Intra-annual variability in nutrients in the Godavari estuary, India

Prasad, Vandana; Kumar, Birendra; Rajeev, K.; Devi, B.M.M.; Reddy, N. P. C.; Sarma, V. V. S. S.; Kumar, M. Dileep

doi:10.1016/j.csr.2010.10.001

Cited by 108 publications

(54 citation statements)

References 34 publications

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“…India is ranked second globally in terms of consumption of nitrogen and phosphate as fertilizer (The Fertilizer Association of India, New Delhi) and consumes about 0.025 Tg per year (1 Tg0 10 12 g). On the other hand, seawater dominates during the dry period due to the closing of dam gates and increased seawater intrusion through tides, resulting in a significant decrease in nutrient levels (Sarma et al, 2010). The relationship between river discharge and DIN indicates that higher DIN concentrations were found in the rivers opened to the east coast compared to the west coast except Narmada, Tapti, Sabarmati and Cochin back waters, which are highly polluted due to local industrial activities (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…These estuaries have characteristic runoff periods, mostly from June to September when the Indian subcontinent receives rainfall, when they exhibit non-steady state behaviour (Vijith et al, 2009). Seasonal runoff into these monsoonal estuaries far exceeds their total volume and when discharges are at peak level, the entire estuary turns into a river (Sarma et al, 2009(Sarma et al, , 2010(Sarma et al, , 2011. Discharges of variable magnitudes occur for a period of 4Á6 months, and other periods, the upstream river almost dries up giving place to dominance of seawater in the estuary.…”

Section: Introductionmentioning

confidence: 99%

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Contribution of N<sub>2</sub>O emissions to the atmosphere from Indian monsoonal estuaries

Gijjapu

Sarma

2013

Tellus B: Chemical and Physical Meteorology

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A B S T R A C T Estuaries are known to contribute a significant amount of nitrous oxide (N 2 O) to the atmosphere; however, the contribution from the Indian estuaries is unknown. We made an attempt to estimate emissions of N 2 O from the Indian estuaries by collecting samples from 28 major and minor estuaries along the Indian coast during the wet and dry periods. The N 2 O was mostly saturated in all measured Indian estuaries during the study period (72Á631%), with exceptionally high saturation in the Ponniyaar estuary (5902%) during the wet period. The N 2 O saturation displayed a strong relation with dissolved inorganic nitrogen (DIN; nitrate ' nitrite and ammonium), ammonium and dissolved oxygen saturation, suggesting that nitrification is the major source of N 2 O in the Indian estuaries. The negative relation between salinity and N 2 O saturation suggests inner estuaries are a strong source compared to outer estuaries. The annual mean N 2 O saturation (2049137%) and fluxes (1.3 mmol N 2 O m (2 d (1 ) in the Indian estuaries were significantly less than European estuaries (271% andThe estimation of flux of N 2 O from the European estuaries was also biased due to the inclusion of an exceptionally high supersaturation value from a small UK estuary, Colne (2645%). However, low N 2 O saturation and fluxes in the Indian estuaries were related to mean low concentration of DIN that led to low nitrification rates compared to world estuaries. Despite India ranking second in artificial fertilizers use, high flushing rates during the wet period reduce residence time leading to less modification within the estuary.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Contribution of N<sub>2</sub>O emissions to the atmosphere from Indian monsoonal estuaries

Gijjapu

Sarma

2013

Tellus B: Chemical and Physical Meteorology

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“…In the Cachoeira River estuary, freshwater outflow significantly increased the amount of ammonium, nitrate and silicate, resulting in higher concentrations of these nutrients during the rainy season. The pattern of increasing nutrients during rainy periods observed in the Cachoeira River estuary is also common in other tropical estuarine ecosystems (EYRE; BALLS, 1999;SARMA et al, 2010), including those located in northeastern Brazil (DITTMAR et al, 2001;BASTOS et al, 2011). However, other estuaries in the same region presented higher nutrient concentrations during the dry period (BRANCO et al, 2002;FLORES MONTES et al, 1998;SANTOS et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

SPATIAL AND TEMPORALVARIATION OF DISSOLVED INORGANIC NUTRIENTS, AND CHLOROPHYLL-α IN a TROPICAL ESTUARY IN NORTHEASTERN BRAZIL: DYNAMICS OF NUTRIENT REMOVAL

