Oceanography The Official Magazine of
The Oceanography Society
Volume 27 Issue 02

View Issue TOC
Volume 27, No. 2
Pages 208 - 225


The Contemporary Challenge of the Sea: Science, Society, and Sustainability

By David M. Karl  
Jump to
Citation References Copyright & Usage
First Paragraph

The ocean covers nearly 71% of the surface of our planet, but it is still largely unexplored despite its fundamental roles in global food production and climate regulation. The most expansive ocean regions, termed subtropical gyres (Figure 1), are the largest ecosystems on Earth, yet we know little about how they are structured, how they function, or how they may respond to stresses imposed on them by human activities. The North Pacific Subtropical Gyre (NPSG) is the largest of these gyres, and it is isolated from other ocean regions by permanent, clockwise-rotating boundary currents. The NPSG is also very old, with present boundaries having been established at least 10 million years ago (McGowan and Walker, 1985). These conditions of great age and isolation create a habitat that is nutrient starved (e.g., nitrate and phosphate) and relatively devoid of photosynthetic microbes called phytoplankton that harvest sunlight and serve as the base of the marine food chain. Although these regions have been termed “oceanic deserts” by analogy to the deserts on land, because of their vast expanse, regions such as the NPSG control global ocean fluxes of carbon and oxygen and therefore sustain planetary habitability. But like many open ocean regions, the NPSG ecosystem is poorly sampled and not well understood.


Karl, D.M. 2014. The contemporary challenge of the sea: Science, society, and sustainability. Oceanography 27(2):208–225, https://doi.org/10.5670/oceanog.2014.57.


Abelson, P.H. 1999. A potential phosphate crisis. Science 283:2,015, https://doi.org/10.1126/science.283.5410.2015.

Ashley, K., D. Cordell, and D. Mavinic. 2011. A brief history of phosphorus: From the philosopher’s stone to nutrient recovery and reuse. Chemosphere 84:737–746, https://doi.org/10.1016/j.chemosphere.2011.03.001.

Azam, F., T. Fenchel, J.G. Field, J.S. Gray, L.A. Meyer-Reil, and F. Thingstad. 1983. The ecological role of water-column microbes in the sea. Marine Ecology Progress Series 10:257–263.

Béjà, O., L. Aravind, E.V. Koonin, M.T. Suzuki, A. Hadd, L.P. Nguyen, S.B. Jovanovich, C.M. Gates, R.A. Feldman, J.L. Spudich, and others. 2000. Bacterial rhodopsin: Evidence for a new type of phototrophy in the sea. Science 289:1,902–1,906, https://doi.org/10.1126/science.289.5486.1902.

Boyd, P.W., T. Jickells, C.S. Law, S. Blain, E.A. Boyle, K.O. Buesseler, K.H. Coale, J.J. Cullen, H.J.W. de Baar, M. Follows, and others. 2007. Mesoscale iron enrichment experiments 1993–2005: Synthesis and future directions. Science 315:612–617, https://doi.org/10.1126/science.1131669.

Brewer, P.G. 2003. Foreword. Pp. I-VIII in Ocean Biogeochemistry: A Synthesis of the Joint Global Ocean Flux Study (JGOFS). M.J. Fasham, ed., Springer-Verlag.

Buesseler, K.O., S.C. Doney, D.M. Karl, P.W. Boyd, K. Caldeira, F. Chai, K.H. Coale, H.J. de Baar, P.G. Falkowski, K.S. Johnson, and others. 2008. Ocean iron fertilization—Moving forward in a sea of uncertainty. Science 319:162, https://doi.org/10.1126/science.1154305.

Chisholm, S.W., R.J. Olson, E.R. Zettler, R. Goericke, J.B. Waterbury, and N.A. Welschmeyer. 1988. A novel free-living prochlorophyte abundant in the oceanic euphotic zone. Nature 334:340–343, https://doi.org/10.1038/334340a0.

Dickey, T.D. 1991. The emergence of concurrent high-resolution physical and bio-optical measurements in the upper ocean and their applications. Reviews of Geophysics 29:383–413, https://doi.org/10.1029/91RG00578.

Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. Proceedings of the National Academy of Sciences of the United States of America 106:12,235–12,240, https://doi.org/10.1073/pnas.0906044106.

Duce, R.A., J. LaRoche, K. Altieri, K.R. Arrigo, A.R. Baker, D.G. Capone, S. Cornell, F. Dentener, J. Galloway, R.S. Ganeshram, and others. 2008. Impacts of atmospheric anthropogenic nitrogen on the open ocean. Science 320:893–897, https://doi.org/10.1126/science.1150369.

Dugdale, R.C., and J.J. Goering. 1967. Uptake of new and regenerated forms of nitrogen in primary productivity. Limnology and Oceanography 12:196–206, https://doi.org/10.4319/lo.1967.12.2.0196.

Elser, J.J. 2012. Phosphorus: A limiting nutrient for humanity? Current Opinion in Biotechnology 23:833–838, https://doi.org/10.1016/j.copbio.2012.03.001.

Fasham, M.J.R., B.M. Balino, and M.C. Bowles, eds. 2001. A new vision of ocean biogeochemistry after a decade of the Joint Global Ocean Flux Study (JGOFS). Ambio Special Report 10, Royal Swedish Academy of Sciences, Stockholm, Sweden, 31 pp.

Frias-Lopez, J., Y. Shi, G.W. Tyson, M.L. Coleman, S.C. Schuster, S.W. Chisholm, and E.F. DeLong. 2008. Microbial community gene expression in ocean surface waters. Proceedings of the National Academy of Sciences of the United States of America 105:3,805–3,810, https://doi.org/10.1073/pnas.0708897105.

