PM06 Emerging Pollutants
Exhibit Hall
8:00 AM - Monday
(PM062) Assessing the Effects of Irgarol 1051 on Marine Phytoplankton Populations in Key Largo Harbor, Florida.
Zamora, Ingrid1, Jochem, Frank 2, Gardinali, Piero3,4, 1 Department of Environmental Studies, Miami, Florida, USA2 Marine Biology Program, Miami, Florida, USA3 Department of Chemistry and Biochemistry, Miami, Florida, USA4 Southeast Environmental Research Center, Florida International University, Miami, Florida, USA
ABSTRACT- The antifouling boosting agent Irgarol 1051 was developed because of its high efficiency towards algae since it is a strong inhibitor of the PS II system. However, different sensitivity among phytoplankton species may result in adverse changes in community structure at contaminated sites. A rapid method to assess water quality and observe these changes in relation to the concentration of Irgarol in surface waters is the use of flow cytometry. This technique has been used to assess herbicide effects on natural phytoplankton communities (Readman, et al., 2004). This study showed that concentrations as low as 100 ng L-1 changed open water marine phytoplankton community structure. Our continuous monitoring in the Florida Keys showed that Irgarol concentrations up to 635 ng L-1 are present in the canal system of Key Largo Harbor marina (KLH), with a sharp decrease in concentrations as stations move offshore from the navigational canal entrance. Because of this contamination pattern, KLH was selected for a limited survey of phytoplankton composition. Preliminary phytoplankton community assessment from surface water collected in KLH and analyzed by flow cytometry and microscopy showed changes in phytoplankton species composition. Typical responses include an abundance decrease in nanoeukaryotes and an increase of diatoms (Skeletonema costatum and Chaetoceros spp.) with increasing Irgarol concentrations *). However, since Irgarol is not the only contaminant present in that environment, dosing experiments using native phytoplankton species collected and cultured from the marina and control sites are underway to establish the effects of environmental Irgarol concentrations on indigenous plankton species in the area.
Key words: marine phytoplankton, Irgarol 1051, Key Largo Harbor Florida