Susceptibility of U.S. Estuaries to Pollution

1988 ◽  
Vol 20 (6-7) ◽  
pp. 211-219
Author(s):  
E. L. Beasley ◽  
M. A. Hiller ◽  
R. B. Biggs

Utilizing data primarily from the U.S. Department of Commerce, both estuaries and watersheds for 78 U.S. systems are analyzed. Watersheds are classified according to total population and discrete subpopulations. The Vollenweider approach, which compares hydraulic loading to nutrient loading of lakes, is adapted to estuaries. By considering total population as a surrogate of point source nutrients, agricultural workers as a surrogate of non-point source toxics and nutrients and chemical + metal workers as a surrogate of point source toxics, we can estimate potential anthropogenic impacts on watersheds. When these surrogates are plotted against hydraulic loading, managers have a tool to identify estuaries most likely to be under greatest anthropogenic presaure. The estuaries with highest susceptibility from total population, as well as the estuaries with the the highest susceptibility to toxic stress, are identified. On a Vollenweider diagram, the phosphorous loadings of freshwater bodies are plotted as a function of hydraulic loading. The permissible-excessive phosphorous loadings have been both theoretically and empirically determined. We have replotted the freshwater data and added 33 U.S. estuary P loadings that were previously unavailable. Estuaries plot on the Vollenweider diagram as a continuum of fresh waterbodies, both in terms of hydraulic loading and phosphorus loading. Most estuaries appear to have permissible P loadings. Analysis of nutrient loading (normalized to hydraulic loading) versus water quality parameters like chlorophyll a indicates that estuaries are more efficient users of nutrients than are freshwater bodies, and that they reach a “nutrient saturation point”. Perhaps this is due to grazing or turbidity. It appears that, in general, the OECD eutrophication modeling approach is applicable to estuarine systems as well as lakes and impoundments.

1999 ◽  
Vol 39 (12) ◽  
pp. 99-107 ◽  
Author(s):  
Takao Kunimatsu ◽  
Miki Sudo ◽  
Takeshi Kawachi

In the last ten years, the number of golf courses has been increasing in some countries as the game gains popularity. This indicates, a need to estimate the nutrient loading from golf courses in order to prevent the eutrophication of water bodies. Nutrient concentrations and flow rates of a brook were measured once a week from 1989 to 1990 at two sites: Site A of a brook flowing out from D-golf course (53 ha) and Site B of the same brook discharging into the golf course from an upper forested basin (23 ha) covered mainly with planted Japanese cypress (Chamaecyparis obtusa SIEB. et ZUCC). The bedrock of the area was granite. The annual values of precipitation and mean temperature were 1947 mm and 13.5°C in 1989, respectively. The arithmetic average values of discharge from the forested basin and the golf course were 0.392 and 1.26 mg/l total nitrogen (TN), 0.0072 and 0.145 mg/l total phosphorus (TP), 0.82 and 3.53 mg/l potassium ion (K+, 5.92 and 8.24 mg/l sodium ion (Na+), 2.1 and 9.9 mg/l suspending solid (0.001–2.0 mm, SS), 0.087 and 0.147 mS/cm electric conductivity (EC), and 0.031 and 0.037 m3/km2•s specific discharge, respectively. The loading rates of the forested basin and the golf course were 5.42 and 13.5 TN, 0.133 and 3.04 TP, 8.84 and 33.9 K+, 55.0 and 73.0 Na+, and 54.3 and 118 SS in kg/ha•y. The leaching and runoff rate of nitrogen in the chemical fertilizers applied on the golf course was calculated as 32%. These results indicated the importance of controlling the phosphorus loading for the management of golf courses.


2018 ◽  
Vol 35 (4) ◽  
pp. 344-360 ◽  
Author(s):  
Rachna Singh ◽  
Jitendra Pandey

2010 ◽  
Vol 28 (4) ◽  
pp. 209-217 ◽  
Author(s):  
Sarah A. White ◽  
Milton D. Taylor ◽  
Stewart L. Chandler ◽  
Ted Whitwell ◽  
Stephen J. Klaine

Abstract Agricultural operations face increasing pressure to remediate runoff to reduce deterioration of surface water quality. Some nursery operations use free water surface constructed wetland systems (CWSs) to remediate nutrient-rich runoff. Our objectives were twofold, first to examine the impact of two hydraulic retention times (HRT, 3.5 and 5.5 day) on CWS performance, and second to determine if increased nutrient loading from internal CWS and nursery sources during the spring contributed to nutrient export in excess of regulatory limits. We quantified nutrient loading and removal efficiency in a free water surface CWS from late winter through late spring over three years and monitored various water quality parameters. Total nitrogen in runoff was reduced from 20.6 ± 2.8 mg·liter−1 (ppm) to 4.1 ± 1.3 mg·liter−1 (ppm) nitrogen after CWS treatment. Phosphorus dynamics in the CWS were more variable and unlike nitrogen dynamics were not consistently influenced by water temperature and hydraulic loading rate. Phosphorus concentrations were reduced from 1.7 ± 0.8 mg·liter−1 (ppm) PO4-P in influent to 1.2 ± 0.6 mg·liter−1 (ppm) PO4-P in CWS effluent, but substantial variability existed among years in both phosphorus loading and removal rates. The CWS was able to efficiently remediate nitrogen even under high spring loading rates.


2018 ◽  
Vol 18 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Sulata Kar ◽  
Papia Das ◽  
Uma Das ◽  
Maibam Bimola ◽  
Devashish Kar ◽  
...  

