Publications

Articles published in refereed journals

Brzezinski, M., D.E. Varela, B.D. Jenkins, K.N. Buck, S.M. Kafrissen and J.L. Jones. 2022. The upper ocean silicon cycle of the subarctic Pacific during the EXPORTS field campaign. Elem Sci Anth, 10: 1. https://doi.org/10.1525/elementa.2021.00087.

Kafrissen, S.M., K.E. Giesbrecht, B.J. McNabb, J.E. Long, C. Martin, S.N. Wyatt, M.G. Lagunas and D.E. Varela. 2022. An 8-year record of phytoplankton productivity and nutrient distributions from surface waters of Saanich Inlet. Sci Data, 9, 377. https://doi.org/10.1038/s41597-022-01434-y.

Meyer, M.G., W. Gong, S.M. Kafrissen, O. Torano, D.E. Varela, A.E. Santoro, N. Cassar, S.M. Gifford, A.K. Niebergall, G. Sharpe and A. Marchetti. 2022. Phytoplankton size-class contributions to new and regenerated production during the EXPORTS Northeast Pacific Ocean field deployment. Elem Sci Anth, 10: 1. https://doi.org/10.1525/elementa.2021.00068.

Giesbrecht, K.E., D.E. Varela, G.F. de Souza and C. Maden. 2022. Natural variations in dissolved silicon isotopes across the Arctic Ocean from the Pacific to the Atlantic. Global Biogeochemical Cycles, 2021GB007107. https://doi.org/10.1029/2021GB007107.

Antacli, J.C., M.P. Hernando, M. De Troch, G. Malanga, M. Mendiolar, D.R. Hernández, D.E. Varela, J. Antoni, R.J. SahadeI and I.R. Schloss. 2021. Ocean warming and freshening effects on lipid metabolism in coastal Antarctic phytoplankton assemblages dominated by sub-Antarctic species. Science of the Total Environment, 790, https://doi.org/10.1016/j.scitotenv.2021.147879.

Giesbrecht, K.E. and D.E. Varela. 2021. Summertime biogenic silica production and silicon limitation in the Pacific Arctic Region from 2006 to 2016. Global Biogeochemical Cycles, 35, e2020GB006629, doi: 10.1029/2020GB006629.

Wan, Z., M.S. Azam, S. Wyatt, K. Ramsay, J.L. Korner, K.S. Elvira, R. Padmawar, D.E. Varela and D.K. Hore. 2021. Algae adhesion onto silicone is sensitive to environment-induced surface restructuring. Langmuir, 31: 9597-9604, doi: 10.1021/acs.langmuir.1c01493.

Wan, Z., B.T. MacVicar, S. Wyatt, D.E. Varela, R. Padmawar and D.K. Hore. 2021. An automated image analysis platform for the study of weakly-adhered cells. Biofouling, 37: 387-396, doi: 10.1080/08927014.2021.1917555.

Antoni, J.S., G.O. Almandoz, M.E. Ferrario, M.P Hernando, D.E.Varela, P.D. Rozema, A.G.J. Buma and I.R. Schloss. 2020. Response of a natural Antarctic phytoplankton assemblage to changes in temperature and salinity. Journal of Experimental Marine Biology and Ecology, 523, doi: 10.1016/j.jembe.2020.151444.

Hernando, M.P., D.E. Varela, G. Malaga, G.O. Almandoz and I.R. Schloss. 2020. Effects of climate- induced changes in temperature and salinity on phytoplankton physiology and stress responses in coastal Antarctica. Journal of Experimental Marine Biology and Ecology, 530-531, doi: 10.1016/ j.jembe.2020.151400.

Comeau, A.M., M.G. Lagunas, K. Scarcella, D.E. Varela and C. Lovejoy. 2019. Nitrate consumers in Arctic marine eukaryotic communities: Comparative diversities of 18S rRNA, 18S rRNA genes, and nitrate reductase genes. Applied and Environmental Microbiology, 85:e00247-19, https://doi.org/10.1128/AEM.00247-19.

Giesbrecht, K.E., D.E. Varela, J. Wiktor and J.M. Grebmeier. 2019. A decade of summertime measurements of phytoplankton biomass, productivity and assemblage composition in the Pacific Arctic region from 2006 to 2016. Deep Sea Research II, 162: 93-113, https://doi.org/10.1016/j.dsr2.2018.06.010.

Michiels, C.C., J.A. Huggins, K.E. Giesbrecht, J.S. Spence, R.L. Simister, D.E. Varela, S.J. Hallam and S.A. Crowe. 2019. Rates and pathways of N2 production in a persistently anoxic fjord: Saanich Inlet, British Columbia. Frontiers in Marine Science 6: 27, doi: 10.3389/fmars.2019.00027.

Crawford, D.W., A.O. Cefarelli, I.A. Wrohan, S.N. Wyatt and D.E. Varela. 2018. Spatial patterns in abundance, taxonomic composition and carbon content of phytoplankton assemblages in Subarctic and Arctic seas.  Progress in Oceanography 162: 132-159, doi:10.1016/j.pocean.2018.01.006.

Hernando, M., I.R. Schloss, G.O. Almandoz, G. Malanga, D. E. Varela and M. De Troch. 2018. Combined effects of temperature and salinity on fatty acid content and lipid damage in Antarctic phytoplankton. Journal of Experimental Marine Biology and Ecology 503: 120-128, doi:10.1016/j.hembe.2018.03.004.

Hill, V., M. Ardyna, S.H. Lee and D.E. Varela. 2018. Decadal trends in phytoplankton production in the Pacific Arctic Region from 1950 to 2012. Deep Sea Research II 152: 82-94, http://dx.doi.org/10.1016/j.dsr2.2016.12.015. Last 3 authors had equal contributions but are listed in alphabetic order.

Hoppe, C.J.M., N. Schuback, D. Semeniuk, K. Giesbrecht, J. Mol, H. Thomas, M.T. Maldonado, B. Rost, D.E. Varela and P.D. Tortell. 2018. Resistance of Arctic phytoplankton to ocean acidification and high irradiance. Polar Biology, 41: 399-413, doi:10.1007/s00300-017-2186-0.

Paparazzo, F.E., G.N. Williams, J.P. Pisoni, M. Solis, J.L. Esteves and D.E. Varela, 2017. Linking phytoplankton nitrogen uptake, macronutrients and chlorophyll-a in SW Atlantic waters: The case of the San Jorge Gulf, Argentina. Journal of Marine Systems 172: 43-50, doi:10.1016/j.jmarsys.2017.02.007.

Suchy, K.D, J.F. Dower, D.E. Varela and M.G Lagunas. 2016. Interannual variability in the relationship between in situ primary productivity and somatic crustacean productivity in a temperate fjord. Marine Ecology Progress Series 545: 91-108, doi:10.3354/meps11608.

Varela, D.E, M.A. Brzezinski, C.P. Beucher, J.L Jones, K.E. Giesbrecht, B. Lansard and A. Mucci. 2016. Heavy silicon isotopic composition of silicic acid and biogenic silica in Arctic waters over the Beaufort shelf and the Canada Basin. Global Biogeochemical Cycles 30: 804-824, doi:10.1002/2015GB005277.

Crawford, D.W., S.N. Wyatt, I.A. Wrohan, A.O. Cefarelli, K.E. Giesbrecht, B. Kelly and D.E. Varela. 2015. Low particulate carbon to nitrogen ratios in marine surface waters of the Arctic. Global Biogeochemical Cycles 29: 2021-2033, doi:10.1002/2015GB005200.

Brown, K.A., F. McLaughlin, P.D. Tortell, D.E. Varela, M. Yamamoto‐Kawai, B. Hunt, and R. Francois. 2014. Determination of particulate organic carbon sources to the surface mixed layer of the Canada Basin, Arctic Ocean. Journal of Geophysical Research: Oceans, doi:10.1002/2013JC009197.

Sutton, J.N., D.E. Varela, M.A. Brzezinski and C.P. Beucher. 2013. Species-dependent silicon isotope fractionation by marine diatoms. Geochimica et Cosmochimica Acta 104, 300-309, doi:10.1016/j.gca.2012.10.057.

Varela, D.E., D.W. Crawford, I.A. Wrohan, S.N. Wyatt and E.C. Carmack. 2013. Pelagic primary productivity and upper ocean nutrient dynamics across Subarctic and Arctic Seas. Journal of Geophysical Research – Oceans 118(12), 7132–7152, doi:10.1002/2013JC009211.

