for clams. Ask who besides marine animals would feel the loss of kelp beds? People economic loss of kelp products. Ask how an oil spill off California would affect this food chain? Otters would die because oil removes air insulation, the trapped air from their fur, and otters do not have subcutaneous fat to keep them warm. Sea weed coated in oil is also not useable. Ask what effect El Niño would have on this delicate relationship knowing El Niño makes warmer waters and sea urchins love warmer water. Urchin population would increase; otters may not be able to eat sufficient urchins to maintain a balance. TWO-MINUTE WARNING (Time required: 2 minutes) Review the key concepts of the kit. ALTERNATE SCRIPTS HELPFUL HINTS GLOSSARY algae any of a group of lower plants having chlorophyll but no vascular system, including many seaweeds and related fresh water plants. bladder structure containing air that is attached to a stipe and helps raise the blades toward the surface of the ocean. M-10: Kelp Page 4 Last Updated 2/27/16

5 blade a flat, elongated organ resembling a leaf. This organ is where most photosynthesis takes place. food chain a sequence of plants and animals that depend on one another for food. The lower elements of the chain (the producers) serve as food for the higher elements (the consumers). frond a connected set of blades attached to a stipe. holdfast the organ that attaches a seaweed to a solid support, usually a rock. kelp macroscopic brown algae. stipe the stem-like organ of a seaweed that connects the fronds to the holdfast. M-10: Kelp Page 5 Last Updated 2/27/16

6 BACKRGROUND INFORMATION I. Comparing seaweed structure to soil plants: Since seaweed exists in a water environment, it does not require strong support or a water conducting system. Seaweed does not contain roots but lives attached to a stable support, usually a rock. The organ of attachment is called a holdfast. Without this holdfast, wave and current action would carry kelp away from the shore. Kelp needs to remain in the intertidal zone to receive the appropriate nutrients and salt content. Instead of water conducting stems, kelp has hollow, flexible stipes, which move with wave action and serve to keep the blade-like fronds upright for increased exposure to sunlight. Since water is used for support of the stipe, it does not have to be rigid like the stem of a soil plant. At the end of each stipe are gas-filled bladders which keep the plant afloat, near the surface for photosynthesis. At the end of the air-bladders hundreds of structures emerge that resemble leaves but are called blades. It is within the blades that most photosynthesis occurs. Blades may be different shapes, but their large, elongated form allows them to spread across the water to capture the maximum amount of sunlight. During severe storms, stipes may break and plants are washed ashore. Usually the holdfast remains in place and a new stipe can grow. Kelp plants also reproduce from spores dropped from the blades. These spores have flagella (moving hairs for swimming). Spores develop into male (sperm) and female (egg) gametes which combine to produce a miniature kelp plant. II. The economic importance of seaweed: The word kelp is derived from Middle English word referring to ash. During this era brown algae, now called kelp, was burned to produce ash for soap-making. Seaweed is primarily complex algae, and has been used as food for hundreds of years. It contains protein, vitamins and minerals. (There are small amounts of seaweed that are vascular plants that have moved back into the water, such as eelgrass.) There are three varieties of marine algae: red (agar-agar), green (sea lettuce), and brown (macroscopic browns are called kelp and have many uses). Here is a more detailed discussion of the three varieties of marine algae (note: other products come from each variety of algae, the descriptions only give a sample): Red (phylum: rhodophyta) produces Nori (used in many oriental foods), agar (a thickening agent and a growth medium), and carrageenan (similar to agar). The blade of these algae is very thin, only a few cells thick. Green (phylum: chlorophyta) produces Anori (used for food similarly to Nori) and ulva (green sea lettuce, which is also edible). The blades are always 2-cells thick. Note: Together, red and green algae make up a significant part (on the order of 50%) of what is washed up on the beach or found in tide pools. Thus what is seen on a field trip is as likely to not be kelp as to be kelp. Brown (phylum: phaeophyta), called kelp, produces algin (a thickening and emulsifying agent used in many products) and laminaria (used in M-10: Kelp Page 6 Last Updated 2/27/16

