To mitigate the rumen enteric methane (CH₄) produced by ruminant livestock, Asparagopsis taxiformis is proposed as an additive to ruminant feed. During the cultivation of Asparagopsis taxiformis in the sea or in terrestrially based systems, this macroalgae, like most seaweeds and phytoplankton, produces a large amount of bromoform (CHBr₃), which contributes to ozone depletion once released into the atmosphere. In this study, we focus on the impact of CHBr₃ on the stratospheric ozone layer resulting from potential emissions from proposed Asparagopsis cultivation in Australia. The impact is assessed by weighting the emissions of CHBr₃ with its ozone depletion potential (ODP), which is traditionally defined for long-lived halocarbons but has also been applied to very short-lived substances (VSLSs). An annual yield of ∼3.5 × 10⁴ Mg dry weight is required to meet the needs of 50 % of the beef feedlot and dairy cattle in Australia. Our study shows that the intensity and impact of CHBr₃ emissions vary, depending on location and cultivation scenarios. Of the proposed locations, tropical farms near the Darwin region are associated with the largest CHBr₃ ODP values. However, farming of Asparagopsis using either ocean or terrestrial cultivation systems at any of the proposed locations does not have the potential to significantly impact the ozone layer. Even if all Asparagopsis farming were performed in Darwin, the CHBr₃ emitted into the atmosphere would amount to less than 0.02 % of the global ODP-weighted emissions. The impact of remaining farming scenarios is also relatively small even if the intended annual yield in Darwin is scaled by a factor of 30 to meet the global requirements, which will increase the global ODP-weighted emissions up to ∼0.5 %.

中文翻译：

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澳大利亚芦笋养殖中溴仿的潜在环境影响

为减少反刍家畜产生的瘤胃肠道甲烷 (CH ₄ ) ，建议将Asparagopsis taxformis作为反刍动物饲料的添加剂。在海中或陆基系统中培养滑行天门冬期间，这种大型藻类与大多数海藻和浮游植物一样，会产生大量的溴仿 (CHBr ₃ )，一旦释放到大气中就会导致臭氧消耗。在这项研究中，我们关注 CHBr ₃对平流层臭氧层的影响，这是由于澳大利亚拟建 的天门冬种植的潜在排放造成的。通过加权 CHBr _{3的排放量来评估影响}臭氧消耗潜能值 (ODP)，传统上定义为长寿命卤化碳，但也适用于寿命极短的物质 (VSLS)。 为满足澳大利亚 50% 的肉牛饲养场和奶牛的需求，需要∼3.5  ×  10 ⁴ Mg 干重的年产量。我们的研究表明，CHBr ₃排放的强度和影响因地点和种植情况而异。在提议的地点中，达尔文地区附近的热带农场与最大的 CHBr ₃  ODP 值相关。然而，种植芦笋在任何拟议地点使用海洋或陆地耕作系统都不会对臭氧层产生重大影响。即使在达尔文进行所有天门冬养殖，排放到大气中的 CHBr ₃也将不到全球 ODP 加权排放量的 0.02%。即使达尔文的预期年产量增加 30 倍以满足全球需求，其余农业情景的影响也相对较小，这将使全球 ODP 加权排放量增加至∼0.5  %。