"There are three volcanic events in the last 100 years, and we had record sockeye salmon runs in those three volcanic dust events," George says. "That's pretty good data." In fact, government scientists from Fisheries and Oceans Canada speculated in a paper published this year in Fisheries Oceanography that the Kasatoshi eruption might be linked to the abundance of returning salmon in 2010.
But other scientists argue salmon biology is more complicated than that. "There's not evidence that that region is iron-limited," argues phytoplankton researcher Maite Maldonado of the University of British Columbia, who sailed on one of the first experimental iron fertilization cruise in the Southern Ocean in 1999. "We have a project right now looking at the salmon, and what we see is not that phytoplankton biomass has changed. What has changed is the timing of when the spring bloom occurs."
Much as migrating birds or spawning insects rely on the timing of spring so that there is enough available food when they arrive in a given region, so, too, the salmon rely on the timing of phytoplankton blooms, followed by the zooplankton bloom that then feeds baby salmon. As the Canadian government scientists note in the Fisheries Oceanography paper: "The 2010 phenomenal run…may forever remain an enigma due to the lack of precise ecological and chemical data."
In the case of the HSRC, however, the participants simply point to what they observed at sea: an influx of sea life, from seabirds to tuna. "More marine life was observed," Chief Councilor Ken Rea of the Old Masset Village Council told the press conference on October 19.
The project is also unlikely to bury much if any carbon dioxide for one simple reason: metabolism. As other iron fertilization experiments have shown, it is relatively easy to get plankton to bloom, but it is harder for that bloom to sink to the bottom of the ocean, where it takes CO2 with it. Instead, as suggested by the trickle-up theory of salmon restoration, the plankton tends to get eaten by tiny animals, which are then eaten by larger animals until, ultimately, all or most of the CO2 sucked up by the tiny plants during their photosynthetic life spans finds its way back to the atmosphere in relatively short order.
To bury carbon at sea requires promoting particular species in the bloom, such as diatoms—shelled algae. When these minute silicon-shelled photosynthesizers die, their corpses can overwhelm natural systems and sink to the bottom, as proved by a scientific research cruise in 2004. But dictating the species composition of a plankton bloom and its aftermath remains beyond the ken of marine biology, causing one researcher involved in the successful 2004 effort, marine biologist Victor Smetacek of the Alfred Wegener Institute for Polar and Marine Research in Germany, to call it beyond control at this stage. It remains unclear at this point which particular species bloomed as a result of the HSRC iron release but the team is sending out for analysis more than 10,000 water samples, data the HSRC team says it will share as other iron fertilization experiments have done. A preliminary review of the data collected is expected by November and a full analysis within the next nine months.