Department of Bioscience, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark
Arctic Research Centre, Aarhus University, Ny Munkegade 114, DK-8000 Århus C, Denmark.
Biol Lett. 2018 Jun;14(6). doi: 10.1098/rsbl.2018.0236.
Macroalgae form the most extensive and productive benthic marine vegetated habitats globally but their inclusion in Blue Carbon (BC) strategies remains controversial. We review the arguments offered to reject or include macroalgae in the BC framework, and identify the challenges that have precluded macroalgae from being incorporated so far. Evidence that macroalgae support significant carbon burial is compelling. The carbon they supply to sediment stocks in angiosperm BC habitats is already included in current assessments, so that macroalgae are de facto recognized as important donors of BC. The key challenges are (i) documenting macroalgal carbon sequestered beyond BC habitat, (ii) tracing it back to source habitats, and (iii) showing that management actions at the habitat lead to increased sequestration at the sink site. These challenges apply equally to carbon exported from BC coastal habitats. Because of the large carbon sink they support, incorporation of macroalgae into BC accounting and actions is an imperative. This requires a paradigm shift in accounting procedures as well as developing methods to enable the capacity to trace carbon from donor to sink habitats in the ocean.
海藻是全球分布最广、生产力最高的底栖海洋植被生境，但它们是否被纳入蓝碳（BC）战略仍存在争议。我们回顾了被提出的拒绝或纳入海藻的 BC 框架的论点，并确定了迄今为止阻止海藻被纳入的挑战。海藻支持大量碳埋存的证据令人信服。它们为被子植物 BC 生境中的沉积物储量提供的碳已经包含在当前的评估中，因此海藻实际上被公认为 BC 的重要贡献者。主要挑战是：（i）记录超出 BC 生境的海藻碳封存；（ii）追溯到源生境；（iii）表明生境的管理行动导致汇点的封存增加。这些挑战同样适用于从 BC 沿海生境输出的碳。由于它们支持的巨大碳汇，将海藻纳入 BC 核算和行动是当务之急。这需要在核算程序上进行范式转变，以及开发能够从源生境追踪到海洋汇点的碳的方法。
