Sinking logs into the bottom of the ocean could provide nutrients in a similar fashion to the hydrothermal vents above (via)
As the world's oceans succumb to overfishing and pollution, the idea of engineering solutions to jump-start the ecosystems we've been destroying is gaining popularity--at least among certain wealthy individuals and ambitious governments.
A businessman from San Francisco named George Russ, for example, got in big trouble last year after conducting an unlicensed geoengineering experiment off the Canadian coast. Russ, CEO of Planktos Inc., sailed from the Bay Area to British Columbia last summer and dumped about 100 tons of iron sulfate into the Pacific Ocean, about 200 miles west of Canada. Russ's idea was to use the nutrient-rich sulfate to stimulate the growth of plankton--a foundational part of the marine food chain--which would reinvigorate declining populations of the region's salmon while absorbing large amounts of carbon from the atmosphere and sequestering it at the bottom of the ocean.
Both Canada and the US government were not happy with Russ. But his experiment appears, at least in its first six months, to be working exactly as planned.
This week, a team of German researchers released a study suggesting that ocean fertilization can be assisted by an experiment a little less controversial than pouring massive amounts of iron sulfate into the ocean. Their recommendation? Try tree wood.
In their experiment, they implanted wood logs along the Mediterranean seafloor, some as deep as 1,700 meters, and left them alone for one year. When they came back, they found that the logs had essentially functioned like large fertilizer pellets for the kind of deep-sea invertebrates that form a bedrock of the marine ecosystem.
"We were surprised how many animals had populated the wood already after one year," said Christina Bienhold, marine microbiologist at Max Planck Institute and co-author of the study. The "main colonizers" of the logs were wood-boring shipworms, she said, which "constitute the vanguard and prepare the habitat for other followers."
Rather than Russ's top-down approach, the researchers make a case for a bottom-up strategy. As the wood decomposes underwater it releases hydrogen sulfide, which attracts microorganisms living on the ocean floor and boosts the biodiversity of the seafloor. The decomposition is similar to the chemical process that allows life to thrive near hydrothermal vents on the bottom of the ocean. James Cameron explored those in his historic deep dive last year.
Is it sustainable in the long term? Cutting down trees to feed the ocean seems a bit counterintuitive, but perhaps other wood sources could work. One thing is more clear: As our environment increasingly falls apart, it looks more and more likely like we're going to geoengineer our way out of the problem.