Sophie '20 | blogs

The Effect of Acidity on Domoic Acid Production of Pseudo-nitzschia Algae

Rising temperatures, melting ice, and increased carbon dioxide in the atmosphere caused by climate change are having great effects on the ocean and its inhabitants, including toxin-producing algae pseudo-nitzschia. However, there has not been much conclusive research on what causes these algae to begin producing domoic acid and become toxic.

My study aims to investigate the effect of pH on domoic acid production of Pseudo-Nitzschia algae. The hypothesis of the study is that pseudo-nitzschia will have a higher average rate of domoic acid production in water with ph 7.9 than water with pH 8.4.

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Goals for January 2019:

My goal this month is to complete further research to determine potential methods for controlling the pH of water in a container. I would like to have a list of possible methods I could use, and what materials are needed for each method. Determining how to control pH in the containers in which I will be growing algae is essential before I can move on with my project, and I plan to focus on testing potential methods this spring for Science Symposium.

Updates: After doing some research I have concluded that the best way to control the pH in water is with a CO2 bubbler system. Other potential methods include using acid to lower pH, but this is harder to control and the acid can corrode containers and be difficult to manage. CO2 bubbling involves injecting bubbles of CO2 through the water to lower the pH.

Goals for February 2019:

My goal for this month is to begin developing a more detailed methodology for my project. Building off my January goal, I will continue research on aquarium CO2 bubbler systems to learn about what is required to build one, or how to acquire one. I will need a tool that can measure pH and automatically adjust the CO2 flow to maintain a steady pH over time.

2/2/19 Update: A slight adjustment to the future plan stated in the January goal: I now hope to test my entire Pseudo-Nitzschia culturing system, not just the pH aspect, during science symposium to determine if I can keep algae alive and control all variables that will be necessary for my project. This will allow time to troubleshoot and to get started on data collection right away in the fall of 2019.

2/9/19 Update: I have finished my mini-lesson assignment, so I can now get back to focusing on my refining my experimental plan. Last week I checked in with Stori and she encouraged me to look into already existing CO2 measurement and control systems, like the ones used in aquariums, instead of trying to build a system myself. I am now focusing on learning more about these systems, their prices, and what is required to set one up. I checked in with Maia, and she has shared her methods document and a few useful articles with me (thanks Maia!), so my next step is to read through these to get a better idea of what she is doing, and how I can adapt her methods for my project.

2/16/19 Update: I presented my mini-lesson on Monday, and I feel it went pretty well. Doing this assignment gave me the opportunity to teach others about what I research every day, and it was a good way to see just how much I have learned about Pseudo-Nitzschia and algae over these past few months. Upon reading Maia's methods section, I definitely learned a lot! Maia has found some really helpful articles and is a lot farther along in her specific design. Being able to talk with Maia about her project going forward is going to be very helpful in designing and executing my project!

3/2/19 Update: Last week I checked in with Stori. She said that she had talked to Bill Cochlan (one of Maia's potential mentors) and he said he could help us get the algae culture set up. He can possibly provide algae culture, nutrients, etc. Stori said there was also the possibility of me doing an internship with Cochlan over the summer. This would be so helpful in doing my project, and I am hopeful that it works out!

3/9/19 Update: After brainstorming some goals for March this week, I realized I did not have a concrete plan for what exactly I would be working on for science symposium this spring. I talked with Maia and Stori and now have a much better idea. Maia will be testing the effect of temperature on the amount of Pseudo-Nitzschia growth, so for science symposium, I will begin looking into the effect of salinity on Pseudo-Nitzschia growth. This upcoming week I will begin researching salinities effect on algae.

3/16/19 Update: On Monday Maia, Stori and I are going to meet with Bill Cochlan. He will hopefully be helping us set up the incubators for growing algae and getting the necessary materials. I have been reading articles Maia shared with me and doing some of my own research on the effect of salinity on Pseudo-nitzschia growth, but I still need to do more research. Some of the studies were carried out in areas where, due to tides, there was a very large change in salinity throughout the seasons. I need to do more research and decide on a range of salinity values to test in my science symposium project.

3/23/19 Update: After going to visit the Cochlan lab on Monday and Friday, my and Maia's plans have changed a bit. Due to limited time, Bill thought it would be more feasible to research the effect of light on the growth of Pseudo-Nitzschia. The difficulty with this is creating a growing environment with controllable and measurable light. In order to do this, it may be necessary to grow the Pseudo-Nitzschia out of an incubator, as the light sensor can not fit inside the incubator. My and Maia's focus this week will be building a space to grow the algae. We received a lot of supplies from the lab, including lights, seawater, nutrients, culture tubes, and the culture of a common algae that is easy to grow. This will be a practice algae for us to use as we set up the incubator/growing environment. Because of this change to the variable we are studying, my science symposium project will also change. It is unlikely that I will have time to complete an entirely different experiment from Maia, so my science symposium poster will be something related to the process of growing algae in a lab.

4/13/19 Update: Over spring break I have been reading a few chapters from the textbook "Algal Culturing Techniques." I have read the sections Maribel recommended, and they have been helpful in learning more about the basics of culturing algae. As soon as class starts again next week, Maia and I (with Maribel's help) will be finally starting to grow algae for Maia's project! I am very excited to get started!