AbstractThe zooplankton assemblage of selected wetlands of Assam, India was assessed to deduce the structural variation in the context of water quality parameters. A two year study between 2012 and 2014 comprising of 530 samples from the five wetlands revealed the presence of 46 taxa, 26 Rotifera, 15 Cladocera, 4 Copepoda and 1 Ostracoda, in varying density. The rotifers dominated in terms of abundance (48 ind. cm−3) followed by the cladocerans (28 ind. cm−3) and the copepods (19 ind. cm−3) and showed significant (p <0.05) correlations with turbidity, alkalinity, hardness and phosphate contents of the water samples. The diversity and the richness of the zooplankton showed an increasing trend with the water temperature. Among the different taxa, Brachionus sp. was most abundant followed by Mesocyclops sp. while Beauchampiella sp. was represented in the least numbers. Application of the cluster analysis allowed the segregation of the different zooplankton based on the similarities of abundance in the samples. The water quality parameters like temperature, alkalinity, turbidity, magnesium and calcium were observed to be significant contributors in shaping the zooplankton community composition of the wetlands, revealed through the correlations and canonical correspondence analysis. As an extension, the information can be used in monitoring the quality of the freshwater habitats of the concerned and similar geographical regions, using the zooplankton as the major constituents. The variations in the abundance of cladoceran, copepod and rotifer zooplanktons can be used to understand the mechanisms that sustain the food webs of the aquatic community of the freshwater bodies.


<em>Abstract</em>.—A CE-QUAL-W2 water quality model was used to characterize the availability of striped bass <em>Morone saxatilis</em> habitat in Lake Greenwood, South Carolina, during 2004 and 2005. Although the lake has a productive fishery, water quality and aquatic habitat are affected by nutrient loading, algal blooms, and extensive oxygen depletion in the bottom waters. The main objectives were to characterize habitat availability and predict the implications of a change in phosphorus loading from the Saluda and Reedy rivers. The baseline scenario of the model showed that habitat was most critical during July and August, when as little of 5% of the reservoir contained tolerable habitat (temperature <28°C and dissolved oxygen >2 mg/L). Favorable habitat (temperature <25°C and dissolved oxygen >2 mg/L) was usually absent for most of July and August. Pulses of higher inflow or freshets produced short-term increases in tolerable habitat, especially in the upper end of the reservoir. Phosphorus-loading scenarios predicted that large reductions (50% or more) would be required to improve habitat substantially during midsummer. For the manager of a striped bass fishery, water quality models can be useful tools for evaluating habitat, especially under marginal conditions, and for predicting the impact of altered water management practices.


1996 ◽  
Vol 33 (4-5) ◽  
pp. 81-88 ◽  
Author(s):  
B. Kronvang ◽  
P. Græsbøll ◽  
S. E. Larsen ◽  
L. M Svendsen ◽  
H. E. Andersen

Since 1989, nutrient loading of the Danish aquatic environment has been monitored in 270 Danish streams draining catchment areas differing in climate, physico-geographic and land usage. Diffuse nutrient loading from non-point sources (mainly agricultural) is now the main cause of eutrophication of the Danish aquatic environment; thus in 1993, diffuse sources accounted for 94% of riverine nitrogen loading and 52% of riverine phosphorus loading. Annual riverine total nitrogen (total-N) loading from diffuse sources during the period 1989-93 was on average 10 times greater in 66 small agricultural catchments (median 23.4 kg N ha−1) than in 9 natural catchments (median 2.2 kg N ha−1). Correspondingly, annual riverine total phosphorus (total-P) loading from diffuse sources was on average 3.5 times greater in the agricultural catchments (0.29 kg P ha−1) than in the natural catchments (0.07 kg P ha−1). The annual total-N and total-P load was found to increase with the proportion of agricultural land in the catchments. In 1993, intensive measurements of phosphorus load in 8 agricultural catchments showed that normal point sampling (fortnightly) underestimates annual total-P loading by a median of 37% as compared to that estimated by frequent sampling. Moreover, estimates of monthly total-P loading are even more biased, especially in late summer and early autumn (−50% to −65%).


2018 ◽  
Vol 10 (4) ◽  
pp. 893-906 ◽  
Author(s):  
Elena Matta ◽  
Hagen Koch ◽  
Florian Selge ◽  
Max Nino Simshäuser ◽  
Karina Rossiter ◽  
...  

Abstract The hydropower production, water supply and aquaculture services of the Itaparica Reservoir are of immense importance for the Brazilian Northeast. Uncontrolled water resources consumption (e.g. irrigation, water supply), climate and land use change effects deteriorated the water quantity and quality in the reservoir, leading to socio-economic and environmental problems. In this work, a depth-averaged shallow water model was set up for the Icó-Mandantes Bay, one major branch of the reservoir, using the open TELEMAC-MASCARET system. The aim was to assess the impacts of the newly built water diversion channel, as well as the effects of a flood and tracer transport from an intermittent tributary, both located in the bay. An alternative approach to estimate the water retention times was additionally implemented. The simulations showed that though the diversion channel did not significantly influence the hydrodynamics of the bay, it is necessary to continuously monitor water quality parameters in the withdrawal, especially during rainy periods after droughts, because of the nutrient inputs from the tributary and the overflows of the nearby drainage systems. Management measures adapting to the continuously changing natural conditions and anthropogenic impacts are thus indispensable and the model presented can be a valuable supporting tool for this purpose.


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