Down By The Ocean

CAL POLY SAN LUIS OBISPO

The vast blue expanse of the ocean is an awe-inspiring sight to behold. In its waves and along its shores, though, may lie answers to scientists' pressing climate change questions—from renewable energy production to carbon sequestration to sustainable agriculture.

Benjamin Ruttenberg, Ph.D., associate professor and director of the Center for Coastal Marine Sciences at California Polytechnic State University, San Luis Obispo, is asking those questions.

“Climate change is here and it's here now—so we have to do absolutely everything we possibly can as soon as we possibly can to try to reduce how much CO2 we're putting in the atmosphere," Dr. Ruttenberg says. “To mitigate the effects of climate change, we need an 'all-of-the-above' strategy. We need to do everything better now. And I believe if we have the right policies, we can do that."

Because a major source of carbon is energy production, renewable energy like solar or wind must be part of the solution. With one project, Ruttenberg is looking at the viability of offshore wind energy and placing wind turbines on floating structures along the California coast. This involves identifying locations with the greatest amount of wind, modeling how much wind power would be produced by a turbine in a particular area and determining if wind power production aligns with demand for energy.

Offshore wind turbines in Scotland that Professor Benjamin Ruttenberg visited in 2018.

Offshore wind turbines in Scotland that Professor Benjamin Ruttenberg visited in 2018.

“One of the questions [we're testing is] how well is offshore wind energy complementary to solar," Ruttenberg says. “When we look at the relative value of offshore wind, it seems to peak in the late afternoon—especially in spring and summer—when demand for electricity is highest, just as solar power production winds down."

The next challenge is understanding the potential impacts of the turbines on the environment, marine mammals, seabirds and fisheries. A journal recently accepted a paper led by former undergraduate student Hayley Farr, B.S. biological science, '18, looking at the environmental impacts from similar types of facilities and equipment, such as fixed bottom offshore wind facilities, floating oil and gas platforms and fishing gear. It found such facilities are likely to have low or mitigable impacts on many aspects of the environment.

Some preliminary research has also begun looking at technology to harness tidal and wave power, but Ruttenberg explains it is still in the early stages.

In addition, Ruttenberg is studying aquaculture to develop sustainable seafood farming methods that produce less carbon and minimize ocean acidification (the result of increased carbon dioxide in the water).

About half the world's seafood is produced through aquaculture, but it's often done with deleterious environmental effects, such as clearing habitats that store carbon and filter the water and adding excess feed that produces waste and eats up the available oxygen. Aquaculture then becomes another carbon-producing industry increasing the amount of CO2 in the atmosphere and ocean.

“We've maxed out what the oceans can produce in terms of fishing—so if we want to continue eating seafood, we're going to have to figure out how to grow it," Ruttenberg says.

While working with Sea Grant Aquaculture Extension Specialist Kevin Johnson, Ph.D., on growing oysters that are more resistant to ocean acidification, Ruttenberg is also researching carbon-neutral aquaculture methods for oysters, native Pismo clams and abalone. He and a team of scientists from four universities have proposed a project to grow algae, abalone and oysters together. The algae would feed the abalone, buffer it from ocean acidification and consume carbon dioxide while the oysters would filter waste out of the water.

Sea Grant Aquaculture Extension Specialist Kevin Johnson grows oysters that are more resistant to ocean acidification.

Sea Grant Aquaculture Extension Specialist Kevin Johnson grows oysters that are more resistant to ocean acidification.

“Our goal is to try to make it as self-sustaining as possible," Ruttenberg says. “Essentially the only input to the system is electricity, and if we can figure out a way to offset the cost of electricity by putting in offshore wind or solar, then essentially you have a facility that's producing all this food with no carbon footprint."

Ruttenberg's research is just a sampling of the ongoing work being done by Cal Poly San Luis Obispo experts to address climate change. The campus's new Institute of Climate Leadership and Resilience (ICLR), which will coordinate the research, also includes projects to study carbon sequestration, redesign former power plants to produce renewable energy and develop a resilient energy assessment toolkit to help low-capacity cities implement microgrids and sustainable energy production.

Erin Pearse, associate professor of mathematics spearheading ICLR's development, explains the collaboration will also introduce climate research into the classroom.

“We're bringing community-based climate projects onto the Cal Poly campus through project-based courses, senior projects or graduate theses so that student groups can develop designs and/or perform analysis of existing designs," Pearse says.