October 6, 2026 — I first met Dr. Helen Gurney-Smith in fall 2024, when Dr. Shannon Meseck and I drove just beyond the U.S.-Canada border to the St. Andrews Biological Station in New Brunswick. We went there to study larval sea scallop respiration when exposed to near-future temperature and pH. This past winter, Dr. Gurney-Smith’s research group drove south to visit us at the NOAA Fisheries Milford Lab in Connecticut. We studied how a proposed method of marine carbon dioxide sequestration may affect the single-celled phytoplankton community in the ocean.
This project was a part of a collaborative effort funded by the NOAA Ocean Acidification Program to engage early-career scientists from U.S. and Canadian fisheries agencies in ocean acidification research. Brady Quinn was the co-principal investigator on this project. Quinn, along with Dr. Gurney-Smith, and Erin Miller made up the Fisheries and Oceans Canada team, while Dr. Meseck, Genevieve Bernatchez, Lauren Witick, and I represented NOAA Fisheries.
Studying the Effects of Buffering Ocean Water with Olivine
Increasing carbon dioxide dissolved in the ocean causes ocean acidification, which is a concern for ecosystems. It’s especially harmful for marine life that build calcium carbonate shells, which can degrade in seawater with lower than normal pH. There are several proposed mechanisms to help keep the pH up in the ocean, including methods to increase alkalinity, effectively buffering seawater. One method is to add a naturally occurring mineral known as olivine to high-risk areas. As olivine dissolves in seawater, it breaks down into parts that can raise the pH of the water, making it less acidic. This works much like taking an antacid for an upset stomach.
When olivine breaks down it releases several elements phytoplankton need to grow, including the trace metals magnesium and iron, along with silica. Silica is an important nutrient for the growth of some phytoplankton, called diatoms. Diatoms are an excellent food for shellfish and other small marine grazers. Similar to plants, they can make oxygen from carbon dioxide through photosynthesis, making them an integral part of marine ecosystems. These diatoms use silica to create a glass-like cell wall, and it is possible that the release of extra silica from olivine could stimulate their growth.