Background:
The sun is the base of all food chains. Phytoplankton use the sun to photosynthesize. As such, these organisms must remain in the "well-lit" or photic zone of the water.
Zooplankton feed off of phytoplankton, so they must also have a way to stay in the photic zone. Being plankton, however, they are not good swimmers; they are "drifters", by name and virtue. To stay in the photic zone, plankton have special adaptations to remain afloat.
Dinoflagellates, a type of phytoplankton, use flagella, or long tails to help stay afloat; ciliates use cilia, or hair-like extensions. Other plankton form chains with each other to gain surface area to stay afloat. Some plankton have vacuoles or other compartments in their bodies to help provide buoyancy. These adaptations give each plankton species an advantage.
Not all plankton float in the water, some are benthic; that is, they are found on the bottom of the lake on rocks and sediment.These plankton do not need to have adaptations to stay afloat as they are neither solitary or have apparatus to move, albeit slowly. Other plankton attach themselves to vegetation in the water. Planktonic, drifting, plankton are the ones who have a vested interest in not sinking. Most zooplankton can move; they undergo a diurnal migration where they migrate to deeper water during the day and return to the top at night. It is thought that these zooplankton undertake this energetically costly migration to avoid predation and to conserve energy. However, when they are feeding in the photic zone, they want to be able to stay suspended while expending as little energy as possible, so they can still utilize flotation adaptations.
Vocabulary:
Photic zone: The depth of water in a lake or ocean that is exposed to sufficient sunlight to photosynthesize.
Plankton: Small organisms that float or drift in great numbers in bodies of salt or fresh water; a primary food source for many animals, and consists of bacteria, protozoans, algae, cnidarians, tiny crustaceans such as copepods, and many other organisms.
Benthic: Non-floating plankton; these plankton do not float in the water - instead they live attached to or on top of a solid surface like rocks, plants, sediment, even a single grain of sand; planktonic diatoms are typically pennate, or not round - this is the most common type of diatom to find in a lake.
Planktonic: Floating in the water column; planktonic diatoms are typically centric, or round.
Phytoplankton: A type of plankton (drifting marine organism that makes up the foundation of the marine food web) that relies on photosynthesis. This group is comprised mostly of single-celled algae, diatoms, and bacteria.
Zooplankton: A type of plankton that feeds on phytoplankton.
Adaptations: Any physical or behavioral trait that allows an organism to better survive in its environment.
Cilia: Hair-like extensions found on ciliates, a type of plankton, to help them move and catch food.
Flagella: Tails found on dianoflagellates, a type of plankton.
Surface area: The total area of all of the faces and curved surface of a solid object.
Density: Mass per unit of volume; a measure of the relative "heaviness" of objects.
Micron: A unit of length equal to one millionth of a meter. This is the unit used to measure plankton size. Conversion formulas: microns = 1000 x mm; millimeters = microns x 0.001.
Photic zone: The depth of water in a lake or ocean that is exposed to sufficient sunlight to photosynthesize.
Plankton: Small organisms that float or drift in great numbers in bodies of salt or fresh water; a primary food source for many animals, and consists of bacteria, protozoans, algae, cnidarians, tiny crustaceans such as copepods, and many other organisms.
Benthic: Non-floating plankton; these plankton do not float in the water - instead they live attached to or on top of a solid surface like rocks, plants, sediment, even a single grain of sand; planktonic diatoms are typically pennate, or not round - this is the most common type of diatom to find in a lake.
Planktonic: Floating in the water column; planktonic diatoms are typically centric, or round.
Phytoplankton: A type of plankton (drifting marine organism that makes up the foundation of the marine food web) that relies on photosynthesis. This group is comprised mostly of single-celled algae, diatoms, and bacteria.
Zooplankton: A type of plankton that feeds on phytoplankton.
Adaptations: Any physical or behavioral trait that allows an organism to better survive in its environment.
Cilia: Hair-like extensions found on ciliates, a type of plankton, to help them move and catch food.
Flagella: Tails found on dianoflagellates, a type of plankton.
Surface area: The total area of all of the faces and curved surface of a solid object.
Density: Mass per unit of volume; a measure of the relative "heaviness" of objects.
Micron: A unit of length equal to one millionth of a meter. This is the unit used to measure plankton size. Conversion formulas: microns = 1000 x mm; millimeters = microns x 0.001.
The Great Plankton Race: Student Pre-Lab Questions
Instructions:
Observe videos/pictures of plankton and Discuss adaptations that they have to help them maintain neutral buoyancy in the water column.
Make a List of Adaptations Below:
Instructions:
Observe videos/pictures of plankton and Discuss adaptations that they have to help them maintain neutral buoyancy in the water column.
Make a List of Adaptations Below:
Questions:
What are Plankton? They are single-celled phytoplankton.
What do plankton eat? What is the difference between phytoplankton and zooplankton?
Plankton eats vegetation in the water. The difference between phytoplankton and zooplankton is that phytoplankton relies on photosynthesis while zooplankton feed on phytoplankton.
Why are plankton important? They are important because they are food for the fish of the sea.
Where would they want to hang out? They would want to hang out at the bottom of the ocean to avoid predators. They would come up only at night.
Why would a plankton want to stay in the photic zone? Plankton use the sun to photosynthesize. They use it to create their own food. To do that, they have to stay in the most well-lit area of the ocean.
How would a plankton stay in the photic zone? Some plankton have special adaptations that allow them to stay in the photic zone.
Brainstorm ways that plankton could reduce sinking rates:
If we could give it many special adaptations, we could reduce sinking rates. For example: you can use a swim bladder to control the plankton's buoyancy.
