Marine Science Faculty Publications

Material Transports

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Book Chapter

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Karenia brevis, HABs, West Florida continental shelf, coastal ocean circulation, prediction

Digital Object Identifier (DOI)


Harmful algal bloom (HAB) occurrences, their interannual variations, and their preferred locations have as much to do with the ocean circulation as with their biological and chemical interactions. This is because the circulation determines the nutrient state of the continental shelf and hence whether or not slower growing HABs can successfully compete against faster growing diatoms. The circulation also determines the transport between the location of an incipient bloom and the location where the bloom may eventually manifest along the shoreline. Thus any viable bloom prediction scheme must begin with an adequate representation of the coastal ocean circulation. In other words, the circulation physics and the organism biology both provide the necessary conditions for bloom development and manifestation; neither alone provides a sufficient condition.

Here we discuss the basic workings of the continental shelf circulation with application to the West Florida Continental Shelf (WFS), where interannual blooms of the harmful algae, Karenia brevis, occur preferentially between the Tampa Bay and Charlotte Harbor estuaries. By exploring the dynamics of the coastal ocean circulation, driven both by local and remote influences, we gain an appreciation for why the WFS may at times be oligotrophic while at other times be nutrient replete. This suggests an Occam’s razor approach to prediction, which may work in some years but find surprise in other years. Thus key to prediction is not only adequate representations of the physics and the biology but also the observations required to mitigate model error growth. In this regard, HAB prediction is similar to weather prediction, just much more demanding. The most pressing needs now are for interdisciplinary, systematically collected water property and transport observations. Better understanding and predictive capabilities will not be gained by studying HABs alone. A similar requirement applies to fisheries resources or to any ecological phenomenon of the coastal ocean.

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Citation / Publisher Attribution

Material Transports, in J. J. Walsh (Ed.), Wind-Borne Illness from Coastal Seas: Present and Future Consequences of Toxic Marine Aerosols, Elsevier, p. 281-310