Sophia Johannessen

johannessen-2015-photo-for-facetsResearch Scientist, Fisheries and Oceans Canada

Institute of Ocean Sciences
9860 W. Saanich Rd.
P.O. Box 6000, Sidney, B.C. V8L 4B2
ph. (250) 363-6616
fax (250) 363-6807

Dr. Johannessen is a geochemical oceanographer. Her research interests range from light and underwater weather at the top of the ocean to burial and reworking of sediments at the bottom. She has worked in the Mid-Atlantic Bight, the Bering Sea and the Arctic Ocean. Currently she works in the coastal waters of British Columbia.


Ph.D. (Oceanography) Dalhousie University 2000
B.Sc. Hon. (Geology and Oceanography) University of British Columbia 1994

Recent research topics

– the effects of climate change on coastal waters
– the footprint of municipal wastewater in the Strait of Georgia
– the potential for carbon sequestration by seagrass meadows (“Blue Carbon”)
– subsurface oxygen, nitrogen and ocean acidification in coastal waters
– the sinking and burial of particles and organic carbon
– the rate of primary productivity in the Salish Sea
– fate of diluted bitumen (dilbit) in B.C. coastal waters

Publications (journal articles)

Johannessen, S. C. 2022. How can blue carbon burial in seagrass meadows increase long-term, net sequestration of carbon? A critical review. Environmental Research Letters 17(9): 093004.

Huang, Y., Fassbender, A. J., Long, J. S., Johannessen, S. C., Bernardi, M. 2022. Partitioning the export of distinct biogenic carbon pools in the Northeast Pacific Ocean using a biogeochemical profiling float.  Global Biogeochemical Cycles 36(2): e2021GB007178.

Jackson, J. M., Johannessen, S. C., Del Bel Belluz, J., Hunt, B.P.V., and Hannah, C.G. 2021. Identification and change of a seasonal subsurface oxygen minimum in Rivers Inlet, British Columbia, 1951 to 2018. Estuaries and Coasts,

Schreiber, L., Fortin, N., Tremblay, J., Wasserscheid, J., Sanschagrin, S., Mason, J., Wright, C., Spear, D., Johannessen, S., Robinson, B., King, T., Lee, K. and Greer, C. 2021. In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions. FEMS Microbiology Ecology, 97(7):fiab082. doi: 10.1093/femsec/fiab082.

Johannessen, S.C., Macdonald, R. W., and Strivens, J.E. 2021. Has primary production declined in the Salish Sea? Canadian Journal of Fisheries and Aquatic Sciences, 78(3), Paper summary

 Archer, S.C., Kahn A., Thiess, M., Law, L., Leys, S., Johannessen, S.C., Layman, C.A., Burke, L., Dunham, A. 2020. Foundation species abundance influences food web topology on glass sponge reefs. Frontiers in Marine Science 7, Pdf

Thomson, R. E., Kulikov, E. A., Spear, D. J., Johannessen, S.C. and Wills, W. P. 2020. A role for gravity currents in tidally-modulated cross-sill exchange and inflow to the southern Strait of Georgia. Journal of Geophysical Research Oceans 125(4),

Johannessen, S. C., Greer, C. W., Hannah, C. G.,  King, T. L., Lee, K., Pawlowicz, R. and Wright, C. A. 2020. Fate of diluted bitumen spilled in the coastal waters of British Columbia, Canada. Marine Pollution Bulletin,150, Pdf

Johannessen, S.C., Macdonald, R. W. and Wright, C. A. 2019. Rain, runoff and diatoms: the effects of the North Pacific 2014-2015 warm anomaly on particle flux in a Canadian west coast fjord. Estuaries and Coasts, 42(4): 1052-1065; doi: 10.1007/s12237-018-00510-0. Pdf

Johannessen, S.C. and Macdonald, R.W. 2018. Reply to Oreska et al. Comment on ‘Geoengineering with seagrasses: is credit due where credit is given?’  Environmental Research Letters 13(3): 038002. doi: 10.1088/1748-9326/aaae71. Pdf

Johannessen, S.C. and Macdonald, R.W. 2018. Reply to Macreadie et al. Comment on ‘Geoengineering with seagrasses: is credit due where credit is given?’  Environmental Research Letters 13(2): 028001. doi: 10.1088/1748-9326/aaa7b5. Pdf

Johannessen, S.C., Macdonald, R.W., Wright, C. A. and Spear, D.J. 2017. Short-term variability in particle flux: storms, blooms and river discharge in a coastal sea. Continental Shelf Research 143: 29-42. Paper summary, Pdf

Loos, E.A., Costa, M., and Johannessen, S. C. 2017. The underwater optical environment of the coastal waters of British Columbia. FACETS 2: 872-891, .doi: 10.1139/facets-2017-0074.  Paper summary, Pdf.

