An in situ Sensor of Phytoplankton Community Structure Based on Light Absorption Gary Kirkpatrick, David Millie, Steven Lohrenz, Mark Moline, Ian Robbins and Oscar Schofield

Acknowledgements National Science Foundation –Biological Sciences Directorate –Ocean Sciences Division National Oceanic and Atmospheric Administration –ECOHAB –MERHAB –Sea Grant Florida Fish and Wildlife Conservation Commission –Florida Fish and Wildlife Research Institute Office of Naval Research

Finding, Tracking and Mapping Harmful Algae

Our Approach to HAB Detection, Tracking and Mapping Based on in situ particulate absorption spectra Originally, analysis by similarity of 4 th derivative spectra Most recently, multiple species regression analysis (after Stæhr and Cullen)

Advantages Over (traditional) Microscopic Enumeration Readily automated – minimal human involvement Good spatial and temporal coverage Less weather dependent Economical

This Presentation Single-species Similarity –laboratory to autonomous field application Multiple-species Community Composition –laboratory to field trials

FO Spectrometer Light Source LWCC FO Reference Water Cross-flow Filter Valve Cleaning Solutions Pump Valve Optical Phytoplankton Discriminator (OPD)

Chl c Chl b phcobilin Laboratory Class Comparisons

Shipboard Underway HAB Detection

OPD Map of HAB

OPD-equipped Vehicles REMUS – Propeller Driven Glider – Buoyancy Driven BreveBuster Payload BSOP Vertical Profiler

Launch Before Dive Gliding OPD-equipped Glider Surveying HAB Mission Track & Satellite Image Resulting Red Tide Distribution

Glider Mission - Sep 28, 2004 – Oct 7, 2004

Karenia brevis Similarity Contours

Fitting Multiple Classes Least squares, multiple regression analyses (after Stæhr and Cullen, 2003). Optimization/reduction algorithm to minimize computational load.

Laboratory Species Mixes OPD vs CHEMTAX

Multiple Class Library

Library Standard Spectra AbsorbanceFourth Derivative

Natural Community Classes OPD Chl a vs CHEMTAX Chl a

Discussion Initial results encouraging. Library of ‘standard’ species incomplete! Libraries need to be regional. Culture ID and condition are critical!! –Garbage in, garbage out!