Wyatt, S.N., D.W. Crawford, I.A. Wrohan and D.E. Varela. 2013. Distribution and composition of suspended biogenic particles in surface waters across Subarctic and Arctic Seas. Journal of Geophysical Research – Oceans 118(12), 6867–6880, doi:10.1002/2013JC009214.

Sastri, A.R., R. J. Nelson, D. E. Varela, K. V. Young, I. Wrohan and W. J. Williams. 2012. Variation of chitobiase-based estimates of crustacean zooplankton production rates in high latitude waters. Journal of Experimental Marine Biology and Ecology 414-415, 54-61, doi:10.1016/j.jembe.2012.01.012.

Tremblay, J.E., D. Robert, D.E. Varela, C. Lovejoy, G. Darnis, R.J. Nelson and A.R. Sastri. 2012. Current state and trends in Canadian Arctic marine ecosystems: I. Primary production. Climatic Change 115, 161-178, doi:10.1007/s10584-012-0496-3.

Varela, D.E., V. Willers and D.W. Crawford, 2011. Effect of zinc availability on growth, morphology and nutrient incorporation in a coastal and an oceanic diatom. Journal of Phycology 47, 302-312, https://doi.org/10.1111/j.1529-8817.2010.00948.x

Marchetti, A., D.E. Varela, V.P. Lance, Z. Johnson, M. Palmucci, M. Giordano and E. V. Armbrust, 2010. Iron and silicic acid effects on phytoplankton productivity, diversity and chemical composition in the central equatorial Pacific Ocean. Limnology and Oceanography 55, 11-29, https://doi.org/10.4319/lo.2010.55.1.0011.

Grundle, G.S., D.A. Timothy and D.E. Varela, 2009. Variations of phytoplankton production and biomass over an annual cycle in Saanich Inlet, a British Columbia fjord. Continental Shelf Research 29: 2257-2269, https://doi.org/10.1016/j.csr.2009.08.013.

Harris, S.L., D.E. Varela, F.W. Whitney and P.J. Harrison, 2009. Nutrient and phytoplankton dynamics off the West Coast of Vancouver Island during the 1997/98 ENSO event. Deep Sea Research II 56, 2487-2502, https://doi.org/10.1016/j.dsr2.2009.02.009.

Chapman, P.M., J. Cullen, C. Garrett, J. Littlepage, T. Pedersen, D. Varela, R. Macdonald, R. Thomson and T. Parsons, 2008. Sewage Treatment Wasted – The Victoria (BC, Canada) example. Editorial. Marine Pollution Bulletin 56, 1815-1816.

Peña, M.A. and D.E. Varela, 2007. Seasonal and interannual variability in phytoplankton and nutrient dynamics along Line P in the NE subarctic Pacific. Progress in Oceanography 75, 200-222, https://doi.org/10.1016/j.pocean.2007.08.009.

Levings, C.D., D.E. Varela, N.M. Mehenbacher, K.L. Barry, G.E. Piercey, M. Guo, G.E. and P.J. Harrison, 2005. Effect of an acid mine drainage effluent on phytoplankton biomass and primary production at Britannia Beach, Howe Sound, British Columbia. Marine Pollution Bulletin 50, 1585-1594, https://doi.org/10.1016/j.marpolbul.2005.06.032.

Milligan, A.J., D.E. Varela, M.A. Brzezinski and F.M.M. Morel, 2004. Dynamics of silicon metabolism and silicon isotopic discrimination in a marine diatom as a function of pCO2. Limnology and Oceanography 49, 322-329, https://doi.org/10.4319/lo.2004.49.2.0322.

Varela, D.E., C.J. Pride and M.A. Brzezinski, 2004. Biological fractionation of silicon isotopes in Southern Ocean surface waters. Global Biogeochemical Cycles 18, GB1047, doi:10.1029/2003GB002140.

Ianson, D., S.E. Allen, S.L. Harris, K.J. Orians, D.E. Varela and C.S. Wong, 2003. The inorganic carbon system in the coastal upwelling region west of Vancouver Island, Canada. Deep Sea Research I 50, 1023-1042, https://doi.org/10.1016/S0967-0637(03)00114-6.

