Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, United States of America.
PLoS One. 2012;7(3):e33885. doi: 10.1371/journal.pone.0033885. Epub 2012 Mar 21.
Continental margins are dynamic, heterogeneous settings that can include canyons, seamounts, and banks. Two of the largest canyons in the world, Zhemchug and Pribilof, cut into the edge of the continental shelf in the southeastern Bering Sea. Here currents and upwelling interact to produce a highly productive area, termed the Green Belt, that supports an abundance of fishes and squids as well as birds and marine mammals. We show that in some areas the floor of these canyons harbors high densities of gorgonian and pennatulacean corals and sponges, likely due to enhanced surface productivity, benthic currents and seafloor topography. Rockfishes, including the commercially important Pacific ocean perch, Sebastes alutus, were associated with corals and sponges as well as with isolated boulders. Sculpins, poachers and pleuronectid flounders were also associated with corals in Pribilof Canyon, where corals were most abundant. Fishes likely use corals and sponges as sources of vertical relief, which may harbor prey as well as provide shelter from predators. Boulders may be equivalent habitat in this regard, but are sparse in the canyons, strongly suggesting that biogenic structure is important fish habitat. Evidence of disturbance to the benthos from fishing activities was observed in these remote canyons. Bottom trawling and other benthic fishing gear has been shown to damage corals and sponges that may be very slow to recover from such disturbance. Regulation of these destructive practices is key to conservation of benthic habitats in these canyons and the ecosystem services they provide.
大陆边缘是动态的、不均匀的环境，其中包括峡谷、海山和海台。世界上最大的两条峡谷之一的捷姆楚格峡谷和普里比洛夫峡谷切入了白令海东南部大陆架的边缘。在这里，海流和上升流相互作用，产生了一个高度生产力的区域，称为“绿带”，它支持着大量的鱼类和鱿鱼以及鸟类和海洋哺乳动物。我们表明，在这些峡谷的某些区域，海床蕴藏着大量的柳珊瑚和海鸡冠珊瑚以及海绵，这可能是由于表层生产力增强、底流和海底地形所致。岩鱼，包括商业上重要的太平洋鲈鱼 Sebastes alutus，与珊瑚和海绵以及孤立的巨石有关。鼠鱼、盗鳕和比目鱼也与普里比洛夫峡谷的珊瑚有关，那里的珊瑚最为丰富。鱼类可能将珊瑚和海绵用作垂直避难所，这些避难所可能藏有猎物，也可能为鱼类提供躲避捕食者的庇护所。在这方面，巨石可能是等效的栖息地，但在峡谷中却很稀少，这强烈表明生物成因结构是重要的鱼类栖息地。在这些偏远的峡谷中，人们观察到了捕鱼活动对海底生物的干扰证据。底拖网和其他海底渔具已被证明会破坏珊瑚和海绵，而这些珊瑚和海绵从这种干扰中恢复可能非常缓慢。对这些破坏性做法进行监管是保护这些峡谷中的海底栖息地及其提供的生态系统服务的关键。
