Assistant Professor I am a biological oceanographer interested the how the ocean environment influences zooplankton populations (animals in the water column between ~50 microns and 10 cm in size). Encompassing a diverse community of animals with different body plans, from crustaceans to gelatinous organisms and the early life stages of fishes, zooplankton form a critical link between the ocean’s primary production and economically important fish species. The oceanographic processes that determine zooplankton distributions and abundance, therefore, are fundamentally connected to broader marine ecosystem functioning. To describe how the ocean environment structures zooplankton communities, members of my research group use towed camera systems, oceanographic sensors, and more conventional gear (e.g., plankton nets). These towed camera systems and associated sensors provide a “new view” of ocean life by resolving detailed spatial relationships among zooplankton taxa, as well as provide novel insights into zooplankton interactions and behavior. I am also interested in applying artificial intelligence and other computational techniques to analyze imagery/video datasets, which will enhance our capabilities for unraveling complex ecological relationships. Education B.A. Vanderbilt University, Biological Sciences 2007 Ph.D. University of Miami, Marine Biology & Fisheries 2013 Postdoctoral Fellowships: University of Georgia, College of Engineering (2013-2015) University of Southern Mississippi, Division of Marine Science (2015-2018) Research Research Areas: Biological Oceanography Research Interests: -Influence of oceanography and ecological interactions on the abundance and distribution of zooplankton and larval fishes -Role of gelatinous organisms in trophic interactions and food webs -Sampling technologies (especially in situ imaging) and computational approaches in marine ecology -Diel vertical migrations of zooplankton and behavioral responses to oceanographic features (e.g., ocean fronts, thin layers, hypoxia) Current Projects: NSF Biological Oceanography - Do fine-scale water column structure and particle aggregations favor gelatinous-dominated food webs in subtropical continental shelf environments? NSF Biological Oceanography - The significance of doliolid microbial interactions: Do doliolids fundamentally alter the trophic structure and productivity of sub-tropical continental shelf food webs? Previous Projects: CONsortium for COastal River-Dominated Ecosystems (CONCORDE) – the influence of river plumes on the abundance and distribution of plankton in the northern Gulf of Mexico Intermediate Trophic Levels (InTro) – the abundance and distribution of marine organisms (from microbes to fish) on the Delaware continental shelf in collaboration with the Naval Research Lab and several academic institutions Selected Publications Greer, A.T., P.I. Duffy, T.J.W. Walles, C. Cousin, L.M. Treible, K.D. Aaron, J.C. Nejstgaard. 2024. Modular shadowgraph imaging for zooplankton ecological studies in diverse field and mesocosm settings. Limnology & Oceanography: Methods doi: 10.1002/lom3.10657 Barua, R., L. Nyman, B. Guo, M.D. Johnson, A.U. Kerkar, J. Hong, A.T. Greer, J. Lehrter, M. McFarland, B. Penta, A.R. Nayak. 2024. In situ imaging of a kleptoplastidic ciliate thin layer indicates traditional sampling underestimates oceanic mixotroph biomass. Communications Earth & Environment doi: 10.1038/s43247-024-01708-w Savidge, W.B., D.K. Savidge, F. Brandini, A.T. Greer, E.E. Hoffmann, M. Roughan, I. da Silveira, I.M. Suthers. 2024. Workshop Report: Western Boundary Current – Subtropical Continental Shelf Interactions. Oceanography 37(3):64-69 doi: 10.5670/oceanog.2024.502 Greer, A.T., M.S. Schmid, P.I. Duffy, K.L. Robinson, M.A. Genung, J.Y. Luo, T. Panaiotis, C. Briseño-Avena, M.E. Frischer, S. Sponaugle, R.K. Cowen. 