Molecular diagnostic procedures for identifying harmful algal bloom (HAB) species, their genes, gene products, and toxins play a central role in many research and resource management activities, but such methods generally require the return of discrete samples to a laboratory for analysis. As a step towards overcoming this impediment we are exploring use of the Environmental Sample Processor (ESP; see photo at right), a robotic electromechanical/fluidic system that can detect remotely, subsurface, and in near real-time, a wide range of waterborne microorganisms and substances they produce via the autonomous application of molecular diagnostic tests.
This project is a collaborative effort with colleagues at the Monterey Bay Aquarium Research Institute and is currently focused on the domoic acid (DA) producing members of the diatom genus Pseudo-nitzschia. Our group is employing a key feature of the ESP that provides the ability to automate both toxin extraction protocols as well as the application of antibody-based probe arrays to detect toxins associated with a given HAB species. We have developed a competitive ELISA for DA that is conducted onboard the ESP (see schematic at left), with results transmitted via radio modem to ship or shore for processing and data interpretation/assessment. Two-way communication with the instrument allows the user to receive data and instrument status reports, as well as alter the ESP’s sampling schedule, modify analytical protocols, etc. Our colleagues at MBARI have developed a complimentary suite of arrays for concurrent detection of the corresponding toxin-producing HAB species. Both toxin and organism detection assays have been conducted successfully during multiple deployments of the ESP in Monterey Bay, CA over several years (see photo below), and limits of detection for these assays are well below those known to cause resource contamination and wildlife mortality events.
Taken together, these capabilities enable the remote, integrated assessment of algal cell abundance and their associated toxin levels – an important feature given the extreme variability in domoic acid production by Pseudo-nitzschia species (see figure right). 
Ultimately, we envision that the ESP will be integrated into the rapidly emerging U.S. Integrated Ocean Observing System. The data generated will be used to drive HAB forecasting models, which will be of direct benefit to coastal managers, public and wildlife health officials, and researchers interested in monitoring the population and toxin dynamics of these and other HABs.
Personnel
Publications
- Sellner, K.G., Doucette, G.J., Kirkpatrick, G. 2003. Harmful algal blooms: causes, impacts and detection. J. Ind. Microbiol. Biotechnol. 30:383-406.
- Babin, M., Cullen, J.J., Roesler, C.S., Donaghay, P.L., Doucette, G.J., Kahru, M., Lewis, M.R., Scholin, C.A., Sieracki, M.E., Sosik, H.M. 2005. New approaches and technologies for observing harmful algal blooms. Oceanography 18:210-227.
- Scholin, C.A., Doucette, G.J., Cembella, A.D. 2008. Prospects for developing automated systems for in situ detection of harmful algae and their toxins. In: Babin, M., Cullen, J., Roessler, C. (eds.), Real time coastal observing systems for ecosystem dynamics and harmful algal blooms. Monographs on Oceanographic Methodologies, Vol. 10. Paris: Intergovernmental Oceanographic Commission of UNESCO. pp. 413-462.
- Greenfield, D.I., Marin, R. III, Doucette, G.J., Mikulski, C.M., Jones, K.L., Jensen, S., Roman, B., Alvarado, N., Feldman, J., Scholin, C.A. 2008. Field applications of the second-generation Environmental Sample Processor (ESP) for remote detection of harmful algae: 2006-2007. L&O: Methods 6:667-679.
- Scholin, C., Doucette, G., Jensen, S., Roman, B., Pargett, D., Marin III, R., Preston, C., Jones, W., Feldman, J., Everlove, C., Harris, A., Avarado, N., Massion, E., Birch, J., Greenfield, D., Wheeler, K., Vrijenhoek, R., Mikulski, C., Jones, K. 2009. Remote detection of marine microbes, small invertebrates, harmful algae and biotoxins using the Environmental Sample Processor (ESP). Oceanography 22:158-167.
- Doucette, G.J., Mikulski, C.M., Jones, K.L., King, K.L., Greenfield, D.I., Marin III, R., Jensen, S., Roman, B., Elliott, C.T., Scholin, C.A.
2009. Remote, subsurface detection of the algal toxin domoic acid onboard the Environmental Sample Processor: assay development and field trials. Harmful Algae. doi:10.1016/j.hal.2009.04.006.