Edible Trawl Yes, you can eat this experiment!
Next Generation Science Standards In this lesson, students will learn how the selection of sampling gear depends on the questions being asked. Students will trawl, sort and measure a catch, and graph their results. Next Generation Science Standards addressed include: Life Sciences LS2C Ecosystems: Dynamics, Functioning and Resilience LS4C Adaptation LS4D Biodiversity and Humans Engineering, Technology, and Applications of Science (ETS1B) Emphasis is on developing possible solutions to sampling ocean life.
Outline What are some ways we sample the ocean? How do scientists know what gear to use? What can the body types of animals tell you about how and where they live? Hands-on fun trawling, sorting, measuring and graphing results. If edible items are used, the trawl catch can be consumed following the activity!
Overview and Supplies Duration: approximately 60 minutes for overview and activity Bin that can comfortably hold about 2 cups of rice per student (I use a 10 lb bag for 18 students). This is the ocean to be sampled. Handheld mesh strainers (note, I use two different sizes (diameter and mesh size) to add teachable moments about gear selection and its influence on what/how much is caught. One plastic bowl/small container per student Assortment of edible animals to put in the ocean. See next slide for ideas One sheet of graph paper per student Colored pencils, crayons or markers Centimeter ruler
Large oyster crackers: Porifera sponge Cereal: Crustacea crab Raspberry gummies: Cnidaria coral Cereal: Echinodermata sea urchin Circular string liccorice: Cnidaria anemone Goldfish crackers: Chordata rattail fish Gummy worms: Nematoda round worm Gummy fish: Chordata cusk eel Small oyster crackers: Mollusca clam or oyster Gummy fish: Chordata tripod fish Gummy worms: Annelida segmented worm NOTE: There is a wide assortment of gummy animals if desired (lobsters, octopus, sharks ).
There are many different platforms from which the ocean is studied. Buoys Vessels Satellites Aircraft
The tools you use depend on the questions you are asking. Are you studying animals with soft bodies?
Are you studying very small animals?
Are you studying very large animals?
Are you studying PELAGIC animals that live in the water column or BENTHIC animals that live on or near the sea floor?
What gear should I use?
Examples of fauna found on or near the sea floor in the Gulf of Mexico Porifera Sponges Cnidaria Corals, anemones, jellies Nematoda Round worms Mollusca Snails, clams, octopus, squid
Annelida Segmented worms Arthropoda Crabs, shrimp, spiders Echinodermata Sea stars, urchins, sand dollars Chordata Animals with backbones
Prepare the ocean 1) Pour the rice into a large bin. This is the large ocean to be sampled. 2) Add all of the animals to the rice. Mix with CLEAN hands if items will be consumed.
Step by Step 1) Call students up a few at a time. Each will take one scoop of rice/animals and pour into their bowl. Explain that their scoop must be made in one continuous motion and in one direction to simulate a real trawl (e.g., no picking and choosing their favorite treats!) 2) Students will sort their catch, tally each of the animals and measure one of each species. 3) Record the information on the data sheet provided (see next slide). 4) Students will graph their results. For younger grades (K-2), I do a bar graph, with Species on the X-axis and Total Number Caught on the Y-axis. 5) With older students, I also have them measure all of the animals they caught and determine the average size.
Porifera sponge Crustacea crab Number caught: Size cm Number caught: Size cm Cnidaria coral Number caught: Cnidaria anemone Number caught: Nematoda round worm Number caught: Size cm Size cm Size cm Echinodermata sea star Number caught: Size cm Echinodermata sea urchin Number caught: Size cm Chordata rattail fish Number caught: Size cm Mollusca clam or oyster Number caught: Size cm Chordata cusk eel Number caught: Size cm Annelida segmented worm Number caught: Size cm Chordata tripod fish Number caught: Size cm
Questions for Discussion and Additional Resources Was everybody s catch exactly the same? Why not? What does this mean in the real world for scientists trying to sample the ocean? Trawling is like taking a snapshot one day, one season, one moment in time. Another scientist sampling another time/day is likely to get very different results. This is the reason ongoing monitoring is very important. Did you know animals can be followed continuously by placing acoustic or satellite tags on them? Check out the Ocearch website to track two great white sharks (http://www.ocearch.org/#sharktracker) Check out the Institute for Marine Mammal Studies website to track sea turtles in the Gulf of Mexico (http://www.imms.org/satellite_tracking_home.php) If two different strainers were used, were there any obvious differences in catch? Scientists use different types of nets (diameter, mesh size, length) depending on what they want to learn about the ecosystem. Bottom trawls provide valuable information, but also can cause problems. Because they are dragged near the seafloor, they can damage habitat.
Questions or Comments? Contact Chris Simoniello, Ph.D. GCOOS Outreach and Education Lead chris.simoniello@gcoos.org