MICROPLASTICS STATION

Transcription

1 MICROPLASTICS STATION INTRODUTION No one though to look for microplastics in the Great Lakes until 2012, when Dr. Sheri Mason at the State University of New York in Fredonia started wondering. She took a journey through Lake Erie, Ontario, and Superior and found a surprising amount of microplastic. Some of it is most certainly from microbeads added to body products, but not all of it. We still don t know the sources of all microplastics or their effects on the Great Lakes, but all of these questions are currently being studied and more research is being designed. Inland Seas began collecting microplastic samples in That year we sampled in various locations in Northern Lake Michigan. In 2014 we sampled in the fall and began a project to track microplastic concentrations in Suttons Bay over time. No one knows how microplastic concentrations change over the course of a year, and nowhere else are they sampling in the same place for years in a row (as far as we know). Inland Seas will fill those gaps by collecting samples as part of our Next-Gen schoolship program. At this station, students will take a microplastic tow and examine the sample for plastics. Instructors will help students understand the research we are contributing to, and inform students about the types and sources of microplastics. This station only occurs in the Next-Gen Schoolship program LEARNING OBJECTIVES 1. Students will understand that we are part of a research project that is monitoring microplastic in Suttons Bay. 2. Students will know the definition of microplastic and some possible sources of microplastics. TOOLS Manta Trawl Beaufort scale Sieves Sample protocol Alcohol Microplastic microscope pictures Sample jars Microplastic types pictures Labeling tape and marker Great lakes sample sites 2012 and 2013 Goggles Adopt a beach monitoring data Microplastics sample Abundance of plastic pieces by size and type tables and pie charts

2 LIMNOLOGY STATION Overview: Students assemble and set up Manta Trawl and learn about how a Manta Trawl works. Discussion begins on what microplastics are and possible impacts of microplastics on the Great Lakes. The Manta Trawl will not be launched until the learning stations begin. Instructor helps students practice explaining the use of the Manta Trawl and information they gathered about microplastics. Objectives: At the end of the station students will be able to: a. Describe how the Manta Trawl works. b. Define and describe microplastics. c. Say that Inland Seas is part of a research project that is monitoring microplastics in the Great Lakes d. (if time) Discuss possible sources of microplastics found in the water and possible impacts of microplastics on the lake. 1. How the Manta Trawl works (5 min) a. Students can unlash the trawl and move it to the cabin top in the stern so everyone can get a good look at it. a. Name the trawl (Manta Trawl). Named this because it looks like a manta ray. b. Tell students that the purpose of the Manta Trawl is to skim the surface of the water. Ask them to figure out how it works, and what they think we will catch. i. How is it oriented in the water? Open end is the bottom ii. What are the wings for? Buoyant, keeps mouth of net at the surface iii. What does the hood do? Hood deflects wave crests into the net iv. What is the mesh for? To contain material of a certain size v. Where does the sample collect? In the cod-end of the trawl vi. Does the size of the holes in the mesh impact what we will get? Explain. Yes, anything smaller than holes will go through mesh, anything larger will be caught in the net. vii. What do you think it will capture? Let students come up with ideas, there are no right answer here, we are hypothesizing! 2. Set-up the Manta Trawl (2 min) a. Attach the towline to the bridle with a bowline b. Move the trawl to the port side of the boat with the net and cod-end extended in preparation for launching. 3. Describe microplastics (7 min) a. What we are looking for with the trawl are microplastics. Instructors can ask students to guess at the definition of microplastics. Microplastics are bits of plastic that are less than 5mm in every dimension. Show a sample that was captured in a mantra trawl from the Great Lakes. b. How do you think plastics get into the lake? Students should be able to propose sources. Let their ideas guide the discussion. i. Microplastics are usually the remains of a larger plastic item. Through abrasion, wave action, and break-down from the sun the larger pieces are broken down into smaller pieces. Plastics can get into the water from

3 rivers, beach-goers, boaters, and wind blowing trash around. There is research underway to find out where plastics originate. ii. Another source is microbeads from body products. Show a body product that contains microbeads and the electron micrograph image that shows the similarity between the microbead and the microplastic collected in the manta trawl. Microbeads probably come from wastewater treatment plants, which cannot filter microbeads out of sewage water. There is legislation proposed to ban microbeads in Michigan by c. How do you think microplastics affect the lake? Students should be able to come up with most of these possibilities; it is not necessary to cover all of this information: i. Plastics are eaten by fish and plankton. The plastic may stay in the animal s stomach, unable to be digested or egested (pooped out). If the stomach fills up there won t be space for food and the animal will starve. But even if the animal is able to eliminate it, the animal wasted energy eating useless food. Data has been collected to show that perch do eat plastic. We don t know for sure if plankton eat plastic particles, but observations suggest this is probably happening. ii. Larger animals can ingest plastic by eating smaller animals that have plastic in their stomachs. This means that larger animals may actually eat more plastic than smaller animals. Data has been collected to show that cormorants (who eat perch) contain much more plastic in their stomachs that perch do. iii. Plastics can absorb chemicals in the water, such as DDT and PCBs which can make the chemicals more available to animals when they eat the plastic. There is evidence of this occurring in the ocean, and scientists are looking into how this happens in a fresh water system. iv. Filter feeding organisms like mussels and snails might also eat microplastics. We suspect they do, but don t know the effects just yet. More research is needed. v. The manta trawl skims water at the surface. There is probably also plastic at the bottom of the lake (many plastics sink). Research is underway to find out if this is happening and the quantity of plastic there. d. We know very little about microplastics in the Great Lakes. Scientists are currently investigating all sorts of questions and you are part of that team. At Inland Seas we are also collecting data to answer questions about how microplastics interact with the lakes. i. The data we collect will help us understand if there are seasonal differences in microplastic abundance. Is it more common in spring or summer or fall? ii. Our data will also give data nearshore, whereas most of the data collected so far are from the main basins of the lakes. Show map of where data has been collected so far. iii. We will send our samples to a scientist it New York whose lab will count and classify any plastic particles we collect. Sheri Sam Mason at SUNY

4 Fredonia. She is the research scientist who first sampled for microplastics on the Great Lakes in Prepare for the presentation. Ask students to plan what they want to share with other groups, review the material, and answer questions. (3 min) a. Logbook: Make sure all students have the information recorded in the box on the microplastics page. i. Name of the device (skims the surface to filter particles out of the water.) ii. Size of microplastics iii. How much we know about microplastic in fresh water systems iv. The research question we are exploring b. The device: Let the students explain how it works. Aim for participation by many. i. Wings help the trawl float. ii. Scoop deflects waves into the trawl. iii. Net filters the water. iv. Cod end collects the sample. c. The sample: Ask a student to explain what we are looking for with the trawl and to show an example of a sample. i. We are looking for tiny bits of plastic in the water, called microplastics. ii. This is a sample that was collected in Lake Ontario (Inland Seas) / St Lawrence River (Manitou) during a 30 min trawl. iii. Our sample will go to a university in New York to be analyzed. iv. We are trying to find out how the amount of plastic in the lake varies seasonally and annually. d. More: If there is time and your group understands this part, ask students to describe how plastic gets into the lake and to share some ideas we have about how microplastics might impact the lake. i. Rivers, beach-goers, boaters and wind can bring plastic of all sizes to the lake. Wave action breaks-down larger plastics. Wastewater treatment plants may release microbeads from body care products and lint from synthetic fabrics. ii. Animals can eat it and clog their digestive systems, plastics absorb toxins from water which might enter the food chain, filter feeding organisms may ingest it, there might be plastic on the bottom of the lake, etc. LEARNING STATION Since the trawl will occur during the learning station rotations, each rotation will have a different job. Fill in content and discussion around this job. Rotation Job Description 1 Get point of sail and launch trawl 2 Keep point of sail 3 Keep point of sail and haul in trawl 4 Process sample 5 Process sample, clean & stow trawl

5 The is the basic sequence for all rotations: 1. Sampling protocol share with all groups a. Show students the data sheet and orient them to what is happening, what previous groups did, and what will happen after they move to the next group. a. In each station while the trawl is underway record the boat speed at least once. b. Use the Beaufort Scale to determine sea state in all stations. b. The manta trawl must be towed for 30 minutes at a speed of 2-3 knots. Help students understand that this is a scientific protocol that must be performed the same way each time, similar to the Otter Trawl. c. The trawl must be towed out of the wake zone. Make sure students understand what the wake zone is. Turbulence inside the wake zone might force under the surface materials that would otherwise float. d. When the sample is processed, all fragments are counted and they are sorted by size and type. Share a photo of a sample so students can look for examples of each type: i. Fragment Hard, jagged plastic particles ii. Pellet Hard, rounded plastic particles iii. Line Fibrous or thin, straight plastic iv. Film Flimsy planes of plastic, such as that from a plastic bag v. Foam Lightweight, sponge-like plastic vi. Other (identify) e. We can perform a saltwater float on board to separate some of the plastics from the sample. Plastic bits will float and we can skim them from the surface, put them under a microscope, and classify and count the particles. f. We send what remains to a research lab in New York to be processed further where the plastics are separated from the lake debris, counted, and classified. 2. Rotation-specific jobs a. 1 st rotation: When conditions are suitable, launch the trawl. i. Crew members, possibly with student help, will set up the Messer davit and put the towline on the davit, doing their best to minimally interrupt the Fish group. ii. One student fills in data sheet (start time, lat/long, boat speed, etc.) with the instructor. iii. One student raises the dayshape with a crewmember. iv. Students lower trawl into water with assistance from the crew. b. 2 nd rotation: Watch the trawl and report any changes in performance to a crewmember so adjustments can be made to sample the surface properly. Record boat speed occasionally and any notes. c. 3 rd rotation: Haul in trawl This will probably occur near the end of the rotation i. Students haul in trawl alongside instructor and crew will need to use the davit. ii. Other students fill in data sheet (end time, lat/long, boat speed, etc.) and record boat speed at least once. iii. Another student lowers the dayshape with a crew member or the instructor.

