JPR Advance Access published online on March 19, 2008
Journal of Plankton Research, doi:10.1093/plankt/fbn038
Hydromedusa Blooms and Upwelling Events in the Bay of Panama, Tropical East Pacific
1 Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama 2 Pennsylvania State University, Department of Finance, University Park, PA 16802, USA
* Corresponding author: Maria Pia Miglietta, Current address: Pennsylvania State University, Department of Biology, University Park, PA 16802, USA, Phone: +507 212 8833, Fax: +507 212 8790 or 8791, Email address: mp.miglietta{at}psu.edu
Received on November 14, 2007; revised on March 12, 2008; accepted on March 16, 2008
| Abstract |
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Seasonal upwelling events dominate coastal areas of some regions of the Tropical East Pacific. The effects of upwelling on gelatinous zooplankton are largely unknown and undocumented for this or any region, although upwelling is known to shape phytoplankton dynamics. Small hydromedusae, the most widespread and diverse representatives of gelatinous plankton, are often neglected in plankton ecology as they are inconspicuous and escape direct observation. Their occurrence is seasonal and standard plankton sampling techniques easily overlook their blooms. In order to investigate whether upwelling affects hydromedusae dynamics we monitored their abundance and diversity in the Bay of Panama, a region on the Pacific Coast of Panama characterized by seasonal upwelling events. Our results show that, although the number of species is relatively constant throughout the year, hydromedusa abundance in the Bay of Panama can be up to two orders of magnitude higher during upwelling than non-upwelling conditions. The difference in the numbers of hydromedusae between the two seasons is mostly due to temporally short medusa blooms that occur only during the upwelling season. Our results point to a link between hydromedusa blooms and upwelling events, and the increased productivity associated with them. The results are consistent with a scenario in which upwelling events act on the benthic colonies thus inducing medusa production.
Key Words: Upwelling Hydromedusa Blooms Panama Plankton-benthos Interaction Hydrozoa Jellyfish
Communicating Editor: Dr Roger Harris