The aim of this project is to add valuable insight into fighting climate change by growing efficient species of algae that absorb CO₂, and reduce atmospheric CO₂ levels.

 

We will grow String algae and Brown algae (Sample A), and Black Beard algae and Hair algae (Sample B) in controlled environments where we will manipulate the CO₂ levels, and measure the algaes’ growth rate in both high and low CO₂ environments. 

I hypothesize that both Samples will grow significantly in high CO₂ than in low CO₂ environment, but Sample A in high CO₂ would grow more than Sample B in high CO₂, because Sample A algaes have evolved in higher CO₂ environment than Sample B.

 

Why Algae?

Algae are considered “simple” plants compared to other plants that have many more parts. But like other plants, Algae also absorb CO₂ and emit oxygen using photosynthesis. However, algae are easy to grow; they’re hardy plants that are relatively resistant to disease, can thrive in any extreme conditions and can adapt quickly to survive in all environments. They are also commodity plants that can be harvested profitably to create the following commercial products: 

1. Skin treatments and Cosmetics
2. Food additives extracted from seaweed aka macroalgae
3. Nutritional supplements like Omega 3 fatty acids
4. Fertilizers especially in organic farming
5. Whole Algae as a protein source
6. Abrasives in water filtration systems and cleaning products

Macroalgae:

• Holdfast- roots and provides support, not nutrients 
• The entire body gets nutrients 
• Stipe provides nutrients to the whole body  
• Blades, Multiple blades are called a frond
• Air-filled bladders or floats help keep the stipe and frond floating they contain gas that helps the entire plant float

Microalgae: 

• Phytoplankton- tiny plants that live in water 
• Contains chlorophyll and it needs sunlight to survive 
• Some live in freshwater and are called pond algae 
• Others are bacteria 
• Live attached to rocks or other hard substances 
• Can appear blue brown orange yellow etc 
• Two types, Diatoms and Dinoflagellates 
• Diatoms can be circles, ovals, triangles, or stars with tiny amounts of oil in them to help them move around in the water to find food and other nutrients 
• Dinoflagellates have two flagella that look like short tails and they help the dinoflagellates move through water they also have oil to help them swim 
• Algal Blooms are made up of diatoms and dinoflagellates that happen when a lot of algae grow quickly. They ruin the environment because they prevent sunlight from reaching other organisms in the water. They also discolor the water reduce the amount of oxygen in the water and cause food poisoning. 

• Algae suck co2 out of the air and suck methane out of cow burps. 3.5 billion years old. 
• Blue-green algae or cyanobacteria 
• Cyanobacteria started creating oxygens 
• Algae capture carbon from the ocean for their photosynthesis but the ocean takes CO2 from the air because everything is equal
• Using algae for fertilizer reduces pollution in those industries 
• Plastics made of Algae don't release any pollutants into the environment 
• Algae falls to the floor when it does, there it stores its captured CO2 

Brown Algae

Scientific name: Phaeophyceae

Phylum: Gyrista

Class: Phaeophyceae; Kjellman

Brown algae or Phaeophyceae are common in cold water along coasts. The color ranges from brown to olive green. That depends on the fucoxanthin (brown pigment) and chlorophyll (Green pigment). Brown algae could either be as big as full-size kelps or as small as small filamentous epiphytes. Other types of brown algae could be found on rocky shores but almost no types are found in freshwater. Laminaria hyperborea and Atlantic ascophyllum nodosum are relatives of the alginic acid and it is used in ice cream, toothpaste, tinned meats, fabric printing, and soap. In water, these algae form a gel which is used for moulding or binding. Brown algae contains polysaccharides which have a high alcohol content. (Polysaccharides are a type of carbohydrate.) Brown algaes plant walls are composed of alginic acid which is a biopolymer made up of hydrophilic polyuronic acid chains. Most brown algae have an alternation between the haploid and diploid generations. Some brown algae is used to make agricultural spray which is used at low concentrations on crops. Other algae and used for land fertilizer. Brown algae has been proven to have benefits, from being a traditionally tasty dish in southeast Asia, to also have benefits for health. 

Black Beard Algae 

Scientific name: Audouinella 

Phylum: Phylum Rhodophyta 

Class: Florideophyceae\

Black Beard Algae (BBA) or Audouinella is part of the red algae family which is from saltwater and freshwater environments. BBA can tolerate high pollutant environments and it thrives on dissolved phosphate and nitrates. Appears in fish tanks when CO2 levels are deficient and takes carbon from hydrogen carbonate creating hydrogen ions and thus increasing the pH levels and acidity in the fish tank. BBA is made of short, branched filaments which grow in thick tufts. The filaments are created on the prostate and erect axes. The filaments normally come with monosporamgia at the tips of the branches. BBA is found from the North Slope of Alaska to Costa Rica. The most common BBA in North America is called Hermannii which tends to grow in cooler waters with a temperature of 11°C.

