Zooplankton and Phytoplankton Contributors to Bioluminescence in Monterey Bay

Steven Haddock (MBARI)
Mark Moline (California Polytechnic State University
Edith Widder (Harbor Branch Oceanographic Institution)

Logistics, Schedule, and Sampling Patterns

Bioluminescence is present in nearly all marine waters and may reach dramatic levels in coastal zones. Presently, however, it is not possible to accurately predict the intensity and distribution of luminescence, or to know when anomalously bright events may occur. Although autotrophic dinoflagellates are often important contributors to the bioluminescence of a region, one cannot simply infer luminescence from remote measurements such as satellite estimations of surface chlorophyll. A large (and variable) fraction of this chlorophyll signal will be due to non-luminous diatoms and dinoflagellates, while the luminescence itself may be produced primarily by heterotrophic dinoflagellates and zooplankton.

The planktonic communities of Monterey Bay have been the focus of scientific research for many decades, and in recent years the Bay has become the target of increased attention by oceanographers and modelers. This historical record provides a level of background information that is found in few marine environments. Similar attention has not been directed toward the bioluminescence of the area, but the detailed background information, combined with the number of unanswered questions about the luminescent organisms, provides an exciting arena for future studies.

In the present study we attempt to improve the modeling and predictability of luminescence in a nearshore environment by measuring bioluminescence and plankton abundances over time and across an oceanographic front. Integrated with physical and biological models, these observations provided the major groundwork for characterizing two disparate coastal water-types: (1) recently upwelled water, which is typical of productive coastal zones and is expected to be relatively low in bioluminescence, and (2) sequestered water, typical of a protected gulf or embayment, which has had a long residence time, and is expected to have relatively high luminescence.

Several elements distinguish this study from any previous endeavors: large-scale deployment (week-long, over tens of kilometers) of luminescence sensors on AUVs, ROVs, and other platforms; a sampling program for luminescent organisms that is tightly integrated, with ancillary physical sensors deployed throughout the surrounding area to provide an oceanographic context to the measurements; direct communication with modelers to optimize sampling plans; and a unique but well-characterized frontal system, which allows simultaneous characterization of two coastal regimes.

Data Index Aircraft AUV CODAR
Drifters Moorings Satellites Ships