x
Contents
3-4 Tidal Choking ........................ .................. . .............. .
42
42
43
3.5 Hydrology and Water Balance ................... .
3.6 Wind Effects ......... .............
. ............. .
3.7 Salinity and Stratification ...
. . . . . . . . .. . . . ...
. . . .. . . .. . . . . . . . . .. 44
3.8 Flushing Time ........
. .. . . . .. . . . .
46
3.9 Nutrient Standing Stock and Particulate Organic Matter . . . . . . . . . . . . . .
48
3.10 Primary Producers .. ....................
................
51
3-11 Primary Production .....................................................
53
3.12 Pelagic and Benthic Metabolism .. .....................
56
3.13 Nutrient Sources and Primary Production. . . . . . . . . . . . . . . . . . . .. . . . . . . ..
56
3.14 Trophic State .................................. ...............................
59
3-15 Human Impact .. ............................ ............................
60
3.16 Management Issues ... . . . . . . . . . . . . . . . . . . . . . .. ......................
. .. 61
4
Acknowledgements ............. ............
. . . . . . . . . . . .
62
References ...................... ................
. . . . . . . . . . . . .
62
Nutrients and Suspended Matter Behaviour
in the Patos Lagoon Estuary (Brazil) ........... .
Introduction . ................... ............... . ........... .
Materials and Methods ................................ .
4.2.1 Data Reduction for Determining Estuarine Behaviour
of Nutrients and Total Suspended Matter ................... .
67
67
69
4.3 Results and Discussions ........... ..............
. .............. .
70
71
71
4.3.1 Salinity.. . . . . . . . . . . . . . . . . . .
. ......... .
4.3.2 Dissolved Oxygen .............. ........... . ......... .
4.3.3 Total Suspended Matter. . .. . ............ .
4.3.4 Phosphate........ . . . . . . . . . . . . . .. ...............
. ........... .
4.3.5 Nitrate, Nitrite and Ammonium .... .
4.3.6 Silicate ....... . ............ .
4.4 Conclusions ......................... .
Acknowledgements . . ............ .
References ............................ .
. ........... 71
71
73
75
78
80
80
80
5
Hydrographical Characteristics of the Estuarine Area of Patos Lagoon. 83
5.1 Introduction. . . . . . . . . . . . . . . . . . .. . . . . . ..... . . . . .. . . . . . . . . . . . . .. . . . . . .. . . ... . . . . . .
83
5.2 Main Characteristics of the Area. . . . . . . . ...................... ' . . .. . . . . . . . .
84
5.3 Data Sampling and Treatment ................................................
86
5.3.1 Longitudinal Surveys ................... ...............................
86
5.3.2 Time Series Surveys ........... .................. ......................
87
5-4 Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .................
. . . . . . . . . . .
88
5.4.1 Longitudinal Salinity and Temperature Distribution
88
5.4.2 Temporal Variations of Water Level, Currents and Salinity
93
5.4.3 Estuarine Classification of the Channel Area. ..................
96
5-4-4 Longitudinal Salt Transport ..
5.5 Discussion and Conclusions .......... .
Acknowledgements ....... .
References ................. .
97
98
99
99