The first of a two-part series.

For the past 100 years, the Haida First Nations tribe in Canada has watched the salmon runs that provided its main food source decline. Both the quantity and quality of its members' catch in the group of islands they call home, off the coast of British Columbia, continued to drop.

In the late 1990s and early 2000s, they became determined to do something about it. They built a hatchery, fixed watersheds damaged by past logging practices and sent more fish into the ocean for their multiyear migrations.

But the larger influx of fish that went out didn't return, and the search for better solutions for the small village of Old Massett on the north end of Graham Island in British Columbia eventually led the Haida down a path that culminated in the largest ocean fertilization project of its kind ever attempted.

In the summer of 2012, the Haida Salmon Restoration Council (HSRC) joined forces with a California businessman, Russ George, and dribbled 100 tons of iron sulfate into Canadian and international waters in the Pacific Ocean off the back of a ship.

The idea, promoted by George, was that this would stimulate the growth of plankton, which would be eaten by larger ocean dwellers and begin a feeding frenzy by the juvenile fish heading into the ocean. That might ultimately lead to higher survival rates and better fishing results when the fish came back to the island streams to spawn.

The sheer size of this experiment, when it was discovered, sent a shock wave through communities of environmentalists and scientists concerned about geoengineering -- schemes to intentionally manipulate the planet's climate. They called the actions a "blatant violation" of international laws set up to restrict the undertaking of such vast experiments due partly to the unknown secondary effects they may cause (Greenwire, Oct. 17, 2012).

But for the past two years, salmon have flowed into rivers along parts of the Pacific Northwest in sometimes record numbers, and questions remain unanswered about the possible success, failure or effects of the experiment.

"I can't stand up and give you a rock-solid statement that says A equals B," said Jason McNamee about whether the experiment had something to do with the massive sockeye and pink salmon runs for the past two years. McNamee is a former director and operations officer of HSRC and still sometimes acts as spokesman for the corporation. But, he said, "the iron sulfide bloom is a likely factor contributing to those runs."

Salmon, volcanoes and money

Where climate change entered into this vast fishing experiment is that it offered the possibility for George and the Haida to cash in on it.

In the mid-2000s, British Columbia's Premier Gordon Campbell was pushing hard to end a moratorium of offshore oil and gas development in the Canadian Pacific.

McNamee said that representatives from a big oil company showed up at Old Massett and asked village officials about potential carbon offset investments -- something the Haida weren't particularly familiar with at the time.

The oil executives didn't have any plan in mind and perhaps only made the offer in an effort to promote goodwill with some of the coastal people in the area. There wasn't a huge market for carbon offsets in North America at the time, but the prospect of funding got the Haida leaders thinking about ways to fund further operations to help bring their fish back.

Ocean fertilization generally involves using a mix of iron sulfate monohydrate -- used also as a livestock feed supplement and in the iron pills used by people who are anemic -- with iron oxide, or rust, into a liquid solution then dumping it into the sea. The principle is that phytoplankton, or algae, eat the iron. The algae are gobbled up by zooplankton, including species like krill or copapods -- food that salmon prefer.

Most experiments of ocean fertilization are done by Mother Nature. Dust storms and volcanic eruptions can drop large amounts of iron particles into the sea.

Sometimes it's hard to link these activities directly with salmon productivity, but some experts think that volcanic eruptions do offer rare glimpses into what would occur with really big influxes of iron into the ocean.

"The two biggest [salmon] runs that have occurred are both associated with volcanoes," said Tim Parsons, a professor emeritus at the University of British Columbia and a research scientist at the Institute of Ocean Sciences in Canada. "In 1956, an eruption of a volcano in Kamchatka produced a run of 20 million salmon in 1958 in the Gulf of Alaska, and more recently, in 2008, a volcanic eruption on the Aleutians produced the run of 35 million salmon in 2010."

Parsons said that the volcanoes "spew iron over the whole of the Pacific," triggering a zooplankton buffet for salmon.

