Importance of different primary producers in supporting a mangrove fish community in Sikao Creek, Thailand

Abstract

Stable carbon and nitrogen isotope analyses were used to study the importance of different primary producers for a trophic support of a fish community in Southern Thailand. These data were combined with results from gut content analysis. Based on gut content analysis the fish species were divided in 6 different trophic groups. The planktivorous fish had the highest average δ13C values indicating that they rely mostly on phytoplankton production; however the other trophic groups had lower average δ13C values. This combined with IsoSource model results provides indications that the mangrove tree production plays a greater role in supporting the fish community than documented in other locations. We explain this by Sikao Creek being isolated from other coastal habitats with alternative primary food source leading to an increased mangrove production importance.