Nitrogen metabolism in the brackish Lake Nakanoumi. IV. Seasonal variation of nitrate nitrogen.

Seike, Yasushi; Kondo, Kunio; Hashitani, Hiroshi; Okumura, Minoru; Fujinaga, Kaoru; Date, Yuko

doi:10.3739/rikusui.51.137

Cited by 25 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The most important source of ammonia is the ammonification of organic matter, so, occurrence of ammonia in the waters used as an indicator for organic pollution. 40 In the present study ammonia range at S2 and S3 were 7.5 and 8.6 mg L -1 during winter ( Figure 4), exhibited a highly significant increase (P≤0.01), at both sites, compared to that in S1. This may be related to the large impact of the domestic discharge from El-Rahawy drain, which is highly loaded with organic matter and bacteria, leading to decomposition of the organic matter, exhausting dissolved oxygen and produce high level of ammonia, 37 and the industrial effluents of Kafr El-Zayat factories discharged into the branch water.…”

mentioning

confidence: 85%

“…39 Nitrate (NO3 -) is the final oxidation product of nitrogen compounds in the aquatic environment, at the same time nitrate is considered as the only thermodynamically stable form of nitrogen in the absence of oxygen and also, in the major nitrogenous compound in the aquatic environment. 40 In the present study nitrite and nitrate peaks were 0.188 and 0.669 mg L -1 , recorded at S3 during winter (Figure 4). Nitrate concentrations were found to be higher than nitrite at all stations due to the fact that NO3 -is the final stable form of nitrogen.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Physico-Chemical Characteristics and Physiological Changes in Oreochromis Niloticus From Rosetta Branch of the River Nile

Salaah¹,

Khalil²,

Gad³

et al. 2018

ECB

View full text Add to dashboard Cite

The River Nile is the essence of life in Egypt, but during the last decades its water quality has been changed by several factors, as a result of anthropogenic activities. The western branch of the River Nile is Rosetta Branch receives different types of pollution. The main origins of most pollutants are El-Rahawy drain and industrial activities in Kafr El-Zayat city. Water samples were analysed for physico-chemical parameters and blood samples for biochemical parameters of the Nile Tilapia; Oreochromis niloticus, to investigate the responses of fish towards these different types of pollution. Samples were collected from three sites from Rosetta branch of the River Nile during summer 2014 and winter 2015. S2 and S3 recorded an increase in water electrical conductivity (EC), total dissolved solids (TDS), biological oxygen demand (BOD) and chemical oxygen demand (COD), while dissolved oxygen (DO) and pH have been depleted. Nitrite, nitrates and ammonia levels also showed an elevation, especially in winter. Moreover, fundamental biochemical parameters such as; glucose, total protein, total lipid, albumin, cholesterol, triglycerides, kidney functions and liver functions in blood serum of O. niloticus recorded remarkable alterations, indicating stressful conditions, caused by the profound pollutants and poor water quality of water at these sites.

show abstract

mentioning

confidence: 85%

mentioning

confidence: 99%

Physico-Chemical Characteristics and Physiological Changes in Oreochromis Niloticus From Rosetta Branch of the River Nile

Salaah¹,

Khalil²,

Gad³

et al. 2018

ECB

View full text Add to dashboard Cite

show abstract

“…4c). The reason is that NO 3 Ϫ -N is discharged from a river into the lake through rainfall and melted snow during April and November-December, and the rates of uptake of NO 3 Ϫ -N by the natural phytoplankton in these months decrease, because phytoplankton activity is diminished by lower temperatures and shorter days (Seike et al 1990). …”

Section: Chemical Characteristics Of Water Qualitymentioning

confidence: 98%

Characteristics of fluctuations in salinity and water quality in brackish Lake Obuchi

et al. 2000

View full text Add to dashboard Cite

Fluctuations in the salinity and physicochemical characteristics of water quality were surveyed in brackish Lake Obuchi on the Shimokita Peninsula in Aomori, Japan. The mean salinity in the surface layer in all regions of Lake Obuchi was about 10 psu, whereas in the basin region at depths of greater than 3 m it was 20 psu. Furthermore, all the year round the halocline was formed at depths of 1-4 m. The maximum density gradient along a vertical axis in the center of the lake was observed at depths of 1-2 m in summer and 2-4 m in spring and fall. The depth of the maximum density gradient fluctuated with the seasons. In summer the water in the bottom layer was anoxic, and Fe, Mn, PO 4 3Ϫ -P, and NH 4 ϩ -N supplied from the bottom sediment accumulated at high concentrations below the halocline. Thus, it was observed that the transfer of substances between the layers above and below the barrier formed by the halocline is suppressed. Although Lake Obuchi is small and shallow, the inflowing seawater easily resides, and a stable halocline readily forms because of the shape of its basin, which suddenly deepens on the Pacific Ocean side.

show abstract

“…The present study would indicate that the smaller phytoplankton in brackish Lake Nakaumi would be of competitive advantage to decompose urea over the larger phytoplankton. Lake Nakaumi has a complicated ecosystem, due to the influences of a large freshwater body from Lake Shinji and a seawater mass from the Japan Sea (Ohtake et al 1982(Ohtake et al , 1984Kondo et al 1990aKondo et al , 1990bSeike et al 1990). To elucidate the influence of cell size on the urea decomposing activity in Lake Nakaumi, further investigations of several…”

Section: Figmentioning

confidence: 99%

Urea decomposing activity of fractionated brackish phytoplankton in Lake Nakaumi

et al. 2000

View full text Add to dashboard Cite

The influence of brackish phytoplankton cell classes upon the response of urea decomposition was investigated in Lake Nakaumi. The urea decomposition rate was 5 to 350 µmol urea m Ϫ3 h Ϫ1 in the light and 3 to 137 µmol urea m Ϫ3 h Ϫ1 in the dark. The urea decomposition rates in the light were obviously higher than in the dark. An extremely high rate (350 µmol urea m Ϫ3 h Ϫ1 ) was observed in Yonago Bay. The rate in the smaller fraction (Ͻ5 µm) exceeded that in the middle (5-25 µm) and larger fractions (Ͼ25 µm). The chlorophyll-and photosynthesis-specific rates for urea decomposition in the light were 0.5 to 3.9 µmol urea mg chl.a Ϫ1 h Ϫ1 and 0.3 to 1.3 µmol urea mg photo.C Ϫ1 . The specific urea decomposing activities were higher in the smaller fraction than in the other two fractions. The present results suggest that in brackish waters urea decomposition occurred with coupling to the standing crop and photosynthetic activity of phytoplankton.

show abstract

Nitrogen metabolism in the brackish Lake Nakanoumi. IV. Seasonal variation of nitrate nitrogen.

Cited by 25 publications

References 17 publications

Physico-Chemical Characteristics and Physiological Changes in Oreochromis Niloticus From Rosetta Branch of the River Nile

Physico-Chemical Characteristics and Physiological Changes in Oreochromis Niloticus From Rosetta Branch of the River Nile

Characteristics of fluctuations in salinity and water quality in brackish Lake Obuchi

Urea decomposing activity of fractionated brackish phytoplankton in Lake Nakaumi

Contact Info

Product

Resources

About