scholarly journals Influence of Salinity Gradient Changes on Phytoplankton Growth Caused by Sluice Construction in Yongjiang River Estuary Area

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2492
Author(s):  
Menglin Yuan ◽  
Cuiling Jiang ◽  
Xi Weng ◽  
Manxue Zhang
Keyword(s):  
Quantitative Research ◽  
Salinity Gradient ◽  
Water Discharge ◽  
Gaussian Model ◽  
River Estuary ◽  
Sharp Decrease ◽  
Phytoplankton Growth ◽  
Salinity Field ◽  
Salinity Changes ◽  
Ecological Threshold

Though the number of sluices and dams in coastal areas has increased rapidly in recent years, the influence of their construction on phytoplankton in estuary areas is hardly known. This paper aims to provide a reference for quantitative research on the ecological influence of sluice construction and give ecological justifications for the setting of environmental standards in the estuary areas. The survey data gained at the lower reach of the Yongjiang River and its estuarine areas in June 2015 were used in MIKE21 software (Danish Hydraulic Institute (DHI), Denmark)) for establishing a two-dimensional numerical model to simulate the salinity field distribution after sluice construction. Based on the simulation results, the salinity gradient changes caused by the construction were analyzed. The one-dimensional Gaussian model was applied to calculated the phytoplankton’s ecological threshold interval over the salinity changes, which helped predict the influence of salinity changes on phytoplankton cell density. The study shows that salinity in the Yongjiang estuary increases obviously, beyond the phytoplankton ecological threshold, after sluice construction without water discharge. Salinity will become a restriction factor to phytoplankton growth after sluice construction in the study area, which may cause a sharp decrease of certain phytoplankton species.

scholarly journals Shifts of Bacterioplankton Metabolic Profiles along the Salinity Gradient in a Subtropical Estuary

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Hidetoshi Urakawa ◽  
Jaffar Ali ◽  
Rheannon D. J. Ketover ◽  
Spencer D. Talmage ◽  
Juan C. Garcia ◽  
...  
Keyword(s):  
Salinity Gradient ◽  
Water Discharge ◽  
River Estuary ◽  
Metabolic Profiles ◽  
Wet Season ◽  
Biolog Ecoplates ◽  
Utilization Patterns ◽  
Subtropical Estuary ◽  
Discharge Patterns ◽  
Bacterioplankton Communities

Understanding the biodegradation potential of river bacterioplankton communities is crucial for watershed management. We investigated the shifts in bacterioplankton metabolic profiles along the salinity gradient of the Caloosahatchee River Estuary, Florida. The carbon source utilization patterns of river bacterioplankton communities were determined by using Biolog EcoPlates. The number of utilized substrates was generally high in the upstream freshwater dominated zone and low in the downstream zone, suggesting a shift in metabolic profiles among bacterioplankton assemblages along the estuarine gradient. The prokaryotic cell numbers also decreased along the estuarine salinity gradient. Seasonal and site-specific differences were found in the numbers of utilized substrates, which were similar in summer and fall (wet season) and winter and spring (dry season). Bacterioplankton assemblages in summer and fall showed more versatile substrate utilization patterns than those of winter and spring communities. Therefore, our data suggest that microbial metabolic patterns in the subtropical estuary are likely influenced by the water discharge patterns created by dry and wet seasons along the salinity gradient.

Seasonal salinity changes in the Fraser River Estuary

1976 ◽  
Vol 3 (2) ◽  
pp. 342-348 ◽  
Author(s):  
Peter R. B. Ward
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Water Discharge ◽  
River Estuary ◽  
Surface Flow ◽  
Velocity Shear ◽  
Fraser River ◽  
Salinity Changes ◽  
Fresh Water Discharge ◽  
Fresh Surface

The Fraser Estuary in British Columbia is characterized by a salt water wedge, which underlies the fresh surface water. The stage of the tide and the fresh water discharge in the Fraser River are the two primary factors influencing the maximum intrusion of the salt water wedge.A systematic set of measurements are presented, documenting the change in the position of the tip of the salt water wedge as a function of fresh water discharge. Tidal conditions did not affect the measurements, since all measurements were made at times when the stage of the tide was the same. The tip of the salt water wedge is shown to be displaced a distance of 22 km (13.8 mi) seawards, as the fresh water discharge increased from 850 to 9000 m3/s (30 000 to 317 000 ft3/s).Vigorous surface to bottom mixing was observed during large ebb flows. The mixing was sufficiently strong to break up the wedge over a large part of the estuary. A calculation is presented showing that this was due to the existence of a strong velocity shear between the saline bottom water and the fresh water surface flow.

Simulation of Salinity Changes Induced by Man-Made Sea Embankment

2014 ◽  
Vol 989-994 ◽  
pp. 1244-1247
Author(s):  
Ting Xu
Keyword(s):  
Large Scale ◽  
Flow Direction ◽  
Salinity Gradient ◽  
River Estuary ◽  
Water Security ◽  
Salinity Changes ◽  
The North ◽  
Wenzhou Shoal ◽  
Salinity Difference ◽  
Sea Area

Understanding the salinity transport mechanism in the estuaries is of great importance for coastal engineering, disaster prevention, water security and intertidal zone aquiculture.In this paper,the large-scale sea embankment in the Oujiang River Estuary (ORE) of Wenzhou shoal was taken as an example.Based on the intoduction of the study area,the 3D marine numerical model (EFDC) was setup and used for simulation of salinity changes induced by the embankment. The results indicated that the ORE is well-mixed estuary. The Ling-Ni Embankment designed in accordance with the flow direction makes the freshwater inflow reach far away, the salinity gradient increase, and the tongue contour reach further. The salinity difference of the north and south side of the embankment sea area is increased.

