Large medusae in surface waters of the Northern California Current: variability in relation to environmental conditions
- 668 Downloads
Blooms of jellyfish around the world have been correlated with climatic variables related to environmental causes. Sizeable populations of large medusae, primarily Chrysaora fuscescens and Aequorea sp., appear annually in shelf waters of the Northeast Pacific Ocean. Previous research has shown that C. fuscescens is abundant seasonally in the inner shelf and exhibits high feeding rates on zooplankton. We examined medusae caught in surface trawls over an 8-year period (2000–2007) using (1) mesoscale surveys sampling 8–10 transects in May, June, and September, and (2) biweekly surveys along two transects from April to August, relating abundance to environmental parameters. C. fuscescens abundances generally peaked in late summer, whereas Aequorea sp. peaked in May or June. General additive models of the mesoscale data indicated that station catches for both species correlated with latitude, temperature, salinity, and distance from shore (and chlorophyll a for Aequorea sp.). Analysis of interannual variability revealed that highest catches of medusae correlated with cool spring–summer conditions, or negative anomalies of the Pacific Decadal Oscillation, and low winter–summer runoff from the Columbia River. Results confirmed our hypothesis of connections between jellyfish populations and regional climate conditions in a region known for strong physical forcing of ecosystem processes.
KeywordsJellyfish Chrysaora Aequorea Climate Upwelling California Current
Unable to display preview. Download preview PDF.
Thanks to the captains and crew of the FV Frosti, FV Ocean Harvester, FV Sea Eagle, FV Piky, RV Miller Freeman, and RV W.E. Ricker, as well as the many seagoing scientists who participated in the fieldwork component of this project. G. Krutzikowsky, C. Morgan, S. Pool, and C. Bucher helped with database management. E. Casillas, J. Field, C. Rice, J. Purcell and two anonymous reviewers provided helpful comments on earlier drafts of the manuscript. This study was funded by the Bonneville Power Administration, the US GLOBEC Northeast Pacific Program, and the Northwest Fisheries Science Center (NOAA). Completion of this manuscript was supported by the National Science Foundation, while the lead author was working at the Foundation. Any opinion, finding, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
- Astorga, D., J. Ruiz & L. Prieto, 2012. Ecological aspects of early life stages of Cotylorhiza tuberculata (Scyphozoa: Rhizostomae) affecting its pelagic population success. Hydrobiologia. doi: 10.1007/s10750-012-1036-x.
- Batchelder, H. P., J. A. Barth, M. P. Kosro, P. T. Strub, R. D. Brodeur, W. T. Peterson, C. T. Tynan, M. D. Ohman, L. W. Botsford, T. M. Powell, F. B. Schwing, D. G. Ainley, D. L. Mackas, B. M. Hickey & S. R. Ramp, 2002. The GLOBEC Northeast Pacific California Current System Program. Oceanography 15: 36–47.CrossRefGoogle Scholar
- Brodeur, R. D., J. J. Ruzicka & J. H. Steele, 2011. Investigating alternate trophic pathways through gelatinous zooplankton and planktivorous fishes in an upwelling ecosystem using end-to-end models. In Omori, K., X. Guo, N. Yoshie, N. Fujii, I. C. Handoh, A. Isobe & S. Tanabe (eds), Interdisciplinary Studies on Environmental Chemistry – Marine Environmental Modeling & Analysis. TERRAPUB, Tokyo: 57–63.Google Scholar
- Haddock, S. H. D., 2008. Reconsidering evidence for potential climate-related increases in jellyfish. Limnology and Oceanography 53: 2759–2762.Google Scholar
- Hastie, T. J. & R. J. Tibshirani, 1990. Generalized Additive Models. Chapman and Hall, New York: 335 pp.Google Scholar
- Holst, S., 2012. Effects of climate warming on strobilation and ephyra production of North Sea scyphozoan jellyfish. Hydrobiologia. doi: 10.1007/s10750-012-1043-y.
- Miller, T. W. & R. D. Brodeur, 2007. Diets of and trophic relationships among dominant marine nekton within the Northern California Current ecosystem. Fishery Bulletin 105: 548–559.Google Scholar
- Parsons, T. R. & C. M. Lalli, 2002. Jellyfish population explosions: revisiting a hypothesis of possible causes. La Mer 40: 111–121.Google Scholar
- Peterson, W. T., 2009. Copepod species richness as an indicator of long-term changes in the coastal ecosystem of the Northern California Current. CalCOFI Reports 50: 73–81.Google Scholar
- Purcell, J. E., D. Atienza, V. Fuentes, A. Olariaga, U. Tilves, C. Colahan & J.-M. Gili, 2012. Temperature effects on asexual reproduction rates of Scyphozoan species from the northwest Mediterranean Sea. Hydrobiologia. doi: 10.1007/s10750-012-1047-7.
- Ruzicka, J. J., R. D. Brodeur & T. C. Wainwright, 2007. Seasonal food web models for the Oregon inner-shelf ecosystem: investigating the role of large jellyfish. CalCOFI Reports 48: 106–128.Google Scholar
- Thein, H., H. Ikeda & S. I. Uye, 2012. The potential role of podocysts in perpetuation of the common jellyfish Aurelia aurita s.l. (Cnidaria: Scyphozoa) in anthropogenically perturbed coastal waters. Hydrobiologia. doi: 10.1007/s10750-012-1045-9.
- Wood, S. N., 2006. Generalized Additive Models: An Introduction with R. Chapman and Hall, New York: 391 pp.Google Scholar