pH timeseries from moorings in the Boulder Patch, Beaufort Sea, Alaska, 2016-2018

In the nearshore Alaskan Beaufort Sea, discrete, isolated rocky habitats harbor biological communities that are unusually diverse for the region, with markedly different fauna and flora than found in the surrounding soft sediment areas. The boulder fields also support tightly linked food webs, with connections to higher trophic levels such as fishes and seals. These systems are highly vulnerable to disturbances, including sedimentation from human activities and coastal erosion, fluctuations in salinity from seasonal river discharge, and temperature increases from heat influx originating at lower latitudes and from atmospheric warming. Spatial isolation of these boulder fields and the slow development of benthic communities limit ecosystem recovery from disturbance. To assess the possible ecological effects of such environmental disturbances, this field program undertook an investigation of the biological communities and environmental conditions across the Stefansson Sound Boulder Patch, the largest of the Beaufort Sea nearshore boulder fields. The overlying objectives of this program were to: 1) monitor incident and in situ photosynthetically active radiation (PAR), salinity, temperature, currents, and pH to define the spatial variability in annual kelp productivity and biomass; 2) characterize benthic community structure changes across environmental gradients in the Boulder Patch and 3) collect annual measurements of kelp growth in the Boulder Patch to provide a nearly continuous record of kelp growth since 1976. Within and in addition to these objectives, individual research projects were completed, using experimental approaches, timeseries analysis and historical data to gain an in depth understanding of mechanisms (past and present) that resulted in the Boulder Patch community we see today and how this community may vary in future conditions. To understand spatiotemporal variability in environmental conditions, pH was recorded by SeaFETs moored near the benthos at two locations in the Boulder Patch, (Stefansson Sound, Beaufort Sea, Alaska). These data were collected as part of a larger study to gain an in-depth understanding of mechanisms (past and present) that resulted in the Boulder Patch community we see today and how this community may vary in future conditions.阿拉斯加博福特海近岸区域中，离散孤立的岩质生境孕育了该区域罕见多样的生物群落，其动植物群落与周边软沉积环境存在显著差异。这些砾石场同时支撑着紧密关联的食物网，其营养联系可延伸至鱼类、海豹等更高营养级生物。该类生态系统极易受到各类干扰影响，包括人类活动引发的沉积作用、海岸侵蚀，季节性河流径流导致的盐度波动，以及源自低纬度热输入与大气变暖引发的温度升高。这些砾石场的空间隔离特性与底栖群落缓慢的发育速率，限制了其受干扰后的生态系统恢复能力。 为评估此类环境干扰可能带来的生态影响，本野外调查项目针对博福特海近岸最大的砾石场——斯特凡松湾砾石斑（Stefansson Sound Boulder Patch）展开了生物群落与环境条件的全域调查。本项目的首要研究目标包括： 1) 监测入射与原位光合有效辐射（photosynthetically active radiation, PAR）、盐度、温度、海流与pH值，以明确年度大型褐藻生产力与生物量的空间变异特征； 2) 刻画斯特凡松湾砾石斑内沿环境梯度分布的底栖群落结构变化； 3) 采集年度大型褐藻生长数据，以构建自1976年起近乎连续的褐藻生长记录。 除上述核心目标外，本项目还通过实验方法、时间序列分析与历史数据开展了多项独立研究，以深入解析塑造当前斯特凡松湾砾石斑群落的过往与现存机制，以及该群落未来可能的变化趋势。为探明环境条件的时空变异特征，研究人员在该砾石斑的两处底栖生境附近部署了SeaFET传感器（SeaFETs）以记录pH值数据，采样点位位于阿拉斯加博福特海斯特凡松湾。上述数据隶属于一项更大规模的研究，该研究旨在深入解析塑造当前斯特凡松湾砾石斑群落的过往与现存机制，以及该群落未来的变化趋势。