Phytoplankton Community Structure in Lower Pearl River Estuary

Silwal, S., Dash, P., Sackreiter, J., Ochs, C., Moorhead, R. J., & Pinckney, J. (2015). Phytoplankton Community Structure in Lower Pearl River Estuary. Coastal and Estuarine Research Federation (CERF) Meeting. Portland, OR.

Phytoplankton blooms pose a significant threat to water quality for several reasons including the fact that some of the species can produce potent toxins. Traditionally, phytoplankton communities are visually inspected using inverted microscopes or enumerated using microscopic cell counts for monitoring. These traditional methods are expensive, tedious and time consuming, and sometimes inaccurate. ChemTax, a factor analysis algorithm, offers an alternative to these traditional methods by providing the relative and absolute abundances of algal groups from high performance liquid chromatography (HPLC) derived photo-pigment data. Further, FlowCAM (Fluid Imaging Technologies) represents an automated microscope with the ability to compute the community structure by rapidly acquiring large sets of particle image data. Furthermore, molecular techniques such as Quantitative Polymerase Chain Reaction (qPCR) can provide rapid quantification of total cells for an algal group, a specific genus or the total number of cells producing a specific type of toxin. In addition to these laboratory techniques, high resolution imagery acquired by Unmanned Aerial Systems (UAS) can provide synoptic views of specific phytoplankton blooms. The main objective of this research is to compare and contrast all these alternative methods for phytoplankton enumeration and evaluate the potential of each of these methods. Two field campaigns were undertaken (one in December, 2014 and another in March 2015) and at least three more field campaigns are planned before December, 2015 to Lower Pearl River Estuary located near Slidell, Louisiana for collecting water samples for HPLC photopigments, FlowCAM, and qPCR analyses. In addition to several other analyses, Enzyme-linked immunosorbent assay (ELISA) was used to measure the concentration of phycotoxins and algorithms will be developed to obtain synoptic distribution of phytoplankton blooms from UAS imagery.