Data from: Rapid scavenging of jellyfish carcasses reveals the importance of gelatinous material to deep-sea food webs

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.

水母暴发（jellyfish blooms）在全球众多海域均十分常见，而人为活动引发的环境变化似乎已在部分区域使其暴发规模有所扩大。尽管近期在深海海底已观测到大量水母尸骸沉降事件，但脊椎动物腐尸所典型具备的高密度食尸生物（necrophage）聚集现象与快速消耗速率，却尚未见诸报道。这使得学界形成了一种认知范式：相较于脊椎动物有机质沉降，水母尸骸沉降向更高营养级（trophic level）传递的能量十分有限。本研究通过在挪威海域深海开展的诱饵相机（baited camera）布设观测显示，深海食腐动物可在水母诱饵周围快速形成高密度聚集群（峰值密度可达1000只以上），并可在2.5小时内将整具水母尸骸完全消耗。本研究同时发现，水母腐尸的食腐消耗速率与相近质量的鱼类腐尸并无显著差异；同时揭示，东北大西洋半深海带（bathyal zone）典型的食腐生物群落——包括大西洋盲鳗（Atlantic hagfish）、铠甲虾（galatheid crabs）、十足目虾类（decapod shrimp）以及丽沙钩虾科端足类（lyssianasid amphipods）——均可取食这两类腐尸。这类快速的水母腐尸消耗速率表明，在部分区域，凝胶状有机质对海洋有机通量（organic fluxes）的贡献可能被严重低估——因为水母尸骸沉降的消失速度可能远快于此前的学术认知。本研究结果同时证实，凝胶状腐尸所蕴含的能量可被高效传递至大量深海食腐动物及食物网中，从而缓解水母种群数量增加可能对深海生态系统及浮游-底栖耦合（pelagic–benthic coupling）过程带来的预期负面影响（如海底窒息现象）。