Molecular and chemical ecology of intertidal sand-dwelling protists in the northwest of Ireland using a GIS-based sampling strategy

Eutrophication in coastal waters has increased in the last decades around the globe owing to growing human populations in coastal areas and the development of industrial and agricultural activities. The EU - Water Framework... [ view full abstract ]

Eutrophication in coastal waters has increased in the last decades around the globe owing to growing human populations in coastal areas and the development of industrial and agricultural activities. The EU - Water Framework Directive (WFD) introduced in 2000 set out measures to improve the quality of all water bodies by 2015. Phytoplankton diversity is considered a suitable biological indicator to determine the trophic state of coastal waters.
This study focuses on intertidal sand-dwelling protists (protozoa and microalgae) in northwest Irish beaches. A stratified simple semi-random sampling strategy based on GIS analysis of a 2km buffer zone along the northwest/west coast of Ireland was used for the selection of coastal sites to sample. The typology of 50 coastal spatial units was described based on topographical and land cover parameters following GIS analysis in ArcMap Version 10.2.2 (ESRI) of publicly available database sets. Similarity analysis was then applied to build clusters of spatial units to define the sampling effort.
The well-established molecular method PCR-DGGE (Polymerase Chain Reaction – Denaturant Gradient Electrophoresis) and HPLC-based pigment analysis were used to investigate the community structure of microphytobenthos (benthic protists) in intertidal sediments at various sampling sites. The molecular data generated will provide the foundations for the future ecological mapping of particular benthic protists species, population and/or communities. It is anticipated that the results obtained on benthic protist community diversity could permit the development of a new environmental quality index that could be incorporated in the future to extent monitoring programmes.