1. Ecological damage by scuba divers has been extensively studied in marine ecosystems, particularly coral reefs, whereas the impacts on freshwater environments such as groundwater springs is unknown. In the Silfra groundwater fissure in Iceland, a vast increase in diver entries has occurred during the last decade, prompting concerns over potential ecosystem impacts and visitor carrying capacity.
2. Here, a mixed‐method approach was used to assess the impacts of scuba diving in Silfra. (a) Divers were recorded under water to observe the mechanisms of diver‐related disturbances, (b) benthic material was collected along transects in Silfra and the undisturbed fissure Flosagjá to compare biofilm biomass and zoobenthic communities between and within fissures, and (c) the perceptions and experiences of stakeholders surrounding the dive tourism in Silfra were explored.
3. Underwater observations showed that 91.4% of the divers caused at least a single disturbance, resulting in biofilm detachments and/or sediment stirring. Diver fins caused the most frequent disturbances, predominantly through fin‐generated currents but also by directly contacting the substrate. Benthic biofilm biomass was lower in Silfra than Flosagjá and exhibited a negative correlation with dive‐use. Some disturbance‐tolerant zoobenthic groups exhibited moderate to strong correlations with dive‐use.
4. All stakeholders had negative perceptions towards increasing diver entries, but although entry limitation could improve tourism quality, disturbance might only minimally be reduced as springs like Silfra may be particularly sensitive.
5. Springs are characteristically stable and uniform environments that can be vulnerable to disturbance. Their use for scuba diving should be carefully managed through a holistic approach and an active collaboration between all stakeholders.

中文翻译：

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地下水生态系统中的休闲水肺潜水：干扰机制，生态影响和利益相关者的看法

1. 在海洋生态系统中，尤其是在珊瑚礁中，潜水员对生态造成的破坏已得到广泛研究，而对诸如地下水泉等淡水环境的影响尚不清楚。在冰岛的西尔夫拉（Silfra）地下水裂缝中，过去十年来，潜水员的入境大量增加，这引发了人们对潜在的生态系统影响和游客承载能力的担忧。
2. 在这里，采用了一种混合方法来评估Silfra水肺潜水的影响。（a）在水下记录潜水员，以观察与潜水员有关的干扰的机制;（b）在Silfra和未受干扰的裂隙Flosagjá的断面收集底栖物质，以比较裂隙之间和裂隙内的生物膜生物量和底栖动物群落，以及（c）探索了围绕Silfra潜水旅游业的利益相关者的看法和经验。
3. 水下观察表明，有91.4％的潜水员至少造成了一次干扰，导致生物膜脱离和/或沉积物搅动。潜水鳍引起最频繁的干扰，主要是由鳍产生的电流引起的，也有直接与基板接触的干扰。Silfra底栖生物膜生物量低于Flosagjá，并且与潜水使用呈负相关。某些耐干扰的动物底栖动物与潜水使用表现出中度到强烈的相关性。
4. 所有利益相关者对增加潜水员人数持负面看法，但是尽管入境限制可以提高旅游质量，但由于像西尔弗拉（Silfra）之类的泉水可能特别敏感，因此干扰可能只会最小程度地减少。
5. 弹簧的特征是稳定且均匀的环境，容易受到干扰。应通过整体方法和所有利益相关者之间的积极合作，认真管理其在水肺潜水中的使用。