Texas Observatory for Algal Succession Time Series

The TOAST Network

The primary instrument deployed at TOAST network sites is the Imaging FlowCytobot (IFCB, Fig. 1), an instrument providing continuous, automated imaging of phytoplankton in the nearshore waters at the University of Texas’ Marine Science Institute pier lab in Port Aransas and at Surfside Beach, TX (Fig 2). The IFCB sampling is ongoing and has been running continuously since 2007 at Port Aransas and since 2017 at Surfside Beach. The IFCB is an imaging-in-flow instrument that combines high-resolution video and flow cytometer technology to capture high-resolution images of the plankton. Plant pigments in the phytoplankton cells produce fluorescence that triggers the video camera in the IFCB. The IFCB captures images of organisms from ~10 to greater than 100 micrometers. As the IFCB collects data, the images are saved to an internal computer and also transmitted to the Campbell laboratory at TAMU for processing. Using a machine learning approach, the images are classified into over 100 categories, and the abundance of each category is recorded. When the abundance of harmful species increases above our notification threshold, an automated early warning email is generated. Time series plots are updated hourly: https://geo.gcoos.org/hab/

The real-time and continuous operation of the IFCB has been instrumental in providing early warning for toxic HABs and has provided insight into the seasonal dynamics of phytoplankton along the coast of Texas. In 2008, images from the IFCB provided evidence for the first Dinophysis (Image A, below) bloom in the Gulf of Mexico. This dinoflagellate produces okadaic acid, a toxin that accumulates in oysters and other filter-feeding shellfish and results in the syndrome known as Diarrhetic Shellfish Poisoning (DSP). Because of the early warning, oyster harvesting was closed, contaminated oysters recalled, and no instances of DSP or other human illness were reported. It has since provided successful early warning for 8 HAB events of D. ovum or Karenia brevis (Image E) and also contributed to the discovery of a new species of dinoflagellate, Prorocentrum texanum (Image C).