Marine census finds stunning diversity

It began with one big question, a whole lot of fish and an improbable outcome.

Two scientists, frustrated over the lack of information about global marine biodiversity, were chatting in a research office in Woods Hole, Mass., and posed a deceptively simple challenge — find out what lives in the world's oceans and where.

The query in the late 1990s set off of an international scientific effort to come up with a global catalogue of everything from whales to tiny microbes in waters from the top of the world to the bottom.

Ten years after the project took root, researchers wrapped up the first Census of Marine Life on Monday, with findings that include the discovery of thousands of new species and an understanding of how climate change is altering the ecosystem.

"The success is beyond our wildest dreams," Ron O'Dor, a senior scientist with the census, said in Halifax before the release of the project's major findings in London.

"We all knew that something was doable, but I don't think anyone believed that we would accomplish as much and learn as much and change as much from unknown to known as has been the case."

The project, an ambitious attempt to document the diversity, distribution and abundance of all marine life, involved about 2,700 researchers from 80 countries working on 17 field programs.

The research yielded insights into areas of the oceans that had never been seen before, using technologies that were either new or adapted to suit harsh climates and allow them to do things like see a shrimp three kilometres down in the water column.

Manhattan-sized school of herring

In one expedition, scientists used sonar to look through U.S. waters and, in about a minute, found a school of herring the size of Manhattan.

"This was something that no one ever imagined was possible before," O'Dor said. "We've shown that it is possible and people are going to start doing it more and more."

The research has also established the first rough baseline of what types of life are in the oceans, where they're located, how much there are and where they migrate.

Paul Snelgrove, a marine biologist at Memorial University in Newfoundland who helped write the final census report, says that will be of critical importance in assessing everything from future climate change and the health of fish stocks to whether certain species are in danger of disappearing.

That type of research is being sought by scientists and governments evaluating the effects of the Deepwater Horizon rig explosion that spilled 4.9 million barrels of oil into the Gulf of Mexico last April.

A census team had earlier conducted deep-water sampling of the area, giving them a pristine look at the environment before the accident.

"It seemed like an esoteric exercise to many people and yet all of a sudden this has become extraordinarily valuable data because it does represent the baseline," Snelgrove said from St. John's before heading to London for the release of several census books, maps and databases.

"We now have this very complete record of what was there…. So this will certainly help in evaluating what sort of long-term effects the spill has had."

1,200 new species

Scientists now estimate there are one million marine species, excluding up to one billion microbes — valuable microscopic organisms that act as decomposers in the ecosystem.

The project identified 1,200 new species and has yet to name more than 5,000, many or all of which could be new to science.

Researchers say they discovered a greater diversity of creatures than expected and found life in the most inhospitable parts of the planet, including areas devoid of light or near vents so hot they would melt lead.

"Everywhere we look we find life and in the more remote places, often undescribed life," Snelgrove said. "Everywhere we look there are surprises and it's really quite wonderful."

But they also documented a marine environment being reshaped by human activity.

More than 9,000 salmon on the West Coast were tagged with small sensors that gathered data on where they travelled, water temperatures and salinity.

'Ocean is changing'

They showed that fish are migrating at different times and aren't as plentiful because of changes in water temperatures and food sources — both linked to climate change.

"One of the things that's come out of these tagging studies is that quite clearly the ocean is changing," O'Dor said.

Other tagging projects showed how one tuna swam across the Pacific three times, how green sturgeon in California rivers moved up to Alaska and how other species made their way from New Zealand to Alaska.

The research resulted in regulations being changed to protect endangered sturgeon from fishing nets, and renewed calls for co-operation between countries in managing fisheries.

Snelgrove said the research will continue even though the census has ended.

"The census has really brought people together, gotten them working on parallel problems using similar techniques," he said. "But when they go home they're not going to stop doing research and there are still lots of questions out there."