Ocean Acidification Elementary Investigation 15

Transcription

1 Ocean Acidification Elementary Investigation 15 Investigation Introduction This investigation is intended as a supplement to existing science instructional materials. It is targeted for 4 th -5 th grade students. This unit examines the issue of ocean acidification, which is emerging as one of the effects of increased CO2 levels in Earth s atmosphere. Before teaching this unit, it is recommended that the teacher go to the Teachers' Guide to High Quality Educational Materials on Climate Change and Global Warming and read the Top Ten Things you need to know about Global Warming. This concise primer outlines important information to know before teaching this unit. It can be found at Outcomes Part 1 Seawater Part 2 Shellfish Part 3 CO2 and Water Part 4 Little Changes, Big Effects Part 5: Taking Action Focus Question Is seawater more like lemons or bleach? Focus Question: How does acid affect shellfish? Focus Question: How does Earth s atmosphere affect the acidity (ph) of seawater? Focus Questions: What happens if shellfish are reduced in the ocean s ecosystem? If the ocean is so large, why do small changes make a difference? Focus Question- What can be done to reduce ocean acidification? Outcome: Students will be able to explain whether different types of water are acidic, basic or neutral. Outcome: Students will conduct an investigation on the effect of acid on shells and describe their findings. Outcome: Students will conduct an investigation to test the response of water s acidity (ph) to carbon dioxide gas introduced into solution from their breath. Outcome: After engaging in a simulation activity that illustrates what happens to the organisms in a food web when various components are altered, students will be able to explain the effect of increased CO2 from their breath on seawater. Outcome: Students will be able to describe ways they can reduce the amount of CO2 in the atmosphere using video resources and measuring and calculating the carbon stored in trees.

2 Ocean Acidification Elementary Investigation 16 INTRODUCING STUDENTS TO THE PROBLEM Begin the Investigation by having students watch this video. As students watch the video, have them generate questions about the video content and the problems presented. In WA State Ocean Acidification is about People After the video, have students share their questions, recording for the class to review throughout the unit.

3 Ocean Acidification Elementary Investigation 17 Part 1: Seawater Focus Question: Is seawater more like lemons or bleach? Outcome: Students will be able to explain whether different types of water are acidic, basic or neutral. Teacher Background All liquids can be described by their acidity. Liquids with high acidity and many free hydrogen ions (H+) are called acids. Acids are used for a wide range of purposes, such as catalyzing reactions, preserving foods, and conducting energy in batteries. Liquids with low acidity and very few free hydrogen ions, or many free hydroxide ions (OH-), are called bases. These substances are very useful as soaps and other cleaning agents. Foods that are acidic (like lemons) taste sour, and things that are basic (like soap or some medicines) taste bitter and feel slippery. It s dangerous to taste and touch many liquid, so we need a better way to judge the acidity of different liquids. Scientists safely measure acidity by measuring ph values. The ph scale measures how many free hydrogen ions are present in a liquid, but the measurement is somewhat counterintuitive: the lower the ph, the greater the concentration of free hydrogen ions, and the higher the ph, the lower the concentration. Acids have low ph measurements, from 0 to less than 7. Neutral liquids have ph measurements of 7. Bases have high ph measurements, from more than 7 to 14. The ph scale helps researchers measure both very large and very small acidity differences between fluids. Battery acid and drain cleaner have very different ph values. On the other hand, oceans, rivers, and lakes have small ph differences. Earth scientists measure these small ph differences to learn about aquatic organisms and their environments. Acidic substance Chemical Name Chemical Formula Approximate ph Lemon or lime Citric Acid C6H8O7 2 juice White vinegar Acetic Acid CH3COOH 3 Vitamin C tablet Ascorbic Acid C6H8O6 3 dissolved in water Lemon-lime soft Carbonic and H2CO3 + C6H8O7 3-4 drink Citric Acid Cream of tarter Potassium KHC4H4O6 3-4 dissolved in water Bitartrate Seltzer water Carbonic Acid H2CO3 4-5

4 Ocean Acidification Elementary Investigation 18 Unbuffered, uncoated aspirin dissolved in water Acetylsalicylic Acid C9H8O4 5 Milk Lactic Acid C3H6O3 6.7 Tap or distilled Water H2O 7 water Baking soda Sodium NaHCO3 8 dissolved in water Bicarbonate Antacid dissolved in water CaCO3 + CaOH + MgOH 10 Soap/washing soda Oxiclean Calcium Carbonate+ Calcium Hydroxide + Magnesium Hydroxide Sodium Carbonate Sodium Percarbonate + Sodium Carbonate Na2CO3 11 2(Na2CO3. 1.5H2O2) 11 Teaching young students about this idea should be focused on the concept of substances being classified as basic, neutral or acid. ph values, chemical names and formulas are for the use of the teacher.