R. Pawlowicz, R. Di Costanzo, M. Halverson, E. Devred and S. Johannessen 2017. Advection, surface area, and sediment load of the Fraser River plume under variable wind and river forcing. Atmosphere-Ocean 55(4-5): 293-313. Paper summary

Johannessen, S. C. and Macdonald, R. W. 2016. Geoengineering with seagrasses: Is credit due where credit is given? Environmental Research Letters 11: 113001. doi 10.1088/1748-1936/11/11/113001. Paper summary, Pdf.

Ianson, D., Allen, S. E., Moore-Maley, B.L., Johannessen, S. C. and Macdonald, R. W. 2016. Vulnerability of a semienclosed estuarine sea to ocean acidification in contrast with hypoxia. Geophysical Research Letters doi 10.1002/2016GL068996.  Paper summary, Pdf.

Johannessen, S.C., Macdonald, R.W., Burd, B., van Roodselaar, A. and Bertold, S. 2015. Local environmental conditions determine the footprint of municipal effluent in coastal waters: A case study in the Strait of Georgia, British Columbia. Science of the Total Environment 508: 228-239.  Paper summary, Pdf.

Macdonald, R.W., Kuzyk, Z.Z.A. and Johannessen, S.C. 2015. The vulnerability of Arctic shelf sediments to climate change. Environmental Reviews 23: 461-479. Paper summary

Macdonald, R.W., Kuzyk, Z.Z.A. and Johannessen, S.C. 2015. It is not just about the ice: A geochemical perspective on the changing Arctic Ocean. Environmental Studies and Sciences 5(3): 288-301. Paper summary

Yunker, M.B., Macdonald, R.W., Ross, P.S., Johannessen, S.C. and Dangerfield, N. 2015. Assessment of alkane and PAH provenance and potential bioavailability in coastal marine sediments subject to a north to south gradient of increasing anthropogenic sources in British Columbia, Canada. Organic Geochemistry 89-90: 80-116. Paper summary

Kuzyk, Z.Z.A., Macdonald, R.W. and Johannessen, S.C. 2015. Calculating rates and dates and interpreting contaminant profiles in biomixed sediment cores. In J. M. Blais et al. (eds.) Environmental Contaminants, Developments in Paleoenvironmental Research 18, DOI: 10.1007/978-94-017-9541-8_4, p. 61-87. Paper summary

Johannessen, S.C., Masson, D. and Macdonald, R.W. 2014. Oxygen in the deep Strait of Georgia, 1951-2009: The roles of mixing, deep-water renewal, and remineralization of organic carbon. Limnology and Oceanography 59(1): 211-222. Paper summary, Pdf.

Riche, O., Johannessen, S.C. and Macdonald, R.W. 2014. Why timing matters in a coastal sea: trends, variability and tipping points in the Strait of Georgia, Canada. Journal of Marine Systems 131: 36-53.

Sutton, J.N., Johannessen, S.C. and Macdonald, R.W. 2013. A nitrogen budget for the Strait of Georgia, British Columbia. Biogeosciences 10: 7179-7194.

Bailey, J.N., Macdonald, R.W., Sanei, H., Outridge, P.M., Johannessen, S.C., Hochheim, K., Barber, D. and Stern, G.A. 2013. Change at the margin of the North Water Polynya, Baffin Bay, inferred from organic matter records in dated sediment cores. Marine Geology 341: 1-13.

Johannessen, S.C. and Macdonald, R.W. 2012. There is no 1954 in that core! Interpreting sedimentation rates and contaminant trends in marine sediment cores. Marine Pollution Bulletin 64(4): 675-678.

Dinn, P.M., Johannessen, S.C., Ross, P.S., Macdonald, R.W., Whiticar, M.J., Lowe, C.J. and van Roodselaar, A. 2012. PBDE and PCB accumulation in benthos near marine wastewater outfalls: The role of sediment organic carbon. Environmental Pollution 171: 241-248.

Dinn, P.M., Johannessen, S.C., Macdonald, R.W., Lowe, C.J. and Whiticar, M.J. 2012. Effect of receiving environment on the transport and fate of polybrominated diphenyl ethers near two submarine municipal outfalls. Environmental Toxicology and Chemistry 31(3): 566-573.

P.B.C. Grant, S. Johannessen, R. Macdonald, M. Yunker, M. Sanborn, P. Shaw, N. Dangerfield, C. Wright and P.S. Ross 2011. Environmental fractionation of PCBs and PBDEs during particle transport as recorded by sediments in coastal waters  Environmental Toxicology and Chemistry 30(7): 1522-1532

Beaudin, L., Johannessen, S. C. and Macdonald, R. W. 2010. Coupling laser ablation and atomic fluorescence spectrophotometry: an example using mercury analysis of small sections of fish scales. Analytical Chemistry 82: 8785-8788.

Wong, C. S., Christian, J. R, Wong, S.-K. E., Page, J., Xie, L. and Johannessen, S. C. 2010.  Carbon dioxide in surface seawater of the eastern North Pacific Ocean (Line P), 1973-2005. Deep-Sea Research I 57, 687-695.

