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How kelp can help: Zhenna's California research
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Cover photo by Kristen Davis, Geno Pawlak conducting observational dives on ORI’s Santa Barbara kelp farm.
Can kelp help?
As a fast-growing marine organism, kelp already sequesters carbon and, at scale, could potentially play a crucial role in mitigating climate change.
Depending on the species, kelp can live for over a year and can grow from two to 30 metres tall, with some species reaching growth rates of up to 61 centimetres per day. This rapid growth increases its capacity for photosynthesis, which, in turn, increases the absorption of carbon dioxide from the surrounding environment.
When kelp reaches the end of its life cycle, much of the carbon it has absorbed is stored in its tissues. As the kelp decomposes and sinks to the ocean floor, this carbon is effectively sequestered, delaying its release back into the atmosphere. Due to its high growth rate compared to land forests, kelp offers a unique advantage in terms of carbon sequestration, capturing CO2 at a faster rate than many land-based ecosystems.
At CCR, we are trying to further increase our understanding of how we might get more macroalgae to grow and provide new ecosystems in the ocean, together with a flux of carbon from the surface waters to the deep ocean. This project is being undertaken in collaboration with groups such as Running Tide and Kelp Blue.
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Zhenna's research in California
Written by Zhenna Azimrayat-Andrews, PhD student at Centre for Climate Repair.
The Atmosphere-Ocean Dynamics group within the Department of Applied Mathematics and Theoretical Physics is currently working on a project which is aiming to characterise and quantify the carbon dioxide removal potential of giant kelp forests. Marine carbon dioxide removal (mCDR) strategies, such as the use of kelp forests, are gaining traction as promising technologies to reduce atmospheric carbon dioxide concentrations and Cambridge’s research group has united with Stanford University, along with other universities in California (UCSB, UCSD, UCI), for an international collaboration researching mCDR.
The Santa Barbara Channel is home to Ocean Rainforest Inc.’s (ORI) pilot Californian kelp farm (growing Macrocystis pyrifera). Through ORI’s partnership with Stanford and their collaborators, the site is being used to collect data on the fluid dynamics, biogeochemistry, and carbon dioxide removal potential of kelp farms. Gaining information for all of these factors will help to better understand kelp forest growth, and how it can be utilised as an mCDR technology.
I am a new PhD student studying in the Department of Earth Sciences and I visited Santa Barbara in July this summer to help with this data collection. The environmental data collected from this expedition will be used by me and my team to improve the OceanBioME modelling environment with John Taylor, Sasha Turchyn, and Jago Strong-Wright.
The expedition was carried out over four days this July and consisted of a variety of observational and data collection methods. On day one, Monday the 15th of July, Prof. Kristen Davis and Prof. Geno Pawlak conducted observational scuba dives along ORI’s farm lines, to monitor growth rates of the giant kelp. These observations were used to plan the week’s data collection efficiently and carry out assessments on the progress of the kelp farm’s growth.
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Nick Nidzieko’s oceanography lab at UCSB, with UCSB’s vessel used for data collection.
Day two comprised instrument and data recovery. The researchers used a machine named the “wire walker” for collecting a myriad of different data points. It is a scaffold which houses sensors monitoring the light availability, pH, carbon content of the water, and more. Throughout a period of collection, it “walks” its way up a suspension cable, collecting these data from different depths over a period of time. During its time in the water, it develops what the researchers call its furry coat (of algae), and it must be taken apart to be thoroughly cleaned in between each round of data collection. Once this is complete, its data can be downloaded, and it can be prepared to be redeployed. This meant that I had an afternoon at UCSB’s oceanography lab to become very acquainted with the wire walker, UCSB’s resident pressure washer, and lots of tag-along shrimp unfortunately making their home in the wire walker’s furry coat.
Days three and four of the expedition were biogeochemistry days and the team visited the kelp farm and took samples from the water both upstream and downstream of the farm. These were taken using CTD casts which are testing for pCO2, O2, and pH at different depths. The results of these casts should indicate how much carbon dioxide is absorbed by the kelp as water flows through the farm, and this data will be used in Cambridge to improve the accuracy of our kelp forest models.
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CTD cast sample collection, with Dave Mucciarone, Rob Dunbar, and Zhenna Azimrayat Andrews
This expedition allowed me to understand where my data is sourced from and the effort, preparation, and teamwork which goes into obtaining it. The trip was successful, notwithstanding the reliable speed bumps which accompany fieldwork, and I am now looking forward to applying what I have learnt to my studies.
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Team photo with Prof. Nick Nidzieko, PhD student Madolyn Kelm, Prof. Kristen Davis, Prof. Stephen Monismith, Prof. Geno Pawlak, Prof. Rob Dunbar, Dave Mucciarone, intern Savanna Saunders, and PhD student Zhenna Azimrayat Andrews.
Thanks to Centre for Climate Repair PhD student Zhenna Azimrayat-Andrews for sharing her experience. You can read more about Remove strategies here.
