Researchers study climate change impacts on Sitka Sound kelp forest

Kelp forest in Sitka Sound, being studied by researchers from University of California Santa Cruz. (Photo by Rachel Cassandra/KCAW)
A kelp forest in Sitka Sound, being studied by researchers from University of California Santa Cruz. (Photo by Rachel Cassandra/KCAW)

The kelp forests in Sitka Sound are rich ecosystems, full of animals that feed on seaweed.

The Sitka Sound Science Center is hosting researchers from the University of California Santa Cruz who are examining these forests.

The University of California Santa Cruz’s researchers load a bright orange inflatable boat up with scuba gear.

They’re looking for the kelp forest in Sitka Sound that they’ve been researching.

One of the researchers for the project, Umi Hoshijima is a postdoctoral researcher with UC Santa Cruz.

He says they’re studying: red and green sea urchins, the dusky turban snail and a few other snails, the pinto abalone, and a few limpets.

The researchers pull up to a spot of water with bits of kelp showing on the surface; confirm the location on their GPS; and anchor up.

They suit up in their scuba gear, lean back into the water and disappear under the waves.

Hoshijima said they were creating a snapshot of the underwater world just below the surface.

“For every single one of these critters that we’re interested in, we’re going down with a set of calipers to get their size down to the nearest millimeter,” he said.

They place a small, square frame made of PVC every few feet on the ocean floor, then count and measure every single creature of interest within that square.

It’s tedious work, but one of many things being done to understand the kelp forest.

“What we’re trying to do with the survey is to spend our time looking really closely at small patches of the bottom, to get an idea of the little critters down there,” Hoshijima said.

Researcher Umi Hoshijima, heading to the kelp forest he’s studying. (Photo by Rachel Cassandra/KCAW)
Researcher Umi Hoshijima, heading to the kelp forest he’s studying. (Photo by Rachel Cassandra/KCAW)

This is the field component of the invertebrate research, part of a larger project headed by researcher Kristy Kroeker through UC Santa Cruz and funded by the National Science Foundation.

The six researchers involved will look at invertebrates, as well as algae.

There also is a lab component, where researchers take these animals and change the temperature and pH, or acidity, of their water, so they can test how the creatures of the kelp forest would respond to changing ocean conditions.

Hoshijima says the variables they’re measuring in the lab, include “the amount of food they’re eating, how much they grow, and how much oxygen they’re breathing.”

Kroeker’s team is especially interested in the impacts of ocean acidification and temperatures in the surface oceans rising, which is crucial for understanding the future of kelp forests on a warming planet.

“We’re concerned that in the near future, a lot of the animals that we know and love in the kelp forest will actually have problems dealing with the more acidic environment,” Hoshijima said. “That’s been shown to decrease the thickness of shells, for things like mussels and oysters and different clams. It’s actually even been shown in some species to impact the, impact the brains of fish.”

This year’s data will act as a kind of baseline for understanding changes in the kelp forest. The project has funding for five years of research.

Hoshijima said the researchers can really spend the time to dig deep into the into the kelp forest.

With all this scientific understanding, Hoshijima hopes the research could impact the world, especially concerning climate change.

“We need to have a better idea of how our coastlines could end up changing in the near future,” he said. “And by sort of teasing apart how that could happen, we might be able to enact policy and change things in a way that we can protect our resources for the near future.”

KCAW - Sitka

KCAW is our partner station in Sitka. KTOO collaborates with partners across the state to cover important news and to share stories with our audiences.

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