Water Quality Data (Grab Samples) from the Shark River Slough, Everglades National Park (FCE LTER), Florida, USA, May 2001 - ongoing

Water quality samples are being collected using ISCO autosamplers at all Florida Coastal Everglades Long Term Ecological Research (FCE LTER) Program wetland sites (that is, all sites except TS/Ph-9, 10, and 11). The autosamplers contain 24 1L bottles. Water is sampled by programming the autosamplers to take composite samples once every 3 days. These samples are a composite of four 250mL subsamples drawn every 18 hours (a sampling scheme that captures a dawn, noon, dusk, and midnight sample in every three day composite). The samples are collected every 3-4 weeks and analyzed for total phosphorus (TP), total nitrogen (TN), and salinity. When sites are visited to collect these samples, we also collect a grab sample that is immediately put on ice. A portion of these grab samples is filtered through a filter (Whatman GF/F from 2000 to 2017 and Whatman polydisc GW from 2017 to ongoing) immediately upon return to the lab, and the filtered samples are analyzed for inorganic nutrients such as NO2-, NO3-, NH4+, SRP, and DOC. The unfiltered fraction of these grab samples is analyzed for TP and TN. We use these monthly grab samples to generate relationships between TP and SRP, and between TN and NO2- + NO3- + NH4+. Dissolved nutrients are measured using standard rapid flow analyzer (RFA) techniques. TP is analyzed with a modified Solorzano and Sharp (1980) technique. TN is measured with an ANTEK 9000N analyzer, TOC and DOC are quantified on a Shimadzu TOC Analyzer, and salinity is measured with a YSI conductivity meter or refractometer. In January 2007 a 6 days interval began for SRS1d, SRS2 & SRS3; the ISCOs did not change their sampling scheduled, they kept collecting water sample every 18 hours and switching bottles every three days; once in the lab, the 3 days was turned into 6 days by combining two bottles into 2 liters container. In addition to the regular water quality monitoring, we use the rain level actuators at all freshwater sites to trigger water sampling after rain events exceed a given threshold of duration and/or intensity. As currently programmed, when the threshold of = 2.5 cm of rain per hour is passed, the autosampler at that site collects a 1000mL sample 30 minutes after the threshold has been reached. Rain event samples are collected, treated, and analyzed as all other water quality samples. Related Shark River Slough water quality data packages: ISCO extensive water quality (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1072) Rainfall-driven autosampler water quality (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1253) Related Taylor Slough water quality data packages: ISCO extensive water quality from TS/Ph1a, TS/Ph1b (inactive), TS/Ph2, and TS/Ph3 (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1079) ISCO extensive water quality from TS/Ph6a, TS/Ph7a, and TS/Ph8 (inactive) (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1074) Grab sample water quality from TS/Ph1a, TS/Ph1b (inactive), TS/Ph2, and TS/Ph3 (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1080) Grab sample water quality from TS/Ph6a, TS/Ph7a, and TS/Ph8 (inactive) (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1075)

研究团队依托ISCO自动采样器（ISCO autosamplers），于佛罗里达海岸大沼泽地长期生态研究（Florida Coastal Everglades Long Term Ecological Research, FCE LTER）计划的全部湿地站点（TS/Ph-9、10、11站点除外）采集水质样本。该类自动采样器搭载24个1升容量的采样瓶。采样流程通过编程设置为每3天采集一次混合水样：每18小时采集250毫升子样本，每3天的混合样本将覆盖黎明、正午、黄昏与午夜四个时段的水样，以此实现完整日周期的采样覆盖。样本采集周期为每3至4周一次，检测指标涵盖总磷（total phosphorus, TP）、总氮（total nitrogen, TN）与盐度。

在赴站点采集上述混合样本的同时，研究团队还会同步采集即时抓取样本，并即刻将其置于冰上保存。返回实验室后，部分抓取样本将立即进行过滤处理：2000年至2017年采用Whatman GF/F滤膜，2017年至今改用Whatman polydisc GW滤膜；过滤后的样本用于检测亚硝酸盐（nitrite, NO₂⁻）、硝酸盐（nitrate, NO₃⁻）、氨氮（ammonia nitrogen, NH₄⁺）、可溶性活性磷（soluble reactive phosphorus, SRP）与溶解性有机碳（dissolved organic carbon, DOC）等无机营养盐组分。未经过滤的抓取样本分样则用于检测TP与TN。研究团队依托这些月度抓取样本，建立了TP与SRP、TN与NO₂⁻+NO₃⁻+NH₄⁺之间的相关性定量关系。

溶解态营养盐采用标准快速流动分析仪（rapid flow analyzer, RFA）技术进行检测；TP检测采用改良版Solorzano与Sharp（1980）方法；TN采用ANTEK 9000N分析仪测定，总有机碳（total organic carbon, TOC）与DOC通过岛津（Shimadzu）TOC分析仪定量，盐度则使用YSI电导仪或折射计测定。

2007年1月起，SRS1d、SRS2与SRS3站点的采样周期调整为6天：原ISCO自动采样器并未改变原有采样设置，仍维持每18小时采集一次水样、每3天轮换采样瓶的运行逻辑；返回实验室后，将两瓶采样瓶中的水样合并至2升容器中，从而将原3天的混合样本周期转换为6天。

除常规水质监测外，研究团队还在所有淡水站点部署了雨量触发装置，当降雨事件的时长和/或强度达到设定阈值时，自动触发水样采集。当前的触发设置为：当每小时降雨量达到2.5厘米及以上的阈值时，对应站点的自动采样器将在阈值触发后30分钟采集1000毫升水样。降雨事件采集的水样，其处理与检测流程与其他常规水质样本完全一致。

相关鲨鱼河沼泽（Shark River Slough）水质数据包：
ISCO大范围水质数据集（https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1072）
降雨驱动型自动采样器水质数据集（https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1253）

相关泰勒沼泽（Taylor Slough）水质数据包：
TS/Ph1a、TS/Ph1b（已停用）、TS/Ph2及TS/Ph3站点的ISCO大范围水质数据集（https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1079）
TS/Ph6a、TS/Ph7a及TS/Ph8（已停用）站点的ISCO大范围水质数据集（https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1074）
TS/Ph1a、TS/Ph1b（已停用）、TS/Ph2及TS/Ph3站点的抓取样本水质数据集（https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1080）
TS/Ph6a、TS/Ph7a及TS/Ph8（已停用）站点的抓取样本水质数据集（https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-fce&identifier=1075）