The effects of competition and purple urchin grazing on the recovery of giant kelp forests

Calvin Munson – Raimondi-Carr Lab

Positions: 1 – 2 interns

Tentative dates: June – September 2024

Project Location: Long Marine Lab on the UCSC Coastal Science Campus, possible day trips to Monterey

Project Background: Forests of giant kelp have declined dramatically along central California in response to the 2014-2016 marine heatwave. In many areas, forests have transitioned to “sea urchin barrens” devoid of algae and covered with purple sea urchins. There is great interest in understanding the process of forest recovery, in part to inform possible restoration efforts. We are using kelp cultivation techniques and mesocosms (cattle troughs) at CBB and Long Marine Lab to experimentally evaluate the role of intra-specific competition and sea urchin grazing on the survival of young kelp sporophytes. We are also designing field experiments to replicate these methods in the field. Results of these studies will allow researchers and managers to better understand the levels of kelp recruitment and sea urchin densities for kelp recovery.

Intern duties: The intern(s) will engage and assist in all elements of these experiments, including the design, implementation (kelp culturing in CBB, setup of the experiments, observation and data collection) and analysis. Kelp culturing will consist of the identification and quantification of early kelp life stages (spores, gametophytes, sporophytes) under microscopes. If the intern(s) are scientific diving certified, they may have the opportunity to participate in sample collection from the field if interested, but the position will primarily be lab/mesocosm work. Additionally, the mentor (Calvin) will teach the students coding in the R statistical software in order for them to conduct their own data analyses and visualizations for their final CAMINO products (no coding experience is necessary). The objective is to mentor the student through all aspects of an experimental research project. Fortunately, these lab and mesocosm experiments are short (4 weeks), which makes multiple rounds of experimentation feasible and not subject to weather conditions.

Intern qualifications: Ability to commit to the day-long duration of observations during peak mesocosm experiments and working for ~20hr each week. Microscope lab experience is helpful but not required. We assume that CAMINO students are not scientific diving certified, but that would be added value to the project and the student’s experience if they were.

Do you recommend the intern(s) volunteer in your lab during Spring quarter?
That would be nice, but not necessary.