La Nina is coming, right on the heels of a powerful El Nino. Locally, coastal residents are already seeing high winds and upwelling in the ocean. That could be good news for the kelp, which has been battered in recent years by a set of conditions likely set in motion by warming seas.
Dave Rudie is chair of the California Sea Urchin Commission and a partner in Pacific Rim Seafood, in Fort Bragg’s North Harbor. The abalone and red urchin fisheries on the north coast have been among the casualties of the urchin barrens, the shallow waters off the California coast that are now 96% devoid of kelp and teeming with the purple urchins that ate it. Rudie says that, according to 25 years’ worth of research funded by the Commission, there is always a high recruitment of all kinds of urchin during an El Nino year, with purple outnumbering red by a ratio of about 10 to 1. But this time, the water was already warm, due to the ‘warm blob’ that’s been heating the waters since 2013. And the pycnopodia seastar, the urchin’s one remaining predator, had been wiped out by a mysterious wasting disease. The kelp was already wilting due to the warm waters, “and when all these urchin showed up, they had nothing to eat,” Rudie explained. “So they scoured the bottom,” devouring whatever they could find. The water did cool off a bit in 2019, but “the problem was that there were so many urchins when the kelp settled out, they just ate the baby kelp.” Cold water, which is expected with the coming La Nina, could be beneficial for the kelp, but, Rudie observed, “Again, the problem is, with so many purple urchins out there, although the kelp may grow because of the cold water, it may not be able to because there are so many purple urchins ready to eat it.”
In Fort Bragg, aquaculture plays a large part in an initiative called the Blue Economy, which seeks to promote environmentally restorative businesses. A tour of South Harbor on Sunday included a visit to a monitoring device that’s part of an initial study to find out if aquaculture could be a viable path for an entrepreneur. Jamie Miller, with California Sea Grant, is the coastal Mendocino extension fellow. She’s working with the City of Fort Bragg and Noyo Harbor District on an aquaculture feasibility study, which at this point consists of a set of four water quality sensors. There are no animals involved yet, pending a scientific collections permit. There are three sites in the South Harbor, one in a slip in the mooring basin, and two closer to the mouth of the harbor. A fourth sensor is in the North Harbor, at the field station for the Noyo Center for Marine Science. The plan is to raise Pacific oyster, purple sea urchin, and red abalone. “And then in terms of seaweed, we’ll have bull kelp and dulse,” Miller summarized, before heading down the dock to stand next to an unassuming piece of PVC with some holes drilled into it at the end of a slip in the mooring basin. The sensors and the urchin ranch, which is also at the field station, have been in the water for about two months.
They monitor water temperature, salinity and dissolved oxygen, from the surface to about one meter above the bottom, to best gauge the conditions for the animals that might be raised there. They gather data every hour, and upload it to a publicly available system every four hours. Miller told the harbor tourists that she has made some graphs on the site, “So you can monitor the water quality yourself and view it for your own purposes.”
The operation she thinks would be attractive to aspiring aquaculturists is called a floating upwelling system, or FLUPSY, which is essentially a floating raft with an aeration system, that could theoretically be run in a slip right there in the harbor.
Miller believes the data could be useful to people in the private or public sector, for scientists working on restoration as well as those who might benefit from a boost into a commercial operation. “And aquaculture is definitely an option to support all of those efforts,” she said. “I see it as all of the above. Right now it’s a proof of concept study, so it’s very much research based. But we’re going to be gathering that baseline information that can hopefully support all these other projects and make recommendations for the future.” When the city’s one-year study is done, Miller says the plan is to give its three sensors to the Noyo Center, so the monitoring can go on.
She’s hoping to get the animals in the water this month. “We’re just waiting for approval,” she said. “The animals are ready to go, so we can put them in the water as soon as we get it.”
What animals are going to be put in the water? How will they be protected from seals and sealions?