A, B, Seas: The Fundamentals of Oceanography
In this workshop, students will learn some of the basic concepts of oceanography with a focus on how global-level changes can influence ocean cycles, such as climate change.
In the A, B, Seas workshop, students will have the opportunity to engage in several hands-on activities, explore the physical, biological and chemical aspects of the oceans. They will gain insight into how the scientific method can be used to understand the marine environment and to mitigate the effects of climate change.
This workshop was created by Dalhousie University and updated by the Let’s Talk Science National Office to include climate science in 2023.
This workshop discusses topics which can lead to feelings of eco-anxiety among volunteers, educators and youth if not presented in a thoughtful manner. The most important things to remember are to be honest, hopeful, developmentally appropriate, and action oriented. This workshop was created with these guidelines in mind. For more details, refer to the volunteer resource, Being Conscious of Eco-Anxiety.
What You Need
Station A: Physical Factors
- 8 empty water bottles
- Warm water
- Cold water
- Freshwater
- Saltwater (35 ppt)
- Food colouring (red, blue, yellow)
- A, B, Seas - Activity 1A Task Card
- A, B, Seas - Activity 1B Task Card
Station B: Biology of the Blue
- Microscope
- Slides
- Cover slips
- Plastic pipette
- Kim wipes
- Paper towel
- Beakers
- Marine sample (Artemia)
- Paper
- Pen
- A, B, Seas - Activity 2 Task Card
Station C: Chemical Clues
- Straws
- Beakers or other clear plastic containers
- Eggs
- pH paper
- Household products such as:
- Carbonated beverage (e.g. Coca Cola, Pepsi, Sprite)
- Lemon juice
- Vinegar
- Baking soda
- Dish soap or laundry detergent
- Bottled water
- A, B, Seas - Activity 3 Task Card
- A, B, Seas - pH Guide
Guide:
Worksheet:
Safety Notes
For Station A: Physical Factors, things can get messy, so it is best to have a shallow tray to work on in order to limit the spread of spills and have cleaning materials readily available.
For Station B: Biology of the Blue, students may be working with glassware, such as slides, cover slips and beakers. Have gloves available and ensure students notify any adult of injuries sustained due to sharp glass. Use alternatives to glassware where applicable (e.g. reusable plastic etc.). When working with microscopes, ensure students know the most appropriate way to transport it (using the arm) and are conscious of the eyepiece and magnifying lens.
For Station C: Chemical Clues, students can use different clues, such as smell or visual cues, to guess what the substance is. However, they should be warned not to taste any of the substances – none of the products are harmful but this will help enforce proper procedure when working with potentially dangerous compounds in the future.
What To Do
Station A: Physical Factors
Activity 1A – Thermocline
- Put two to three drops of food colour into four water bottles. Put red drops in two bottles and blue in the other two.
- Pour the warm water into the two bottles with the red drops until it overflows, then do the same with the cold water in the remaining
- Using an index card, cover the mouth of one of the bottles full of cold water and carefully place it over the mouth of a bottle with warm water.
- Slowly remove the index card and observe the mixing that The cold water should sink down into the warm water.
- Repeat steps 2 to 4, but this time place the bottle with warm water over the bottle with cold Here there should be little to no mixing between the two liquids.
Activity 1B – Halocline
- Put two to three drops of food colour into four water Put blue drops in two bottles and green in the other two.
- Pour the saltwater into the two bottles with the blue drops until it overflows, then do the same with the freshwater in the remaining bottles with the green
- Using an index card, cover the mouth of one of the bottles full of saltwater and carefully place it over the mouth of a bottle with freshwater.
- Slowly remove the index card and observe the mixing that occurs. The saltwater should sink down into the
- Repeat steps 2 to 4, but this time place the bottle with freshwater over the bottle with Here there should be little to no mixing between the two liquids.
Station B: Biology of the Blue
Activity 2 - Discovering plankton
- Before moving onto preparing a wet-mount slide, have students practice focusing the microscope using prepared slides of different zooplankton, plankton and aquatic microorganisms depending on what is available.
- Have students work in group of threes, view the sample and record on their paper any distinguishing features of the sample which can include colour, smell, and movement. Have each group guess what the sample is.
- Have each student take their turn preparing a slide of a different species by:
- Taking the sample out of the large beaker using the plastic pipette.
- Placing a pea-sized drop on the slide.
- Placing a cover slip over the sample. Leaders may need to help draw out excess water using Kim wipes.
