Submarine canyons: hotspots of benthic biomass and productivity in the deep sea
Submarine canyons: hotspots of benthic biomass and productivity in the deep sea
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DOI：
10.1098/rspb.2010.0462
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发表时间：
2010-09-22
影响因子：
4.7
通讯作者：
Clark, Malcolm R.
中科院分区：
文献类型：
--
作者：
De Leo, Fabio C.;Smith, Craig R.;Clark, Malcolm R.
海底峡谷是横跨所有大洋的大陆和岛屿边缘的引人注目和广泛的地形特征。峡谷可通过海岸碎屑出口的夹带、致密的陆架-水瀑布、再悬浮颗粒物质的导流和沉积物沉积的集中，而成为有机质通量和沉积增强的地点。尽管海底峡谷具有不同寻常的生态特征和沿大洋大陆边缘的全球分布，但关于海底峡谷对深海生态系统结构和生产力的影响，只有零星的信息。在这里，我们展示了深海峡谷，如新西兰东部边缘的凯库拉峡谷(42°01‘S，173°03’E)，可以在大范围内维持巨大的大型底栖无脊椎动物的生物量。我们报告的生物量值比之前报告的500米以下深海(非化学合成)生境的生物量值高出100倍。我们还提供了来自深海拖曳相机图像的证据，即峡谷中拥有非凡底栖生物生物量的地区也有大量的大型哺乳动物(鼠尾)鱼类，很可能以大型和巨型底栖动物为食。底拖网捕捞数据还表明，凯库拉峡谷的底栖摄食性鱼类数量比邻近山坡高得多。我们的结果表明，凯库拉峡谷是迄今为止所描述的深海中最具生产力的栖息地之一。一份新的全球清单显示，世界上至少有660个海底峡谷，其中大约100个可能是类似凯库拉峡谷的生物质热点。这种深海峡谷作为潜在的生产和商业渔业生产热点的重要性值得进一步深入研究。
Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42 degrees 01'S, 173 degrees 03'E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro-and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study.