Seagrass biomass and their role as carbon reservoirs in the localities of San Andres Island and La Guajira, Colombian Caribbean

Abstract

Seagrass meadows have stood out for being very effective fixing atmospheric carbon, among others, due to their ability to produce plant biomass. Therefore, the values of shoot density (m2), biomass (cores) and carbon present in 12 locations with Thalassia testudinum at the Colombian Caribbean (La Guajira and San Andrés Island) were quantified. The biological samples were processed in laboratory until obtaining the values of aerial, underground and total dry weight, and the estimation of the carbon was stablishing from a ratio of 35 % of the dry biomass. Statistical tests were carried out to determine significant differences between the sites, highlighting the aerial biomass in La Guajira and the underground biomass in San Andrés. It was calculated that the total carbon in the seagrasses' biomass from La Guajira were 197 484 Mg C and in San Andrés 1835.4 Mg C. The difference between locations were due to particular geomorphological and intrinsic factors. It is highlighted that, although the carbon retained in the biomass (aerial and underground) is comparatively lower than in sediments, it constitutes the pillar of conservation of both carbon sink as well as for the sustainability of the ecosystem.