Data from Place-based management can reduce human impacts on coral reefs in a changing climate

Declining natural resources have led to a cultural renaissance across the Pacific that seeks to revive customary ridge-to-reef management approaches to protect freshwater and restore abundant coral reef fisheries. We applied a linked land-sea modeling framework based on remote sensing and empirical data, which couples groundwater nutrient export and coral reef models at fine spatial resolution. This spatially-explicit (60 x 60 m) framework simultaneously tracks changes in multiple benthic and fish indicators as a function of marine closures, land-use and climate change scenarios. We applied this framework in Hā‘ena and Ka‘ūpūlehu, located at opposite ends of the Hawaiian Archipelago to investigate the effects of coastal development and marine closures on coral reefs in the face of climate change. Our results indicated that projected coastal development and bleaching can result in a significant decrease in benthic habitat quality and community-led marine closures can result in a significant increase in fish biomass. In general, Ka‘ūpūlehu is more vulnerable to land-based nutrients and coral bleaching than Hā‘ena due to high coral cover and limited dilution and mixing from low rainfall and wave power, except for the shallow and wave sheltered back-reef areas of Hā‘ena, which support high coral cover and act as nursery habitat for fishes. By coupling spatially explicit land-sea models with scenario planning, we identified priority areas on land where upgrading cesspools can reduce human impacts on coral reefs in the face of projected climate change impacts.

日渐枯竭的自然资源推动了太平洋地区的文化复兴，当地旨在复兴传统的“从山脊到珊瑚礁”（ridge-to-reef）全域管理模式，以保护淡水生态系统并恢复繁盛的珊瑚礁渔业资源。本研究采用了一套基于遥感（remote sensing）与实测数据构建的海陆联动建模框架，该框架以精细空间分辨率耦合了地下水养分输出模型与珊瑚礁模型。这套空间显式（spatially-explicit，60×60米）框架能够同时追踪多种底栖（benthic）生物与鱼类指标的变化，其变化受海洋禁渔区（marine closures）、土地利用方式以及气候变化情景的共同影响。本研究将该框架应用于夏威夷群岛两端的哈伊纳（Hā‘ena）与卡乌普莱胡（Ka‘ūpūlehu）两地，以探究气候变化背景下沿海开发与海洋禁渔区对珊瑚礁的影响。研究结果显示，预测中的沿海开发与珊瑚白化（coral bleaching）事件会显著降低底栖生境质量，而由社区主导的海洋禁渔区则能显著提升鱼类生物量。总体而言，卡乌普莱胡相较于哈伊纳，更易受陆地来源养分与珊瑚白化的影响——这是由于其珊瑚盖度更高，且受降雨偏少与波浪能不足的限制，水体稀释与混合能力较弱；唯有哈伊纳的浅水区与受波浪庇护的礁后区域除外，这些区域珊瑚盖度较高，同时作为鱼类的育幼栖息地。通过将空间显式海陆模型与情景规划相结合，本研究确定了陆地优先整治区域：在这些区域升级化粪池（cesspools），能够在应对预测中的气候变化影响时，降低人类活动对珊瑚礁的负面影响。