Aquatic Sciences Meeting, Albuquerque 2001

SS05 Groundwater at Aquatic Margins (Environmental Connections)

Date: Wednesday, February 14, 2001, Time: 11:30:00 AM

Location: Cimarron

Troccoli-Ghinaglia, L, , CINVESTAV-IPN, , Merida, Mexico, troccoli@mda.cinvestav.mx

Herrera-Silveira, J, A, CINVESTAV-IPN, U., Merida, Mexico, jherrera@mda.cinvestav.mx

Comin, F, A, University of Barcelona, Barcelona, Spain, comin@porthos.bio.ub.es

CONNECTION BETWEEN GROUNDWATER AND PHYTOPLANKTON IN A CARBONATE COASTAL ZONE

The North coast of the Yucatan Peninsula (SE Mexico) is a karstic zone without rivers but influenced by many groundwater discharges (GD). In order to study the connection between the GD and phytoplankton structure community, monthly water samples were collected (june/98-may/99) in Dzilam de Bravo port covering an area of 4 km2, measuring hydrology, inorganic nutrients, chlorophyll-a and phytoplankton community. The salinity of the GD were < 15 psu, nitrate >20 µM and silicate >30 µM. Near coast phytoplankton was dominated by benthic diatoms and big size dinoflagellates, while the marine stations were dominated by pelagic diatoms an little size dinoflagellates. Heterogeneity index showed a gradient from the coast to ocean in accordance with phytoplankton diversity and chlorophyll-a results. In spite of high concentrations of DIN and silicate the N:P ratios suggest that phytoplankton growth is limited by phosphate. In these coastal zone the GD affect the hydrology and phytoplankton community and aquatic productivity. These freshwater and nutrient sources has been subestimated in coastal studies in the zone.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks