South Carolina Cooperative Fish & Wildlife Research Unit, Department of Forestry and Environmental Conservation, Clemson University, Clemson, South Carolina, United States of America.
U.S. Fish and Wildlife Service, Migratory Bird Program/Science Applications, Chiefland, Florida, United States of America.
PLoS One. 2023 Jun 23;18(6):e0287316. doi: 10.1371/journal.pone.0287316. eCollection 2023.
The Gulf of Mexico supports many seabird species, yet data gaps describing species composition and habitat use are prevalent. We used vessel-based observations from the Gulf of Mexico Marine Assessment Program for Protected Species to identify and characterize distinct seabird assemblages in the northern Gulf of Mexico (within the U.S. Exclusive Economic Zone; nGoM). Using cluster analysis of 17 seabird species, we identified assemblages based on seabird relative density. Vessel-based surveys documented the location, species, and number of seabirds across the nGoM between 2017-2019. For each assemblage, we identified the (co-)dominant species, spatial distribution, and areas of greater relative density. We also assessed the relationship of the total relative density within each assemblage with environmental, spatial, and temporal covariates. Of the species assessed, 76% (n = 13) breed predominantly outside the nGoM basin. We identified four seabird assemblages. Two assemblages, one dominated by black tern and the other co-dominated by northern gannet/laughing gull, occurred on the continental shelf. An assemblage dominated by sooty tern occurred along the continental slope into pelagic waters. The fourth assemblage had no dominant species, was broadly distributed, and was composed of observations with low relative density ('singles' assemblage). Differentiation of assemblages was linked to migratory patterns, residency, and breeding location. The spatial distributions and relationships of the black tern and northern gannet/laughing gull assemblages with environmental covariates indicate associations with river outflows and ports. The sooty tern assemblage overlapped an area prone to mesoscale feature formation. The singles assemblage may reflect commuting and dispersive behaviors. These findings highlight the importance of seasonal migrations and dynamic features across the seascape, shaping seabird assemblages. Considering the potential far-ranging effects of interactions with seabirds in the nGoM, awareness of these unique patterns and potential links with other fauna could inform future monitoring, research, restoration, offshore energy, and aquaculture development in this highly industrialized sea.
墨西哥湾支持着许多海鸟物种，但有关物种组成和栖息地利用的数据空白仍然很普遍。我们使用墨西哥湾海洋评估计划保护物种的船只观测数据，来确定和描述墨西哥湾北部（在美国专属经济区范围内；nGoM）独特的海鸟群落。我们使用 17 种海鸟的聚类分析，根据海鸟的相对密度来确定群落。船只调查记录了 2017-2019 年期间 nGoM 内的海鸟位置、物种和数量。对于每个群落，我们确定了主要物种、空间分布和相对密度较高的区域。我们还评估了每个群落内总相对密度与环境、空间和时间协变量的关系。在所评估的物种中，76%（n=13）主要在 nGoM 盆地以外繁殖。我们确定了四个海鸟群落。两个群落，一个由黑燕鸥主导，另一个由北方塘鹅/海鸥共同主导，位于大陆架上。一个由乌燕鸥主导的群落则沿着大陆坡延伸到远洋水域。第四个群落没有优势物种，分布广泛，由相对密度较低的观测结果组成（“单一”群落）。群落的分化与迁徙模式、居留和繁殖地有关。黑燕鸥和北方塘鹅/海鸥群落与环境协变量的空间分布和关系表明，它们与河流流出物和港口有关。乌燕鸥群落与中尺度特征形成的区域重叠。单一群落可能反映了通勤和扩散行为。这些发现强调了季节性迁徙和整个海域动态特征的重要性，这些特征塑造了海鸟群落。考虑到 nGoM 中与海鸟相互作用的潜在深远影响，对这些独特模式及其与其他动物群的潜在联系的认识，可以为未来在这个高度工业化的海域进行监测、研究、恢复、海上能源和水产养殖开发提供信息。
