This “re-plumbing” of the earth’s surface, recently referred to as Anthroturbation, rapidly expanded during the Industrial Revolution (~1800 CE) and the “Great Acceleration” (~ 1950 CE), leading to the concept of the Anthropocene. Some of the most compelling questions regarding the effects of the Anthropocene are how has this manipulation of the surface of our planet impacted the organisms and biogeochemistry of aquatic ecosystems, and how will these changes continue into the future? Although the general concept of critical zones has been somewhat included aquatic systems, I propose that these dynamic and vulnerable corridors of change are worthy of their own designation as aquatic critical zones (ACZs). While natural ACZs have always existed, anthropogenic “re-plumbing” of ACZs has resulted in alterations of their spatiotemporal patterns, and their response, from the molecular to organismal level, needs greater consideration in global biogeochemical models. The impacts of anthropogenic and climate effects on ecosystems, from gene to landscape scales, need to be better explored. Here, I discuss adaptive biogeochemical and organismal ramifications of global change on ACZs, along with potential hydrologic, geomorphic, and ecosystem services that could be linked to define ACZs as a critical research area. Finally, I posit that the poleward biogeographic shifts of organisms in response to climate warming will impact global biogeochemistry - with an emphasis on carbon cycling.
I am currently a full professor and holder of the Jon and Beverly Thompson Endowed Chair in Geological Sciences at the University of Florida (UF), Gainesville, Florida. Before joining UF I held full professor positions at Tulane University and Texas A&M University. My general areas of expertise are organic geochemistry, chemical oceanography, and global carbon cycling in aquatic ecosystems. I have published over 230 articles in refereed journals and am sole and/or co-author of 7 books, with another book on Chemical Oceanography of the Gulf of Mexico - due out in 2019. I am currently Editor-in-Chief of the journal Marine Chemistry, and have served as an Associate Editor for numerous other journals. I am the recipient of two Fulbright Research Awards, became a Fellow of the American Association for the Advancement of Science (AAAS) in 2012, in 2017 was named Geochemical Fellow of the Geochemical Society (GS) and The European Association of Geochemistry (EAG), Fellow of the Association for the Sciences of Limnology and Oceanography (ASLO), in 2018 was recipient of the Qilu Friendship Medal/Award from the Shandong Province of China, and most recently became Fellow of the American Geophysical Union (AGU) in 2019.
Many of the central issues in research concerning global climate change involve understanding the exchange and transport of organic and inorganic pools of carbon – in the context of the global carbon budget. If we are to successfully balance and model global carbon fluxes, it is important to understand the dynamics of carbon cycling in the most productive environments. In general, the most productive environments are located in land-margin ecosystems such as watershed soils, freshwater, and marine coastal systems. During the past few years my research has centered on organic carbon cycling from source-to-sink with work focused on the transport of soils in watersheds of large river systems to coastal environments. I have used state-of-the-art techniques to determine the role of terrestrial versus aquatic carbon sources in the overall carbon cycles of these ecosystems.