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The Green Machine1 Charles Jacoby, Nanette Holland, and Debbi Berger2 The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with nondiscrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service. U.S. Department of Agriculture, Cooperative Exte nsion Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean. Copyright Information This document is copyrighted by the University of Florid a, Institute of Food and Agricultural Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all conventions, but permits free reproduction by all agents and offices of the Cooperative Extension Servi ce and the people of the State of Florida. Permission is granted to others to use these materials in part or in full for educational purposes, provided that full credit is given to the UF/IFAS, citing the publication, its source, and date of publication. 1 This document is CIR1512, an Activity in an Invasive Specie s Curriculum (CIR1496), and it is reprinted by permission of the Tampa Bay Estuary Program and The Florida Aquarium. Original EDIS publication date : January, 2007. It was supported by the Tampa Bay Estuary Program, the Florida Aquarium, the Department of Fisheries and Aquatic Scie nces of the University of Florida, and the National Sea Grant Colle ge Program of the Nationa l Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce, under NOAA Grant No. NA 16RG-2195. Visit the EDIS Web Site at http://edis.ifas.ufl.edu 2 Charles Jacoby, Assistant Professor, Depa rtment of Fisheries and Aquatic Sciences, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611; Nanette Holland, Public Outreach Coordinator, Tampa Bay Estuary Program, 100 8th Avenue S.E., MS I-1 / NEP, St. Petersburg, FL 33701; Debbi Berger, Vice President of Education, The Florida Aquarium, Inc., 701 Channelside Drive, Tampa, Florida, 33602.
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T T h h e e G G r r e e e e n n M M a a c c h h i i n n e e Objectives: Students will: !" Be able to id entify two s a mpling methods used in reef research. !" Be able to e xplain which sampling methods most accuratel y represent th e reef as a whole. !" Be able to explain why different methods are appropriate for different studies. !" Be in troduced to Green Tide, Caulerpa brachyp u s an invasive algae affecting coastal Florida. Materials: !" Large open area (open classroom size or larger) !" 10 15 who l e pieces of constructio n paper. !" Approximat ely 60 cup lids or Tupperware lids a n d 25 35 paperclips. !" Two metric tape measures. !" 1 x 1 meter quadrat of PVC pi pe with ten 10 cm x 10 cm squares formed by string. !" Calculators. Background: Increasing in numbers, spreading, or occupying space are common characteristics of an invasive species that is a non-native species that can cause harm. Measuring changes in abundance, the number of organisms in an area, or cover, the space cove red by plants or animals, becomes important to scienti s ts that attempt to study effects and impacts of an invasive species. Green Tide on a co ral reef provides an exa m ple of how scientists accomplish this critical task. 1 Sneak Peek Students will be introduced to Green Tide, a nonna tive underwater al ga affecting Florida reefs. They will expl ore two me thods t o sample coral reefs: quadrat and point transect. Stu d ents will calc ulate the amount of Green Tide, c o ral and fish found on a reef in the classroom. This activity incorporates math skills and data gathering, recording and analysis. Aligned wi th the followin g Sun shin e State Stan dards an d FCAT Benchmarks for grad es 6-8: SC.D.2 .3 .2 AA SC.G.2 .3 .4 AA SC.F.1 .3 .7 CS SC.H.2 .2 .1 CS SC.G.2 .3 .3 CS AA = annually assessed CS = con t e n t sam p led