- Have the student who prepared the slide place the sample under the microscope on the 4 times objective. Leaders demonstrate how you can adjust the focus.
- Have the student who prepared the slide move onto the 10 times objective. Have the student focus the microscope.
- All other students in the group will draw and record what they see.
- Repeat Steps 3 to 6 with another student from the group. Compare what the other slides of different species the group members prepared look like.
Station C: Chemical Clues
Activity 3A – Solutions
- Have students work in pairs, or choose one or more volunteers to help test each If in pairs, assign each group a different solution to try to identify.
- Give students strips of pH paper (or litmus paper if using instead) to dip into their Show them how to use the guide accompanying the pH kit to determine pH based on the colour of the strip.
- Accompanying the kit will be a banner showing the pH scale, as well as names of some common household products (including the ones that the students will be testing) below their corresponding pH Have students place their beakers on the banner where they think the pH matches.
- Reveal the identities of each solution. How did everyone do? Discuss any discrepancies and potential reasons (i.e. pH paper imprecise, difficult to read, ).
Activity 3B – Comparing Solutions
- Pour water into a clean beaker, and measure the pH using a strip of pH paper. It should have a pH of about 7 (if it is tap water, it may not be exact, but it shouldn’t be noticeably different).
- Have one or more volunteers use straws to blow bubbles in the water for 1-2
- Check the pH again with a new strip of paper. What is it now? Repeat once or twice Does the pH continue to change?
Activity 3C – Ocean Acidification
Pass around the eggs, with shells in various dissolved forms, so that students can observe the effect the vinegar has on the eggshells. Encourage the students to draw comparisons between what they learned in the previous two activities and what has happened to the eggs.
Refer to the Updated Guide for more detailed set-up instructions and question prompts for students after each activity.
Discovery
Station A: Physical Factors
The ocean is an incredibly complex and dynamic body of water and it, much like our atmosphere, is divided into a multitude of layers. Water has an incredible heat capacity which means that it takes a lot of energy to change it from state to state. This capacity has made the ocean into a thermal regulator for our planet. It’s this regulation which makes day-night and winter-summer temperature changes more gradual.
Seawater experiences an inverse relationship between temperature and density. The colder the water, the more dense it is and vice versa. Density is also affected by salinity. The relationship between density, salinity, and temperature drive convective ocean mixing. This conveyor belt of movement provides consistent mixing of warm salty water from areas of high evaporation like the tropics with cold freshwater from areas of high precipitation and river output.
Station B: Biology of the Blue
A microscope is used to magnify objects that may be too small for the naked eye, allowing scientists to see microscopic organisms that would otherwise go undiscovered, like plankton. Although generally small, plankton plays an important role in aquatic environments. An organism can be classified as a plankton if they are incapable of sustained horizontal Within this category there are phytoplankton, plant plankton such as algae, and zooplankton, animal plankton such as tiny crustaceans. Even though they are often small, phytoplankton and zooplankton are key components of marine ecosystems by acting as the base of many marine food webs.
Station C: Chemical Clues
One way of describing the chemical properties of different substances is to talk about how acidic or basic (alkaline) they are. Some compounds are acidic, which means that when they are dissolved in water, they will have a higher concentration of hydrogen ions (H+) than pure water. Other compounds are basic, which means that when they dissolve, they will have a lower concentration of hydrogen ions than pure water. The pH scale is the commonly used to describe how acidic or basic different substances are. The scale ranges from 0 to 14, with numbers from 0 to 7 representing acidic compounds, and numbers greater than 7 representing basic compounds.
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Stratification in seawater affects marine life. Phytoplankton rely on stratification because they need to stay up near the surface in order to get enough light and nutrients. The songs of whales will refract differently under the conditions created by the stratified layers of the ocean. The layers allow for the sound to get trapped in a layer and travel huge distances. However, the stratification of seawater has been changing over several decades due to climate change and global warming, with an average of 1% increase in stratification per decade, mostly due to temperature increases on the surface of seawater and some local changes in salinity.
