Dissolved oxygen (DO) is considered one of the most important environmental variables of water quality. This work aimed to provide, for the first time, insights regarding DO dynamics on a representative site of the productive Ria Formosa coastal lagoon, south Europe, using a real time monitoring station observatory (acquiring data every 15 min) deployed for a period of two and a half years. This comprehensive data set represents an added value contributing to a better understanding of the DO variability throughout analyzing semidiurnal, daily, fortnightly tidal cycles (spring tide vs. neap tide), seasonal and interannual periods. This observational station was able to capture distinct temporal signatures, including episodic upwelling and meteorological events advancing the knowledge about the functioning of Ria Formosa. DO was highly variable presenting an evident seasonal distribution with the maximum concentration in spring and the minimum in summer night periods. Critical values <5 mg/L were recorded only in 3% of the global data set with negligible hypoxia events, showing infrequent DO stressful conditions in the study area. In addition, the disclosure of its diel dynamics over long periods, provided by this data set, allows to determine the impact of biological activity upon the DO variability and related ecosystem metabolism behavior (autotrophic vs. heterotrophic), through the metric estimation of Net Ecosystem Metabolism (NEM). NEM in the study area revealed to be slightly heterotrophic along one year of observation, reflecting the median percentage of DO saturation (93%). The acquired data set is highly valuable and can contribute to Ria Formosa management and protection, which is imperative for building knowledge-based societies.

溶解氧（DO）被认为是水质最重要的环境变量之一。这项工作旨在使用部署在两个时期内的实时监测站观测站（每15分钟获取一次数据），首次提供有关在南欧富有生产力的Ria Formosa沿海泻湖代表性站点上DO动力学的见解。半年了 这些全面的数据集代表了附加价值，有助于通过分析半日，每日，每两周的潮汐周期（春季潮汐与春季潮汐对比）更好地了解溶解氧的变化。小潮），季节性和年际期间。这个观测站能够捕捉到独特的时间特征，包括突发的上升流和气象事件，从而增强了有关福尔摩沙（Ria Formosa）功能的知识。DO高度可变，呈现明显的季节分布，春季最大浓度，夏季夜晚最小。仅在缺氧事件可忽略不计的全球数据集中有3％记录了临界值<5 mg / L，这表明研究区域很少发生DO应激状态。此外，由该数据集提供的长期Diel动态信息可以确定生物活性对DO变异性和相关生态系统代谢行为的影响（自养对异养），通过对净生态系统代谢（NEM）的度量估算。研究区域的NEM在观察到的一年中显示为异养性，反映了DO饱和度的中位数百分比（93％）。所获得的数据集非常有价值，并且可以为Ria Formosa的管理和保护做出贡献，这对于建设知识型社会至关重要。