How can coral reef scientists determine how many plants or animals live in an area? Working underwater to determine how ma ny living things are there can be tricky. Sampling is one way to determ ine how many plants or animals, including coral, are on a reef. Sampling focuses on counting living things in a few small sections of the reef, and the results are used to estimate quantities for the whole reef. Green Tide, or Caulerpa brachypus is a non-native alga that is spreading along the East Coast of southern Fl orida. It smothers and kills corals, forcing fish and invertebrates to find other places for food and shelter. Determining how much Green Tide is on reefs represents an important step in understanding and potentially stopping its spread. What are two common sampling methods? Quadrats are survey grids of a fixed size and shape. In one of the most common forms of sampling, these grids are randomly placed in the study area (not only in the most or least diverse sections). Once the quadrat is placed on the reef surface, plants and animals within the grid can be counted or the area covered by plan ts and animals can be estimated (e.g. coral covering more than 50% of the grid). Point Transects use a tape measure anchored at a randomly chosen point and stretched to a predetermi ned length. In this method, the presence of coral, rock, algae or an y plant or animal of interest at predetermined intervals (e.g. every 10 cm) is recorded. Divers using quadrat equi pped with a camera to measure coral cover. 2(Courtesy of University of Hawaii Botany department: http://www.hawaii.edu/reefalgae/publications/methodsmanual/photoquadratsurvey.htm )
Procedure: 1. Before class, place five pieces of construction paper in each of 2-3 patches to represent coral reefs on sand (make the total area of sand and coral to be sampled at le ast 3 X 3 meters). Scatter lids and paper clips around the reefs. The lids represent Green Tide and the paper clips are fish. Do not place paper clips on top of the lids. 2. Count the fish and measure the area covered by coral (construction paper) and Green Tide (lids). 3. Split students into at least th ree groups. Each group will perform both sampling methods and record their data. a. For the quadrat method, have students randomly place the quadrat within the area to be sa mpled. Classify the area under each 10 cm-squared part of the grid as coral, sand or Green Tide based on whichever covers more than 50% of the area. Have the students count the number of fish in their quadrat. Repeat this several times. Instruct students to select the random areas by using criteria such as paces in predetermined directions. b. For the point transect method, place one end of the tape measure randomly on the reef. Stretch the tape measure out to 1.5 meters in any direction. Have students record what is directly under the tape every 10 cm. 6. Use the worksheet to determine th e total percentage cover of coral and Green Tide and fish density for each method. 3
THE GREEN MACHINE WORKSHEET NAME ____________________________________ DATE ____________________________________ QUADRAT METHOD TOTAL # OF GRIDS IN QUADRAT # OF GRIDS CONTAINING 50% OR MORE CORAL OR GREEN TIDE % COVER OF CORAL OR GREEN TIDE (# OF GRIDS CONTAINING CORAL OR GREEN TIDE / TOTAL # OF GRIDS) CORAL GREEN TIDE TOTAL QUADRAT AREA # OF FISH IN QUADRAT FISH DENSITY (# OF FISH / TOTAL QUADRAT AREA) FISH POINT TRANSECT METHOD TOTAL # OF POINTS SAMPLED # OF POINTS DIRECTLY OVER CORAL OR GREEN TIDE % COVER OF CORAL OR GREEN TIDE (# OF POINTS OVER CORAL OR GREEN TIDE / TOTAL # OF POINTS) CORAL GREEN TIDE TOTAL # OF POINTS SAMPLED # OF POINTS DIRECTLY OVER FISH WIDTH OF TAPE TOTAL AREA SAMPLED (TOTAL # OF POINTS x WIDTH OF TAPE) FISH DENSITY (# OF POINTS DIRECTLY OVER FISH / TOTAL AREA SAMPLED) FISH 4
1. Which method was the hardest to do and why? Which method was the easiest to do and why? 2. Pick one of the sampling methods and explain why your estimates of fish, coral or Green Tide differ from wh at is actually on your classroom reef. 3. If you were a scientist studying Green Tide, which method would you use and why? 4. Using what you learned in this e xperiment, why do you think Green Tide poses a problem for corals and fish? 5
6 Glossary: Invader/Invasive Species A plant or animal that is not native and causes harm, including disrupting natural ecosystems. Non-native species A species introduced to a region intentionally or accidentally. Quadrats Survey grids of a fixed size and shape. Point transect A series of points surveyed along a tape measure anchored at a random point and stretched to a predetermined length.