Nutrients and Eutrophication

Abstract

Excess nutrientsfrom fertiliser application, pollution discharge and water regulations outflow through rivers from lands to oceans, seriously impact coastal ecosystems. Terrestrial runoff of waters polluted with nutrients (primarily nitrogen [N] and phosphorus [P] compounds) from point source/s, such as sewage treatment plant (STP) discharges, and diffuse sourcesvia river discharges, such as fertiliser losses, are having devastating adverse effects in coastal and marine ecosystems globally (Carpenter et al., Ecol Appl 8:559–568, 1998; Halpern et al., Science 319:948–952, 2008; Crain et al., Ecol Lett 11:1304–1315, 2008; Smith and Schindler, Trends Ecol Evol 24:201–207, 2009). The nutrients can be dissolved such as dissolved nitrate and Phosphate typically discharged from STPs or agricultural runoff or in a particulate form, often associated with soil erosion.

A first ecological coherent assessment of eutrophication across the North-East Atlantic waters (2015–2020)

“…Eutrophication can have a substantial impact on the marine environment, limiting access to ecosystem services by acting as a pressure on multiple ecosystem components (Best et al, 2007;Duarte et al, 2008a,b;Paerl and Piehler, 2008;Paerl, 2009;Clark et al, 2017;Korpinen et al, 2021;Devlin and Brodie, 2023). Even at low concentrations, increased nutrient loads and changing proportions of nutrients can result in increasing phytoplankton biomass and species shifts which can affect trophic levels (Burson et al, 2016;Grosse et al, 2017;Piroddi et al, 2021;Graves et al, 2023).…”

“…Natural processes regulate the balance between nutrient availability and the growth of marine plants and animals in ecosystems. Excess nutrients introduced into the sea by human activities can disturb this balance, resulting in accelerated growth of phytoplankton (Devlin and Brodie, 2023). This leads to adverse effects on water quality and marine ecology such as extensive micro-and macro-algae blooms (e.g., green tides, with impact on human health), turbid water and eventually hypoxia, potentially causing mortality of fish, shellfish and seagrasses (Figure 1) in a process known as eutrophication (De Jong, 2007;Paerl and Piehler, 2008;Nixon, 2009;Devlin et al, 2011;Ferreira et al, 2011;Große et al, 2016;Desmit et al, 2018).…”

“…Furthermore, chlorophyll concentrations, as a proxy for phytoplankton biomass, can be determined with high confidence by combining field measurements with satellite, numerical models and autonomous measurements such as ferry-box data (Petersen et al, 2008;Kratzer et al, 2011;Karlsson et al, 2016;Bean et al, 2017). Undesirable disturbance from eutrophication also includes depletion of oxygen caused by decomposition of accumulated organic material produced by phytoplankton during their growing seasons (Devlin and Brodie, 2023). Oxygen concentrations are typically determined by collecting samples at depth and subsequent laboratory analysis by Winkler method (Greenwood et al, 2010), though autonomous measurements can also be taken via well-calibrated oxygen optodes.…”

Advances in the Applications of Clinoptilolite-Rich Tuffs

“…But phosphate and nitrate ions are also contaminants. The primary cause of eutrophication in lakes, reservoirs, and rivers is an overabundance of these anions [ 66 , 67 , 68 ]. Globally, elevated concentrations of these ions during the last ten years have sparked grave worries.…”

“…The negatively charged zeolite lattice reduces phosphate and nitrate adsorption efficiency by clinoptilolite; therefore, zeolite surface modification, such as coating with cationic surfactants [ 68 , 69 , 70 , 71 ], is applied to enable zeolite removal efficiency. Recent research, however, highlights the toxicity of cationic surfactants and advises using them with care [ 72 , 73 ].…”