Two years ago this month, an edge-pushing environmental entrepreneur and a company formed by a Native Canadian village set off a wave of international protest by dispersing a pink slurry of 100 tons of iron-rich dust over one of the 60-mile-wide ocean eddies that routinely drift across the salmon feeding grounds of the Gulf of Alaska.

Their goal, in the face of steep declines in Pacific salmon catches, was to trigger a plankton population explosion with the infusion of iron, a vital nutrient that’s lacking in those waters. Volcanic eruptions had been shown to do the same thing. Why not humans?

The plankton bloom, in theory, would nourish millions of juvenile fish that circulate in the Gulf before returning to the coast to spawn.

Along with a boosted catch, a second hoped-for payoff was the sale of carbon credits on international markets aimed at offsetting greenhouse gas pollution by financing projects that absorb heat-trapping carbon dioxide — typically by planting trees but in this case through spurring plankton growth. More than $2 million was invested in the project through the tribal company, the Haida Salmon Restoration Corporation.

The protests mainly came from groups and scientists critical of geo-engineering, large-scale efforts to harness or control the shared environment to serve human needs — particularly if the efforts were private. They asserted the project violated international ocean-dumping rules and a moratorium on ocean fertilization.

Russ George, the iron-dust entrepreneur (who is now in a legal fight with his former partners), has defended the effort as stewardship, not pollution.

Don’t count on a quick resolution of either the litigation or any prosecution arising from a long-running investigation by Canada’s environment agency, which has asserted in court that the project violated Canadian law.

But now that independent scientists have appraised the 2012 iron pulse, and millions of young salmon that were at sea that summer are heading up streams, and into nets, it’s at least possible to begin assessing outcomes and lessons from this freelance effort at treating the open sea like a farmer’s field — and a carbon safe-deposit box.

One lesson is that while privately financed science is playing a growing role in advancing knowledge, proprietary and legal issues can limit vital transparency. Most of the data collected during the iron-seeding effort in 2012 – some gathered with instruments loaned by Canadian and United States ocean agencies – are not yet public.

(George says this is in part because of the lawsuits and Canadian investigation, in which he says computers were seized.)

Much has been learned, nonetheless. NASA satellites independently measured a rare late-summer bloom of phytoplankton that independent researchers tied to the iron release. But those same researchers, led by Peng Xiu of the University of Maine, concluded in a paper earlier this year that the small area and short lifetime of the bloom meant its didn’t come close to comparing to the carbon absorption from a 2008 eruption and other natural sources of iron.

Photo

Other more conventional (if much smaller) scientific tests of iron fertilization in waters near Antarctica found a mix of results on oceanic carbon dioxide uptake, meaning lots more research needs to be done before anyone can bank on ocean repositories as a significant offset for smokestack carbon dioxide emissions.

The problem is that no new basic research of this sort has been initiated in recent years. Researchers say funding agencies have been rendered gun-shy by the continuing battle between George and his main critic, the technology watchdog organization ETC Group, which long predates the salmon project.

What about the prime question for the fishing communities in the region: Did the iron supplement boost salmon spawning runs and harvests?

George insists the project was “a phenomenal success,” pointing to big recent salmon hauls along the coast.

In a paper just published in the Journal of Plankton Research, two Canadian marine scientists, Sonia Batten and James Gower, reported evidence of a critical intervening step – a growth spurt in just the right kind of tiny animals, crustacean zooplankton, that young salmon thrive on.

But Batten and other fisheries scientists warns there’s too much natural variability in both North Pacific conditions and salmon reproduction to tease out an impact from 100 tons of dust spread on a single eddy in the North Pacific in single year.

There’s one more question. Are there better options for sustaining salmon harvests and sopping CO2 in a cash-strapped world?

Wilf Luedke, Canada’s chief of salmon stock assessment for the south British Columbia coast, told me he has nothing against careful tests of deep-sea iron fertilization, but worries that the debate – given the complexity in climate and ocean conditions shaping salmon populations — could distract from more clear-cut, and cheaper, ways to aid salmon, and absorb carbon dioxide, closer to shore.

These include conserving carbon-absorbing eelgrass beds in coastal inlets and continuing to restore salmon rivers and streams long beset by dams, careless logging and encroaching development.

“We can’t fix oceans in the short term,” he said. “But how we deal with rivers and watersheds, that we can fix right now.”

Privately-financed science, and creative entrepreneurship, clearly can play an important role in addressing humanity’s pressing problems – from reviving struggling coastal economies to feeding the world to stemming climate change.

But such efforts have to roll out in ways that don’t end up creating more problems than they solve.

Postscript, 2:25 p.m. | I was remiss in not including a direct link to a fine new feature by David Biello in Aeon Magazine on plankton fertilization and the Anthropocene. Here’s an excerpt from his closing thought: