Video simulation in the Baltic Sea predicts overfishing, and an overload of nutrients or sewage in the water, will result in fewer large fish and more smaller ones. (Credit: Baltic Nest Institute, Stockholm, University of British Columbia, Vancouver)
A team of international researchers has developed a powerful new computer tool which uses 3D gaming technology to evaluate the oceans’ rapidly dwindling food resources.
The Nereus model incorporates climate change models, data related to human activities, and changes in the oceans’ food webs to calculate a timeline for harvestable marine life from 1960 to the year 2060.
Nereus is designed to answer some big questions: How healthy will the world’s oceans be in the future, and will they support enough fish to help feed tomorrow’s hungry world?
Canadian fishery expert Villy Christensen directs the Nereus program at the University of British Columbia. At the recent annual meeting in Vancouver of the American Association for the Advancement of Science, Christensen presented some preliminary results. “We found that the fish biomass in the world ocean is around two billion tons,” he said.
While that biomass has remained relatively stable and resilient over time, Christiansen says its makeup has dramatically shifted.
“We are saying goodbye to the big fish in the oceans such as carp and grouper. For those we’ve seen about a 55 percent decline just in the last 40 years. And then it’s hello to small fish. We’re seeing many more of the small fish, the fish that we are not interested in.”
These small fish - between 10 and 20 centimeters - are a dietary mainstay of foraging animals like whales, but they are not easy to harvest in the open ocean by commercial fishing fleets.
Christensen notes that at a time when many of the world’s fisheries are in decline, the global market for fresh fish is on the rise. “And we are running out of seafood. World supply is stagnant,” Christensen says.
Climate change, overfishing and a more acidic ocean are putting stress on global fisheries, according to Nereus team researcher William Cheung. The assistant fisheries professor at the University of British Columbia looked at how those factors affected 1,000 species of fish and invertebrates, and found both good news and bad in the outlook.
“We find that just by warming alone we may increase the catch potential in the North Atlantic region by 50 percent because the fish are moving to these high latitudes. However, if we incorporate ocean acidification and de-oxygenation into the equation, we find that some of the regions change from winners to losers.”
Greenhouse gas emissions from burning fossil fuels are changing ocean habitat, making it more acidic. That in turn affects the size and distribution of fish.
Christensen says the ocean modeling tool uses 3D gaming technology to communicate that information, turning scientific modeling data into a virtual world.
Christensen says what viewers see are predictions of ocean conditions and the quantity and size of the fish.
“The framework is set up with spatial information at a one-half degree, or 50-kilometer scale,” he says.
Christiansen says the information can help local officials make better decisions about how to manage the ocean environment and marine resources near where they live.
The $13-million Nereus Predicting the Future Ocean program is a joint initiative between the Nippon Foundation of Japan and the University of British Columbia. Other collaborators include U.S. and European universities and the United Nations Environment Program.