Name of Plankton: Spidey
Explanation of Name: We decided to name it Spidey because we made our plankton a spider.
Special Adaptations: Our plankton has eight legs to float.
Testing your Plankton:
Directions: Place your plankton into the tank and TIME how long (in seconds) that it takes for your plankton to sink to the bottom of the tank. Try it 3 times (making sure to dry between trials). After your 3 trials, average your floating time and calculate the RATE (distance/time) of your plankton sinking.
What are Plankton? They are single-celled phytoplankton.
What do plankton eat? What is the difference between phytoplankton and zooplankton?
Plankton eats vegetation in the water. The difference between phytoplankton and zooplankton is that phytoplankton relies on photosynthesis while zooplankton feed on phytoplankton.
Why are plankton important? They are important because they are food for the fish of the sea.
Where would they want to hang out? They would want to hang out at the bottom of the ocean to avoid predators. They would come up only at night.
Why would a plankton want to stay in the photic zone? Plankton use the sun to photosynthesize. They use it to create their own food. To do that, they have to stay in the most well-lit area of the ocean.
How would a plankton stay in the photic zone? Some plankton have special adaptations that allow them to stay in the photic zone.
Brainstorm ways that plankton could reduce sinking rates:
If we could give it many special adaptations, we could reduce sinking rates. For example: you can use a swim bladder to control the plankton's buoyancy.
Name of Plankton: Spidey
Explanation of Name: We decided to name it Spidey because we made our plankton a spider.
Special Adaptations: Our plankton has eight legs to float.
Testing your Plankton:
Directions: Place your plankton into the tank and TIME how long (in seconds) that it takes for your plankton to sink to the bottom of the tank. Try it 3 times (making sure to dry between trials). After your 3 trials, average your floating time and calculate the RATE (distance/time) of your plankton sinking.
Your Plankton Results:
1) How long did it take your plankton to sink below the photic zone? ( What was the rate? )
Our plankton did not sink it just floated.
2) Was this longer than you expected, shorter than you expected, or about what you expected?
This was not what I expected.
3) How did this compare to the sinking rates of your classmates' plankton creation?
Some floated and some sank kind of fast.
4) What other observations did you make about sinking rates of planktons?
I had observed that many of the smallest planktons sunk slower than the bigger planktons. I guess it depends on the size.
5) Explain why a plankton would want to go up and down in the water column?
It is caused by diurnal migration. Plankton would go down in the mornings because that is when their predators hunt for food, near the photic zone. They would go up at night, when their predators have left the photic zone. That is called diurnal migration. The reason why plankton do that is because they want to preserve their energy and to keep safe from the other creatures that want to eat them.
6) If plankton cannot swim against the current, how do they move within the water column?
They drift along with the current. The phytoplankton are not good swimmers so they have to find a way to move.
7) Describe the features of the winning plankton ( slowest sinking rate ). How was it different/similar to yours?
The winning plankton was
8) This race was performed in freshwater: How would the performance of your plankton be different in saltwater? Why?
If we had tested out our plankton in saltwater, our plankton would sink.If we had added an unknown amount of salt into the tank, our plankton would have sunk. It would sink because the saltwater is dense and that would've helped our plankton sink.
9) This race was performed in room temperature water. How would the performance of your plankton be different in very cold water? In very hot water? Why?
Cold water would have made it sink slowly while hot water would make it sink like a rock.
10) What factors, other than buoyancy, influence the evolution of plankton's external features?
The swim bladder helped with the buoyancy, the shape and size of the plankton also helped with that.The spines and legs of our plankton helped it to sink/float.
Conclusion: Explain what you learned about plankton and their adaptations, buoyancy and water composition by doing this laboratory activity. Please make sure to include your correct vocabulary and write in complete sentences.
I learned that
1) How long did it take your plankton to sink below the photic zone? ( What was the rate? )
Our plankton did not sink it just floated.
2) Was this longer than you expected, shorter than you expected, or about what you expected?
This was not what I expected.
3) How did this compare to the sinking rates of your classmates' plankton creation?
Some floated and some sank kind of fast.
4) What other observations did you make about sinking rates of planktons?
I had observed that many of the smallest planktons sunk slower than the bigger planktons. I guess it depends on the size.
5) Explain why a plankton would want to go up and down in the water column?
It is caused by diurnal migration. Plankton would go down in the mornings because that is when their predators hunt for food, near the photic zone. They would go up at night, when their predators have left the photic zone. That is called diurnal migration. The reason why plankton do that is because they want to preserve their energy and to keep safe from the other creatures that want to eat them.
6) If plankton cannot swim against the current, how do they move within the water column?
They drift along with the current. The phytoplankton are not good swimmers so they have to find a way to move.
7) Describe the features of the winning plankton ( slowest sinking rate ). How was it different/similar to yours?
The winning plankton was
8) This race was performed in freshwater: How would the performance of your plankton be different in saltwater? Why?
If we had tested out our plankton in saltwater, our plankton would sink.If we had added an unknown amount of salt into the tank, our plankton would have sunk. It would sink because the saltwater is dense and that would've helped our plankton sink.
9) This race was performed in room temperature water. How would the performance of your plankton be different in very cold water? In very hot water? Why?
Cold water would have made it sink slowly while hot water would make it sink like a rock.
10) What factors, other than buoyancy, influence the evolution of plankton's external features?
The swim bladder helped with the buoyancy, the shape and size of the plankton also helped with that.The spines and legs of our plankton helped it to sink/float.
Conclusion: Explain what you learned about plankton and their adaptations, buoyancy and water composition by doing this laboratory activity. Please make sure to include your correct vocabulary and write in complete sentences.
I learned that