科学一般要求定性、定量，用数据说话，用公式/模型表达。

在探索的过程中，一步步接近事实、一层层揭示机理。然而，由于地学的特点，“水土风光”的差异，在研究的过程中可能会有时空差异。

在水环境中，营养化是重要的研究方向之一。富营养化研究的很多，贫营养化也是营养化的一面。

现有两篇文献，可以看一看。

A quarter-century of nutrient load reduction leads to halving river nutrient fluxes and increasing nutrient limitation in coastal waters of central Japan
Saki Katazakai & Jing Zhang
Environmental Monitoring and Assessment volume 193, Article number: 573 (2021)

https://doi.org/10.1007/s10661-021-09279-5

Abstract
Nutrient load reduction is widely used to improve coastal water quality, but it can lead to oligotrophication. This paper evaluates the current status of river water origin and the water recharge system based on isotope values and dissolved compositions recorded in 2018, and it also assesses the impact of nutrient load reduction efforts on river nutrient fluxes and coastal water quality using 25 years of monitoring data. This study focuses on the coast of Toyama Bay as a model area because (1) up to 20% of terrestrially derived nutrient support the growth of coastal primary productivity, and (2) the adjacent land is a typical city in a population-dense area (~ 500 persons/km2), a demographic characteristic that exists in 88% of Japan’s total land area and 96% of the total length of the country’s coastline. Since the government adopted new wastewater treatment systems in 1993, river nutrient supplies in the study area have been halved, while the total river flow and annual precipitation have remained almost unchanged. The reduction in riverine nutrient supply has increased phosphorus deficiencies in the coastal waters. Most notably, the decline in nutrient concentrations in coastal surface waters and the enlarged nutrient-restricted areas are facing most parts of Japan, suggesting a resulting 25–50% decrease in CO2 uptake by primary production. This study is in agreement with previous studies from various countries in emphasizing the importance of setting appropriate nutrient-management goals for maintaining a sustainable marine environment. This paper recommends the need to accumulate various case studies of different areas and to share in a timely manner scientific evidence on a regional and global scale.

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Cyanobacterial blooms in oligotrophic lakes: Shifting the high-nutrient paradigm
Kaitlin L. Reinl, Justin D. Brookes, Cayelan C. Carey, Ted D. Harris, Bas W. Ibelings, Ana M. Morales-Williams, Lisette N. De Senerpont Domis, Karen S. Atkins, Peter D. F. Isles, Jorrit P. Mesman, Rebecca L. North, Lars G. Rudstam, Julio A. A. Stelzer, Jason J. Venkiteswaran, Kiyoko Yokota, Qing Zhan,

https://doi.org/10.1111/fwb.13791

 Abstract

    Freshwater cyanobacterial blooms have become ubiquitous, posing major threats to ecological and public health.
    Decades of research have focused on understanding drivers of these blooms with a primary focus on eutrophic systems; however, cyanobacterial blooms also occur in oligotrophic systems, but have received far less attention, resulting in a gap in our understanding of cyanobacterial blooms overall.
    In this review, we explore evidence of cyanobacterial blooms in oligotrophic freshwater systems and provide explanations for those occurrences.
    We show that through their unique physiological adaptations, cyanobacteria are able to thrive under a wide range of environmental conditions, including low-nutrient waterbodies.
    We contend that to fully understand cyanobacterial blooms, and thereby mitigate and manage them, we must expand our inquiries to consider systems along the trophic gradient, and not solely focus on eutrophic systems, thus shifting the high-nutrient paradigm to a trophic-gradient paradigm.