5 Ocean Acidification Elementary Investigation 19 Getting Ready Assemble materials for a class of ~24-36 students working in groups of 3-4 Lemon juice ~10 ml Bleach or ammonia (for teacher use only) ~10 ml Safety goggles for teacher Artificial seawater ~100 ml Tap water ~100 ml Unflavored seltzer water ~100 ml Distilled water ~100 ml White paper (10 sheets) Label tape & marker (10 sets) Small test tubes & rack (4 tubes and 1 rack per group; 2 tubes and 1 rack for teacher demonstration) ph paper, Range or Dropper bottles with ~100 ml red cabbage ph indicator (1 bottle per group; refill if needed) Labeled disposable pipettes (to transfer solutions into test tubes) 6- One for each type of solution Prepare student handouts- Student Lab Procedure If color copies aren t available, plan to project ph scale.

6 Ocean Acidification Elementary Investigation 20 Guiding the Investigation Engage Students: Show video Have students record ideas in their science notebooks. Conduct demonstration: Wear goggles. Use ph paper or put red cabbage indicator into lemon juice until color change is apparent. Have students record their observations. Then put ph paper or red cabbage indicator into the bleach or ammonia until color change is apparent. Have students record their observations. Introduce the terms acid, base and neutral. Remind students we never taste chemicals. Many of the other chemicals listed are also readily available to include in the teacher demonstration, but additional tests are optional. Acid- sour substance having ph below 7 Base- bitter substance having a ph above 7 Neutral- substance that isn t an acid or a base and has a ph of 7 Present focus question to students. Record on board and have students record in their notebooks: Is seawater more like lemons or bleach? Making Predictions Arrange students into groups. Have them discuss whether tap water, distilled water, seawater, and seltzer water will be more like lemons (acid) or like bleach (base). After the discussion, have students enter their group s prediction into their notebooks. These sentence stems may be helpful: I predict tap water will be a(n). I predict distilled water will be a(n). I predict seawater will be a(n). I predict seltzer water will be a(n). Materials and methods For each lab group of 3-4 students: 4 test tubes 1 test tube rack Label tape & marker ph paper or dropper bottle of ph indicator White paper

7 Ocean Acidification Elementary Investigation 21 Distilled water Seawater Tap Water Seltzer water Student Lab Procedure 1) Label four test tubes: distilled water, seawater, tap water, seltzer water. Place all the labeled tubes in the rack. 2) In your notebook, write down the date of the experiment, the time of day, and your lab partners names. Fill in the data table with the names of the solutions you will test. It will look something like this: Liquid Lemon Juice Bleach (or Ammonia) Distilled Water Seawater Tap Water Seltzer Water Predicted Acidity 1 = most acidic 4 = least acidic X X Color Actual Acidity ph Under liquid, list all of the acids and bases the teacher demonstrated. Also list the four types of water you plan to test. Under predicted acidity, rank the fluids based on how acidic you think they will be. Use 1 for the fluid you think will be most acidic, use 2 for the next most acidic fluid, and so on. The last number should be for the least acidic fluid (which is the same as the most basic fluid). You ll fill in the next two columns as you collect and examine your data. 3) Use the appropriate pipette to transfer a few milliliters samples of your water types to their labeled tubes. Be sure to follow the labels. Don t add more than

8 Ocean Acidification Elementary Investigation 22 one type of fluid to any test tube. Be sure not to share pipettes among different solutions only use a pipette for the solution indicated on its label. 4) Use ph paper or add a few drops of ph indicator to the water samples in each test tube. Gently swirl the tube to mix it if necessary. You should see each fluid or paper turn a color. (The ph indicator will stain your clothes and notebooks, so be careful!) 5) Write down the color of each solution in the color column of your data table. Compare the test tubes in front of the white paper if you have trouble telling different colors apart. Analyzing Results The pictures below show the complete color range of wide range ph indicator. Red colors indicate more acidic fluids, and blue, green, and yellow colors indicate more basic (less acidic) fluids. 1) Use the color scales above to rank the acidity of your fluids in the actual acidity column of your data table. Again, use 1 for the fluid you think will be most acidic, use 2 for the next most acidic fluid, and so on. The last number should be for the least acidic fluid (which is the same as the most basic fluid). 2) Use the color scales above to estimate the ph of your fluids, and write down the ph value in the ph column of your data table. 3) After a class discussion of your results, answer the following questions.

