5th UF Water Institute Symposium Abstract

Submitter's Name Laibin Huang
Session Name Poster Session - Coastal Waters
Poster Number 11
Author(s) laibin huang,  soil and water science dapartment (Presenting Author)
  Caitlin  Young,  Department of Geological Sciences
  Andrea  Pain, Department of Geological Sciences
  Jonathan B.  Martin, Department of Geological Sciences
  Andrew  Ogram, soil and water science dapartment
  The responses of key nitrogen cycling genes to seasonal and tidal variations in a tropical estuary
  To study the effect of different seasons and tidal variations on the abundance of key nitrogen (N) cycling genes around the Yucatan Peninsula, Mexico, water samples were taken across the halocline in the groundwater system, Cenote 7 Bocas (C7B), during the dry season (April, 2014) and wet season (September, 2014). Corresponding samples were taken from an area associated with submarine groundwater discharge (Pargos Spring) during low and high tides during the wet season. Results showed that: 1) Most key N cycling genes were enriched during the wet season in C7B and at high tides in Pargos, and significantly higher numbers of denitrification genes (nirK and nirS) were observed at high tides in Pargos, indicating that lower groundwater input to coastal regions may favor nitrate removal; 2) Most N cycling genes were more abundant at higher pH in this area, and that nitrite reductases (nirK, nirS, nrfA genes) were significantly positively related to salinity in Pargos; 3) The similarity between the lower depths of C7B and a channel leading to the Pargos spring was possibly due to the connection between Pargos and a cenote similar to C7B; and 4) seasonal and tidal variations clearly change the distribution of N cycling genes in these freshwater and marine systems. The results have implications for the impacts of sea level rise on coastal submarine estuaries.