Establishing Management Strategies for Boca de Camichín Estuarine System Using Nutrient Carrying Capacity

Abstract

Coastal lagoons are considered one of the most important ecosystems on the planet because they provide the necessary conditions for the biological cycle of a large number of species. However, in recent years, water quality in these systems has deteriorated because of population growth and human activities, which has led to increased inputs of organic matter and nutrients such as nitrogen and phosphorus. In order to determine the nutrient carrying capacity of coastal lagoons in tropical areas, a study was carried out at the estuarine system of Boca de Camichín, Nayarit using a model developed by the International Land Ocean Interactions in the Coastal Zone This work was conducted during three climatic seasons (hot-dry, rainy and cold-dry) between April 2008 and February 2009. Results obtained show that the system is clearly heterotrophic, which is caused by considerable production of organic matter. High productivity is maintained due to hydrodynamic movement, the penetration of sea water through a deep channel as well as the influence of a large river (San Pedro River). In all of the studied seasons, mass balances indicate that different concentrations of phosphate (19–90 tP/month) and nitrogen (90–162 tN/month) accumulate in the interior of the estuary. These results show that the Boca de Camichín system may be very close to its carrying capacity; therefore potential human activities that generate new organic matter that are discharged to Boca de Camichín lagoon should be controlled. Our results also show that it is essential to determine the nutrient carrying capacity of these types of systems in order to take proper management actions that ensure resource sustainability.