My scientific research focuses on how oceanographic, climatic and anthropogenic factors influence the functioning of coastal ecosystems, spanning the boundaries of disciplines and ecosystems. I also work at the boundary between science and policy in my professional service. I am a member of the California Ocean Protection Council’s Science Advisory Team (OPC-SAT) and serve on the Governing Council for the Central and Northern California Ocean Observing System (CeNCOOS). I earned my BS in Biology from Brooklyn College, City University of New York and my PhD in marine ecology from Oregon State University. I spent two years as an National Science Foundation International Postdoctoral Fellow at the Estación Costera de Investigaciones Marinas, Universidad Católica in Las Cruces, Chile and then another two years as postdoctoral fellow with the Partnership for Interdisciplinary Studies of Coastal Oceans. Before coming to SF State, I was a Professor of Biology at Sonoma State University.
My students and I have done field work in rocky intertidal, sandy beach and salt marsh ecosystems, and studied the nearshore and surf zone ecosystems that wash over them. We address questions about the physiological ecology intertidal seaweeds such as how heat and desiccation stress, changes on ocean pH or nutrient availability influence their distribution and abundance. We examine how these factors combine with species interactions to influence intertidal community structure and function. We investigate how surf zone phytoplankton assemblages are influenced by nearshore physical processes. We study ecosystem connectivity between sandy beaches, subtidal kelp forests and other nearby ecosystems. We are interested in how conservation and natural resource management actions, such as marine protected areas and species specific regulations for harvest or take, influence the structure and functioning of marine ecosystems and populations. We conduct experimental and observational research to increase our understanding of how environmental conditions and human activities, including conservation and management policies, influence marine life and ecosystem health. We communicate what we learn to inform conservation and management policies, and to enhance public understanding and appreciation of marine science.
Hacker SD, Menge BA, Nielsen KJ, Chan F, Gouhier TC. 2019. Regional processes are stronger determinants of rocky intertidal community dynamics than local biotic interactions. Ecology.DOI: 10.1002/ecy.2763
Saarman ET, Owens B, Murray SN, Weisberg SB, Ambrose RF, Field JC, Nielsen KJ, Carr MH. 2018. An ecological framework for informing permitting decisions on scientific activities in protected areas. PloS one 13(6):e0199126.
Freiwald, J, Meyer, R, Caselle, JE, Blanchette, CA, Hovel, K, Neilson, D, Dugan, J, Altstatt, J, Nielsen, KJ and Bursek, J. 2018. Citizen science monitoring of marine protected areas: Case studies and recommendations for integration into monitoring programs. Marine Ecology39, p.e12470. doi.org/10.1111/maec.12470
Ramirez KS, Berhe AA, Burt J, Gil-Romera G, Johnson RF, Koltz AM, Lacher I, McGlynn T, Nielsen KJ, Schmidt R, Simonis JL. 2018. The future of ecology is collaborative, inclusive and deconstructs biases. Nature Ecology & Evolution2(2):200.
F. Chan, J. A. Barth, C. A. Blanchette , R. H. Byrne, F. Chavez, O. Cheriton, R. A. Feely, G. Friederich, B. Gaylord, T. Gouhier, S. Hacker, T. Hill, G. Hofmann, M. A. McManus, B. A. Menge, K. J. Nielsen, A. Russell, E. Sanford, J. Sevadjian & L. Washburn 2017. Persistent spatial structuring of coastal ocean acidification in the California Current System. Scientific Reports | 7: 2526 | DOI:10.1038/s41598-017-02777-y
Blanchette, C.A., M.W. Denny, J.M. Engle, B. Helmuth, L.P. Miller, K.J. Nielsen, and J. Smith. 2016. Intertidal. In H. Mooney and E. Zavaleta, (Eds.) Ecosystems of California. University of California Press.
Bruce A. Menge, Tarik C. Gouhier, Sally D. Hacker, Francis Chan, and Karina J. Nielsen 2015. Are meta-ecosystems organized hierarchically? A model and test in rocky intertidal habitats. Ecological Monographs 85:213–233.
