Comparing the biogeochemical functioning of two arid subtropical coastal lagoons: the effect of wastewater discharges

ABSTRACT Nutrient flux, net metabolism, and N 2 fixation denitrification processes were estimated compared in two semi-arid subtropical coastal lagoons the Gulf of California: El Soldado (ES), where no wastewater is discharged, Rancho (ER), shrimp farm effluents are regularly discharged. Biogeochemical evaluated with LOICZ model. Flushing time was <2 days both systems. fluxes higher ER than ES systems acted as nutrient sinks for most year. showed a larger flow rate summer autumn due to input shrimp-farm effluents. Nitrogen increased winter response supply from upwellings. autotrophic metabolism spring, autumn, winter, but heterotrophic summer. Denitrification dominated (−2.21 mmol m day −1 ) values those (−0.45 ). The comparative analysis between evidenced significant changes its biogeochemical performance caused by anthropogenic nutrients, can orient environmental management lagoons.