2015

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Monthly sampling campaigns were carried out between February 2010 and January 2011 to evaluate the spatial and temporal distribution of nutrients (ammonium, nitrite, nitrate, dissolved organic nitrogen, phosphate, dissolved organic phosphorus and silicate) and chlorophyll-a along a salinity gradient in the tropical Cachoeira River estuary, subject to the untreated effluents of a sewage treatment plant (STP). During the study period the lowest and highest river discharge occurred in February and April 2010, respectively. High river outflow promoted increased concentrations of inorganic nitrogen and silicate but did not affect the concentration of phosphate. Based on the chlorophyll-a concentration the estuary may be classified as eutrophic / hypereutrophic in its inner portion and mesotrophic in the lower region. The inner portion is more affected by the nutrient load carried out by the river and STP, while dilution by seawater contributed to the reduction of the nutrient concentrations in the lower reaches of the estuary. The results indicate that nutrient uptake by the phytoplankton is the most effective dissolved inorganic nutrient removal processes, especially for phosphate. Mixing diagrams suggest that the coupling of nitrification and denitrification processes is also responsible for the elimination of nitrogen from this ecosystem. R E S U M OCampanhas de amostragens mensais foram realizadas entre fevereiro de 2010 e janeiro de 2011 para avaliar a distribuição espacial e temporal de nutrientes (amônia, nitrito, nitrato, nitrogênio orgânico dissolvido, fosfato, fósforo orgânico dissolvido e silicato) e clorofila-a, ao longo do gradiente de salinidade no estuário tropical do Rio Cachoeira. Este estuário é sujeito aos efluentes de esgotos não tratados de uma estação de tratamento de esgoto (ETE). No período estudado a maior e menor vazão do rio ocorreram em fevereiro e abril de 2010, respectivamente. A alta vazão do rio promoveu aumento das concentrações de nitrogênio inorgânico e silicato, mas não afetou as concentrações de fosfato. Baseado nas concentrações de clorofila-a, o estuário pode ser classificado como eutrófico/hipereutrófico na porção interna e mesotrófico na região externa. A porção interna é mais afetada pela carga de nutrientes do rio e da ETE, enquanto a diluição pela água marinha contribuiu para diminuir as concentrações de nutrientes na porção externa. Os resultados indicam que a absorção de nutrientes pelo fitoplâncton é o processo mais eficiente na remoção desses nutrientes, especialmente do fosfato. No entanto, os diagramas de mistura sugerem que a nitrificação e denitrificação acopladas no rio também são responsáveis pela eliminação do nitrogênio do ecossistema.

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“…It appears, therefore, that atmospheric condition plays an important role in warming and cooling of the studied area, thus overshadowing the differences brought by the tide (Dehari, 2970;sarma et al, 2010).…”

Section: Temperaturementioning

confidence: 99%

Between River and Sea: What Control a Daily Variation of Physicochemical Properties of Estuary?

Mchenga¹,

Suratman²,

Tahir³

2017

Int.J.Curr.Res.Aca.Rev.

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Article InfoPhysico-chemical features are among important factor that contributes to the variability of the estuarine environment. This study has been conducted to assess diurnal fluctuations of some physicochemical features in relation to tides in the surface water of Terengganu river estuary. The three stations were set al.,ong the area which linked the river to the coastal water where salinity, temperature, dissolved Oxygen, pH, TSS, chlorophyll-a, Phosphate and silicate nutrients were measured at the surface water for every 2 hrs over a period of 12 hrs during spring tide of September 2012. The salinity changes were found to follow the tidal rhythm, while the daily variation of the remaining feature were found to be more pronounced than the tidal induced variation.With exception to salinity, gradual increases in all features were observed during the day tides, which generally, decreased from afternoon and early morning. The effect of tidal amplitude which said to be important in determining the extent of variation was more pronounced at lower estuary. The remaining stations were observed to be strongly influenced by the river flow.

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Intra-annual variability in nutrients in the Godavari estuary, India

Cited by 108 publications

References 34 publications

Contribution of N<sub>2</sub>O emissions to the atmosphere from Indian monsoonal estuaries

Contribution of N<sub>2</sub>O emissions to the atmosphere from Indian monsoonal estuaries

SPATIAL AND TEMPORALVARIATION OF DISSOLVED INORGANIC NUTRIENTS, AND CHLOROPHYLL-α IN a TROPICAL ESTUARY IN NORTHEASTERN BRAZIL: DYNAMICS OF NUTRIENT REMOVAL

Between River and Sea: What Control a Daily Variation of Physicochemical Properties of Estuary?

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