Hare, A. A., Stern, G. A., Kuzyk, Z. Z. A., Macdonald, R. W., Johannessen, S. C. and Wang, F. 2010. Natural and anthropogenic mercury distribution in marine sediments from Hudson Bay, Canada. Environmental Science & Technology 44: 5805-5811.

Pospelova, V., Esenkulova, S., Johannessen, S. C., O’Brien, M. C. and Macdonald, R. W. 2010. Organic-walled dinoflagellate cyst production, composition and flux from 1996 to 1998 in the central Strait of Georgia (BC, Canada): A sediment trap study.  Marine Micropaleontology 75: 17-37.

Kuzyk, Z. Z. A., Macdonald, R. W., Johannessen, S. C. and Stern, G. A. 2010. Biogeochemical controls on PCB deposition in Hudson Bay.  Environmental Science & Technology 44: 3280-3285.

Kuzyk, Z. Z. A., Macdonald, R. W., Johannessen, S. C., Gobeil, C. and Stern, G. A. 2009. Towards a sediment and organic carbon budget for Hudson Bay. Marine Geology 264: 190-208.

Johannessen, S. C. and Macdonald, R. W. 2009. Effects of local and global change on an inland sea: the Strait of Georgia, British Columbia. Climate Research 40(1): 1-21.

Ross, P. S., Couillard, C. M., Ikonomou, M., Johannessen, S. C., Lebeuf, M., Macdonald, R. W. and Tomy, G. 2009. Large and growing environmental reservoirs of Deca-BDE present an emerging health risk for fish and marine mammals. Marine Pollution Bulletin 58: 7-10.

Burd, B., Macdonald, R. W., Johannessen, S. C. and van Roodselaar, A. 2008. Responses of subtidal benthos of the Strait of Georgia to ambient sediment conditions and natural and anthropogenic deposition.  Marine Environmental Research 66: 62-79.

Macdonald, R. W., Johannessen, S. C., Gobeil, C., Wright, C., Burd, B. and van Roodselaar, A. 2008. Sediment redox tracers in Strait of Georgia sediments – can they inform us of the loadings of organic carbon from municipal wastewater? Marine Environmental Research 66: 87-100.

Johannessen, S. C., Macdonald, R. W., Wright, C. A., Burd, B., Shaw, D. P. and van Roodselaar, A. 2008. Joined by geochemistry, divided by history: PCBs and PBDEs in Strait of Georgia sediments.  Marine Environmental Research 66: 112-120.

Johannessen, S. C., Potentier, G., Wright, C. A., Masson, D. and Macdonald, R. W. 2008. Water column organic carbon in a Pacific Marginal sea (Strait of Georgia, Canada).  Marine Environmental Research 66: 49-61.

Johannessen, S.C., Peña, M. A. and Quenneville, M. 2007.  Photochemical production of carbon dioxide during a coastal phytoplankton bloom. Estuarine, Coastal and Shelf Science 73: 236-242.

Johannessen, S. C., Masson, D. and Macdonald, R. W. 2006. Distribution and cycling of suspended particles inferred from transmissivity in the Strait of Georgia, Haro Strait and Juan de Fuca Strait. Atmosphere-Ocean 44(1): 17-27.

Johannessen, S. C., Macdonald, R. W. and Eek, K. M. 2005. Historical Trends in Mercury Sedimentation and Mixing in the Strait of Georgia, Canada.  Environmental Science & Technology, 39: 4361-4368.

Johannessen, S. C. O’Brien, M. C., Denman, K. L. and Macdonald, R. W. 2005. Seasonal and spatial variations in the source and transport of sinking particles in the Strait of Georgia, British Columbia, Canada. Marine Geology 216: 59-77.

Macdonald, R. W., Morton, B. and Johannessen, S. C. 2003. A review of marine environmental contaminant issues in the North Pacific: the dangers and how to identify them. Environmental Reviews 11:103-139.

Johannessen, S. C., Macdonald, R. W. and Paton, D. W. 2003. A sediment and organic carbon budget for the greater Strait of Georgia. Estuarine, Coastal and Shelf Science, 56:845-860.

Johannessen, S. C., Miller, W. L. and Cullen, J. J. 2003. Calculation of UV attenuation and colored dissolved organic matter absorption spectra from measurements of ocean color. Journal of Geophysical Research 108(C9): 3301, doi:10.1029/2000JC000514.

Johannessen, S. C. and Miller, W. L. 2001. Quantum yield for the photochemical production of dissolved inorganic carbon in seawater. Marine Chemistry 76: 271-283.

Belzile, C., Johannessen, S. C., Gosselin, M., Demers, S. and Miller, W. L. 2000. Ultraviolet attenuation by dissolved and particulate constituents of first-year ice during late spring in an Arctic polynya. Limnology and Oceanography 45(6): 1265-1273.