9 Ocean Acidification Elementary Investigation Which fluid was most acidic? 2. Which was least acidic? 3. What was the ph of seawater? 4. What was the ph of tap water? 5. What was the ph of distilled water? 6. What was the ph of seltzer water? 7. Describe the most surprising result you observed during this experiment. 8. Is seawater more like lemons or bleach? Explain why you think so using your data as evidence.

10 Ocean Acidification Elementary Investigation 24 Part 2: Shellfish Focus Question: How does acid affect shellfish? Outcome: Students will conduct an investigation on the effect of acid on shells and describe their findings. Teacher Background The process of ocean acidification (the decreasing ph of the ocean water) affects the organisms living within those waters. Many organisms use various forms of calcium carbonate to form their shells and skeleton. The increasing acidity of the water affects these organisms. As CO2 is absorbed into the water the resulting chemical process reduces the amount of available carbonate ions used to by organisms to create their shells and skeleton. In addition to reducing the available carbonate ions, the decreased ph makes the ocean water more corrosive. Some of the organisms most immediately affected by ocean acidification include: sea urchins, abalone, corals, and some species of plankton (such as pteropods and coccolithophores). If the ocean water continues to grow more acidic these organisms will be unable to form their shells and grow. The loss of these organisms will greatly impact the marine food web. Plankton is at the base of the marine food web. Plankton are organisms that cannot swim against the current. Some plankton are algae and some are animal-like. Phytoplankton (algae-plankton) include coccolithophores and zooplankton (animal plankton) include pteropods. Planktonic feeders include bivalves (mussels, clams, scallops, and oysters), sand crabs, and anchovies. Baleen whales, such as blue whales, are also planktonic feeders. As the base of the marine food web plankton are incredibly important. If oceans become inhospitable to plankton the removal of that portion of the marine food web could result in disaster to many other marine species. The increasing acidity of the ocean also has an effect on habitat. Coral reefs provide habitat for a large and diverse number of organisms. Many species of fish and invertebrates inhabit coral reef. If the coral can no longer successfully grow at optimum rates they will not be able to maintain the reef. Without the reefs the biodiversity of the ocean will decrease. Ocean acidification may also affect important fisheries. Sea urchins, crabs, lobsters, oyster, and shrimp all use calcium carbonate to create their shells and skeletons. These are very important fisheries worldwide. A loss in species

11 Ocean Acidification Elementary Investigation 25 population would not only affect the marine food web, but would also affect the availability of food for humans as well as a means of livelihood for many people worldwide. Getting Ready Materials Experiment 1: Small dishes (petri dishes, Tupperware dishes)- enough for 2 per group of 3-4 students Tap water Vinegar ph strips (ph strips are sold at pet and aquarium stores or science supply houses.) Shells, piece of dead coral, urchin test (skeleton), chicken bones chalk will work as well, but to make the connection more powerful it is better to use a shell/skeleton of an organism (If you have a personal collection of shells you can use those or your local marine science center may have a collection of shells that they can distribute for classroom use). Whiteboards, 1 per group (or large piece of paper per group) Experiment 2: Two 1-liter bottles or containers with lids Tap water Carbonated water Chicken bones, clam shells, urchin tests, small abalone shells, other snail shells, piece of coral skeleton Guiding the Activity Instruct students to use the procedure below to test different items in the liquids (i.e. one team tests clam shells, another tests urchin tests, student groups may be allowed to decide which item they would most like to test). Then students present their findings to the rest of the class at the end. Students may need support to write their hypotheses. This sentence stem may be used as a scaffold: If is placed in, then.