Seawater is also slightly basic. However, a decrease in the pH of seawater in recent times has largely been influenced by human activity. Burning fossil fuels releases excess carbon dioxide (CO2) and other greenhouse gases, contributing to global warming and climate change. While some of the CO2 stays in the atmosphere, about a third of the CO2 is absorbed by the oceans. The CO2 quickly reacts with water to form carbonic acid and bicarbonate ions. Hydrogen ions build up in the ocean, gradually making it more
Marine organisms are highly sensitive to changes in pH, so even minor fluctuations can have substantial impacts on ocean ecosystems. Numerous groups of species rely on carbonate in the water to construct their shells or skeletons, which are made up of compound called calcium carbonate (or limestone). However, as the amount of carbon dioxide dissolved in the water increases due to global warming and climate change, an imbalance in the carbon cycle is The excess CO2 and H+ ions drive a chemical reaction that converts carbonate (CO32-) to bicarbonate (HCO3-). The lower the pH of the oceans, the less carbonate that is available for marine organisms to use as building blocks in their shells and skeletons, and existing limestone begins to dissolve.
Learn more about the United Nations Sustainable Development Goals and how they apply to the activity. Consider integrating conversations about the following goals to get students thinking about how the information from the workshop applies to their world:
What's Happening?
Station A: Physical Factors
The ocean is an incredibly complex and dynamic body of water and it, much like our atmosphere, is divided into a multitude of layers. Water has an incredible heat capacity which means that it takes a lot of energy to change it from state to state. This capacity has made the ocean into a thermal regulator for our planet. It’s this regulation which makes day-night and winter-summer temperature changes more gradual.
Seawater experiences an inverse relationship between temperature and density. The colder the water, the more dense it is and vice versa. Density is also affected by salinity. The relationship between density, salinity, and temperature drive convective ocean mixing. This conveyor belt of movement provides consistent mixing of warm salty water from areas of high evaporation like the tropics with cold freshwater from areas of high precipitation and river output.
Station B: Biology of the Blue
A microscope is used to magnify objects that may be too small for the naked eye, allowing scientists to see microscopic organisms that would otherwise go undiscovered, like plankton. Although generally small, plankton plays an important role in aquatic environments. An organism can be classified as a plankton if they are incapable of sustained horizontal Within this category there are phytoplankton, plant plankton such as algae, and zooplankton, animal plankton such as tiny crustaceans. Even though they are often small, phytoplankton and zooplankton are key components of marine ecosystems by acting as the base of many marine food webs.
Station C: Chemical Clues
One way of describing the chemical properties of different substances is to talk about how acidic or basic (alkaline) they are. Some compounds are acidic, which means that when they are dissolved in water, they will have a higher concentration of hydrogen ions (H+) than pure water. Other compounds are basic, which means that when they dissolve, they will have a lower concentration of hydrogen ions than pure water. The pH scale is the commonly used to describe how acidic or basic different substances are. The scale ranges from 0 to 14, with numbers from 0 to 7 representing acidic compounds, and numbers greater than 7 representing basic compounds.
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Why Does it Matter?
Stratification in seawater affects marine life. Phytoplankton rely on stratification because they need to stay up near the surface in order to get enough light and nutrients. The songs of whales will refract differently under the conditions created by the stratified layers of the ocean. The layers allow for the sound to get trapped in a layer and travel huge distances. However, the stratification of seawater has been changing over several decades due to climate change and global warming, with an average of 1% increase in stratification per decade, mostly due to temperature increases on the surface of seawater and some local changes in salinity.
Seawater is also slightly basic. However, a decrease in the pH of seawater in recent times has largely been influenced by human activity. Burning fossil fuels releases excess carbon dioxide (CO2) and other greenhouse gases, contributing to global warming and climate change. While some of the CO2 stays in the atmosphere, about a third of the CO2 is absorbed by the oceans. The CO2 quickly reacts with water to form carbonic acid and bicarbonate ions. Hydrogen ions build up in the ocean, gradually making it more
Marine organisms are highly sensitive to changes in pH, so even minor fluctuations can have substantial impacts on ocean ecosystems. Numerous groups of species rely on carbonate in the water to construct their shells or skeletons, which are made up of compound called calcium carbonate (or limestone). However, as the amount of carbon dioxide dissolved in the water increases due to global warming and climate change, an imbalance in the carbon cycle is The excess CO2 and H+ ions drive a chemical reaction that converts carbonate (CO32-) to bicarbonate (HCO3-). The lower the pH of the oceans, the less carbonate that is available for marine organisms to use as building blocks in their shells and skeletons, and existing limestone begins to dissolve.
Investigate Further
Learn more about the United Nations Sustainable Development Goals and how they apply to the activity. Consider integrating conversations about the following goals to get students thinking about how the information from the workshop applies to their world:
