Friedlander Alan M, Ballesteros Enric, Clemente Sabrina, Gonçalves Emanuel J, Estep Andrew, Rose Paul, Sala Enric
Pristine Seas, National Geographic Society, Washington, DC, United States of America.
Fisheries Ecology Research Lab, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America.
PLoS One. 2017 Nov 14;12(11):e0187935. doi: 10.1371/journal.pone.0187935. eCollection 2017.
The islands of Madeira and Selvagens are less than 300 km apart but offer a clear contrast between a densely populated and highly developed island (Madeira), and a largely uninhabited and remote archipelago (Selvagens) within Macaronesia in the eastern Atlantic. The Madeira Archipelago has ~260,000 inhabitants and receives over six million visitor days annually. The Selvagens Islands Reserve is one of the oldest nature reserves in Portugal and comprises two islands and several islets, including the surrounding shelf to a depth of 200 m. Only reserve rangers and a small unit of the maritime police inhabit these islands. The benthic community around Selvagens was dominated by erect and turf algae, while the community at Madeira was comprised of crustose coralline and turf algae, sessile invertebrates, and sea urchin barrens. The sea urchin Diadema africanum was 65% more abundant at Madeira than at Selvagens. Total fish biomass was 3.2 times larger at Selvagens than at Madeira, and biomass of top predators was more than 10 times larger at Selvagens. Several commercially important species (e.g., groupers, jacks), which have been overfished throughout the region, were more common and of larger size at Selvagens than at Madeira. Important sea urchin predators (e.g., hogfishes, triggerfishes) were also in higher abundance at Selvagens compared to Madeira. The effects of fishing and other anthropogenic influences are evident around Madeira. This is in stark contrast to Selvagens, which harbors healthy benthic communities with diverse algal assemblages and high fish biomass, including an abundance of large commercially important species. The clear differences between these two island groups highlights the importance of expanding and strengthening the protection around Selvagens, which harbors one of the last intact marine ecosystems in the North Atlantic, and the need to increase management and protection around Madeira.
马德拉群岛和塞尔瓦根斯群岛相距不到300公里，但形成了鲜明对比：一个是人口密集且高度发达的岛屿（马德拉），另一个是位于东大西洋马卡罗尼西亚地区、基本无人居住且偏远的群岛（塞尔瓦根斯）。马德拉群岛有大约26万居民，每年接待游客超过600万人次。塞尔瓦根斯群岛保护区是葡萄牙最古老的自然保护区之一，由两个岛屿和几个小岛组成，包括周边深度达200米的大陆架。只有保护区护林员和一小队海上警察居住在这些岛屿上。塞尔瓦根斯周围的底栖生物群落以直立藻类和草皮藻类为主，而马德拉的群落则由壳状珊瑚藻、草皮藻类、固着无脊椎动物和海胆荒漠组成。马德拉的非洲冠海胆数量比塞尔瓦根斯多65%。塞尔瓦根斯的鱼类总生物量是马德拉的3.2倍，顶级捕食者的生物量在塞尔瓦根斯比马德拉大10倍以上。一些在整个地区都被过度捕捞的具有商业重要性的物种（如石斑鱼、鲹科鱼）在塞尔瓦根斯比在马德拉更常见且体型更大。重要的海胆捕食者（如猪齿鱼、扳机鱼）在塞尔瓦根斯的数量也比马德拉多。捕捞和其他人为影响在马德拉周围的影响很明显。这与塞尔瓦根斯形成了鲜明对比，塞尔瓦根斯拥有健康的底栖生物群落，藻类组合多样，鱼类生物量高，包括大量具有商业重要性的大型物种。这两个岛屿群之间的明显差异凸显了扩大和加强对塞尔瓦根斯周围保护的重要性，塞尔瓦根斯拥有北大西洋最后一个完整的海洋生态系统之一，同时也凸显了加强马德拉周围管理和保护的必要性。
