RESUMO
High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function.
Assuntos
Hidrobiologia , Qualidade da Água , Rios , Previsões , Monitoramento AmbientalRESUMO
Agriculture is necessary for food production, but agricultural inputs of phosphorus (P) to waterways can lead to harmful algal blooms in downstream reservoirs. Some of the P that enters these water bodies can be stored in reservoir sediments and later contribute to internal P loading, supplementing external P loads carried in from rivers. Increased P can lead to harmful algal blooms. However, how P is cycling in the sediment of these water bodies varies spatially and temporally has been relatively unstudied. Our objective was to understand how P concentration and form vary spatiotemporally, as well as how P is processed in the sediment of the reservoir. We sampled 30 locations in both August and October 2018 around Milford Reservoir (Kansas), a man-made eutrophic reservoir with frequent harmful algal blooms. We collected water chemistry samples, field measurements of temperature, dissolved oxygen, and pH, and sediment samples to analyze for P chemical speciation and phosphatase enzyme activity. We show that P release by phosphatase activity was higher under anaerobic and basic conditions, which subsequently affects spatiotemporal variation in sediment P pools. We found that low oxygen positively influenced phosphatase activity and sediment P pools, and may drive high internal P loading and harmful algal blooms in the summer months. This research increased our understanding of P cycling in a reservoir highly impacted by agricultural inputs and contributed to a small but growing body of research on internal P loading in midwestern reservoirs.
RESUMO
As we build a more diverse, equitable, and inclusive culture in the ecological research community, we must work to support new ecologists by empowering them with the knowledge, tools, validation, and sense of belonging in ecology to succeed. Undergraduate research experiences (UREs) are critical for a student's professional and interpersonal skill development and key for recruiting and retaining students from diverse groups to ecology. However, few resources exist that speak directly to an undergraduate researcher on the diversity, equity, and inclusion (DEI) dimensions of embarking on a first research experience. Here, we write primarily for undergraduate readers, though a broader audience of readers, especially URE mentors, will also find this useful. We explain many of the ways a URE benefits undergraduate researchers and describe how URE students from different positionalities can contribute to an inclusive research culture. We address three common sources of anxiety for URE students through a DEI lens: imposter syndrome, communicating with mentors, and safety in fieldwork. We discuss the benefits as well as the unique vulnerabilities and risks associated with fieldwork, including the potential for harassment and assault. Imposter syndrome and toxic field experiences are known to drive students, including students from underrepresented minority groups, out of STEM. Our goal is to encourage all students, including those from underrepresented groups, to apply for UREs, build awareness of their contributions to inclusion in ecology research, and provide strategies for overcoming known barriers.