Table_1_Identifying the wetlands of international importance in Beibu Gulf along the East Asian – Australasian Flyway, based on multiple citizen science datasets.xlsx

The Beibu Gulf (Gulf of Tonkin, Vinh Bac Bo in Vietnamese), located midway along the East Asian-Australasian Flyway (EAAF), is a critical stopover and wintering region for migratory waterbirds. This transboundary coastal region, spanning between China and Vietnam, harbors diverse wetland habitats that provide refuge to waterbird species, including highly threatened species such as the spoon-billed sandpiper (CR) and the black-faced spoonbill (EN). However, the scarcity of comprehensive assessments regarding waterbird abundances, distribution, key wetland habitats, and regional threats hinders our understanding of its conservation significance at the flyway level. Further research is needed to address these knowledge gaps and facilitate effective conservation efforts in the Beibu Gulf. By synthesizing accessible citizen science datasets and published records from wetland sites in south China and northeast Vietnam, we concluded that at least 97 waterbird species used the Gulf’s wetlands during their annual cycle. Among surveys conducted from 2014 to 2022, 5 and 11 waterbird species were considered as first and second class protected species under the National Key Protected Wild Animal List in China; 2 species were listed as Critically Endangered on the IUCN Red List, 4 as Endangered and 2 as Vulnerable, underlying the critical importance of the Beibu Gulf for the survival of these species. Our study identified 25 sites in the Beibu Gulf that met the criteria for designation as internationally important wetlands. Alarmingly, less than a quarter (n = 5, or 20%) of these sites benefit from national or international protection. Localized threats, including aquatic resource harvesting, hunting, and aquaculture/fisheries, were widespread in the region. This study provides a crucial scientific baseline for continued waterbird monitoring, site prioritization, and the development of effective habitat management plans to conserve vital coastal wetland habitats in the Beibu Gulf in China and Vietnam.

北部湾（又称东京湾，越南语称Vinh Bac Bo）地处东亚-澳大利西亚迁飞区（East Asian-Australasian Flyway, EAAF）的中段，是迁徙水鸟至关重要的中途停歇地与越冬栖息地。这片跨越中国与越南的跨界滨海区域，孕育了多样的湿地生境，为各类水鸟提供了庇护场所，其中包括极危物种勺嘴鹬（CR）与濒危物种黑脸琵鹭（EN）等高度受胁物种。
然而，当前针对该区域水鸟种群丰度、分布格局、关键湿地生境以及区域性威胁的综合评估仍较为匮乏，这阻碍了我们从迁飞区层面认知其保护价值。填补此类认知空白、助力北部湾地区开展高效保护工作，亟需进一步的研究。
本研究整合了中国华南与越南北部湿地站点的公开公民科学数据集及已发表的观测记录，最终确认至少有97种水鸟在其年度生命周期中会使用北部湾的湿地生境。在2014至2022年开展的调查中，有5种、11种水鸟分别被列入中国《国家重点保护野生动物名录》中的一级、二级保护物种；另有2种被国际自然保护联盟（International Union for Conservation of Nature, IUCN）红色名录列为极危（CR）、4种列为濒危（EN）、2种列为易危（VU），这凸显了北部湾对于这些物种存续的关键意义。
本研究共识别出北部湾地区25处符合国际重要湿地认定标准的站点。令人警觉的是，其中仅有不足四分之一（n=5，占比20%）的站点获得了国家级或国际级保护。该区域内还普遍存在水生资源采收、狩猎以及水产养殖/渔业等本地化威胁。
本研究为持续开展水鸟监测、优先保护站点遴选以及制定高效的生境管理方案提供了关键的科学基线，以助力中国与越南境内北部湾地区重要滨海湿地生境的保护工作。