My research interests include 1) effects of human activity on water, carbon, and nutrient fluxes from land to sea, and 2) responses of coastal ecosystems to changes in land-derived inputs.
Environmental changes as a consequence of human activity, including changes in land use, land cover, and global warming, provide the context for much of my work. These changes are having a profound influence on the transport of water and water-borne constituents from land to sea. In turn, changes in the fluxes of water, carbon, and nutrients to estuaries and the coastal ocean are altering fundamental ecosystem properties such as primary production and food web structure.
Changes in land-sea fluxes have broader implications as well, including alteration of the global carbon budget and potential impacts of freshwater inputs on global ocean circulation and climate. To identify and explore changes in land-sea coupling I use a wide variety of approaches including analysis of historic data sets, field studies of biogeochemical cycling and constituent transport, and modeling. In my field studies, I frequently take advantage of stable isotopes and other natural markers to track the fate of water, organic matter, and nutrients from land through estuarine and marine systems.
Behnke, M.I., J.W. McClelland, S.E. Tank, A.M. Kellerman, R.M. Holmes, N. Haghipour, T.I. Eglinton, P.A. Raymond, A. Suslova, A.V. Zhulidov, T. Gurtovaya, N. Zomov, S. Zimov, E.A. Mutter, E. Amos, and R.G.M. Spencer. 2021. Pan-Arctic riverine dissolved organic matter: Synchronous molecular stability, shifting sources and subsidies. Global Biogeochemical Cycles 35:e2020GB006871, doi:10.1029/2020GB006871.
Bristol, E.M., C.T. Connolly, T.D. Lorenson, B.M. Richmond, A.G. Ilgen, R.C. Chones, D.L. Bull, M. Kanevskiy, G. Iwahana, B.M. Jones, and J.W. McClelland. 2021. Geochemistry of coastal permafrost and erosion-driven organic matter fluxes to the Beaufort Sea near Drew Point, Alaska. Frontiers in Earth Science 8:598933, doi:10.3389/feart.2020.598933.
Connolly, C.T., B.C. Crump, K.H. Dunton, and J.W. McClelland. 2021. Seasonality of dissolved organic matter in lagoon ecosystems along the Alaska Beaufort Sea coast. Limnology and Oceanography 66:4299-4313, doi:10.1002/lno.11962.
Rawlins, M.A., Connolly, C.T., and J.W. McClelland. 2021. Modeling terrestrial dissolved organic carbon loading to western Arctic rivers. Journal of Geophysical Sciences – Biogeosciences 126, e2021JG006420, doi:10.1029/2021JG006420.
Xu, X., H. Wei, G. Barker, K. Holt, S. Julian, T. Light, S. Melton, A. Salamanca, K.B. Moffett, J.W. McClelland, and A.K. Hardison. 2021. Tidal freshwater zones as hotspots for biogeochemical cycling: Sediment organic matter decomposition in the lower reaches of two south Texas rivers. Estuaries and Coasts 44:722-733, doi:10.1007/s12237-020-00791-4.
Connolly, C.T., M.B. Cardenas, G.A. Burkart, R.G.M. Spencer, and J.W. McClelland. 2020. Groundwater as a major source of dissolved organic matter to Arctic coastal waters. Nature Communications 11, 1479, doi:10.1038/s41467-020-15250-8.
Jones, A.E., A.K. Hardison, B.R. Hodges, J.W. McClelland, and K.B. Moffett. 2020. Defining a riverine tidal freshwater zone and its spatiotemporal dynamics. Water Resources Research 56, e2019WR026619, doi:10.1029/2019WR026619.
Tank, S.E., J.E. Vonk, M.A. Walvoord, J.W. McClelland, I. Laurion, and B.W. Abbott. 2020. Landscape matters: Predicting the biogeochemical effects of permafrost thaw on aquatic networks with a state factor approach, Permafrost and Periglacial Processes, doi:10.1002/ppp.2057.
Glibert, P.M., J.J. Middelburg, J.W. McClelland, and J. Vander Zanden. 2019. Stable isotope tracers: Enriching our perspectives and questions on sources, fates, rates and pathways of major elements in aquatic systems. Limnology and Oceanography 64:950-981, doi:10.1002/lno.11087.
Wild, B., A. Andersson, L. Bröder, J. Vonk, G. Hugelius, J.W. McClelland, W. Song, P.A. Raymond, and Ö. Gustafsson. 2019. Rivers across the Siberian Arctic unearth the patterns of carbon release from thawing permafrost. Proceedings of the National Academy of Sciences, doi:10.1073/pnas.1811797116.