Fig 1 - uploaded by Dale Robertson
Content may be subject to copyright.
Salton Sea, California, with major tributaries and U.S. Geological Survey gaging stations identified
Source publication
Salton Sea, California, like many other lakes, has become eutrophic because of excessive nutrient loading, primarily phosphorus
(P). A Total Maximum Daily Load (TMDL) is being prepared for P to reduce the input of P to the Sea. In order to better understand
how P-load reductions should affect the average annual water quality of this terminal saline...
Similar publications
EM38 device of electromagnetic induction technique was utilized for soil salinity assessment in Akarsu and Yemisli irrigation districts having different quality and quantity irrigation sources. Calibration equations of EM38 readings (ECa) versus standard soil salinity (ECe) for the districts were found statistically representative. Salinity increas...
Citations
... The Salton Sea has faced and continues to face many of the problems typical of a terminal lake: large fluctuations in water level (Schroeder et al., 2002), increased salinity (Schroeder et al., 2002), and increased concentrations of other constituents, such as nutrients (Holdren and Montaño, 2002). The Salton Sea is presently eutrophic to hypereutrophic (Robertson and Schladow, 2008) and is suffering marked degradation as a consequence of human activity. Although efforts to rehabilitate the Salton Sea ecosystem have been underway for more than a decade, that goal has not been achieved. ...
The Colorado River Quantification Settlement Agreement (QSA) of 2003 gives urgency for studying the environmental consequences of the cessation of mitigation water transfers to the Salton Sea. The Salton Sea Stochastic Simulation Model (S⁴M) is a spatially-driven, stochastic, simulation model representing water flow, i.e., water volume and quantity of Total Dissolved Solids and Phosphorus, in the Lower Colorado River Basin, Mexicali Valley, and the Salton Sea Basin. The S⁴M is formulated as a compartment model based on difference equations with a daily time step using STELLA® v8.0. The model was developed, evaluated, and applied to simulate the potential effects on the population dynamics, i.e., natality, mortality, emigration, and immigration, of selected fish and avian species at the Salton Sea under two different scenarios: 1) QSA water transfers to Sea end after 2017 and 2) QSA water transfers continue at 2017 levels. Oneway ANOVAs were performed for the water quantity, water quality, and selected variables involving the fish and bird population dynamics under the two water transfer scenarios. Results indicate that if cessation of the QSA water transfers after 2017 occurs, then fish and bird populations will be significantly (P < 0.05) and negatively impacted by year 2024, compared to continuing the QSA water transfers. Further, if no restoration action is taken in stabilizing the Sea elevation and reducing salinity but continuing QSA water transfers (at 2017 levels), i.e., scenario 2; results indicate that Salton Sea avian and fish population dynamics will be negatively impacted, although somewhat delayed.
... Vera Istva´novicset al.developeda program that complemented lake-specific ecological criteria within the range existing and concluded that the simple objectivesare the good choice in the initial stages of eutrophication management [2]. Dale M.et al. applied eutrophication programs to three different application, includingthe Seepage Lake, BATHTUB, and WiLMSModel to verify specific empirical models Model [3]. Simulation results show that the reduction of external P load would reduce near-surface TP. ...
... Most empirical models that predict phosphorus concentrations are very sensitive to the residence time of water in the lake, and they are not capable of accurately simulating water quality in closed-basin seepage lakes-lakes without continuous outlets and, therefore, with very long residence times. One empirical model that has been shown by Robertson and Schladow (2008) to be relatively insensitive to residence time is the Canfield and Bachmann (1981) natural-lake model. This model has also been shown to be one of the best empirical models for predicting the phosphorus concentrations of lakes in Wisconsin (Robertson and others, 2002;Robertson and Rose, 2008). ...
... Most empirical models that predict phosphorus concentrations are very sensitive to the residence time of water in the lake, and they are not capable of simulating water quality in closed-basin, terminal lakes-lakes without continuous outlets and therefore with relatively long residence times. One empirical model that has been shown by Robertson and Schladow (2008) to be relatively insensitive to residence time is the Canfield and Bachman (1981) naturallake model. This model has also been shown to be one of the best empirical models for predicting the phosphorus concentrations of lakes in Wisconsin others, 2002, 2005;Robertson and Rose, 2008). ...
... A detailed study of the water quality of the Salton Sea and its tributaries was conducted in 1999 by the U.S. Department of Interior's Bureau of Reclamation (USBR; Holdren & Montaño, 2002). Based on the observed nitrogen-to-phosphorus ratios that ranged from 25:1 to 400:1 and dissolved nutrient concentrations , it can be concluded that phosphorus is the algal growth-limiting nutrient (Holdren & Montaño, 2002; Robertson et al., 2008). Furthermore, the majority of the external phosphorus to the system (*1,450,000 kg yr -1 ) comes from the three main inflows, the New ...