2023. In situ imaging across ecosystems to resolve the fine-scale oceanographic drivers of a globally significant planktonic grazer. Limnology & Oceanography 68(1):192-207. doi: 10.1002/lno.12259 Treible, L.M., L.M. Chiaverano, A.T. Greer. 2022. Fine-scale habitat associations of medusae and ctenophores along a gradient of river influence and dissolved oxygen. Estuarine, Coastal, and Shelf Science 272:107887. doi: 10.1016/j.ecss.2022.107887 McManus, M.A., A.T. Greer, A.V. Timmerman, J.C. Sevadjian, C.B. Woodson, R.K. Cowen, D.A. Fong, S. Monismith, O.M. Cheriton. 2021. Characterization of the biological, physical and chemical properties of a toxic thin layer in a temperate marine system. Marine Ecology Progress Series 678:17-35. doi: 10.3354/meps13879 Greer, A.T., L.M. Chiaverano, L.M. Treible, C. Briseño-Avena, F.J. Hernandez. 2021. From spatial pattern to ecological process through imaging zooplankton interactions. ICES Journal of Marine Science 78(8):2664–2674. doi: 10.1093/icesjms/fsab149 Greer, A.T., J.C. Lehrter, B.M. Binder, A.R. Nayak, R. Barua, A.E. Rice, J.H. Cohen, M.N. McFarland, A. Hagemeyer, N.D. Stockley, K.M. Boswell, I. Shulman, S. deRada, B. Penta. 2020. High-resolution sampling of a broad marine life size spectrum reveals differing size- and composition-based associations with physical oceanographic structure. Frontiers in Marine Science 7:542701, doi: 10.3389/fmars.2020.542701 Greer, A.T., A.D. Boyette, V.J. Cruz, M.K. Cambazoglu, B. Dzwonkowski, L.M. Chiaverano, S.L. Dykstra, C. Briseño-Avena, R.K. Cowen, and J.D. Wiggert. 2020. Contrasting fine-scale distributional patterns of zooplankton driven by the formation of a diatom-dominated thin layer. Limnology & Oceanography, 65(9):2236-2258. doi: 10.1002/lno.11450 Parra, S.M., V. Sanial, A.D. Boyette, M.K. Cambazoglu, I.M. Soto, A.T. Greer, L.M. Chiaverano, A. Hoover, and M.S. Dinniman. 2020. Bonnet Carré Spillway freshwater transport and corresponding biochemical properties in the Mississippi Bight. Continental Shelf Research 199:104114. doi: 10.1016/j.csr.2020.104114 Parra, S.M., A.T. Greer, J.W. Book, A.L. Deary, I.M. Soto, C. Culpepper, F.J. Hernandez, and T.N. Miles. 2019. Acoustic detection of zooplankton diel vertical migration behaviors on the northern Gulf of Mexico shelf. Limnology & Oceanography 64(5):2092-2113. doi: 10.1002/lno.11171 Greer, A.T., L.M. Chiaverano, J.G. Ditty, and F.J. Hernandez. 2019. In situ observations of fish larvae encased within a pelagic gelatinous matrix. Marine Ecology Progress Series 614:209-214. doi: 10.3354/meps12916 Dzwonkowski, B., S. Fournier, J.T. Reager, S. Milroy, K. Park, A.M Shiller, A.T. Greer, I. Soto, S.L. Dykstra, and V. Sanial. 2018. Tracking sea surface salinity and dissolved oxygen on a river-influenced, seasonally stratified shelf, Mississippi Bight, northern Gulf of Mexico. Continental Shelf Research 169:25-33. doi: 10.1016/j.csr.2018.09.009 Greer, A.T., A.M. Shiller, E.E. Hofmann, J.D. Wiggert, S.J. Warner, S.M. Parra, C. Pan, J.W. Book, D. Joung, S. Dykstra, J.W. Krause, B. Dzwonkowski, I.M. Soto, M.K. Cambazoglu, A.L. Deary, C. Briseño-Avena, A.D. Boyette, J.A. Kastler, L. Hode, U. Nwankwo, L.M. Chiaverano, V. Sanial, S.J. O’Brien, P.J. Fitzpatrick, Y. Lau, M.S. Dinniman, K.M. Martin, P. Ho, A.K. Mojzis, S.D. Howden, F.J. Hernandez, I. Church, T.N. Miles, S. Sponaugle, J.N. Moum, R.A. Arnone, R.K. Cowen, G.A. Jacobs, O. Schofield, and W.M. Graham. 2018. Functioning of coastal river-dominated ecosystems and implications for oil spill response: from observations to mechanisms and models. Oceanography 31(3):90-103. doi: 10.5670/oceanog.2018.302 Greer, A.T., L.M. Chiaverano, J.Y. Luo, R.K. Cowen, and W.M. Graham. 