Barnes David K A, Fleming Andrew, Sands Chester J, Quartino Maria Liliana, Deregibus Dolores
British Antarctic Survey, Natural Environment Research Council, Madingley Road, Cambridge CB3 0ET, UK
British Antarctic Survey, Natural Environment Research Council, Madingley Road, Cambridge CB3 0ET, UK.
Philos Trans A Math Phys Eng Sci. 2018 Jun 28;376(2122). doi: 10.1098/rsta.2017.0176.
Sea ice, including icebergs, has a complex relationship with the carbon held within animals (blue carbon) in the polar regions. Sea-ice losses around West Antarctica's continental shelf generate longer phytoplankton blooms but also make it a hotspot for coastal iceberg disturbance. This matters because in polar regions ice scour limits blue carbon storage ecosystem services, which work as a powerful negative feedback on climate change (less sea ice increases phytoplankton blooms, benthic growth, seabed carbon and sequestration). This resets benthic biota succession (maintaining regional biodiversity) and also fertilizes the ocean with nutrients, generating phytoplankton blooms, which cascade carbon capture into seabed storage and burial by benthos. Small icebergs scour coastal shallows, whereas giant icebergs ground deeper, offshore. Significant benthic communities establish where ice shelves have disintegrated (giant icebergs calving), and rapidly grow to accumulate blue carbon storage. When 5000 km giant icebergs calve, we estimate that they generate approximately 10 tonnes of immobilized zoobenthic carbon per year (t C yr). However, their collisions with the seabed crush and recycle vast benthic communities, costing an estimated 4 × 10 t C yr We calculate that giant iceberg formation (ice shelf disintegration) has a net potential of approximately 10 t C yr sequestration benefits as well as more widely known negative impacts.This article is part of the theme issue 'The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change'.
海冰，包括冰山，与极地地区动物体内所含的碳（蓝碳）有着复杂的关系。南极西部大陆架周围海冰的减少会使浮游植物的繁殖期延长，但也使其成为沿海冰山扰动的热点地区。这一点很重要，因为在极地地区，冰蚀会限制蓝碳储存生态系统服务，而蓝碳储存生态系统服务对气候变化起到强大的负反馈作用（海冰减少会增加浮游植物繁殖、底栖生物生长、海床碳和碳固存）。这会重置底栖生物群落演替（维持区域生物多样性），还会为海洋提供养分，促使浮游植物繁殖，进而将碳捕获过程级联到海床储存和底栖生物掩埋过程中。小型冰山冲刷沿海浅滩，而巨型冰山则在更深的近海搁浅。在冰架解体（巨型冰山崩解）的地方会形成重要的底栖生物群落，并迅速生长以积累蓝碳储存。当5000公里长的巨型冰山崩解时，我们估计它们每年会产生约10吨固定化底栖动物碳（t C yr）。然而，它们与海床的碰撞会碾碎并循环利用大量底栖生物群落，估计每年造成4×10 t C yr的损失。我们计算得出，巨型冰山形成（冰架解体）具有约10 t C yr的净潜在固存效益以及更为人所知的负面影响。本文是主题为“南极半岛西部的海洋系统：快速变化地区的现状与发展战略”的一部分。
