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Nutrient Limitation in Phytoplankton

Raised of $3,000 Goal
Funded on 6/16/23
Successfully Funded
  • $3,410
  • 113%
  • Funded
    on 6/16/23

About This Project

Marine phytoplankton activity is abundant at a global scale and play a major role in the carbon cycle. However, the availability of nutrients is limited in the ocean, thus restraining the activity of phytoplankton. Proposed ocean-based climate solutions include adding nutrients to trigger phytoplankton blooms, but previous research indicates the impact is uncertain. We will address the nutrient requirements and how the cells use these nutrients in phytoplankton.

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What is the context of this research?

Tiny marine microbes known as phytoplankton are vastly abundant in the ocean and one of the major primary producers in the ocean. However, nutrient availability such as phosphorus and trace metals may limit phytoplankton growth. Major regions of the ocean are limited in iron, and phosphorus becomes limited at certain times of the year. Growth limiting levels of cobalt and zinc have been measured in oceanic surface levels. Previous research indicates that nutrient limitation in phytoplankton biomass varies depending on the nutrient and region. My experiments aim to identify which nutrients cause productivity, the minimum requirement of each nutrient, and their respective pathways in the cell via proteomics.

What is the significance of this project?

Despite the fact that the ocean has absorbed nearly a third of the atmospheric carbon dioxide, the global climate is on track to exceed a 1.5 degrees Celsius increase. Therefore, scientists are studying ways to store excess carbon dioxide in a timely matter. One proposed solution is to add small amounts of trace nutrients to trigger phytoplankton blooms, specifically additions of iron. However, previous research indicates that variable cellular stoichiometry, rapid turnover of nutrients within the food web, and the differing bioavailability complicate inferences of nutrient limitations. Therefore, it is important to understand which nutrients are prioritized by phytoplankton and their minimal requirements before introducing nutrient additions as an ocean-based climate solution.

What are the goals of the project?

To determine which nutrients propel growth in phytoplankton, I will collect raw samples in one-liter bottles from seawater in the Costa Rica Thermal Dome, which is known for enhanced primary productivity of cyanobacteria, in May 2023. There will be four experiments divided across six treatments repeated three times per treatment: control, iron, cobalt, zinc, iron and cobalt, and iron and zinc. After a period of time, nutrients will be added to each bottle to determine impact of these additional nutrients. Each experiment will be 18 bottles. The biomass of the phytoplankton will be measured to determine how much growth occurred before and after nutrient additions.


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Previous experiments demonstrated that certain nutrients enhanced phytoplankton productivity (Boyd et. al 2007; Cavet et. al 2003; Saito et. al 2002). However, these experiments also revealed considerable challenges in quantifying new biomass growth and attributing new growth to which nutrients. As a result, the utilization of fertilization-based geoengineering approaches for carbon dioxide removal is difficult to assess.

This proposal will enable identifying and quantifying nutrient fertilization caused by cobalt, zinc, and iron. Your support of our project will help us further the efficiency of fertilization as an ocean-based climate solution and assist in providing a quantitative accounting required for assessing carbon credits.

This project is also funded by the 2021 Ocean and Climate Innovation Accelerator (OCIA) Award.

Endorsed by

There are still important fundamental questions to learn about phytoplankton, and the growing interest in Ocean CDR techniques increases the urgency to answer them. Dominique is making an important contribution here.

Project Timeline

The project will be divided into two parts: the research cruise and in situ benchwork. The research cruise part includes the collection of marine cyanobacteria samples from the Costa Rica Thermal Dome and experimentation on the samples with nutrient additions which would occur during month-long expenditure on the ship. The in situ benchwork would include potential further experiments and protein analysis using mass spectrometry.

Apr 25, 2023

Travel to Golfito, Costa Rica

May 02, 2023

Sail on Research Vessel Atlantis Ship into the North Pacific Ocean

May 17, 2023

Project Launched

Jun 01, 2023

Complete four incubation experiments on phytoplankton growth 

Jun 09, 2023

Dock Research Vessel Atlantis Ship at Scripps Institution of Oceanography

Meet the Team

Dominique Kelly
Dominique Kelly


Woods Hole Oceanographic Institution
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Team Bio

The Saito Lab is a research team based at Woods Hole Oceanographic Institution that focuses on studying the interactions between metals and microbes using analytical chemistry and proteomics. The laboratory is an interdisciplinary group of researchers, ranging from specialization in chemistry, biology, and geology. Makoto Saito is the principal investigator for the lab and the Senior Scientist in the Marine Chemistry and Geochemistry Department.

Dominique Kelly

Dominique joined the lab after completing her Bachelor's in Environmental Science & Policy at Smith College. During her undergraduate career, she primarily studied physiology of marine mammals, but she became interested in studying biogeochemical cycles after studying the impact of hydraulic interactions in trees during droughts. Now, looking to expand her knowledge on the physiology of microbes and biochemistry in marine science, she is completing a post-Bachelorette fellowship program in the lab and studying nutrient limitation in phytoplankton Prochlorococcus marinus. She plans to pursue graduate school in an ocean science program.

Additional Information

Project Backers

  • 2Backers
  • 113%Funded
  • $3,410Total Donations
  • $1,705.00Average Donation
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