2018. Ecology and behaviour of holoplanktonic scyphomedusae and their interactions with larval and juvenile fishes in the northern Gulf of Mexico. ICES Journal of Marine Science 75(2):751-763. doi: 10.1093/icesjms/fsx168 Greer, A.T., C. Briseño-Avena, A.L. Deary, F.J. Hernandez, R.K. Cowen, and W.M. Graham. 2017. Associations between lobster phyllosoma and gelatinous zooplankton in relation to oceanographic properties in the northern Gulf of Mexico. Fisheries Oceanography 26(6):693-704. doi: 10.1111/fog.12228 Dzwonkowski, B., A.T. Greer, C. Briseño-Avena, J.W. Krause, I.M. Soto, F.J. Hernandez, A.L. Deary, J.D. Wiggert, D. Joung, P.J. Fitzpatrick, S.J. O’Brien, S.L. Dykstra, Y. Lau, M.K. Cambazoglu, G. Lockridge, S.D. Howden, A.M. Shiller, and W.M. Graham. 2017. Estuarine influence on biogeochemical properties of the Alabama shelf during the fall season. Continental Shelf Research 140:96-109. doi: 10.1016/j.csr.2017.05.001 Greer, A.T., C.B. Woodson, C.E. Smith, C.M. Guigand, and R.K. Cowen. 2016. Examining mesozooplankton patch structure and its implications for trophic interactions in the northern Gulf of Mexico. Journal of Plankton Research 38(4):1115-1134. doi: 10.1093/plankt/fbw033 Greer, A.T., C.B. Woodson, C.M. Guigand, and R.K. Cowen. 2016. Larval fishes utilize Batesian mimicry as a survival strategy in the plankton. Marine Ecology Progress Series 551 (Feature Article):1-12. doi: 10.3354/meps11751 Greer, A.T. and C.B. Woodson. 2016. Application of a predator-prey overlap metric to determine the impact of sub-grid scale feeding dynamics on ecosystem productivity. ICES Journal of Marine Science 73(4):1051-1061. doi: 10.1093/icesjms/fsw001 Greer, A.T., R.K. Cowen, C.M. Guigand, and J.A. Hare. 2015. Fine-scale planktonic habitat partitioning at a shelf-slope front revealed by a high-resolution imaging system. Journal of Marine Systems 142:111-125. doi: 10.1016/j.jmarsys.2014.10.008 Luo, J.Y., B. Grassian, D. Tang, J.O. Irisson, A.T. Greer, C.M. Guigand, S. McClatchie, and R.K. Cowen. 2014. Environmental drivers of the fine-scale distribution of a gelatinous zooplankton community across a mesoscale front. Marine Ecology Progress Series 510: 129-149. doi: 10.3354/meps10908 Greer, A.T., R.K. Cowen, C.M Guigand, J.A. Hare, and D. Tang. 2014. The role of internal waves in larval fish interactions with predators and prey. Progress in Oceanography 127:47-61. doi: 10.1016/j.pocean.2014.05.010 Sevadjian, J.C., M.A. McManus, J.P. Ryan, A.T. Greer, R.K. Cowen, and C.B. Woodson. 2014. Across-shore variability in plankton layering and abundance associated with physical forcing in Monterey Bay, California. Continental Shelf Research 72:138-151. doi: 10.1016/j.csr.2013.09.018 Timmerman, A.H.V, M.A. McManus, O.M. Cheriton, R.K. Cowen, A.T. Greer, R.M. Kudela, K.C. Ruttenberg, and J.C. Sevadjian. 2014. Hidden thin layers of toxic diatoms in a coastal bay. Deep Sea Research II 101:129-140. doi: 10.1016/j.dsr2.2013.05.030 Greer, A.T., R.K. Cowen, C.M. Guigand, M.A. McManus, J.C. Sevadjian, and A.H.V. Timmerman. 2013. Relationships between phytoplankton thin layers and the fine-scale vertical distribution of two trophic levels of zooplankton. Journal of Plankton Research 35(5) (Featured Article and cover image):939-956. doi: 10.1093/plankt/fbt056 Cowen, R.K., A.T. Greer, C.M. Guigand, J.A. Hare, D.E. Richardson, and H.J. Walsh. 2013. Evaluation of the In Situ Ichthyoplankton Imaging System (ISIIS): Comparison with the traditional (bongo net) sampler. Fishery Bulletin 38:1-12. doi: 10.7755/FB.111.1.1 McClatchie, S., R.K. Cowen, K. Nieto, A.T. Greer, J.Y. Luo, C. Guigand, D. Demer, D. Griffith, and D. Rudnick. 2012. Resolution of fine biological structure including small narcomedusae across a front in the Southern California Bight. Journal of Geophysical Research 117:C04020. doi: 10.1029/2011JC007565 Courses Regularly Taught MARS 1021E MARS 8010 MARS 8210
