GFDL - Geophysical Fluid Dynamics Laboratory

Ryan R. Rykaczewski

Ryan Rykaczewski, Nippon Foundation

Assistant Professor

Marine Science Program

Department of Biological Sciences

University of South Carolina

715 Sumter St.

Columbia, SC  29208    USA

Phone: +1-803-777-8159



In collaboration with the Nereus Program and Princeton University/GFDL Climate and Ecosystems: John Dunne, Charlie Stock, and Jorge Sarmiento

CV:  pdf

Research website:

Research Interests

I am interested in exploring the responses of ecosystem and fisheries production to past and future climate variability and climate change. This research involves consideration of theory, observations, and models.  Currently, I investigate the biogeochemical implications of changes in physical climate that are particularly robust in the projections of atmosphere-ocean general circulation models (e.g., meridional shifts in zonal winds, increases in ocean stratification, and changes in phenology). In the past, changes in primary production, carbon export, the structure of food webs, and fisheries have often correlated with simple physical climate measures such as SST. However, these relationships rarely reflect an understanding of the actual mechanisms relating the environment to the physics. My recent research questions whether reliance on past correlations is appropriate for prediction of future conditions; the empirical relationships between biological and physical processes may differ as the earth system is perturbed in a manner not observed over the past century.

Key areas of interest:

  • mechanisms of fisheries-climate interactions

  • atmospheric forcing of marine biogeochemistry (e.g., oxygen, pH, nutrient cycling) and ecosystems
  • size spectra of phytoplankton and zooplankton communties; size-structured interactions
  • large-scale and long-term changes to marine environments
  • nonlinear relationships between physics and ecosystems
  • dynamics of upwelling systems, eastern boundary currents, and small pelagic fish populations
  • ecology of marine zooplankton; mediation of trophic transfers (physics-chemistry-phytoplankton-zooplankton-fish)



Ph.D. Oceanography Scripps Institution of Oceanography, University of California, San Diego. La Jolla, CA. Advisor: Dr. David M. Checkley, Jr.



Marine Science and Biology          (with Chemistry minor) University of Miami. Coral Gables, FL. Advisor: Dr. Donald B. Olson.

Graduate Research Program at USC

My group at the University of South Carolina
is actively recruiting prospective graduate students an postdoctoral researchers who are
interested in the responses of
marine ecosystems to climate variability
and change.  Please contact me by email at to discuss
opportunities.  Graduate appointments are
available in both the School of the Earth, Ocean, and Environment and the Department of Biological Sciences.


*Grieve, BD, EN Curchitser, and RR Rykaczewski. In press. Range expansion of the invasive lionfish in the Northwest Atlantic with climate change. Marine Ecology Progress Series, doi:10.3354/meps11638. Link to MEPS.

Cheung, WWL, TL Frölicher, RG Asch, M Jones, ML Pinsky, G Reygondeau, KB Rodgers, RR Rykaczewski, JL Sarmiento, CA Stock, and JR Watson. In press. Building confidence in projections of the responses of living marine resources to climate change.  ICES Journal of Marine Science, doi:10.1093/icesjms/fsv250. Link to ICES Journal of Marine Science.

García-Reyes, M, WJ Sydeman, DS Schoeman, RR Rykaczewski, BA Black, AJ Smit, and SJ Bograd. 2015. Under pressure: Climate change, upwelling and eastern boundary upwelling ecosystems. Frontiers in Marine Science 2:109, doi:10.3389/fmars.2015.00109. Link to Frontiers in Marine Science .

Fisher, JL, WT Peterson, and RR Rykaczewski. 2015. The impact of El Niño events on the pelagic food chain in the northern California Current. Global Change Biology 21:4401?4414, doi:10.1111/gcb.13054. Link to GCB.

Rykaczewski, RR, JP Dunne, WJ Sydeman, M García-Reyes, BA Black, and SJ Bograd. 2015. Poleward displacement of coastal upwelling-favorable winds in the ocean’s eastern boundary currents through the 21st century. Geophysical Research Letters 42:6424?6431, doi:10.1002/2015GL064694. Link to GRL.

Bakun, A, BA Black, SJ Bograd, M García-Reyes, AJ Miller, RR Rykaczewski, and WJ Sydeman. 2015. Anticipated effects of climate change on coastal upwelling ecosystems. Current Climate Change Reports 1:85?93, doi:10.1007/s40641-015-0008-4. Link to Current Climate Change Reports.

**Willis-Norton, E, EL Hazen, S Fossette, G Shillinger, RR Rykaczewski, DG Foley, JP Dunne, and SJ Bograd. 2015. Climate change impacts on leatherback turtle pelagic habitat in the southeast Pacific. Deep-Sea Research Part II: Topical Studies in Oceanography 113:260-267, doi:10.1016/j.dsr2.2013.12.019. Link to DSRII .

