Geospatial characterization of Coral Reef Ecosystems in the Galápagos Archipelago: current distribution, typology, and historical extent

Coral reef ecosystems of the Galápagos Archipelago occupy a biogeographically exceptional position within the Eastern Tropical Pacific (ETP), occurring at the convergence of multiple oceanographic regimes that generate highly variable and often marginal conditions for reef development. This dataset presents georeferenced shapefiles delineating the current and historical distribution of coral reef ecosystems across the Galápagos Archipelago, developed in support of the IUCN Red List of Ecosystems (RLE) global assessment of coral reefs. Reef units were classified following the typological framework adopted for the RLE assessment, distinguishing Type A-alternative (accreting coral reefs with fringing reef, reef crest, spur-and-groove, and bommie geomorphologies), Type B (marginal coral reefs lacking net biogenic accretion), Type C (subtidal rocky reefs with coral communities), and transitional categories (B(C) and C(B)), following the IUCN Global Ecosystems Typology functional groups M1.3 (Photic Coral Reefs) and M1.6 (Subtidal Rocky Reefs). Type A reefs sensu stricto (barrier reefs, atolls of 1000s of years) are absent from the archipelago based on available coral dating evidence, and no classic Type A formations were identified. Spatial boundaries were delineated based on historical records, personal field ground-truthing, photoquadrat surveys, and photogrammetry-derived orthomosaic data. Attribute information includes reef type classification, historical reef type where records are available, and descriptions of historical and current reef condition. The dataset documents a total mapped reef extent of approximately 79.6 ha, of which Darwin Reef (Type A-alternative) accounts for 15.6 ha and Wolf Reef (Type A-alternative) for approximately 5 ha, with Porites lobata as the primary framework-building species at both sites. The remaining reef area across the archipelago totals approximately 59 ha, with the largest representations at Floreana Island (northeastern coastline, Corona del Diablo–Punta Cormorán to Champion Island; ~28 ha) and Marchena Island (Punta Espejo; ~24 ha). Type C and transitional C(B) reefs account for approximately 34 ha, while Type B and transitional B(C) reefs account for approximately 25 ha. Type C reefs are mapped selectively, given that isolated coral colonies occur broadly along shallow coastlines across the archipelago wherever oceanographic conditions permit, and were included only where coral abundance or structural complexity justified cartographic representation. The dataset further incorporates records of historical reef loss and degradation. The most significant documented loss corresponds to Urvina Bay (Isabela Island), where a tectonic uplift event associated with the 1954 eruption of Alcedo Volcano caused the permanent aerial exposure of approximately 122 ha of reef, previously dominated by Porites lobata, Pavona clavus, Pavona gigantea, pocilloporid framework, and Psammocora stellata, and classified as Type A-alternative and, mostly, Type B. Additionally, the extreme El Niño event of 1982–1983 resulted in widespread coral mortality across multiple reef sites in the archipelago. Differential recovery trajectories have been documented among affected sites: some localities, such as Corona del Diablo (northern Floreana Island), have shown partial recovery, while others, such as Punta Espinoza (Fernandina Island), exhibit minimal recovery and retain only isolated coral colonies and structural remnants of historical reef frameworks. The majority of reef areas affected by this event were likely classified as Type B circa 1975, with the exception of Darwin and Wolf reefs, which retain their Type A-alternative classification to the present. This dataset is intended for use within the IUCN RLE assessment framework and is subject to a restricted data sharing agreement. File access is restricted pending formal peer-reviewed publication of the underlying data.加拉帕戈斯群岛（Galápagos Archipelago）的珊瑚礁生态系统在东热带太平洋（Eastern Tropical Pacific, ETP）中处于生物地理学上的特殊位置，坐落于多重海洋学格局的交汇区域，为珊瑚礁发育创造了高度多变且通常处于边缘的环境条件。本数据集提供了地理参考形状文件（georeferenced shapefiles），用于勾勒加拉帕戈斯群岛当前及历史时期的珊瑚礁生态系统分布，其开发旨在支撑《国际自然保护联盟生态系统红色名录》（IUCN Red List of Ecosystems, RLE）的全球珊瑚礁评估工作。 珊瑚礁单元的分类遵循RLE评估采用的类型学框架，区分出A型-替代型（具备岸礁、礁脊、脊沟与圆丘地貌的堆积型珊瑚礁）、B型（缺乏净生物成因堆积的边缘型珊瑚礁）、C型（附生珊瑚群落的潮下岩礁），以及过渡类别（B(C)与C(B)），对应国际自然保护联盟全球生态系统类型学中的功能群M1.3（透光带珊瑚礁）与M1.6（潮下岩礁）。根据现有珊瑚测年证据，加拉帕戈斯群岛不存在严格意义上的A型礁（堡礁、千年尺度环礁），亦未发现典型A型礁构造。 空间边界的划定基于历史记录、实地野外验证、样方摄影调查以及摄影测量生成的正射影像数据。属性信息包括礁体类型分类、有记录可查的历史礁体类型，以及历史与当前礁体状况描述。本数据集共绘制了约79.6公顷的礁体分布范围，其中达尔文礁（Type A-alternative）占15.6公顷，沃尔夫礁（Type A-alternative）约5公顷，两处均以团块滨珊瑚（Porites lobata）作为主要造架物种。群岛其余礁体总面积约59公顷，分布最集中的区域为弗洛雷阿纳岛（东北海岸线，从恶魔之冠（Corona del Diablo）至鸬鹚角（Punta Cormorán）再到冠军岛；约28公顷）与马尔琴纳岛（埃斯佩霍角（Punta Espejo）；约24公顷）。其中C型与过渡型C(B)礁体约占34公顷，B型与过渡型B(C)礁体约占25公顷。由于孤立珊瑚群落广泛分布于群岛内符合海洋学条件的浅海沿岸区域，C型礁体仅在珊瑚丰度或结构复杂度足以支撑制图表达的区域被选择性绘制。 本数据集还纳入了历史礁体损失与退化的记录。最显著的有据可查的礁体损失发生在乌维纳湾（伊莎贝拉岛）：1954年阿尔塞多火山喷发引发的构造抬升事件，导致约122公顷礁体永久裸露于空气中，该区域此前以团块滨珊瑚、团块轴孔珊瑚（Pavona clavus）、巨形轴孔珊瑚（Pavona gigantea）、杯形珊瑚科造架结构与星状沙珊瑚（Psammocora stellata）为优势类群，且被归类为A型-替代型及多数为B型礁体。此外，1982–1983年的极强厄尔尼诺事件导致群岛内多处礁体发生大规模珊瑚死亡。受影响区域已被记录下差异化的恢复轨迹：部分区域如恶魔之冠（弗洛雷阿纳岛北部）已出现部分恢复，而另一些区域如埃斯皮诺萨角（费尔南迪纳岛）仅恢复极微，仅残存孤立珊瑚群落与历史礁体框架的结构遗迹。除达尔文与沃尔夫礁至今仍保持A型-替代型分类外，此次事件受影响的多数礁体在1975年左右大概率被归类为B型。 本数据集旨在服务于IUCN RLE评估框架，受限于受限数据共享协议。文件访问需待相关基础数据经同行评议正式发表后方可开放。