Bakker, J. K.J. Nielsen, J. Alberti, O.O. Iribarne, D.P.J. Kuijper, M. Schrama & B.R. Silliman. In Press. Saltwater-Terrestrial Boundary. In K. LaPierre and T. Hanley (Eds.) Trophic Ecology: Bottom-Up and Top-Down Interactions across Aquatic and Terrestrial Systems. Cambridge University Press.
Burnaford, J., K.J. Nielsen & S.L. Williams. 2014. Celestial mechanics affect emersion time and patterns of abundance of an ecosystem engineer, the intertidal kelp Saccharina sessilis. Marine Ecology Progress Series.
Krenz , C., B. A. Menge, T. L. Freidenburg, J. Lubchenco, F. T. Chan, M. M. Foley & K. J. Nielsen. 2011. Ecological subsidies to rocky intertidal communities: linear or non-linear changes along a consistent geographic upwelling transition? Journal of Experimental Marine Biology and Ecology 409: 361-370.
McPhee-Shaw, E. K. J. Nielsen, J. L. Largier & B. A. Menge. 2011. Nearshore Chlorophyll-a events and wave-driven transport. Geophysical Research Letters 38
Thompson, S. A.*, H. Knoll*, C. A. Blanchette & K. J. Nielsen. 2010. Population consequences of biomass loss due to commercial collection of the wild seaweed Postelsia palmaeformis. Marine Ecology Progress Series 413:17-31.
Sanford, E., M. E. Wood*, K. J. Nielsen.2010. A non-lethal method for estimation of gonad and pyloric caecum indices in sea stars. Invertebrate Biology 128:372-380.
Menge, B. A., F. T. Chan, K. J. Nielsen, E. D. Lorenzo & J. Lubchenco. 2009. Climatic variation alters supply side ecology: impact of climate patterns on phytoplankton and mussel recruitment. Ecological Monographs 79:379-95.
Kavanaugh, M. T.*, K. J. Nielsen, B. A. Menge, F. T. Chan, R. M. Letelier, L. M. Goodrich. 2009. Experimental assessment of the effects of shade on an intertidal kelp: do phytoplankton blooms inhibit growth of open coast macroalgae? Limnology & Oceanography 54:276-288.
Nielsen, K. J. Algae, overview. In M. Denny and M. S. Gaines, (Eds,), Encyclopedia of the Rocky Intertidal. 2007. The University of California Press, Berkeley.
Barth, J. A., B. A. Menge, J. Lubchenco, F. T. Chan, J. M. Bane, A. R. Kirincich, M. A. McManus, K. J. Nielsen, S. D. Pierce & L. Washburn. 2007. Delayed upwelling alters nearshore coastal ocean ecosystems in the northern California Current. Proceedings of the National Academy of Sciences 104:3791-3794.
Nielsen, K. J., C. A. Blanchette, B. A. Menge & J. Lubchenco 2006. Physiological snapshots reflect ecological performance of the sea palm, Postesia palmaeformis, (Phaeophyceae) across intertidal elevation and exposure gradients. Journal of Phycology 42, 548–559.
Bracken, M. & K. J. Nielsen 2004. Nitrogen loading by invertebrates increases diversity of intertidal seaweeds. Ecology 85(10):2828-2836
Grantham, B. A., F. T. Chan, K. J. Nielsen, D. Fox, J. A. Barth, A. Huyer, J. Lubchenco, and B. A. Menge 2004. Nearshore upwelling-driven hypoxia signals ecosystem and oceanographic changes in the NE Pacific. Nature 429:479-754
Nielsen, K. J. & S. A. Navarrete 2004. Mesoscale regulation comes from the bottom-up: intertidal interactions between consumers and upwelling. Ecology Letters 7(1):31-41.
Nielsen, K. J. 2003. Nutrient loading and consumers: agents of change in open-coast macrophyte assemblages. Proceedings of the National Academy of Sciences 100: 7660-7665.
Wieters, E., D. M. Kaplan, A. Sotomayor, S. A. Navarrete, J. L. Largier, K. J. Nielsen & F. Véliz. 2003. Spatial and temporal variation in chlorophyll-a with respect to local upwelling intensity in central Chile. Marine Ecology Progress Series 249:93-105.
Nielsen, K. J. 2001. Bottom-up and top-down forces in tidepools: test of a simple food-chain model in an intertidal community. Ecological Monographs 71(2): 187-217.