Temporal analyses of the fish functional arrangement of Celestún coastal lagoon, in Yucatan, Mexico

Abstract

Coastal lagoons have been recognized for hosting a great abundance and diversity of biotic components, offering a wide range of services, and are some of the most economically productive; however, they are among the most threatened and stressed ecosystems. The Celestún Biosphere Reserve could be one of the most studied lagoons on the Yucatan coast; yet, little attention has been paid to temporal processes and environmental indicators. In the present study, the Celestún ichthyofauna was analyzed over 11 years to determine its functional arrangement and detect sensitive groups that can be used to determine changes in the system. A total of 92 species were segregated into 10 functional groups (FGs). Most species feed on mobile benthic crustaceans and inhabit estuaries, grass beds, and mangroves. Among the FGs that can be useful as indicators are FG1, FG3, FG4, FG5, FG6, FG8, and FG9 which can help detect increases in organic matter entering the lagoon, since they feed on detritus and plant matter. FG7 and FG10, which as top predators influence the structure and dynamics of food webs. In terms of conservation, it is important to pay attention to FG2 of which most species are in compromised conservation categories. In the 11 years here analyzed, the Celestún lagoon underwent important changes. An increase in species and functional richness, density, and biomass in 1993–1994, a constant decrease until 2011–2012, followed by an increase in 2013; this last increase may be related to the cessation of the multispecies fishery and the policies implemented in the Biosphere Reserve in 2000. Finally, it was observed that the increases are related to specific FGs, while the decreases affected the whole community.