Data from: Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes

High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might perform unique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, potentially leading to high vulnerability of functions. We studied the natural propensity of assemblages to be functionally buffered against loss prior to fishing activities, using functional trait combinations, in coral reef fish assemblages across unfished wilderness areas of the Indo-Pacific: Chagos Archipelago, New Caledonia and French Polynesia. Fish functional diversity in these wilderness areas is highly vulnerable to fishing, explained by species- and abundance-based redundancy packed into a small combination of traits, leaving most other trait combinations (60%) sensitive to fishing, with no redundancy. Functional vulnerability peaks for mobile and sedentary top predators, and large species in general. Functional vulnerability decreases for certain functional entities in New Caledonia, where overall functional redundancy was higher. Uncovering these baseline patterns of functional vulnerability can offer early warning signals of the damaging effects from fishing, and may serve as baselines to guide precautionary and even proactive conservation actions.

学界普遍认为，在环境持续变化的背景下，较高的物种丰富度（species richness）有助于维持多项生态系统功能与服务的供给。然而，部分物种可能承担独特的功能角色，其余物种则存在功能冗余。因此，若某类生态功能的冗余度极低，那么高物种丰富度在维持生态系统功能方面的益处便难以确定，这可能会导致该类功能的脆弱性大幅提升。本研究以印度-太平洋海域未受捕捞的荒野区域——包括查戈斯群岛、新喀里多尼亚以及法属波利尼西亚——的珊瑚礁鱼类群落为研究对象，通过功能性状（functional trait）组合分析，探究群落于捕捞活动开展前天然具备的功能抗损失缓冲能力。研究发现，上述荒野区域中的鱼类功能多样性极易受到捕捞活动的影响，这是因为基于物种和个体丰度的功能冗余仅集中于少量性状组合中，导致其余绝大多数（60%）性状组合对捕捞活动极为敏感且无功能冗余。功能脆弱性在移动性和定居性顶级捕食者，以及总体上的大型物种中达到峰值。在整体功能冗余度更高的新喀里多尼亚，部分功能类群的功能脆弱性有所降低。揭示此类功能脆弱性的基线格局，可为捕捞活动的破坏性影响提供早期预警信号，同时亦可作为基准，指导预防性乃至前瞻性的保护行动。