May 26, 2023

Diving into Kelp Science: An Exclusive Interview with Dr. Jen Smith 🌱

El Niño and Giant Kelp Loss in San Diego, CA

Historically, La Jolla's rocky coastline has been home to a vibrant and thriving kelp forest, which has played a crucial role in supporting marine biodiversity, and is a popular destination for swimming, diving, surfing, and kayaking.

Unfortunately, these once-lush kelp forests have experienced a dramatic decline in the past decade, raising concerns about their disappearance and prompting the need for research to better understand why it has not returned, and how best to restore it.

SeaTrees is thrilled to actively support Scripps Institution of Oceanography in its dedicated efforts to address this problem. We had the privilege of sitting down with Lead Scientist Dr. Jen Smith to learn more about her scientific research plans.

Q: How long have you been studying seaweed, and what’s your background in seaweed science?

A: I received my PhD in Marine Botany from the University of Hawaii in 2003. I have been studying seaweeds for about 25 years. When I moved back to CA in 2005 I started working more on our local coastal ecosystems. Since beginning my Professorship at Scripps Institution of Oceanography in 2008 I have regularly had students working in the kelp forests of La Jolla.

Q: What are the key scientific research goals for the La Jolla kelp forest?

A: One of our main goals is to try to determine if the lack of recovery of giant kelp in north La Jolla is due to the residual effects of the last El Niño event or some other change to the environment that no longer supports kelp recruitment and growth. There was a large die-back of giant kelp associated with the warm water and low nutrient conditions that were characteristic of the 2015 El Niño event. While kelp has recovered in many locations, north La Jolla is still largely devoid of kelp. Is this due to a lack of “seed” supply or some other changes that have occurred at these sites? To address these questions, we will track changes in the La Jolla kelp forest over time, spanning several sites from the north to the south, determine if some populations are more thermally tolerant than others using lab experiments, and explore restoration potential at key sites using outplants of juvenile giant kelp individuals.

Q: How is your study in La Jolla different from other kelp restoration projects?

A: We are specifically focused on doing kelp restoration research. We are also working in a system where the cause of kelp loss was not due to a sea urchin outbreak. Here we will explore if there are individuals/population of giant kelp that can survive warmer waters than others. If we do find thermal tolerance, we will use these individuals to conduct experimental restoration outplants. Further, we will test the differential success of different outplant methods to optimize approaches for performing restoration in future efforts.

Q: El Nino conditions are predicted this year. Do you have predictions on how this will affect kelp forests in Southern California?

A: It’s hard to say at this point in time. If the predictions are correct, it will likely lead to another decline in our kelp forest populations. Depending on how long the event lasts and how extreme conditions are, it could result in mortality of giant kelp, possible expansion of invasive species such as the “devil weed” Sargassum hornerii and/or disease outbreaks such as the seastar wasting disease.

Q: Is there enough resilience in the kelp forests to withstand a strong El Niño?

A: I don’t have reason to believe this is the case, at least for Macrocystis pyrifera. It all depends on the specific conditions, though. If a thermocline persists, it may be fine in deeper water.

Q: What is your hope in being able to provide tools for communities to restore their local kelp forests?

A: We hope to develop some simple techniques that could be transferred to other stakeholders/community members for use in future restoration activities.

Here's a big SeaTrees thank you to Dr. Jen Smith for chatting with us and shedding light on the potential challenges and opportunities presented by this new kelp restoration science project. We look forward to our ongoing collaboration to safeguard and restore these vital marine ecosystems. To learn more about this project, check out the video below!