Raybaud Virginie, Beaugrand Grégory, Goberville Eric, Delebecq Gaspard, Destombe Christophe, Valero Myriam, Davoult Dominique, Morin Pascal, Gevaert François
Université Lille 1, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Wimereux, France ; CNRS, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Wimereux, France.
PLoS One. 2013 Jun 26;8(6):e66044. doi: 10.1371/journal.pone.0066044. Print 2013.
Kelp ecosystems form widespread underwater forests playing a major role in structuring the biodiversity at a regional scale. Some seaweeds such as Laminaria digitata are also economically important, being exploited for their alginate and iodine content. Although some studies have shown that kelp ecosystems are regressing and that multiple causes are likely to be at the origin of the disappearance of certain populations, the extent to which global climate change may play a role remains speculative. Here we show that many populations of L. digitata along European coasts are on the verge of local extinction due to a climate-caused increase in sea temperature. By modeling the spatial distribution of the seaweed, we evaluate the possible implications of global climate change for the geographical patterns of the species using temperature data from the Coupled Model Intercomparison Project phase 5 (CMIP5). Projections of the future range of L. digitata throughout the 21st century show large shifts in the suitable habitat of the kelp and a northward retreat of the southern limit of its current geographic distribution from France to Danish coasts and the southern regions of the United Kingdom. However, these projections depend on the intensity of warming. A medium to high warming is expected to lead to the extirpation of the species as early as the first half of the 21st century and there is high confidence that regional extinction will spread northwards by the end of this century. These changes are likely to cause the decline of species whose life cycle is closely dependent upon L. digitata and lead to the establishment of new ecosystems with lower ecological and economic values.
海带生态系统形成了广泛的水下森林，在区域尺度上对生物多样性的构建起着重要作用。一些海藻，如掌状海带，也具有重要的经济价值，因其富含藻酸盐和碘而被开发利用。尽管一些研究表明海带生态系统正在衰退，且多种原因可能是某些种群消失的根源，但全球气候变化可能起到的作用程度仍具有推测性。在此，我们表明欧洲沿海的许多掌状海带种群正因气候导致的海水温度上升而濒临局部灭绝。通过对这种海藻的空间分布进行建模，我们利用耦合模式比较计划第5阶段（CMIP5）的温度数据，评估全球气候变化对该物种地理分布格局的可能影响。对掌状海带在整个21世纪未来分布范围的预测显示，海带适宜栖息地发生了大幅变化，其当前地理分布的南部界限从法国向北退缩至丹麦海岸和英国南部地区。然而，这些预测取决于变暖的强度。预计中等至高度变暖最早将导致该物种在21世纪上半叶灭绝，并且人们高度确信到本世纪末区域灭绝将向北蔓延。这些变化可能导致生命周期紧密依赖掌状海带的物种数量减少，并导致建立生态和经济价值较低的新生态系统。