Hair Algae

Scientific name: Bryopsis 

Phylum: Phylum Phaeophyta 

Genus: Marine Macroalgae 

Hair algae or Bryopsis consists of many single tubular filaments. Each of those cells is made up of an erect thallus that is often branched into pinnules. There have been 60 discovered species of this algae. Hair algae is usually found in tropical and subtropical coastal areas. Hair algae can be either epilithic or free-floating. The increase in pollution and climate change is thought to be the cause of the increase in hair algae. Hair algae are found in many places all over the world, there have been sightings in Singapore, where hair algae covered 30-40% of the coral and sightings in the United States where the algae appeared around the East Coast. Hair algae is found to thrive in lakes with less oxygen. Microbes break down the algae and the decomposition of the algae causes oxygen shortages and toxic environments for living creatures all around. If hair algae is growing it is usually a sign of high levels of phosphates. Hair algae is made up of 50% carbon, 10% nitrogen, and 2% phosphorus.

String algae 

Class: Zygnematophyceae

Order: Zygnematales

Family: Zygnemataceae

Genus: Spirogyra

Spirogyra (common names include water silk, mermaid's tresses, string algae and blanketweed) is a genus of filamentous charophyte green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is characteristic of the genus. Spirogyra species, of which there are more than 400, are commonly found in freshwater habitats.Spirogyra measures approximately 10 to 100 μm in width and may grow to several centimeters in length. It is often observed as green slimy patches on the ground near ponds and other water bodies having stagnant water.

Photosynthesis:

Photosynthesis is a natural process where a living organism converts light energy into chemical energy. That chemical energy is then stored and converted into carbs and sugars to fuel the living organism. Algae accounts for more than 50% of the world's photosynthesis.

 

 

 

 

Controlled: 

Size of jars, quantity of water in each jar, weight of bread (algae food) added to each jar, amount of algae in each jar, temperature of the environment the jars are placed in, amount of CO₂ pumped into the high CO₂ environments

 

Dependent: 

The growth rate of all four species of algaes in both high and low CO₂ environments

 

Independent: 

Species of algaes, amount of CO₂ between the high CO₂ and low CO₂ environments

 

  

 

Materials:

• 4 species of algae: (Sample A) Brown algae and Hair algae, and (Sample B) String algae and Black Beard algae
• 4 clear glass jars with lids that can be screwed on tightly to prevent gas from escaping
• 2 one-way valves and tubes 
• Power drill to insert valves and tubings into the lids of two glass jars
• CO₂ - SodaStream
• Weighing scale
• 80 oz Water 
• 4 Bread slices 

Proceudre: 

 

1. Label each jar so you can tell them apart. Two jars with valves in the lids to pump CO2 into them should be labelled separately as A-CO2 and B-CO2, and Sample A algaes and Sample B algaes would be introduced into them respectively. The other two jars without the algae would be the jars without added CO2, and they should be labeled as A and B to hold algaes from Samples A and B respectively. 
2. Measure 4 equal parts of water of 20 oz each, and add the equal parts to each of the four jars. 
3. Weigh four equal pieces of bread at 25 oz each, and add one of the equal four pieces to each of the four jars. 
4. Divide both Sample A algaes into equal parts. Place one equal part of each algae into the Jar labelled A-CO2, and the other equal part in the Jar labelled A. 
5. Divide both Sample A algaes into equal parts. Place one equal part of each algae into the Jar labelled A-CO2, and the other equal part in the Jar labelled A. 
6. Seal the lids of all four jars, and place the jars next to each other in an area with similar light exposure. 
7. Connect the jars labelled A-CO2 and B-CO2 to SodaStream, and pump in a controlled amount of CO2 from the SodaStream for 20 seconds through the piping and one-way valve inserted in the lids of the jars. 
8. Measure and record the weight of all four jars with the water, the bread and the algae samples in them. 
9. Pump in CO2 from Soda Stream into the A-CO2 jars and B-CO2 jars for 20 seconds at a time every 24 hours. 
10. Record the weight of the sealed jars at regular intervals to observe the changes. 

Weight of Jars with Algae samples (measured in Ounces) over a period of time:

Jar Label	02/26/2024	02/29/2024	03/03/2024	03/05/2024	03/07/2024	03/09/2024	03/11/2024	03/12/2024
Sample A CO2	40.5	44.4	44.52	45.82	46.01	46.2	46.62	47.62
Sample B CO2	40.5	44	44.12	45.2	45.4	45.82	46.22	46.49
Sample A	40	43.15	43.18	43.21	43.24	43.27	43.32	43.37
Sample B	40	42.8	42.82	42.89	42.92	42.98	43.03	43.11

 

Throughout the experiment, I observed that Sample B-CO₂ grew more than I expected it to. During my research, I found every source saying that the Sample B algae appear only when CO₂ levels are low. So I found it surprising that Sample B-CO₂ grew more than regular sample B. Also, I observed that algae in Sample A demonstrated a significantly higher capacity for CO₂ absorption compared to Sample B, which was expected based on my research. This finding suggests that Sample A algae may hold greater promise as a CO2 absorber in mitigating atmospheric CO2 level as my research also indicated. 