Berges, J.A., D.E. Varela and P.J. Harrison, 2002. Effects of temperature on growth rate, composition and nitrogen metabolism in the marine diatom Thalassiosira pseudonana (Bacillariophyceae). Marine Ecology Progress Series 225, 139-146, https://doi:10.3354/meps225139.

Harrison, P.J., P.W. Boyd, D.E. Varela, S. Takeda, A. Shiomoto and T. Odate, 1999. Comparison of factors controlling phytoplankton productivity in the NE and NW subarctic Pacific gyres. Progress in Oceanography 43, 205-234, https://doi.org/10.1016/S0079-6611(99)00015-4.

Varela, D.E. and P.J. Harrison, 1999. Effect of ammonium on nitrate utilization by Emiliania huxleyi, a coccolithophore from the oceanic northeastern Pacific. Marine Ecology Progress Series 186, 67-74, https://doi:10.3354/meps186067.

Varela, D.E. and P.J. Harrison, 1999. Seasonal variability in nitrogenous nutrition of phytoplankton assemblages in the northeastern subarctic Pacific Ocean. Deep Sea Research II 46, 2505-2538, https://doi.org/10.1016/S0967-0645(99)00074-0.

Boyd, P.W., D.L. Muggli, D.E. Varela, R.H. Goldblatt, R. Chretien, K.J. Orians and P.J. Harrison, 1996. In vitro iron enrichment in the NE subarctic Pacific. Marine Ecology Progress Series 136, 179-193, https://doi:10.3354/meps136179.

Boyd, P.W., S. Strom, F.A. Whitney, S. Doherty, M.E. Wen, P.J. Harrison, C.S. Wong and D.E. Varela, 1995. The NE subarctic Pacific in winter: I. Biological standing stocks. Marine Ecology Progress Series 128, 11-24, https:// doi:10.3354/meps128011.

Esteves, J.L. and D.E. Varela, 1991. Dynamics of nutrient cycling of the Valdés Bay-Punta Cero Pond system (Peninsula Valdés, Patagonia) Argentine. Oceanologica Acta 14, 51-58, https://archimer.ifremer.fr/doc/00101/21273/18883.pdf

Other publications

Varela, D.E., K. L. Barry, M. Guo, G.E. Piercey, N.M. Mehlenbacher, P.J. Harrison and C.D. Levings, 2000. Water quality and oceanographic data near a deep water outfall discharging acid mine drainage from Britannia Mine into Howe Sound, British Columbia. Can. Data Rep. Fish. Aquat. Sci. 1063, 43 pp.

Varela, D., M. Soon, M. Guo, S.E. Calvert and P.J. Harrison, 2000. Macronutrient, chlorophyll a and particulate nitrogen and carbon concentrations, and nitrogen uptake rates for the euphotic zone in the NE subarctic Pacific during Canadian JGOFS I (1992-1994) and JGOFS II (1995-1997 ). JGOFS Canada Data Sets 1989-1998, CD-ROM Version 1.0 Dec. 2000, Marine Environmental Data Service, Department of Fisheries and Oceans, Canada. http://store.pangaea.de/Projects/JGOFS/Canada/home/datasets/varela/readme.htm

Varela, D.E., 1998. Nitrogenous nutrition of phytoplankton from the northeastern subarctic Pacific Ocean. Ph.D. thesis. Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, Canada. 198 pp.

Clifford, P.J., K. Yin, P.J. Harrison, M.A. St John, R. Goldblatt and D.E. Varela, 1992. Plankton production and nutrient dynamics in the Fraser River plume, 1991. Dept. Oceanography, UBC. Manuscr. Rep. 59, 415 pp.

Varela, D.E., 1990. Nitrogen remineralization in coastal marine sediments. M.A. thesis. Marine Program, Biology Department, Boston University, Boston, USA. 60 pp.

Varela, D.E. and J. Helfrich, 1987. Bacterial uptake of glutamic acid in oxic and anoxic waters in a coastal pond. Biological Bulletin 173, 434.

Varela, D.E., 1985. Qualitative and quantitative study of benthic macrofauna in Nueva Bay (Nuevo Gulf, Province of Chubut, Argentina). Honours thesis. Universidad Nacional del Sur, Bahía Blanca, Argentina.