File:SECTOR ORIENTAL DEL GOLFO DE CARIACO, VENEZUELA. UNA DESCRIPCIÓN DE SU DINÁMICA HIDROQUÍMICA, PROCESOS, Y DEL ROL DE LA SURGENCIA COSTERA ESTACIONAL.pdf

The hydrochemical, physical-chemical, and biological dynamics were studied in the eastern waters of the gulf of Cariaco, where wind and precipitation patterns govern these processes to a significant degree. Average monthly values for both surface and bottom waters were respectively as follows: temperature: 25.69 °C each; salinity: 35.41 and 35.75 units; density anomaly (ó-t): 23.43 and 23.84 kg/m3; oxygen concentration: 184.49 and 178.38 mmol/kg; pH: 7.98 and 7.94; nitrates: 3.18 and 4.22 μmol/L; nitrites: 0.45 and 0.60 μmol/L; ammonium: 1.25 and 1.39 μmol/L; total nitrogen: 25.28 and 26.31 μmol/L. Phosphate concentrations between surface and bottom waters varied between 0.60 and 0.79 μmol/L, whereas those of total phosphorus ranged from 2 to 170 μmol/L. Surface and bottom chlorophyll a concentrations ranged from 5.19 to 4.33 mg/m3, respectively. ANOVA (P<0.05) did not reveal any significant variation between the values studied, but it did show differences between the values for different months. Decomposition of organic matter was detected, as typified by both oxygen utilization greater than 50 mmol/kg and denitrification (N*), which increased ammonium concentration and reduced the pH during periods of upwelling relaxation. There was an imbalance between the maxima of chlorophyll a and those of nutrients, which evidenced that phosphorus could be an inhibitor of phytoplankton production, especially during upwelling letup, when Readfield ratio increases from N:P = 16:1 up to N:P = 24:1.