Bell-bottom jeans, Abba, and the Labrador Current - one of the three is not making a retro comeback. Temperature-tracking coral reefs indicate that the circulation of water in the Atlantic Ocean has changed dramatically since the 1970′s.
That could be part of the reason areas in the northern hemisphere have had harsh winter storms and summer droughts say researchers.
The evidence for changing currents comes from ancient gorgonian coral reefs growing off the coast of Nova Scotia. The reef was studied by a team of biochemists and oceanographers from Switzerland, Canada, and the United States.
Like most organisms, corals are what they eat and changes in their diet are recorded in the reef structure.
The Canadian corals showed that the cold, south-bound Labrador current is losing ground to the warm, north-bound Gulf Stream current. The corals of the deep north Atlantic have been feasting on nutrient-rich warm water since the 1970′s.
The researchers looked at the concentrations of a certain isotope of nitrogen, called delta 15. Different concentrations of the isotope allow scientists to trace a creature's food sources.