Density of herbivorous fishes of the Gulf of California

Through collaborative monitoring involving multiple academic, government, and civil institutions over a span of 16 years (2005 to 2020), we compiled 884 records of the density of 13 species of marine herbivorous fishes. The data was collected through 15,542 visual censuses conducted by scuba diving in 34 localities, encompassing 268 rocky and coral reef sites. These censuses utilized belt transects (250 m², 100 m², and 60 m²) parallel to the coastline at similar depth profiles. Trained underwater monitors recorded abundances of all adult individuals of the 13 targeted species along the transects. The information for each transect in the database is presented as the average fish density (individuals per square meter), estimated based on the abundance for each species. The database integrates information on latitude, longitude, type of management, localities in the Gulf of California, institutions, initial and final years of data collection, total number of years, as well as mean, standard deviation, sample size, slope (annual rate of change), probability value, standard error, and minimum and maximum values calculated for each species within each locality. This dataset serves as a historical benchmark for assessing the status of 13 species in the Gulf of California. It enables the examination of changes in herbivorous fish communities over time and across various locations, which is crucial given the impact of global changes leading to tropicalization in the study area. The data is particularly important for providing valuable insights to those managing protected areas in the Gulf and the broader eastern tropical Pacific region.本数据集依托多所学术机构、政府部门与民间组织的协同监测工作，历时16年（2005年至2020年），共收集得到13种海洋植食性鱼类的密度记录共884条。 数据采集采用水肺潜水目视调查法，在34个调查区域内共完成15542次调查，覆盖268个岩礁与珊瑚礁点位。本次调查采用与海岸线平行的样带法，样方面积分别为250平方米、100平方米及60平方米，且所有样带均设置于相近深度的剖面区域。受过专业培训的水下监测人员沿样带记录了13种目标物种的所有成体个体丰度。数据库中每条样带的信息以平均鱼类密度（单位：个体/平方米）的形式呈现，该密度基于各物种的个体丰度估算得到。数据集整合了纬度、经度、管理类型、加利福尼亚湾（Gulf of California）的调查区域名称、参与机构、数据采集的起始与终止年份、总监测年限，以及针对每个区域内各物种计算得到的平均值、标准差、样本量、斜率（年变化率）、概率值、标准误，还有最小值与最大值。 本数据集可作为评估加利福尼亚湾内13个物种种群现状的历史基准。其支持开展植食性鱼类群落在不同时间与空间维度上的变化分析，而鉴于全球变化对本研究区域造成的热带化影响，此类分析具备重要意义。此外，该数据集可为加利福尼亚湾及更广范围东热带太平洋区域的保护区管理者提供极具价值的参考依据。