## 3 Results  
### Water Quality  
Table 1 shows the mean values of water quality variables grouped by main sectors, types of drainage, and seasonality. Water temperature differed among sectors (KW = 21.949, \(p\) < 0.01) and types of drainage (KW = 6.743, \(p\) < 0.01). These differences were attributed to warmer water temperature in REMACAM, located to the north of Esmeraldas. REMACAM includes eight of the nine sites corresponding to natural drainages, RVSMMC includes nine of the eleven shrimp drainages in this study. There were no temperature differences among the seasons. (KW = 3.387, \(p\) > 0.05). There were no significative differences in the salinity between systems (KW = 0.77359, \(p\) > 0.05) and sectors (KW = 4.5588, \(p\) > 0.05). Muisne exhibited the highest salinity variation (15,507 \(\pm\) 11,075 ppt). Dissolved oxygen levels did not differ among sectors (KW = 0.30855, \(p\) > 0.05) and sampling periods (KW = 3.0769, \(p\) > 0.05). However, the SF drains with a mean of 5.16 \(\pm\) 1.37 mg O\({}_{2}\)/L exceeded the natural MG drains (KW = 4.6878, \(p\) < 0.05) with a mean of 4.19 \(\pm\)1.26 mg O\({}_{2}\)/L. The biochemical oxygen demand in five days (BOD\({}_{5}\)) presented differences among sectors (F\({}_{3,36}\) = 2.98 \(p\) < 0.01) that were restricted towards Cojimies (8.21 \(\pm\) 2.75 mg O\({}_{2}\)/L) and Muisne (12.16 \(\pm\) 4.21 mg O\({}_{2}\)/L), having robust differences between sampling periods (F\({}_{1,38}\) = 11.25, \(p\) < 0.01), increasing the BOD\({}_{5}\) in summer periods (13.65 \(\pm\) 6.49 mg O\({}_{2}\)/L) and improving the condition of the water in winter (8.36 \(\pm\) 2.74 mg O\({}_{2}\)/L) without differing between estuaries and type of drainage. The pH exhibited differences among sectors (F\({}_{3,33}\) = 6.37, \(p\) < 0.01) which occurred between Muisne (7.74 \(\pm\) 0.16) and Cojimies (7.45 \(\pm\) 0.36) with respect to Tambillo with the lowest pH of 6.90 \(\pm\) 0.51. In addition, the water from natural drainages was more acidic than the water from shrimp drainages (F\({}_{1,35}\) = 4.301, \(p\) < 0.05). The differences in pH were amplified when considering the main systems (F\({}_{1,35}\) = 10.46, \(p\) < 0.01) and seasonality (F\({}_{1,35}\) = 34.23, \(p\) < 0.001), observing a decrease in the pH from a summer value (7.74 \(\pm\) 0.17) compared to winter (7.08 \(\pm\) 0.43), the rainy and warm period of the Ecuadorean coast. No differences in Redox values were found among sectors (F\({}_{3,36}\) = 2.858, \(p\) > 0.05), types of drainage (F\({}_{1,38}\) = 2.306, \(p\) > 0.05) and sampling periods (F\({}_{1,38}\) = 1.698, \(p\) > 0.05). The greatest differences occurred in organic variables, with subtle differences in ammonium content when considering sectors (F\({}_{3,36}\) = 2.832, \(p\) < 0.01), which extends to main systems (F\({}_{1,38}\) = 8.787, \(p\) < 0.01) and drainage type (F\({}_{1,38}\) = 8.459, \(p\) < 0.01), where RVS doubles REM. The ammonium content increased during the summer months (F\({}_{1,38}\) = 4.688, \(p\) < 0.05). The nitrate content differed among sectors (F\({}_{3,36}\) = 6.65, \(p\) < 0.01) with the highest record in Cojimies (0.270 \(\pm\) 0.237 mg/L) that exceeded Tambillo (0.051 \(\pm\) 0.058 mg/L) and Palma Real (0.034 \(\pm\) 0.031 mg/L). The difference was greater between main systems (F\({}_{1,38}\) = 14.38, \(p\) < 0.001). The nitrate content in RVS (0.21 \(\pm\) 0.18 mg/L) was four times the value observed in REM (0.04 \(\pm\) 0.05 mg/L). However, there were no differences between types of drainage (F\({}_{1,38}\) = 2.05, \(p\) > 0.05) or sampling period (F\({}_{1,38}\) = 0.465, \(p\) > 0.05). Likewise, differences in nitrite levels among sectors were also found (F\({}_{3,36}\) = 4.45, \(p\) < 0.01).