Numerical modeling of general circulation, thermohaline structure, and residence time in Gorgan Bay, Iran

Ranjbar, Mohammad Hassan; Zaker, Nasser Hadjizadeh

doi:10.1007/s10236-017-1116-6

Cited by 21 publications

(11 citation statements)

References 19 publications

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“…Therefore, this indicates that the chemo-biological properties of seawaters and nutrients are directly controlled by the hydrography of the Gorgan Bay, which water masses circulation has a counterclockwise pattern due to the Coriolis effects. 45,46 Moreover, satellite imagery (2006−2016) also confirmed that land-use change and increased agricultural fields and settlements (up to 59%) happened in the Gorgan Bay watershed, 27 determining the discharge of agricultural waste in the area as probably the main cause of water quality decline. According to our results, the Department of Environment in Iran also reported that the aggregate ecoregions of PO 4 −3 and NO 3 −1 in the bay in 2016 were approximately higher than EPA criteria and the probability of a hypertrophic state was of 65%, raising serious concerns about Gorgan Bay.…”

Section: Resultsmentioning

confidence: 96%

Steroid Fingerprint Analysis of Endangered Caspian Seal (Pusa caspica) through the Gorgan Bay (Caspian Sea)

Jafarabadi

Mashjoor

Dehkordi

et al. 2020

Environ. Sci. Technol.

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The profile of steroid congeners was evaluated in Caspian seals Pusa caspica by age, sex, and tissue-specific bioaccumulation, and compared with that of abiotic matrices (seawater, surface sediment, and suspended particulate materials, SPMs) from Miankaleh Wildlife/Gorgan Bay, (Caspian Sea, Iran). To identify the level of human fecal contamination, ∑25 sterol congeners were measured in all abiotic/biotic samples, revealing coprostanol, a proxy for human feces, as the most abundant sterol (seawater: 45.1–20.3 ng L–1; surface sediment: 90.2–70.3 ng g–1 dw; SPMs: 187.7–157.6 ng g–1 dw). The quantification of ∑25 sterols in seals followed the order of brain > liver > kidney > heart > blood > spleen > muscle > intestine > blubber > fur, and in both sexes coprostanol level (8.95–21.01% of ∑25s) was higher in blubber and fur, followed by cholesterol in brain, liver, kidney, heart, and blood, cholestanone in intestine and muscle, and β-sitosterol in spleen. Though no age/sex differentiation was observed, the mean concentration of ∑25s was higher in male than females and pup. Different diagnostic ratios revealed sterols originating from human and nonhuman sewage sources. Findings pinpoint the urgent necessity to investigate the ecotoxicity of fecal sterols in mammals, and consequent implications for human health.

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Section: Resultsmentioning

confidence: 96%

Steroid Fingerprint Analysis of Endangered Caspian Seal (Pusa caspica) through the Gorgan Bay (Caspian Sea)

Jafarabadi

Mashjoor

Dehkordi

et al. 2020

Environ. Sci. Technol.

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“…Gorgan bay is a shallow water body, which connects to the Caspian Sea via two small mouths. Given the large water residence time of the Gorgan bay (>100 days) (Kheirabadi et al., 2018 ; Modabberi et al., 2020 ; Ranjbar & Hadjizadeh Zaker, 2018 ), the satellite‐based studies were reported the bay region as a hotspot associated with Chl‐ a in the Caspian Sea with a monthly estimated Chl‐ a concentration up to 85 μg/L (Modabberi et al., 2020 ). However, in situ measured Chl‐ a concentrations reveal a large overestimation of the satellite‐based Chl‐ a in this bay.…”

Section: Resultsmentioning

confidence: 99%

Satellite‐Based Monitoring of Eutrophication in the Earth's Largest Transboundary Lake

et al. 2023

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The world's large lakes and their life‐supporting services are rapidly threatened by eutrophication in the warming climate during the Anthropocene. Here, MODIS‐Aqua level 3 chlorophyll‐ a data (2018–2021) were used to monitor trophic state in our planet's largest lake, that is, the Caspian Sea that accounts for approximately 40% of the total lacustrine waters on Earth. We also used the in situ measurements of chlorophyll‐ a data (2009–2019) to further verify the accuracy of the data derived from the MODIS‐Aqua and to explore the deep chlorophyll‐ a maxima (DCMs) in the south Caspian Sea. Our findings show an acceptable agreement between the chlorophyll‐ a data derived from the MODIS‐Aqua and those measured in situ in the coast of Iran (coefficient of determination = 0.71). The oligotrophic, mesotrophic, and eutrophic states cover 66%, 20%, and 13% of the sea surface area, respectively. The DCMs are dominantly regulated by water transparency and they generally observe at depths of less than 20 and 30 m during the cold (autumn and winter) and warm (spring and summer) seasons, respectively. Our results suggest an ever‐increasing chlorophyll‐ a in the shallow zones (i.e., coasts) and even in deep regions of the sea, mainly due to nutrient inputs from the Volga river delta. Alarming increase of chlorophyll‐ a in this transboundary lake can amplify eutrophication under the lens of global warming and further threaten the lake ecosystem's health, where almost all legal agreements have not yet been implemented to protect the lake environment and its rich resources.

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“…Within this context, the evaluation of the local transport time scales is crucial to estimate the channel renewal features. In particular, water residence times influence the water quality and the ecological status of marine coastal systems by controlling the physical, chemical, and biological processes taking place there [16][17][18][19]. They play a significant role in shaping the spatio-temporal distribution of pollutants and nutrients in coastal water bodies, thus influencing both the gross primary production, the trophic web structure and the eutrophication of coastal aquatic environments [20,21].…”

Section: Introductionmentioning

confidence: 99%

Water Circulation and Transport Time Scales in the Beagle Channel, Southernmost Tip of South America

Cucco

Martín

Quattrocchi

et al. 2022

JMSE

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The Beagle Channel is a long and narrow interoceanic passage within the Tierra del Fuego archipelago in the southernmost tip of South America. A high-resolution 3D hydrodynamic model based on the finite elements method was applied to investigate the residual circulation, water fluxes and transport time scales inside this channel. Numerical solutions were analyzed at seasonal time scale and the model results compared with observed ocean data. The circulation pattern is characterized by a west-to-east residual flow with low intensity and low seasonal variability. The water fluxes through the channel were estimated to be, on average, around 12,700 m3/s, with inflow through its western entrance and eastwards outflow mainly through the Mackinlay Strait. The water residence times vary seasonally with basin averages between 36 and 43 days and maximum values between 53 and 95 days. The results provide an overview of the hydrodynamics and water residence times in the Beagle Channel, a unique ecosystem threatened by recent anthropogenic pressures and climate change.

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Numerical modeling of general circulation, thermohaline structure, and residence time in Gorgan Bay, Iran

Cited by 21 publications

References 19 publications

Steroid Fingerprint Analysis of Endangered Caspian Seal (Pusa caspica) through the Gorgan Bay (Caspian Sea)

Steroid Fingerprint Analysis of Endangered Caspian Seal (Pusa caspica) through the Gorgan Bay (Caspian Sea)

Satellite‐Based Monitoring of Eutrophication in the Earth's Largest Transboundary Lake

Water Circulation and Transport Time Scales in the Beagle Channel, Southernmost Tip of South America

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