... River (*51%), the Alamo River (*38%), and the Whitewater River (*4%) (Robertson et al., 2008 ...
... Mass flux of phosphorus from stream inflows to the Salton Sea (based on data from Robertson et al. (2008) compared to the inferred phosphorus flux required to account for measured changes in volume averaged Sea concentrations, based on data from Holdren & Montaño (2002) ...
A linked hydrodynamic and water quality model was developed and applied to the Salton Sea. The hydrodynamic component is based
on the one-dimensional numerical model, DLM. The water quality model is based on a new conceptual model for nutrient cycling
in the Sea, and simulates temperature, total suspended sediment concentration, nutrient concentrations, including PO4−3, NO3−1 and NH4+1, DO concentration and chlorophyll a concentration as functions of depth and time. Existing water temperature data from 1997 were used to verify that the model
could accurately represent the onset and breakup of thermal stratification. 1999 is the only year with a near-complete dataset
for water quality variables for the Salton Sea. The linked hydrodynamic and water quality model was run for 1999, and by adjustment
of rate coefficients and other water quality parameters, a good match with the data was obtained. In this article, the model
is fully described and the model results for reductions in external phosphorus load on chlorophyll a distribution are presented.
To determine how climate-induced changes in hydrology and water level may affect the trophic state (productivity) of stratified lakes, two relatively pristine dimictic temperate lakes in Wisconsin, USA, were examined. Both are closed-basin lakes that experience changes in water level and degradation in water quality during periods of high water. One, a seepage lake with no inlets or outlets, has a small drainage basin and hydrology dominated by precipitation and groundwater exchange causing small changes in water and phosphorus (P) loading, which resulted in small changes in water level, P concentrations, and productivity. The other, a terminal lake with inlets but no outlets, has a large drainage basin and hydrology dominated by runoff causing large changes in water and P loading, which resulted in large changes in water level, P concentrations, and productivity. Eutrophication models accurately predicted the effects of changes in hydrology, P loading, and water level on their trophic state. If climate changes, larger changes in hydrology and water levels than previously observed could occur. If this causes increased water and P loading, stratified (dimictic and monomictic) lakes are expected to experience higher water levels and become more eutrophic, especially those with large developed drainage basins.
Our objective was to evaluate changes in water quality parameters during 1983-2007 in a subtropical drinking water reservoir (area: 7 km(2)) located in Lake Manatee Watershed (area: 338 km(2)) in Florida, USA. Most water quality parameters (color, turbidity, Secchi depth, pH, EC, dissolved oxygen, total alkalinity, cations, anions, and lead) were below the Florida potable water standards. Concentrations of copper exceeded the potable water standard of <30 μg l(-1) in about half of the samples. About 75 % of total N in lake was organic N (0.93 mg l(-1)) with the remainder (25 %) as inorganic N (NH(3)-N: 0.19, NO(3)-N: 0.17 mg l(-1)), while 86 % of total P was orthophosphate. Mean total N/P was <6:1 indicating N limitation in the lake. Mean monthly concentration of chlorophyll-a was much lower than the EPA water quality threshold of 20 μg l(-1). Concentrations of total N showed significant increase from 1983 to 1994 and a decrease from 1997 to 2007. Total P showed significant increase during 1983-2007. Mean concentrations of total N (n = 215; 1.24 mg l(-1)) were lower, and total P (n = 286; 0.26 mg l(-1)) was much higher than the EPA numeric criteria of 1.27 mg total N l(-1) and 0.05 mg total P l(-1) for Florida's colored lakes, respectively. Seasonal trends were observed for many water quality parameters where concentrations were typically elevated during wet months (June-September). Results suggest that reducing transport of organic N may be one potential option to protect water quality in this drinking water reservoir.
The Salton Sea (Sea) is a eutrophic to hypereutrophic lake characterized by high nutrient concentrations, low water clarity,
and high biological productivity. Based on dissolved phosphorus (P) and nitrogen (N) concentrations and N:P ratios, P is typically
the limiting nutrient in the Sea and, therefore, should be the primary nutrient of concern when considering management efforts.
Flows in the major tributaries to the Sea have been measured since 1965, whereas total P (TP) concentrations were only measured
intermittently by various agencies since 1968. These data were used to estimate annual P loading from 1965 to 2002. Annual
loads have increased steadily from ∼940,000 kg around 1968 to ∼1,450,000 kg in 2002 (∼55% increase), primarily a result of
increased TP concentrations and loads in the New River. Although the eutrophic condition of the Salton Sea is of great concern,
only limited nutrient data are available for the Sea. It is difficult to determine whether the eutrophic state of the Sea
has degraded or possibly even improved slightly in response to the change in P loading because of variability in the data
and changes in the sampling and analytical methodologies.
