Fish Stocks Are Declining Worldwide, And Climate Change Is On The Hook

December 14, 2015, NPR.org, Claire Leschin-Hoar

A fisherman shovels grey sole, a type of flounder, out of the hold of a ship at the Portland Fish Pier in Maine, September 2015. New research finds the ability of fish populations to reproduce and replenish themselves is declining across the globe. The worst news comes from the North Atlantic, where most species are declining.For anyone paying attention, it’s no secret there’s a lot of weird stuff going on in the oceans right now. We’ve got a monster El Nino looming in the Pacific. Ocean acidification is prompting hand wringing among oyster lovers. Migrating fish populations have caused tensions between countries over fishing rights. And fishermen say they’re seeing unusual patterns in fish stocks they haven’t seen before.

Researchers now have more grim news to add to the mix. An analysis published Monday in the Proceedings of the National Academy of Sciences finds that the ability of fish populations to reproduce and replenish themselves is declining across the globe.

“This, as far as we know, is the first global-scale study that documents the actual productivity of fish stocks is in decline,” says lead author Gregory L. Britten, a doctoral student at the University of California, Irvine.

Britten and some fellow researchers looked at data from a global database of 262 commercial fish stocks in dozens of large marine ecosystems across the globe. They say they’ve identified a pattern of decline in juvenile fish (young fish that have not yet reached reproductive age) that is closely tied to a decline in the amount of phytoplankton, or microalgae, in the water.

“We think it is a lack of food availability for these small fish,” says Britten. “When fish are young, their primary food is phytoplankton and microscopic animals. If they don’t find food in a matter of days, they can die.”

The worst news comes from the North Atlantic, where the vast majority of species, including Atlantic cod, European and American plaice, and sole are declining. In this case, Britten says historically heavy fishing may also play a role. Large fish, able to produce the biggest, most robust eggs, are harvested from the water. At the same time, documented declines of phytoplankton made it much more difficult for those fish stocks to bounce back when they did reproduce, despite aggressive fishery management efforts, says Britten.

When the researchers looked at plankton and fish reproduction declines in individual ecosystems, the results varied. In the North Pacific — for example, the Gulf of Alaska — there were no significant declines. But in other regions of the world, like Australia and South America, it was clear that the lack of phytoplankton was the strongest driver in diminishing fish populations.

“When you averaged globally, there was a decline,” says Britten. “Decline in phytoplankton was a factor in all species. It was a consistent variable.”

And it’s directly linked to climate change: Change in ocean temperature affects the phytoplankton population, which is impacting fish stocks, he says.

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The pH is Falling! Oysters and Economics on the Hill

November 25th, 2014  By Kinberly Dunn, WWF Canada Blog

That’s right – the pH is falling. The pH of our oceans to be exact.

ocean acidification

WWF-Canada President and CEO, David Miller speaking at yesterday’s Oceans on the Hill event . © House of Commons

 

Yesterday afternoon, WWF-Canada and the All Party Ocean Caucus hosted an Oceans on the Hill event to highlight this global issue, which is generally referred to as ocean acidification.

Ocean acidification takes place when carbon dioxide in our atmosphere is absorbed by the ocean, lowering the pH. This naturally occurring process is accelerated by our fossil fuel emissions, resulting in global oceans that are now 26 per cent more acidic than before the industrial revolution.

Parliamentarians, staffers, industry reps, and NGOs gathered in Centre Block to hear from Bill Dewey, Manager of Public Policy and Communications for Taylor Shellfish Farms. Bill came to Parliament to give us an on-the-ground report of ocean acidification’s impacts on the shellfish industry in the Pacific Northwest. As WWF’s CEO David Miller remarked, Bill helped us to “make the connection between the global and the local.”

I come from the dual backgrounds of business and environmental management, so I was pretty excited when I learned that this Oceans on the Hill would not only connect the global to the local, but also provide a real-life, tangible translation of what acidification means for industry.

Oyster farmers in the Pacific Northwest have experienced severe losses in recent years, since the acidification process also means a shortage of the carbonate ions that shellfish larvae need to build their shells. In some areas, there has been acomplete failure of wild oyster seed. The industry has been forced to adapt in order to survive.

Listening to Bill’s presentation – to the story of Taylor’s journey – I couldn’t help but recall this simple truth:

Environmental issues are never just environmental issues. Never.

They’re economic issues too. For ocean acidification, this means negative impacts for the shellfish industry in the Pacific Northwest. It means money spent on sophisticated water monitoring and treatment equipment, so that businesses can remain viable. Unchecked, it could also mean up to a trillion dollars a year in global economic losses by the end of the century.

And they’re people issues. For Canadian shellfish farmers and their supply chains, this means jobs in coastal, rural, and Aboriginal communities – many of which are filled by young people. It means opportunities for those communities to combat outward migration and keep people at home. And, most simply, it means the sustainment of a food source that has been an inherent part of coastal living for hundreds of years.

And so perhaps this was the greater message of yesterday’s event – for me, and for all those who attended. A reminder that it’s not environment or economy, as we are sometimes led to believe, but rather environment for economy. Environmentfor people.

And frankly – whether we’re talking about falling pH or something else – we can no longer afford to think about it any other way.

See article here