Sweetman Andrew K, Smith Craig R, Dale Trine, Jones Daniel O B
International Research Institute of Stavanger, Mekjarvik 12, Randaberg 4070, Norway
University of Hawaii at Manoa, 1000 Pope Road, Honolulu, HI 96822, USA.
Proc Biol Sci. 2014 Dec 7;281(1796):20142210. doi: 10.1098/rspb.2014.2210.
Jellyfish blooms are common in many oceans, and anthropogenic changes appear to have increased their magnitude in some regions. Although mass falls of jellyfish carcasses have been observed recently at the deep seafloor, the dense necrophage aggregations and rapid consumption rates typical for vertebrate carrion have not been documented. This has led to a paradigm of limited energy transfer to higher trophic levels at jelly falls relative to vertebrate organic falls. We show from baited camera deployments in the Norwegian deep sea that dense aggregations of deep-sea scavengers (more than 1000 animals at peak densities) can rapidly form at jellyfish baits and consume entire jellyfish carcasses in 2.5 h. We also show that scavenging rates on jellyfish are not significantly different from fish carrion of similar mass, and reveal that scavenging communities typical for the NE Atlantic bathyal zone, including the Atlantic hagfish, galatheid crabs, decapod shrimp and lyssianasid amphipods, consume both types of carcasses. These rapid jellyfish carrion consumption rates suggest that the contribution of gelatinous material to organic fluxes may be seriously underestimated in some regions, because jelly falls may disappear much more rapidly than previously thought. Our results also demonstrate that the energy contained in gelatinous carrion can be efficiently incorporated into large numbers of deep-sea scavengers and food webs, lessening the expected impacts (e.g. smothering of the seafloor) of enhanced jellyfish production on deep-sea ecosystems and pelagic-benthic coupling.
水母大量繁殖在许多海洋中都很常见，而且人为因素的变化似乎已导致某些区域水母数量增加。尽管最近在深海海底观察到水母尸体大量坠落，但尚未记录到像脊椎动物尸体那样典型的密集食腐动物聚集和快速消耗率。这导致了一种范式，即相对于脊椎动物有机物质坠落，水母坠落向更高营养级的能量转移有限。我们通过在挪威深海部署诱饵相机发现，在水母诱饵处可迅速形成密集的深海食腐动物聚集（密度峰值时超过1000只动物），并在2.5小时内消耗掉整个水母尸体。我们还表明，水母的食腐率与类似质量的鱼类尸体并无显著差异，并揭示了东北大西洋半深海区典型的食腐动物群落，包括大西洋盲鳗、铠甲虾、十足目虾类和深海等足类动物，会消耗这两种类型的尸体。这些快速的水母尸体消耗率表明，在某些区域，凝胶状物质对有机通量的贡献可能被严重低估，因为水母坠落消失的速度可能比之前认为的要快得多。我们的研究结果还表明，凝胶状尸体所含的能量可以有效地融入大量深海食腐动物和食物网中，减轻水母数量增加对深海生态系统和远洋 - 底栖耦合的预期影响（例如海底窒息）。
