Grid in PNMTIAG marine area

To estimate the spatial distribution of different variables the maritime area of the four archipelagos of the Maritime-Terrestrial National Park of the Atlantic Islands of Galicia (PNMTIAG) in Galicia (Spain): Cortegada, Sálvora, Ons and Cíes, was divided into 500 x 500 m grids. Some of the grids are not this size because they have been cut by de cost line or the park’s maritime limits. For stratified samplings two strata have been defined in Sálvora, Ons and Cíes with a geographical criterion: East (E in EW field) and West (W in EW field). The definition of the strata was based on the north-south geographical orientation of these archipelagos. This geographical orientation defines one side exposed to the ocean and the other sheltered which presupposes different habitats and ecological characteristics.

The attribute table of this vector shapefile has four fields: i) ID; ii) EW, with value W for the west stratum grids and E for the east stratum grids; iii) Grid, containing the name of the grids; iv) Archipelag, indicating the archipelago corresponding to each grid.

The grids were used in several studies. Created to quantify the fishing effort of the artisanal fleet between 2016 and 2017. It was used to study the stock and spatial distribution of Ammodytidae in 2018 and 2019. Also used to study interactions between both professional fishing and recreative boats and seabirds.

为探明西班牙加利西亚大区大西洋群岛海陆国家公园（Parque Nacional Marítimo-Terrestre de las Islas Atlánticas de Galicia，PNMTIAG）所辖科尔泰加达（Cortegada）、萨尔沃拉（Sálvora）、翁斯（Ons）与西斯（Cíes）四个群岛海域内各类变量的空间分布特征，研究人员将该海域划分为500m×500m的网格单元。部分网格因受海岸线或公园海域边界切割，尺寸并非标准的500m×500m。
针对萨尔沃拉、翁斯及西斯群岛，研究人员以地理方位为依据划定了两个分层：东层（EW字段取值为E）与西层（EW字段取值为W）。该分层方案基于上述群岛的南北走向地理特征制定——此类走向使得群岛一侧直面大洋、另一侧受水域遮蔽，进而孕育出截然不同的生境与生态属性。
该矢量形状文件的属性表包含四个字段：i) ID；ii) EW字段，西层网格取值为W，东层网格取值为E；iii) Grid字段，存储各网格的标识名称；iv) Archipelag字段，标注各网格所属的群岛。
该网格数据集已被应用于多项科研工作：2016至2017年间用于量化手工作业渔船的捕捞努力量；2018至2019年间用于研究玉筋鱼科（Ammodytidae）的种群资源与空间分布格局；此外还被用于探究商业捕捞船队、休闲游艇与海鸟之间的相互作用关系。