Microbiological and chemical enrichment of freshwater-surface microlayers relative to the bulk-subsurface water

1974 ◽  
Vol 20 (7) ◽  
pp. 1051-1057 ◽  
Author(s):  
Roger F. Hatcher ◽  
Bruce C. Parker

Concentrations of bacteria, fungi, ammonium, nitrate, nitrite, orthophosphate, sulfate, and certain metals were enriched in freshwater-surface microlayer samples relative to the bulk-subsurface water. Results differed markedly depending on which of three methods for surface-microlayer collection was used. This report suggests that the biologically and chemically rich freshwater-surface microlayers contribute to ecological functions and interactions between subsurface water and the atmosphere not heretofore investigated in freshwater.

2021 ◽  
Vol 203 (9) ◽  
pp. 5547-5559
Author(s):  
Piotr Perliński ◽  
Zbigniew J. Mudryk ◽  
Marta Zdanowicz ◽  
Łukasz Kubera

AbstractThe aim of this paper was to determine the abundance and secondary production by bacteria inhabiting the surface microlayer and subsurface water in a specific water basin, i.e., polluted estuarine harbour channel. In a 3-year seasonal cycle, the total number of bacteria and their biomass were higher in the surface microlayer (SML) 7.57 × 108cells dm−3 and 15.86 µg C dm−3 than in the subsurface water (SSW) 4.25 × 108cells dm−3 and 9.11 µg C dm−3 of the studied channel. The opposite relationship was noted in the level of the secondary production (SML—37.16 μg C dm−3 h−1, SSW—60.26 μg C dm−3 h−1) in this water basin. According to the analysed microbiological parameters, the total number of bacteria and secondary production varied along the horizontal profile in the water of the studied channel. The total number of bacteria and their secondary production showed the seasonal variation as well.


2014 ◽  
Vol 24 (3) ◽  
pp. 475-491 ◽  
Author(s):  
Qing Liu ◽  
Xiaojuan Hu ◽  
Jiangluan Jiang ◽  
Junyi Zhang ◽  
Zhihui Wu ◽  
...  

1988 ◽  
Vol 23 (2) ◽  
pp. 292-300 ◽  
Author(s):  
R. James Maguire ◽  
Richard J. Tkacz

Abstract The surface microlayer of the Niagara River at Niagara-on-the-Lake was sampled 34 times in 1985-86, and was shown to contain PCBs, chlorobenzenes and chlorinated hydrocarbons at concentrations generally up to 40 times greater than concentrations 1n subsurface water. Organisms which spend part or all of their lives at the air-water interface are thus likely to be at increased risk relative to subsurface water exposure. A small “spill” of PCBs 1n the river on July 29, 1986 was only detected in the surface micro-layer, and not in subsurface water. On this date, concentrations of PCBs in the surface microlayer were up to 6,400 times larger than concentrations in the subsurface water, and 1t appeared that the “spill” was downstream of Niagara Falls and the Whirlpool. Despite such high concentrations of chlorinated hydrocarbons in the surface microlayer, at no time during this study did the microlayer contribute significantly, relative to subsurface water, to the loading (i.e., amounts) of these chemicals from the Niagara River to Lake Ontario.


2017 ◽  
Vol 66 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Iwona Kostrzewska-Szlakowska ◽  
Bartosz Kiersztyn

Nutrient and organic matter concentration, microbial biomass and activities were studied at the surface microlayers (SML) and subsurface waters (SSW) in two small forest lakes of different water colour. The SML in polyhumic lake is more enriched with dissolved inorganic nitrogen (0.141 mg l–1) than that of oligohumic lake (0.124 mg l–1), the former also contains higher levels of total nitrogen (2.66 mg l–1). Higher activities of lipase (Vmax 2290 nmol l–1 h–1 in oligo- and 6098 in polyhumic) and glucosidase (Vmax 41 nmol l–1 h–1 in oligo- and 49 in polyhumic) were in the SMLs in both lakes. Phosphatase activity was higher in the oligohumic SML than in SSW (Vmax 632 vs. 339 nmol l–1 h–1) while in polyhumic lake was higher in SSW (Vmax 2258 nmol l–1 h–1 vs. 1908 nmol l–1 h–1). Aminopeptidase activity in the SSW in both lakes was higher than in SMLs (Vmax 2117 in oligo- and 1213 nmol l–1 h–1 in polyhumic). It seems that solar radiation does inhibit neuston microbial community as a whole because secondary production and the share of active bacteria in total bacteria number were higher in SSW. However, in the oligohumic lake the abundance of bacteria in the SML was always higher than in the SSW (4.07 vs. 2.69 × 106 cells ml–1) while in the polyhumic lake was roughly equal (4.48 vs. 4.33 × 106 cells ml–1) in both layers. Results may also suggest that surface communities are not supplemented by immigration from bulk communities. The SML of humic lakes may act as important sinks for allochthonous nutrient resources and may then generate considerable energy pools for microbial food webs.


2018 ◽  
Vol 25 (27) ◽  
pp. 27074-27089 ◽  
Author(s):  
Suhana Shaharom ◽  
Mohd Talib Latif ◽  
Md Firoz Khan ◽  
Siti Norbalqis Mohd Yusof ◽  
Nor Azura Sulong ◽  
...  

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