 

• The data recorded showed that highest growth rate of the weight is of Jar containing Sample A with CO₂ intake
• We also observed that the next highest growth rate is observed in Sample B with CO₂ intake
  • This shows that CO₂ is instrumental in increasing growth rate in algae
• Sample A without CO₂ growth rate is slightly more than Sample B without CO₂

• Our results align with the established biochemical knowledge, indicating that the photosynthetic activity of Sample A plays a pivotal role in its  absorption capabilities.
• While Sample A algae exhibited superior CO₂ absorption, variations in environmental factors such as light intensity, nutrient availability, and CO₂ concentration (we tried to make these factors constant in this experiment) may influence the efficiency of CO₂ absorption in both the samples. Further exploration into optimizing these environmental conditions could enhance CO₂ absorption efficiency.
• Understanding the CO₂ absorption capacities of algae is essential for developing sustainable solutions to mitigate climate change. Our findings contribute valuable insights to ongoing efforts aimed at harnessing natural processes to combat rising atmospheric CO₂ levels.

Future studies could explore additional factors influencing CO₂ absorption, such as temperature fluctuations and microbial interactions, to further refine our understanding of the potential of algae as CO₂ absorbers. Continued research in this area holds promise for advancing eco-friendly strategies for addressing climate change challenges.

• Algae has been proven to absorb atmospheric CO₂, and can be a major tool in combating climate change since algae is easy to grow and can grow in any adverse conditions.
• Algae that is grown to absorb atmospheric CO₂  can also be harvested and used in many secondary applications like the ones listed below.
• Dried algae can be used as a fertilizer because it contains many nutrients that plants need while growing. Algae also increases the soil’s capability of holding water. 
• Algae can be used as animal feed. It has been shown that the proteins that algae contains are helpful for the animals.
• Algae is rich in vitamins like vitamin A, E, C and K with other minerals like iron and magnesium, and also fatty acids like Omega-3. Algae can hence be used as supplements in human diet. 
• Algae has also been shown to have medicinal properties beneficial for humans. And algae is also used in cosmetics and skincare products.

 

We will use this proven information to further investigate on how algae could be crucial in helping our environment by reducing CO₂ and could be beneficial by being used in other products that we can also use.

 

• The only variable we are measuring as shown in the observations is the rate of change of the weight of the jars. We minimise the error in this measurement by observing multiple measurements at the same time and taking the mean of all the measurements. By observing only one variable, we have minimized the sources of errors. 

 

• We pumped the C0₂ for 20 seconds into the A-CO₂ and B-CO₂ jars because that was the easiest way to make the volume of the CO2 pumped consistent. Next time, we could also find a way to more accurately measure the C0₂ pumped. 

• Yonka Paris (2021), What Are the Skin Benefits of Algae? https://us.yonka.com/blogs/blog/skin-benefits-of-algae#:~:text=Algae%20is%20a%20strong%20humectant,even%20in%20sensitive%20skin%20types 
• Fernando Bacha Baz (2020) Use of algae in animal feeding- Ruminants https://nutrinews.com/en/use-of-algae-in-animal-feeding-ruminants/#:~:text=The%20use%20of%20marine%20algae,improved%20conception%20and%20birth%20rates 
• Wu JY, Tso R, Teo HS, Haldar S. The utility of algae as sources of high value nutritional ingredients, particularly for alternative/complementary proteins to improve human health. Front Nutr. 2023 Oct 13;10:1277343. doi: 10.3389/fnut.2023.1277343. PMID: 37904788; PMCID: PMC10613476.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10613476/#:~:text=In%20general%2C%20algae%20are%20abundant,vulgaris%2C%20C 
• Jessica Ainsworth (2021) The Benefits of Algae as Fertilizer https://algenair.com/blogs/news/the-benefits-of-algae-as-a-fertilizer#:~:text=Dried%20algae%20can%20act%20as,also%20help%20improve%20soil%20aeration 
• PhycoTerra (2022) The Unique Benefits of Macroalgae and Microalgae in Agriculture https://phycoterra.com/blog/benefits-of-macroalgae-and-microalgae-in-agriculture/ 
• Wikipedia (2023) Spirogyra https://en.wikipedia.org/wiki/Spirogyra 
• Robert G. Sheath, in Freshwater Algae of North America (2003) Audouinella https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/audouinella 
• Aquasabi(2022) Black Beard Algae (BBA) https://www.aquasabi.com/aquascaping-wiki_algae_bba-black-beard-algae 
• Wikipedia (2024) Bryopsis https://en.wikipedia.org/wiki/Bryopsis 
• Britannica, T. Editors of Encyclopaedia (2024). brown algae. Encyclopedia Britannica. https://www.britannica.com/science/brown-algae 

Din NAS, Mohd Alayudin 'S, Sofian-Seng NS, Rahman HA, Mohd Razali NS, Lim SJ, Wan Mustapha WA. Brown Algae as Functional Food Source of Fucoxanthin: A Review. Foods. 2022 Jul 27;11(15):2235. doi: 10.3390/foods11152235. PMID: 35954003; PMCID: PMC9368577. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9368577/#:~:text=Brown%20algae%20contain%20polysaccharides%20that,them%20grow%20in%20cold%20water

I would like to thank my parents for helping gather all the materials I needed for this project and. I would also like to thank Ms. Rheinstein for coordinating everything.