A bathymetric study to support management plans for La Caimanera coastal lagoon, Gulf of Morrosquillo, Colombia

Abstract

There are large extensions of coastal lagoons in the Colombian Caribbean. In spite of their renowned environmental and socio-economic importance, these ecosystems have been poorly evaluated. To initiate a process for understanding the biophysical features of the La Caimanera lagoon, bathymetric surveys were conducted on a 25 × 25 m grid approach. Echo sounder and GPS were used to collect the data, which was then analyzed with ArcGIS 9.2 to produce bathymetry maps. A total of 3355 data points indicated an average depth of 1.83 m (SD ± 0.55) with a range of 0.7–5.4 m. Higher and lower values were recorded within the access channel and on the western margin of the lagoon respectively, suggesting that depth distribution was probably related to the interaction of different factors. These factors include the hydrological influence of the entrance channel currents and the micro-catchments of the streams located on the southeast side, along with the possible effects of the survey course selection. Apparently, the dynamic of the streams caused sedimentation on the opposite southwest margin, affecting the environmental quality by siltation and the accumulation of organic matter. Research, monitoring programs, and new management plans are necessary to avoid the deterioration of the ecological goods and services derived from this important local ecosystem.