scholarly journals Salinity and freshwater discharge determine rotifer distribution at the Mossoró River Estuary (Semiarid Region of Brazil)

2010 ◽  
Vol 70 (3) ◽  
pp. 551-557 ◽  
Author(s):  
AMA. Medeiros ◽  
JEL. Barbosa ◽  
PR. Medeiros ◽  
RM. Rocha ◽  
LF. Silva
Keyword(s):  
Species Richness ◽  
Rainy Season ◽  
Salinity Gradient ◽  
River Estuary ◽  
Positive Influence ◽  
Freshwater Discharge ◽  
The Other ◽  
Semiarid Region ◽  
Inverse Estuary ◽  
Species Richness And Abundance

The present study aimed at evaluating differences in rotifer distribution in three estuarine zones in an inverse estuary located in the Semiarid Region of Brazil. Zones were chosen based on their proximity to the ocean and river border as a means of reflecting a horizontal salinity gradient. High freshwater discharge during the rainy season was the major determinant of rotifer composition. On the other hand, due to higher salinity values during the dry season, very low values of species richness and abundance were observed in all zones. Therefore, the study highlights the constraints of salinity and the positive influence of seasonality and river proximity on rotifer species in a semiarid estuarine environment.

Study on High Efficiency Technology of Industrial Circulating Water in Yellow River Estuary Area

2015 ◽  
Vol 737 ◽  
pp. 719-722
Author(s):  
Xiao Feng Yang ◽  
Bao Xiang Zhang ◽  
Yu Zhi Shi ◽  
Ming Yuan Fan ◽  
Hai Jiao Liu
Keyword(s):  
Water Resources ◽  
Brackish Water ◽  
High Efficiency ◽  
Yellow River ◽  
Supply And Demand ◽  
Water Discharge ◽  
River Estuary ◽  
Yellow River Estuary ◽  
Recycled Water ◽  
Circulating Water

Most of the water in yellow river estuary mixed with irrigation and leaching water, saline and brackish water, recycled water discharge into the sea without reuse except part for agriculture irrigation and aquaculture, a small part for recycling. In order to improve the efficiency and benefits of water resources utilization, this paper proposes a new way to study industrial water recycling method of the mixed water including irrigation and leaching water, saline and brackish water, recycled water. The research could have an important realistic significance to ease the contradiction between supply and demand of water resources, reduce reliance on the Yellow River and improve regional eco-environment.

scholarly journals Implications of Nutrient Enrichment and Related Environmental Impacts in the Pearl River Estuary, China: Characterizing the Seasonal Influence of Riverine Input

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3245
Author(s):  
Lixia Niu ◽  
Pieter van Gelder ◽  
Xiangxin Luo ◽  
Huayang Cai ◽  
Tao Zhang ◽  
...  
Keyword(s):  
Nutrient Enrichment ◽  
River Discharge ◽  
Nutrient Dynamics ◽  
Southern China ◽  
Salinity Gradient ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
The Pearl River Estuary ◽  
The Pearl River

The Pearl River estuary is an ecologically dynamic region located in southern China that experiences strong gradients in its biogeochemical properties. This study examined the seasonality of nutrient dynamics, identified related environmental responses, and evaluated how river discharge regulated nutrient sink and source. The field investigation showed significant differences of dissolved nutrients with seasons and three zones of the estuary regarding the estuarine characteristics. Spatially, nutrients exhibited a clear decreasing trend along the salinity gradient; temporally, their levels were obviously higher in summer than other seasons. The aquatic environment was overall eutrophic, as a result of increased fluxes of nitrogen and silicate. This estuary was thus highly sensitive to nutrient enrichment and related pollution of eutrophication. River discharge, oceanic current, and atmospheric deposition distinctly influenced the nutrient status. These factors accordingly may influence phytoplankton that are of importance in coastal ecosystems. Phytoplankton (in terms of chlorophyll) was potentially phosphate limited, which then more frequently resulted in nutrient pollution and blooms. Additionally, the nutrient sources were implied according to the cause–effect chains between nutrients, hydrology, and chlorophyll, identified by the PCA-generated quantification. Nitrogen was constrained by marine-riverine waters and their mutual increase-decline trend, and a new source was supplemented along the transport from river to sea, while a different source of terrestrial emission from coastal cities contributed to phosphate greatly.

Denitrification rates measured along a salinity gradient in the eutrophic Neuse River estuary, North Carolina, USA

Estuaries ◽  
2005 ◽  
Vol 28 (4) ◽  
pp. 608-619 ◽  
Author(s):  
John M. Fear ◽  
Suzanne P. Thompson ◽  
Thomas E. Gallo ◽  
Hans W. Paerl
Keyword(s):  
North Carolina ◽  
Salinity Gradient ◽  
River Estuary ◽  
Neuse River Estuary ◽  
Neuse River

Distribution of wood-boring bivalves in the Mamanguape River estuary, Paraíba, Brazil

2002 ◽  
Vol 82 (6) ◽  
pp. 1039-1040 ◽  
Author(s):  
Rosa Maria Veiga Leonel ◽  
Sonia Godoy B.C. Lopes ◽  
Marcos Aversari
Keyword(s):  
Salinity Gradient ◽  
River Estuary ◽  
North East ◽  
Mangrove Tree ◽  
Wood Panels ◽  
One Year ◽  
First Time ◽  
Wood Boring

Wood-boring bivalves of the families Teredinidae and Pholadidae are reported for the first time in Paraíba State, north-east Brazil. During one year, molluscs were collected from mangrove tree logs and from wood panels, along a salinity gradient. Four teredinid (Neoteredo reynei, Teredo bartschi, Nausitora fusticula, Bankia fimbriatula) and one pholad species (Martesia striata) were found.

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