Seagrass meadows are valued coastal habitats that provide ecological and economic benefits around the world. Despite their importance, many meadows are in decline, driven by a variety of anthropogenic impacts. While these declines have been well documented in some regions, other locations (particularly within the tropics) lack long-term monitoring programs needed to resolve seagrass trends over time. Effective and spatially-expansive monitoring within under-represented regions is critical to provide an accurate perspective on seagrass status and trends. We present a comprehensive dataset on seagrass coverage and composition across 24 sites in Bahía Almirante, a lagoon along the Caribbean coast of Panama. Using a single survey, we focus on capturing spatial variation in seagrass physical and elemental characteristics and provide data on key seagrass bio-indicators, such as leaf morphology (length and width), elemental content (% nitrogen and phosphorus) and stable isotopic signatures (δ13C and δ15N). We further explore relationships between these variables and water depth (proxy for light availability) and proximity to shore (proxy for terrestrial inputs). The seagrass assemblage was mostly monospecific (dominated by Thalassia testudinum) and restricted to shallow water (<3 m). Above-ground biomass varied widely, averaging 71.7 g dry mass m−2, yet ranging from 24.8 to 139.6 g dry mass m−2. Leaf nitrogen content averaged 2.2%, ranging from 1.76 to 2.57%, while phosphorus content averaged 0.19% and ranged from 0.15 to 0.23%. These values were high compared to other published reports for T. testudinum, indicating elevated nutrient availability within the lagoon. Seagrass stable isotopic characteristics varied slightly and were comparable with other published values. Leaf carbon signatures (δ13C) ranged from −11.74 to −6.70‰ and were positively correlated to shoreline proximity, suggesting a contribution of terrestrial carbon to seagrass biomass. Leaf nitrogen signatures (δ15N) ranged from −1.75 to 3.15‰ and showed no correlation with shoreline proximity, suggesting that N sources within the bay were not dominated by localized point-source discharge of treated sewage. Correlations between other seagrass bio-indicators and environmental metrics were mixed: seagrass cover declined with depth, while biomass was negatively correlated with N, indicating that light and nutrient availability may jointly regulate seagrass cover and biomass. Our work documents the response of seagrass in Bahía Almirante to light and nutrient availability and highlights the eutrophic status of this bay. Using the broad spatial coverage of our survey as a baseline, we suggest the future implementation of a continuous and spatially expansive seagrass monitoring program within this region to assess the health of these important systems subject to global and local stressors.

中文翻译：

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海草的结构和元素指标显示出巴拿马热带泻湖中的高养分利用率

海草草甸是珍贵的沿海栖息地，可为全世界提供生态和经济利益。尽管它们具有重要意义，但由于各种人为因素的影响，许多草甸的面积仍在下降。尽管这些下降在某些地区已得到充分记录，但其他地区（特别是在热带地区）却缺乏解决海草随时间变化趋势所需的长期监测计划。在代表性不足的区域内进行有效的空间扩展监视对于提供有关海草状况和趋势的准确视角至关重要。我们提供了一个完整的数据集，涵盖了巴拿马加勒比海沿岸泻湖巴伊亚·阿尔米兰特（BahíaAlmirante）内24个地点的海草覆盖和组成。使用一次调查，我们专注于捕获海草物理和元素特征的空间变化，并提供有关关键海草生物指标的数据，例如叶片形态（长度和宽度），元素含量（％氮和磷）和稳定的同位素特征（δ13C和δ15N）。我们进一步探讨了这些变量与水深（对于光的可用性而言为代理）和与海岸的接近度（对于地面输入而言为代理）之间的关系。海草组合主要是单特异性的（主要由地中海藻（Thalassia testudinum）控制），并且仅限于浅水（<3 m）。地上生物量变化很大，平均干重m-2为71.7 g，但干重m-2为24.8至139.6 g。叶片氮含量平均为2.2％，范围为1.76至2.57％，磷含量平均为0.19％，范围为0.15至0.23％。与其他已发表的关于睾丸的报告相比，这些值很高，表明泻湖中养分的利用率较高。海草的稳定同位素特征略有变化，可与其他已发表的值相比较。叶片碳签名（δ13C）的范围为-11.74至-6.70‰，与海岸线接近度呈正相关，表明陆地碳对海草生物量的贡献。叶片氮素特征（δ15N）范围为-1.75至3.15‰，与海岸线的亲缘关系无相关性，表明海湾内的氮源不受处理后污水的局部点源排放的支配。其他海草生物指标与环境指标之间的关系混杂在一起：海草覆盖度随深度而下降，而生物量与氮呈负相关，表明光和养分的可利用性可以共同调节海草的覆盖率和生物量。我们的工作记录了巴伊亚阿尔米兰特（BahíaAlmirante）海草对光和养分供应的响应，并强调了该海湾的富营养化状况。以我们调查的广泛空间覆盖为基线，我们建议该地区未来在空间内进行连续且空间扩展的海草监测计划，以评估受全球和当地压力影响的这些重要系统的健康状况。