"Since the need to grow rapidly in this new ocean environment is a priority for the very young salmon, their abundant survival was for once assured, resulting in the phenomenal returns," he said. "Alternative hypotheses on this whole process are difficult to find in any of the reports on sockeye salmon returns in 2010."

Fertilizing the ocean?

McNamee said that none of the experts had predicted the huge run of sockeye in 2010, but "we would say that it's our belief that the volcanic eruption and the volcanic bloom is the cause of that high return."

In 2012, the Haida and George released iron filings from a ship along a zigzagging path that extended over 5,000 nautical miles, timing the dump to coincide with an ocean eddy that spread the iron across the migration routes of different species of salmon. Satellites showed that the resulting plankton bloom covered around 13,500 square miles of ocean.

The sockeye run occurring this year -- two years after their experiment and in line with sockeye reproduction cycles -- in some ways resembles the pattern of a volcanic eruption in the Aleutian Islands in Alaska in 2008, just as it does the large pink salmon run in 2013 (the pinks have shorter cycles).

But McNamee stops short of making a direct connection.

"The experiment did what it was designed to do," he said. "The experiment was successful because it grew zooplankton, which should have fed the salmon crop in the path of their migration."

But George, the California businessman and director of HSRC before he was later fired, has been a lot more vocal in supporting the project.

"Clearly the 2012 work succeeded beyond our wildest expectations bringing back more than a half a billion additional salmon alone," he said in an email. "Countless other species of marine life were similarly restored and revived."

"The fish only came back because standing biomass in our region of the NE Pacific was even more tremendously restored."

Not everyone agrees with George's statements. Rich Zabel, the director of fish ecology divisions at the National Marine Fisheries Service's Northwest Fisheries Science Center, said that the good sockeye runs that struck the northern Snake River and Columbia River this season were the result of "a combination of positive things happening up and down the coast."

"I wouldn't say it's going to hurt," he said of HSRC's experiment. "But I wouldn't point my finger at this and say this is what caused the good run."

He said that salmon tend to travel thousands of miles in their migrations up and down the coast. Ocean upwellings also bring up iron, but can be variable between years, and cooler waters that occur sometimes can also lead to less predation on salmon.

"We think it's a combination of cooler conditions and few predators that leads to good return years," he said.

Another study that came out Monday in Nature Geoscience shows evidence that natural iron fertilization may not have as great an effect as thought on carbon sequestration. The authors found that while phytoplankton suck CO2 from the atmosphere, much of them could be eaten by other organisms like sea snails that produce calcium carbonate shells that sink to the bottom. But the organisms also emit CO2 back into the atmosphere in the process of creating the shells.

"Anything that's going to increase nutrients is going to help the populations," he said. But "if the fish are passing through, that's one snapshot in their lifetime."

The bigger picture

The trouble with the result of the experiment, though, is that it may not necessarily be as simple a question as whether or not it worked for the salmon.

One problem is that even if the project did benefit the salmon, and even if the resulting algae bloom managed to remove carbon dioxide from the atmosphere, salmon and CO2 aren't the only things at risk here.

"From an ecosystem standpoint, when you perturb the ecosystem, you don't really know how it's going to manifest itself in the food chain," Zabel said.

He said there is a potential for the iron to have a negative impact on other levels of food chains in the oceans. George Leonard, chief scientist of the Ocean Conservancy, said he agrees with many of the problems that Zabel has with the experiment.

"Anything done at that scale could potentially have big changes in the ecosystem," Leonard said.

He said that the Ocean Conservancy doesn't formally have a position on this issue, or on geoengineering in general, but he questioned whether any conclusions can be made on a one-off experiment like this.

"I think it's a great example of a really bad experimental design. If you want to determine cause and effect, that's not the way to do it," he said. "Simply dumping stuff into the ocean and saying, 'See? I told you so' -- that's not science."

"There could be one or a million confounding variables," Leonard said.

But while the experts are still uncertain about what happened during this vast experiment, salmon fishermen have been pleased. The salmon that ate these zooplankton have been seen in record numbers as they swam upstream in the Pacific Northwest, according to news stories from "Marketplace" and the Toronto Globe and Mail.

Tomorrow: Lawyers get involved.