12 Ocean Acidification Elementary Investigation 26 Experiment 1: Student Procedure-done in groups of Fill one dish with tap water and the other dish with vinegar 2. Predict what the ph of each substance will be. 3. Measure and record the ph of both tap water and vinegar. 4. Hypothesize what will happen when the item is immersed in each liquid. 5. Record initial observation of the item(s) to be immersed in the fluids 6. Record observations at 30 minute intervals 7. Draw conclusions from your observations 8. Create a picture or graph on your white board showing your results and present it to the class. Experiment 2: Whole Class Demonstration 1. Place small chicken bones or small pieces of shell into 2 1-liter bottles (1 containing tap water and the other containing carbonated water) 2. Have students predict what will happen in the 2 containers 3. Record observations (in writing and by sketching) each day 4. After the items have started to react to the carbonated water have students review their prediction and determine whether it was correct Upon completion of the Experiment 1, have students address the focus question (How does acid affect shellfish?) in their notebook using evidence from their experiment to support their claims. (Class doesn t have to wait for Experiment 2 to finish dissolving the bones and shells.)

13 Ocean Acidification Elementary Investigation 27 Part 3: CO2 and Water Focus Question: How does Earth s atmosphere affect the acidity (ph) of seawater? Outcome: Students will conduct an investigation to test the response of water s acidity (ph) to carbon dioxide gas introduced into solution from their breath. Teacher Background Carbon dioxide, CO2, is released into the atmosphere due to human activity and mixed into the ocean creating carbonic acid. This allows seawater to dissolve calcium carbonate minerals like the skeletons of diatoms, shells and coral reefs. The process is called ocean acidification. Among other ecological consequences, shellfish larvae are unable to make their shells and cannot reproduce. A common source of CO2 is combustion (burning) of fossil fuels like coal and gasoline. Carbon dioxide also is produced when carbon is burned by living organisms for energy (during respiration) and when dead materials rot. We exhale carbon dioxide in our breath. CO2, when combined with water forms a weak acid, called carbonic acid. This is the same as carbonated water. CO2 + H2O H2CO3 The H2CO3, carbonic acid release extra hydrogen ions into the water causing the water to become more acidic. Getting Ready Materials: Wide Range ph or red cabbage ph indicator 2 clear cups per student 1 lid and 1 straw per student Safety goggles for each student Distilled water Have ph scale ready for students, either by projection or in print.

14 Ocean Acidification Elementary Investigation 28 Guiding the Activity Show the video The Acid Test Some of the content is complex, so have students focus on and take notes on the following prompt: What is causing the oceans to become more acidic? Have a class discussion about the prompt. Explain that the activity that follows allows students to see how CO2 can enter water. Fortunately, we produce CO2 and exhale it in our breath. Describe activity. Have students write a hypothesis. This stem may help: If CO2 is blown into a cup of distilled water, the ph will. Have students make data chart in their science notebooks. Eliminate extra cells if time and materials do not allow for multiple trials. Cup 1- Distilled water Cup 2- Distilled water + breath CO2 from Breaths Effects on ph ph Trial 1 ph Trial 2 ph Trial 3 Average ph Student Procedure 1. Have students wear safety goggles. 2. Number cups 1 and 2 with a marker. Cup #2 will be the control in this investigation. 3. Fill the cups with the same amount of distilled water. If the cups have lines, the lowest line should work. 4. Place drops of indicator to each cup and swirl gently to mix. Make sure color is vibrant enough to see potential color changes. 5. Place lid over cup #1, insert straw and blow for a total of 60 seconds. (You can switch with your lab partner after 30 seconds, but no sharing straws!) 6. Compare the color differences over white paper & record the result on your data chart. 7. Optional- multiple trails are better. If there is enough time, distilled water and indicator, repeat twice for a total of three trials.

15 Ocean Acidification Elementary Investigation 29 Have students write a conclusion for this investigation of the effects of CO2 on the ph of water. Student conclusions should be sure to: Answer the hypothesis the student recorded in their notebook. Include supporting data from the CO2 from Breaths Effects on ph table. Explain how these data support the conclusion. Making Sense Activity: Now is the time to help students make sense of the carbon cycle. Begin with the prompt: So, how does all that CO2 actually get into the atmosphere? Have students write their ideas in their science notebooks. After sufficient time to write, have students turn to an elbow partner and discuss their ideas. Then conduct a class discussion collecting their ideas on the board. Project an image of a simplified version of Earth s Carbon Cycle: Discuss what is presented in the image, having students compare their ideas to what is shown.

