The genetic imprints of kelp found on the shores of Orkney, Iceland, Ireland, France, the USA and Canada are helping scientists solve the mystery of how marine plant life survives extreme changes in climate.
Scientists from Heriot-Watt's International Centre for Island Technology (ICIT) in Orkney, the University of the Algarve in Portugal and Station Biologique de Roscoff in France have analysed the genetic composition of Laminaria digitata, commonly known as oarweed, from 14 populations distributed across the northern Atlantic Ocean.
The scientists now know how closely related the oarweed populations are to one another, and how they have moved around the Atlantic since the last ice age.
They found three distinct genetic clusters: one along the eastern seaboard of Canada and the USA; one in central and northern Europe and one very compact population around Brittany.
The genetic data indicates that the populations off Scotland and Ireland, and around Brittany, survived in those spots since the last ice age around 16,000 years ago, or what Dr Andrew Want, a marine ecologist at the ICIT, describes as “refugee populations that managed to hang on and survive amid dramatic changes as ice sheets retreated.”