Gilbert, J.A., and C.L. Dupont. 2011. Microbial metagenomics: Beyond the genome. Annual Review of Marine Science 3:347–371, https://doi.org/10.1146/annurev-marine-120709-142811.

Goméz-Consarnau, L., J.M. González, M. Coll-Lladó, P. Gourdon, T. Pascher, R. Neutze, C. Pedrós-Alió, and J. Pinhassi. 2007. Light stimulates growth of proteorhodopsin-containing marine Flavobacteria. Nature 445:210–213, https://doi.org/10.1038/nature05381.

Gruber, N. 2011. Warming up, turning sour, losing breath: Ocean biogeochemistry under global change. Philosophical Transactions of the Royal Society A 369:1,980–1,996, https://doi.org/10.1098/rsta.2011.0003.

Karl, D.M. 1999. A sea of change: Biogeochemical variability in the North Pacific subtropical gyre. Ecosystems 2:181–214, https://doi.org/10.1007/s100219900068.

Karl, D.M. 2012. Mid-Pacific oceanography: University of Hawaii and the sea. Mains’l Haul 48:88–99, http://hahana.soest.hawaii.edu/lab/dkarl/2012Mainsl-Haul48-88-99.pdf.

Karl, D.M. 2014a. Microbially mediated transformations of phosphorus in the sea: New views of an old cycle. Annual Review of Marine Science 6:279–337, https://doi.org/10.1146/annurev-marine-010213-135046.

Karl, D.M. 2014b. Solar energy capture and transformation in the sea. Elementa, https://doi.org/10.12952/journal.elementa.000021.

Karl, D.M., R.R. Bidigare, and R.M. Letelier. 2001. Long-term changes in plankton community structure and productivity in the North Pacific Subtropical Gyre: The domain shift hypothesis. Deep Sea Research Part II 48:1,449–1,470, https://doi.org/10.1016/S0967-0645(00)00149-1.

Kim, T.-W., K. Lee, R.G. Najjar, H.-D. Jeong, and H.J. Jeong. 2011. Increasing N abundance in the northwestern Pacific Ocean due to atmospheric nitrogen deposition. Science 334:505–509, https://doi.org/10.1126/science.1206583.

Kintisch, E. 2013. A sea change for US oceanography. Science 339:1,138–1,143, https://doi.org/10.1126/science.339.6124.1138.

Kolber, Z.S., C.L. Van Dover, R.A. Niederman, and P.G. Falkowski. 2000. Bacterial photosynthesis in surface waters of the open ocean. Nature 407:177–179, https://doi.org/10.1038/35025044.

McGowan, J.A., and P.W. Walker. 1985. Dominance and diversity maintenance in an oceanic ecosystem. Ecological Monographs 55:103–118, https://doi.org/10.2307/1942527.

Munk, W.H. 1997. Tribute to Roger Revelle and his contribution to studies of carbon dioxide and climate change. Proceedings of the National Academy of Sciences of the United States of America 94:8,275–8,279.

Pomeroy, L.R. 1974. The ocean’s food web: A changing paradigm. BioScience 24:409–504, https://doi.org/10.2307/1296885.

Rabalais, N.N., W.-J. Cai, J. Carstensen, D.J. Conley, B. Fry, Z. Hu, Z. Quiñones-Rivera, R. Rosenberg, C.P. Slomp, R.E. Turner, and others. 2014. Eutrophication-driven deoxygenation in the coastal ocean. Oceanography 27(1):172–183, https://doi.org/10.5670/oceanog.2014.21.

Redfield, A.C., B.H. Ketchum, and F.A. Richards. 1963. The influence of organisms on the composition of sea water. Pp. 26–77 in The Sea, vol. 2. M.N. Hill, ed, Interscience.

Revelle, R. 1987. How I became an oceanographer and other sea stories. Annual Review of Earth and Planetary Sciences 15:1–23, https://doi.org/10.1146/annurev.ea.15.050187.000245.

Revelle, R., and H.E. Suess. 1957. Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO2 during the past decades. Tellus 9, https://doi.org/10.1111/j.2153-3490.1957.tb01849.x.

Russell, M.J., W. Nitschke, and E. Branscomb. 2013. The inevitable journey to being. Philosophical Transactions of the Royal Society B 368, 20120254, https://doi.org/10.1098/rstb.2012.0254.

Sabine, C.L., R.A. Feely, N. Gruber, R.M. Key, K. Lee, J.L. Bullister, R. Wanninkhof, C.S. Wong, D.W.R. Wallace, B. Tilbrook, and others. 2004. The oceanic sink for anthropogenic CO2. Science 305:367–371, https://doi.org/10.1126/science.1097403.

Steindler, L., M.S. Schwalbach, D.P. Smith, F. Chan, and S.J. Giovannoni. 2011. Energy starved Candidatus Pelagibacter ubique substitutes light-mediated ATP production for endogenous carbon respiration. PloS ONE 6(5):e19725, https://doi.org/10.1371/journal.pone.0019725.

Stommel, H. 1963. Varieties of oceanographic experience. Science 139:572–576, https://doi.org/10.1126/science.139.3555.572.

Venrick, E.L., J.A. McGowan, D.R. Cayan, and T.L. Hayward. 1987. Climate and chlorophyll a: Long-term trends in the central North Pacific Ocean. Science 238:70–72, https://doi.org/10.1126/science.238.4823.70.

Copyright & Usage

This is an open access article made available under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution, and reproduction in any medium or format as long as users cite the materials appropriately, provide a link to the Creative Commons license, and indicate the changes that were made to the original content. Images, animations, videos, or other third-party material used in articles are included in the Creative Commons license unless indicated otherwise in a credit line to the material. If the material is not included in the article’s Creative Commons license, users will need to obtain permission directly from the license holder to reproduce the material.