Titre du document / Document title
The effects of riverine discharge on temperature, salinity, suspended sediment and chlorophyll a in a Mississippi delta estuary measured using a flow-through system
Auteur(s) / Author(s)
LANE Robert R. (1) ;
DAY John W. (1) ;
MARX Brian D. (2) ;
REYES Enrique (3) ;
HYFIELD Emily (4) ;
DAY Jason N. (1) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, ETATS-UNIS
(2) Department of Experimental Statistics, Louisiana State University, Baton Rouge, LA 70803, ETATS-UNIS
(3) East Carolina University, Department of Biology, Greenville, NC 27858, ETATS-UNIS
(4) Post, Buckley, Schuh & Jernigan, Inc, Tampa, FL 33607, ETATS-UNIS
Résumé / Abstract
The impact of diverted Mississippi River water on temperature, salinity, total suspended sediment (TSS) and chlorophyll a were monitored in the Breton Sound estuary from September 7, 2000, to August 28, 2002. Twenty-seven transects were carried out using a flow-through system to continuously measure temperature, salinity, turbidity and fluorescence, and discrete water samples were taken at 16 locations for calibration. Discharge from the river diversion structure ranged from 0 to 213 m
3/s, with several large pulses of water released during the spring of 2001 and 2002. There was a strong seasonal temperature signal in the estuary, with summer highs of >30 °C and winter lows of <12 °C. Incoming river water was usually cooler than estuarine waters, with temperatures as low as 6 °C, but generally equilibrated to the rest of the estuary within several kilometers. Salinity in the upper estuary was fresh throughout the study, and increased up to 14 and 30 PSU along Western and Eastern routes, respectfully, with distance from the diversion. Discharge from the river diversion greatly affected salinity, with the large spring pulses often causing the entire estuary to become fresh for a short period of time (<1 month). There was also a temporal lag of about two weeks between discharge and salinity in the lower estuary. River water entering the estuary had TSS concentrations ranging from 40 to 252 mg/L, with an average of 118 mg/L. Sediment from the river diversion reached about 10-15 km into the estuary during spring pulses. There were highly fluctuating TSS concentrations at the Gulf end of the estuary during winter and spring, due to wind resuspension. Chlorophyll a concentrations were highest in mid-estuary during summer and fall low discharge, and lowest during winter and spring high discharge. Chlorophyll a levels were generally less than 10 μg/L in the upper estuary, with concentrations rising in the mid-estuary generally to 20-30 μg/L during late summer and fall, and decreasing in the lower estuary. There were several periods of less than a month with unusually high chlorophyll a concentrations, ranging from 38 to >60 μg/L, that occurred during late summer and early winter.
Revue / Journal Title
Estuarine, coastal and shelf science
ISSN
0272-7714
CODEN ECSSD3
Source / Source
2007, vol. 74, n
o1-2, pp. 145-154 [10 page(s) (article)] (1 p.1/4)
Langue / Language
Anglais
Editeur / Publisher
Elsevier, Kidlington, ROYAUME-UNI
(1981)
(Revue)
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Localisation / Location
INIST-CNRS, Cote INIST : 16211, 35400014651740.0140
Nº notice refdoc (ud4) : 18875578
