Abiotic oceanographic parameters in coastal southeast Alaska (temperature, salinity, dissolved oxygen, nutrients, light)

Abiotic parameters were collected at 21 sites across two coordinated sampling efforts. In the first set of samples (summerlong set), data were collected from 29 April through 22 August 2017, where each site was visited once during that time frame. Data from this effort include seawater temperature (C), salinity (ppt), dissolved oxygen (mg per L), light (umol per meter squared), and nutrients (umol; nitrate + nitrite, ammonium, phosphate). In the second sampling effort, data were only collected on 14 August 2017 but all 21 sites were visited within an 8-hr time frame using two independently operating boats. Data from this effort include seawater temperature (C), salinity (ppt), dissolved oxygen (mg per L) for some sites, and nutrients (umol; nitrate + nitrite, ammonium, phosphate); light data were not collected. Site name, coordinates, sampling time, sampling dates, and sampled depths for each site are included in the data file for each data point. The purpose of these data was to characterize the fish assemblage within eelgrass communities so that analysis of trophic interactions could be assessed along a gradient of sea otter occupation for an NSF-funded project: Apex Predators, Ecosystems, and Community Sustainability (APECS, http://apecs-ak.org/). Other datasets to support this work are also archived with KNB.

本数据集通过两次协同采样工作，在21个采样点位采集了非生物参数（abiotic parameters）。
首轮采样为夏季长期组（summerlong set），采集时段为2017年4月29日至8月22日，期间每个点位仅被采样一次。本次采样获取的参数包括：海水温度（单位：℃）、盐度（单位：ppt）、溶解氧（单位：mg/L）、光照强度（单位：μmol·m⁻²）以及营养盐（单位：μmol，涵盖硝酸盐+亚硝酸盐、铵盐、磷酸盐）。
第二次采样仅在2017年8月14日开展，使用两艘独立作业的船只，在8小时内完成全部21个点位的采样。本次采样获取的参数包括海水温度、盐度、部分点位的溶解氧，以及营养盐（单位：μmol，涵盖硝酸盐+亚硝酸盐、铵盐、磷酸盐），未采集光照数据。
每个数据点对应的采样点位名称、坐标、采样时刻、采样日期以及采样水深均已收录于数据文件中。
本数据集的采集目的是表征海草床群落（eelgrass communities）内的鱼类群落组成，以便为美国国家科学基金会（National Science Foundation, NSF）资助的“顶级捕食者、生态系统与群落可持续性”（Apex Predators, Ecosystems, and Community Sustainability，缩写APECS，http://apecs-ak.org/）项目，沿海獭栖息梯度开展营养相互作用分析提供支撑。支撑该研究的其他数据集也已存档于KNB。