In the North Atlantic data have been collected extensively for a long time. Wealthy countries in Europe and North America have invested in knowledge of the climate and ecosystem of their own region.
“Much less has been invested in the Tropical and South Atlantic Ocean”, says Noel Keenlyside, professor at the Bjerknes Centre for Climate Research and the University of Bergen.
Keenlyside leads a multi-national team of researchers aiming to combat this imbalance. Funded by the European Union, the project TRIATLAS deals with climate and marine ecosystems in the Tropical and South Atlantic Ocean.
In Recife, Brazil, this month, physical oceanographers and marine biologists met with colleagues working on the relations between fishermen and policymakers. Together they strive to map the current status of Tropical and South Atlantic ecosystems, as well as the possible future development.
On top of human pressure like fisheries, life in these ocean regions is strongly affected by climate change.
Fish face multiple challenges
“It is a big challenge to understand how environmental changes in upwelling zones or changes in nutrients will influence marine ecosystems,” says Noel Keenlyside.
Although the effects on primary productivity may be deduced, the impact this will have on higher levels in the food chain, like fish, is unknown.
Climate models currently fail to represent some features of the South Atlantic Ocean well. Among these is the upwelling off the southwestern coast of Africa, important for fisheries. Temperatures in this highly productive region exhibit large variations, and most climate models cannot reproduce them correctly.
“Organisms have a particular niche they live in. If your model ocean is four degrees too warm, it is difficult to study the effect on the ecosystem,” says Noel Keenlyside.
He highlights the importance of observing the ocean, not only for mapping its current state, but to be able to improve the representation of the Tropical and South Atlantic Ocean in climate models. Only then can the models produce predictions relevant for future fisheries on both sides of the ocean.