Planktonic gross primary productivity and respiration in the National Park Sistema Arrecifal Veracruzano

Planktonic gross primary productivity (GPP) and respiration (RP) were evaluated in the National Park Sistema Arrecifal Veracruzano (NPSAV) at the southwest of Gulf of Mexico from December 2008 to January 2012. The GPP values varied between 0-231 mgC m-3 h-1 and the RP values between 0-447 mgC m-3 h-1. The north was different from south, with Playa Norte being the most productive site of the system. The north is influenced by anthropogenic activities such as a residual water treatment plant, whereas the south is influenced by the river plume of Jamapa during the rainy period. By the contrary Cabezo reef was the lowest productive; this site is the farest from the coast hence with no influence of Jamapa river plume. No differences were detected between sites associated to reefs and sites without reefs. The ratio GPP/RP indicated that the ecosystem is a source of CO2 most of the time, and in short periods of the year as a carbon sink.