7 soups and other foods). The blades of these algae are often thicker than the other two. Note: 70% of the earth s surface is covered with water. This water contains algae! More than half (and maybe as much as 80%) of the oxygen we breathe comes from these algae. To solve the air quality problem, we need to save the oceans as well as the tropical forests! The brown algae, or kelp, that makes up the kelp forests along the Pacific Coast is harvested commercially to provide a variety of useful products. It is an extremely rapid growing plant, reaching ft. in length. If conditions are right (nutrients, sunlight) each stipe may grow 20 centimeters per day. In Southern California barges with an underwater mowing machine cut the upper portion of the kelp (sample picture). State regulations limit cutting to 4 ft. depth. Conveyor belts haul the kelp aboard. Photosynthesis of kelp is increased after cutting as more sunlight reaches the canopy. Approximately 150,000 wet tons of kelp are harvested in California waters by this method. Once harvested, the brown algae, or kelp, are processed to produce algin, a dry powder that acts as a stabilizer and emulsifier in many foods. Algin keeps pigment particles mixed with accompanying liquid (cosmetics, paints). As an emulsifier, the algin binds oily and watery fluids together (salad dressings do not separate). As a stabilizer it thickens and smoothes products such as ice cream, instant puddings and soups. Other uses are fodder for animals, fertilizer for plants, and softens leather for tanning. Green and brown algae are both used in soups, stews, crackers, cookies for flavoring and nutrient content. Red algae are a source of carrageenan and agar. Nori is probably the most popular type, used in soups and stew. Industrially, agar is used a gel for a media base (microbiology) or as a sugar media for cloning flowers such as orchids. III. The kelp forest food chain: Kelp grows in cold waters within the intertidal zone where conditions are just right (nutrient runoff, specific salinity and wave action). The Pacific Coast has one of the greatest diversities of this plant. The kelp otter urchin relationship is a delicate balance (symbiosis 2 dissimilar organisms living together). Reduce one part of this relationship and the delicate chain falls apart. Sea urchins are the only marine animal to directly devour kelp beds. Sea otters help kelp beds flourish by feeding on urchins. Otters have pockets under forearms to carry food to the surface. The absence of sea otter populations, due primarily to fur hunters (see handout), has been shown to have significant consequences for all marine life in the intertidal zone. Without the otters, kelp beds rapidly disappear as sea urchins not only eat the large plants, but also devour any new plants before they can become established. Otters rely on the kelp forest for an urchin food supply, as a safe habitat, and as a safe haven for their young (otters wrap kelp around themselves and young as protection against wave action. Sea otters are one of the animals capable of using a rock as a tool to crack open another of its favorite food, abalone & crabs. Disappearance of kelp beds means loss of habitat and food for many fish species, mollusks, and small marine invertebrates. These animals, in turn, are eaten by crabs, sea stars and larger fish. Going up the food chain, larger mammals (sea lions, otters) and birds (cormorants, gulls) eat the M-10: Kelp Page 7 Last Updated 2/27/16

8 crab, abalone and small fish with the ingested kelp. Fish such as the kelp bass live within the kelp forest, well protected from predators. Kelp provides more carbon to the food chain than do phytoplankton, thus adding to the base of the food chain. In areas where kelp beds are prevalent, many sea animals are fed. Wave action rips kelp blades into small pieces that decompose to become food for filter feeders and small invertebrates. Currents carry this food to surrounding areas. The kelp forest attracts many fish species not only for food but also for protection. However, the dense canopy of kelp limits the amount of sunlight that can penetrate deep waters, thus inhibiting growth and habitat of some fish species. EV SUGGESTS- TIPS, TRICKS, AND NEWS REFERENCES M-10: Kelp Page 8 Last Updated 2/27/16