16 Ocean Acidification Elementary Investigation 30 Part 4: Little Changes, Big Effects Focus Questions: What happens if shellfish are reduced in the ocean s ecosystem? If the ocean is so large, why do small changes make a difference? Outcome: After engaging in a simulation activity that illustrates what happens to the organisms in a food web when various components are altered, students will be able to explain the effect of increased CO2 from their breath on seawater. Teacher Background Baleen whales feed on crustaceans such as amphipods, copepods, and krill, as well as small fish. With changes in ocean temperature, upwelling, acidification and other urban influences, whales can be impacted through the food web. This game demonstrates the relationship between the trophic levels of a food web in the ocean and the potential impact of humans on that food web. Everything is connected. If the balance on one level is disturbed too much by climate change, the other levels will be affected and potentially the food web will collapse. Whale Jenga Vocabulary English and Spanish Word Cards adaptation/adaptacíon: the modification of characteristics of a species of organism over time to adjust to a new condition baleen/ballena: fibrous plates made from keratin that hang from the roof of baleen whales mouths used for filtering food from the water. Baleen whales are classified as Mystecets as they feed with baleen, not teeth. climate change/ cambio de clima: a significant and persistent change in the mean state of the climate or its variability. Climate change occurs in response to changes in some aspect of Earth s environment: these include regular changes in Earth s orbit about the sun, re-arrangement of continents through plate tectonic motions, or anthropogenic modification of the atmosphere. crustaceans/crustáceos: invertebrates in the phylum Arthropoda, with jointed legs, exoskeleton, jaws, gills, and two pairs of antennae; examples: krill, amphipods, and copepods. endangered species/especie en peligro: an animal or plant at risk of becoming extinct as a result of overharvesting, habitat destruction, or other causes.

17 Ocean Acidification Elementary Investigation 31 filter-feeder/conductor de alimentacíon: an animal that eats small particles of food from water bypassing the water through a filtering structure. food web/ web de alimento: all the interactions of predator and prey, along with the flow of nutrients into and out of the ecosystem; how energy is converted and passed from one organism to another. invasive species: introduced organisms that are not endemic to the area and are able to out compete for resources. krill: small shrimp-like belonging to the family Euphasiidae. Krill feed on phytoplankton and some tiny zooplankton and are important food source for whales and many other marine animals. migrate/migrar: to pass periodically from one region to another for purpose of feeding or breeding. plankton/plancton: floating or weakly swimming organisms that move with the currents in all natural waters; can be photosynthetic (phytoplankton) or animals (zooplankton). plankton bloom: high concentration of phytoplankton in an area due to increased reproduction rates. pollution/contaminación: contamination of water, soil and/or air from the discharge of wastes, gases or chemicals. salinity/salinidad: the concentration of dissolved minerals, including salts, in the water. upwelling/corriente ascendente: the rise of nutrient-rich waters from deeper areas of the ocean to the surface of the sea. urban runoff/agua contaminada urbana: water containing pollutants (oil, grease from leaking cars, soaps, pesticides from gardens, animal waste, street debris) which washes into storm drains and rivers and gets carried out to the ocean

18 Ocean Acidification Elementary Investigation 32 Getting Ready Game set up: 1. Place three green blocks side by side with pictures facing out. Place three more green blocks on top of the first layer cross-ways. Continue to stack green blocks this way until all are used up. 2. Stack blue followed by red blocks on top of the green base until all blocks are used up. 3. Place the purple block on the very top. The stacked up blocks represent the food web for Baleen whales in the ocean. 4. Shuffle the playing cards and stack them upside down. Guiding the Activity Explain to the students that this game is a representation of how changes can impact the stability of a whole system. Prior to the game introduce vocabulary to ensure understanding of terminology used on the cards. Word cards are provided to support students and should be posted on a word wall. Playing the game: 1. The first player picks a game card, reads it aloud and follows the instructions written on the card. Only the block being removed or returned may be touched. (You are not allowed to hold the rest of the stack together while removing the blocks.) 2. Put the used cards into a discard pile. 3. Place removed wood blocks into a discard pile off to the side. 4. Continue to take turns until the tower falls and the food web collapses or all cards are used up. 5. Reset to play again using the directions above.