6 iv. Be mindful of the fish station and cooperate with them so all groups have space to do their tasks. d. 4 th rotation: Process sample for storage. Now that the trawl is complete we must get the sample out of the net and preserve it so it can be examined later i. Students observe the instructor as he or she processes the sample and help whenever possible (holding containers, passing equipment, etc.). ii. Students create two labels (one for the lid and one for the jar) with sample number and lat/long, and affix these to the jar. iii. Record observations of the sample in the logbook. e. 5 th rotation i. Perform the saltwater float (if time, can instead start in the 4 th rotation if there is time). Follow the procedure. We don t expect you to count and classify every particle, but you may be able to classify some particles. ii. Show the processed sample and record observations in the logbook. iii. Have students help clean and stow the trawl 3. Steering the boat may happen for some groups a. It is up to the instructor to organize activities and keep all students involved. Your first priority is getting a microplastics sample. If there is time and the captain agrees, students can steer the boat. b. Rotations 1, 2, and 3: Captain will be focused on getting the boat at a steady speed and direction in preparation for launching the trawl and maintaining these conditions while the trawl is in progress. If possible, the captain will let students steer the boat, and will mention the things he is paying attention to (sail conditions, etc.) but will not be able to explain what he is doing in detail. The group instructor can explain these things if he or she is knowledgeable about them. c. Rotations 4 and 5: Students can help the captain steer the boat as normal. The captain will include relevant seamanship information as able. 4. Additional conversations about microplastics fill in as there is time a. Where do microplastics come from? b. How do you think plastics get into the lake? c. How can we prevent plastics from entering the water? d. Compare plastics in the Great Lakes to plastics in the Oceans. Use the tables and pie charts that compare the Great Lakes to the Oceans. e. How do you think microplastics might affect the food web? A description of biomagnification would be appropriate here. f. Where else might we find microplastics besides the Great Lakes? All water bodies could contain microplastics. New research is being proposed to survey many of the Great Rivers in the USA. g. Where do you think we could find the most plastic: on the surface, at the bottom, or in the middle of the water column? Plastics are different densities, about half of them float and about half of them sink in fresh water. Although being small makes it more likely particles will be pushed around by currents and float due to surface tension, size does not change density.

7 2012 Microplastic Sample Sites

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11 Categories of Microplastics Microplastic Type Description Potential Sources Fragment Hard, jagged plastic particle Bottles, hard sturdy plastic Line/Fiber Thin of fibrous, straight Fishing line/nets, clothing, or textiles Pellet Hard, rounded plastic particle Virgin resin pellet, or facial cleansers Film Thin plane of flimsy plastic Plastic bags, wrappers, or sheeting Foam Lightweight, sponge-like plastic Foam floats, Styrofoam, cushioning Lines

12 Abundance of plastic pieces (count/km 2 ) by size particle size (mm) Great Lakes >4.75 North Atlantic Oceanic Gyre > count/km 2 736, ,400 17,650 21, ,130 6,226 % of total 81% 17% 2% 37% 52% 11% Great Lakes: North Atlantic Oceanic Gyre:

13 Abundance of plastic pieces (count/km 2 ) by type Great Lakes North Atlantic Oceanic Gyre Fragment 382,233 53,016 Film 9,282 1,527 Foam 74, Pellet 436, Line 4,349 3,631 Total count 906,289 58,292 Great Lakes 1% North Atlan@c Oceanic Gyre 3% 6% 48% 42% 8% 1% 91%

14 Locations of beach surveys, number of surveys conducted, and percentages of litter comprised of plastic for the five Great Lakes. All data collected by Adopta-Beach volunteers in 2013.

15 BEAUFORT SCALE

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