McOwen, CJ, WWL Cheung, RR Rykaczewski, RA Watson, and LJ Wood. 2015. Is fisheries production within Large Marine Ecosystems determined by bottom-up or top-down forcing? Fish and Fisheries 16(4):623-632 doi:10.1111/faf.12082. Link to  Fish & Fisheries.

Black, BA, WJ Sydeman, DC Frank, D Griffin, DW Stahle, M García-Reyes, RR Rykaczewski, SJ Bograd, and WT Peterson. 2014. Six centuries of variability and extremes in a coupled marine-terrestrial ecosystem. Science 345(6203):1498-1502, doi:10.1126/science.1253209. Link to Science. Press Release.

Sydeman, WJ, M García-Reyes, DS Schoeman, RR Rykaczewski, SA Thompson, BA Black, SJ Bograd. 2014. Climate change and wind intensification in coastal upwelling ecosystems. Science 345(6192):77-80, doi:10.1126/science.1251635. Link to Science. Press Release. Los Angeles Times article.

García-Reyes, M, WJ Sydeman, BB Black, RR Rykaczewski, DS Schoeman, SA Thompson, and SJ Bograd. 2013. Relative influence of oceanic and terrestrial pressure systems in driving upwelling-favorable winds. Geophysical Research Letters 40:5311-5315, doi:10.1002/2013GL057729. Link.

Österblom, H, A Merrie, M Metian, WJ Boonstra, T Blenckner, JR Watson, RR Rykaczewski, Y Ota, JL Sarmiento, V Christensen, M Schlüter, S Birnbaum, BG Gustafsson, C Humborg, C Mörth, B Müller-Karulis, MT Tomczak, M Troel, C Folke. 2013. Modeling social-ecological scenarios in marine systems. BioScience 63:735-744, doi:10.1525/bio.2013.63.9.9. Link to BioScience. Press Release.

García-Reyes, M, WJ Sydeman, SA Thompson, BA Black, RR Rykaczewski, JA Thayer, and SJ Bograd. 2013. Integrated assessment of wind effects on Central California?s pelagic ecosystem. Ecosystems 16(5):722-735 doi:10.1007/s10021-013-9643-6. Link.

Beaulieu, C, SA Henson, JL Sarmiento, JP Dunne, SC Doney,
RR Rykaczewski, and L Bopp. 2013. Factors challenging our ability to
detect long-term trends in ocean chlorophyll. Biogeosciences 10:
2711-2724, doi:10.5194/bg-10-2711-2013. Link.

Hazen, EL, E Jorgensen, RR Rykaczewski, SJ
Bograd, DG Foley, ID Jonsen, SA Shaffer, JP Dunne, DP Costa, LB Crowder, and BA
Block. 2012. Predicted habitat shifts of Pacific top predators in a changing
climate. Nature Climate Change
doi:10.1038/nclimate1686. Link.

Sydeman, WJ, SA Thompson, JA Santora, JC Field, WT
Peterson, RA Tanasichuk, HJ Freeland, SJ Bograd, and RR Rykaczewski.
positioning of the North Pacific Current affect downstream ecosystem
productivity? Geophysical Research Letters 38:L12606, doi:10.1029/2011GL047212. Link. Copy.

Rykaczewski, RR and JP
Dunne. 2011. A measured look at ocean chlorophyll trends. Nature 472:E5-E6, doi:10.1038/nature09952 [A comment arising
from DG Boyce et al. Nature
466:591-296 (2010)]. Link. Copy. Discussion.

Decima, M, MR Landry, and RR Rykaczewski. 2011.
Broad-scale patterns in mesozooplankton biomass and grazing in the eastern
equatorial Pacific. 
Deep-Sea Research Part II: Topical Studies in Oceanography
58:387-399, doi:10.1016/j.dsr2.2010.08.006. Link.

CA, MA Alexander, NA Bond, K Brander, WWL Cheung, EN Curchitser, TL Delworth,
JP Dunne, SM Griffies, MA Haltuch, JA Hare, AB Hollowed, P Lehodey, SA Levin,
JS Link, KA Rose, RR Rykaczewski, JL Sarmiento, RJ Stouffer, FB Schwing,
GA Vecchi, FE Werner. 2011. On the use of IPCC-class models to assess the
impact of climate on living marine resources. Progress in Oceanography 88:1-27,
doi:10.1016/j.pocean.2010.09.00. Link. Copy.

Rykaczewski, RR and JP
Dunne. 2010. Enhanced nutrient supply to the California Current Ecosystem with
global warming and increased stratification in an earth system model. Geophysical Research Letters 37:L21606, doi:10.1029/2010GL045019. Link. Copy.

Rykaczewski, RR and DM
Checkley. 2008. Influence of ocean winds on the pelagic ecosystem in upwelling
regions. Proceedings of the National Academy of Sciences of the United States of America 105:1965-1970, doi:10.1073/pnas.0711777105. Link. Copy.

(with *graduate- and **undergraduate-student first authors)

Rykaczewski BONGO tow for zooplankton, CCE-LTER, CalCOFI

BONGO towing for zooplankton

Photo courtesy of Andrew L. King