19 Ocean Acidification Elementary Investigation 33 Review and Assessment Questions: 1. What surprised you in playing this game? 2. What did you discover about human influences on the environment? 3. What questions would you like to investigate further? Optional Extensions: 1. Create additional cards for the game 2. Look for local impacts on the ocean that could influence the food web and find solutions you can facilitate.

20 Ocean Acidification Elementary Investigation 34 Part 5: Taking Action Focus Question- What can be done to reduce ocean acidification? Outcome: Students will be able to describe ways they can reduce the amount of CO2 in the atmosphere using video resources and measuring and calculating the carbon stored in trees. Teacher Background Though it is obvious that increase levels of CO2 in the atmosphere is a tremendous problem, requiring large-scale actions, there still are many things that students can do to reduce the amount of carbon entering our atmosphere. It may be helpful to refer back to their notes from Part 3 s Making Sense Activity. Growing trees is one way to remove carbon from the atmosphere. As trees grow, they help to remove CO2 from the atmosphere by absorbing and storing carbon in their tissues. To grow a pound of wood, an average tree takes in about 1.5 pounds of CO2 and gives off about 1.1 pounds of oxygen. The wood continues to store the carbon, even when the wood is made into lumber or other products. Getting Ready Make sure computer will show How to Help Reduce Global Warming and Forest Fast Break: Carbon Storage Prepare for constructing for Carbon Storage Measuring Tape. Tape can be precut by teacher or students can cut out strips. Students will also need transparent tape. Guiding the Activity After writing the focus question in their notebook, help students understand that to reduce ocean acidification, people have to reduce carbon dioxide in the atmosphere.

21 Ocean Acidification Elementary Investigation 35 Prepare students to watch the video, asking them to take notes on ideas of how they can help reduce carbon going into the atmosphere. Show How To Help Reduce Global Warming. Have students discuss their notes with an elbow partner, collecting ideas on the board. The last action shown is to plant a tree. Ask students how much carbon they think can be stored in a tree. Show video Forest Fast Break: Carbon Storage Explain to students that they are going to make a measuring device that will tell them how much carbon is stored in a tree. Provide students with Carbon Storage Measuring Tape template. Have students cut out tape (or precut if desired) and assemble strips in order. Once students have assembled their tapes, have them draw this data table in their science notebook. Tree Diameter to closest 2 inches This tree stores the same amount of carbon as the amount of carbon produced by: Pounds of CO2 equivalent Prepare students to go outdoors, using this script to present the background information necessary for the activity. Use the carbon emitted visuals to illustrate as noted. 1. What do trees need to grow? 2. Take a deep breath. Doesn t the air smell fresh and clean? What do trees give us that we need to breathe?

22 Ocean Acidification Elementary Investigation Trees take in CO2 from the air for photosynthesis to make their own food and release oxygen into the air in the process. We breathe the oxygen in. 4. What do we breathe out or exhale? 5. All living creatures emit or exhale CO2 into the atmosphere. 6. Our cars, factories, homes, and various activities we do also give off or emit CO2 into the atmosphere. This has become a concern. But we know that trees take in CO2 to grow and they also store the CO2 as carbon in wood and roots so trees can help restore the balance of CO2 in the atmosphere (air) 7. Scientists have estimated the amounts of CO2 these various activities give off or emit. For example (bring 4 students up to hold the 4 example small signs): 1 year of students breathing = 18,945 lbs of CO2 equivalent Explain again that almost all living things emit CO2 and this is CO2 that should be in the atmosphere. But we as humans have are adding more through other activities such as: 50 miles on the bus = 15 lbs of CO2 equivalent Flight to Disneyland = 611 lbs of CO2 equivalent 1 year of heating a home = 8018 lbs of CO2 equivalent 1 year of a cow breathing= 4920 lbs of CO2 equivalent One year of SUV CO2 emissions =16,395 pounds of CO2 8. Let s go outside and see how much carbon is stored in some of the trees in our schoolyard. Have students prepare to go outdoors. If this is not a regular routine, go to FOSS s Taking Students Outdoors at for guidance. The student s task is to measure three trees and record each tree s diameter and the carbon equivalent on their data table. After returning to the classroom, have students discuss share how much carbon was in their trees. To assess activity, have students write to the following prompts: I can reduce the amount of carbon by: This will help reduce ocean acidification by: