Oil spills, El Niño, and sea stars. Lessons learned from Carol Blanchette

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Dylan Ruan, Living Lab Intern, UCSB Sustainability

Few researchers at UCSB are as familiar with California’s marine ecosystem as Dr. Carol Blanchette.

Her principal field of research is in the rocky intertidal and with that comes a peerless understanding of California’s marine ecosystems.

It was this expertise that allowed Carol to play a role in UCSB’s response to the Refugio oil spill. Unlike offshore oil spills where a rupture in a pipeline gushes steady streams of oil into the ocean, the Refugio oil spill occurred on land and flowed out near the shoreline. This had potentially devastating consequences on the rocky intertidal zone.

One of the research programs Carol is heavily involved in requires long-term monitoring of intertidal ecosystems. This entails being constantly mindful of the number of species present, their sizes, and activity. This knowledge may be tedious to collect, but its value shines in the aftermath of a disaster like an oil spill.

“The practical application of that sort of knowledge,” Carol said. “Is that without it, we don’t really have a way of understanding what we’ve lost when something like an oil spill happens.” Fortunately, a number of these sites exist along the coast and allowed for Carol and her team to extract data and assess the damage to the natural resources.

Carol’s research allows her to address a number of potential disruptions to the ecosystem. Some, like an oil spill, are manmade. Others are forces of nature. Coastal marine organisms, Carol says, will have unique reactions to the forecasted “Godzilla” El Niño.

El Niño years are associated with higher storm intensity which could have a range of effects from scouring of beaches and coastal erosion to massive beaching of kelp forest communities onshore.

Most Californians are worried about the incoming storms. But Carol stressed that much of the impact of El Niño is already being felt in the Pacific Ocean.

Warmer waters have a habit of shifting species distributions as animals move to locations that have preferable temperatures.

“We’ve already seen impacts from just the warm water that has preceded this El Niño,” Carol said. “We’re seeing a lot of different fish species from subtropical to even tropical fish like the Hammerhead shark.” Small pelagic red crabs usually home to the coasts of Baja have begun washing up on Santa Cruz islands as much as one year ago.

Even more astonishing is the potential that the El Niño could have in affecting animal disease.

The sea star wasting disease has become the largest known marine epidemic and killed sea stars in great numbers from Alaska to Baja. The disease was noticed in Southern California near Santa Barbara around late 2013 when the ocean waters began to warm. This signals a potential link between the warmer temperatures brought by El Niño and the significance of disease spread.

This raises the concern for marine biologists. El Niño is associated with a band of warm water that sloshes from the western Pacific to the Americas. As climate change causes El Niño events to become more common and intense, the increase in warm water along the eastern Pacific could pave the way for more diseases to afflict marine organisms.

The documentation of El Niño events, Carol says, is still a recent undertaking. “El Niño’s occur anywhere between every five to nine or so years. We’ve only been able to sample a few in the last 30 years and each one has been different from the last. There is no typical El Niño–each one seems to have its own signature.”

Climate change is making events like El Niño even more difficult to deal with. For ecologists like Carol one of the greatest challenges to the research will be predicting how complex ecosystems will respond to the changing climate.

The challenge, Carol says, is that “the predictions you might have for any single species alone could be completely changed by that species living in its ecosystem and its interactions with others.” In an ecosystem the interactions a species has with its environment changes the entire predictive process.

One of these interactions is that of pteropods and salmon. Pteropods are tiny marine snails that are a primary food source for salmon. Ocean acidification has severely impacted the pteropods as they have a difficult time growing and reproducing in an ocean that is becoming more acidic. As the pteropod population plummets, we can expect the salmon population to follow suit. Ocean acidification may not affect salmon directly, but its interaction with the pteropods will have consequences for its future.

The work that Carol does studying complex ecosystems of marine animals is valuable in the study of resilience of the ecosystems to a changing climate. Some species have an ability to acclimate or adapt to changing climate conditions. “A lot of species,” Carol said. “Have flexibility in their genetic code that enable them to be able to grow or reproduce or produce shells under different types of conditions. The key is giving these species enough space and enough time to catch up with changing climate.”