Effects of salmon farming on the benthic ecosystem of coastal shallow- and deep-water sites: towards a DNA-based environmental impact assessment

水产养殖是世界上增长最快的食品生产部门之一，大西洋鲑鱼(Salmo Salar)是最重要的海洋水产养殖物种之一。该行业每年的快速增长带来了显著的社会经济效益，但同时也带来了越来越大的环境影响。在DFG项目的第一个资助期(去掉符号)，我可以证明，对微生物底栖生物群落的DNA元编码与监督机器学习(SML)相结合是一种非常有效的方法，可以(A)评估通过水产养殖影响沿海底栖生态系统的压力因素，以及(B)量化受鲑鱼养殖影响的沿海生态系统的环境质量。结果表明，这项技术未来可能会取代传统的基于大型底栖无脊椎动物显微鉴定的昂贵、冗长、容易出错和繁琐的生物监测作为生物指标。然而，项目(去掉标志)也表明，关于水产养殖应激源对沿海底栖生态系统的影响的关键基本生态学知识在现阶段仍然缺乏。拟议延续项目的目的是填补这一知识空白，使新技术能够在常规环境监测方案中得到实施。具体地说，拟议的项目旨在调查底栖微生物群落对鲑鱼养殖对沿海生态系统施加的不同程度压力的空间和时间响应。拟议的后续项目应澄清哪些海底微生物群落的变化是自然季节演替模式造成的，哪些具体是水产养殖压力造成的。(去掉符号)的结果表明，在浅海水域，自然季节影响可能是在水产养殖压力下构建底栖动物群落的一个明显强于深层沿海水域的共性因素。这项基础生态研究的预期结果对确定全世界浅水和深水水产养殖场的特定DNA生物指标具有很高的相关性。因此，将在两个沿海系统进行比较研究。在随后的DFG知识转移项目中，可以检验这些新发现，目的是在受水产养殖影响的沿海水域生态监测的官方条例中实施DNA元编码/SML技术。这一科学概念和方法将得到广泛应用，包括近海钻探、海底采矿、近海风力发电场、海底拖网和沿海水域各种其他类型的工业和娱乐活动的环境影响评估。

Aquaculture is among the fastest growing food production sectors worldwide, with Atlantic salmon (Salmo salar) being among the most important marine aquaculture species. The rapid annual growth of this industry has yielded in significant socio-economic benefits but is accompanied by increasing environmental impact. In the first funding period of DFG project (sign removed) I could show that DNA metabarcoding of microbial benthic communities in combination with supervised machine learning (SML) is a very powerful method to (a) assess stress factors affecting benthic coastal ecosystems through aquaculture and (b) to quantify the environmental quality of coastal ecosystems under the influence of salmon farming. The obtained results suggested that this technology may in the future replace the much more expensive, lengthy, error-prone and tedious traditional biomonitoring based on the microscopic identification of benthic macroinvertebrates as bioindicators. However, project (sign removed) has also shown what crucial basic ecological knowledge about the impact of aquaculture stressors on benthic coastal ecosystems is still missing at this stage. The aim of the proposed continuation project is to fill this knowledge gap to the extent that the new technology can be implemented in routine environmental monitoring programmes. Specifically, the proposed project aims to investigate the spatial and temporal response of benthic microbial communities to different levels of stress exerted on coastal ecosystems by salmon farming. The proposed follow-up project should clarify which changes in benthic microbial communities are due to natural seasonal succession patterns and which are specifically caused by aquaculture stressors. Results from (sign removed) suggest that in shallower coastal waters natural seasonal influences may be a significantly stronger co-factor for structuring benthic communities under aquaculture stress than in deep coastal waters. The expected findings from this basic ecological research are of high relevance for the identification of specific DNA bioindicators in shallow- and deep-water aquaculture sites worldwide. Therefore, comparative studies will be carried out in both coastal systems. In a subsequent DFG knowledge transfer project, these new findings could then be tested with the aim of implementing the DNA metabarcoding/SML technology in official regulations for the ecological monitoring of coastal waters under the influence of aquaculture. Such a scientific concept and methodological approach will be widely applicable, including environmental impact assessments of offshore drilling, seabed mining, offshore wind farms, bottom trawling and various other types of industrial and recreational activities in coastal waters.