Paper No. 163-2
Presentation Time: 5:50 PM
THE ROLE OF THE MARINE BIOLOGICAL PUMP IN DRIVING ECOSYSTEM RECOVERY FOLLOWING THE CRETACEOUS-PALEOGENE (K-PG) MASS EXTINCTION EVENT
JONES, Heather L.1, WHITESIDE, Jessica H.2, ROEHL, Ursula3, WESTERHOLD, Thomas3, HULL, Pincelli M.4, BIRCH, Heather5, ROBINSON, Libby J.2, ALEGRET, Laia6, HENEHAN, Michael J.7, LOWERY, Christopher M.8, NEGRA, M. Hedi9, SEPÚLVEDA, Julio10, VAN DIJK, Joep10, VELLEKOOP, Johan11, PATZKOWSKY, Mark E.1 and BRALOWER, Timothy J.1, (1)Department of Geosciences, The Pennsylvania State University, University Park, PA 16802, (2)Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, SO14 3ZH, United Kingdom, (3)MARUM - Center for Marine Environmental Research, Bremen University, Leobener Strasse, Bremen, 28359, Germany, (4)Department of Earth and Planetary Sciences, Yale University, 210 Whitney Ave., New Haven, CT 06511, (5)School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol, BS8 1RJ, United Kingdom, (6)Dept. Ciencias de la Tierra & IUCA, University of Zaragoza, Zaragoza, 50009, Spain, (7)Geochemistry of the Earth's surface, GFZ German Research Centre for Geosciences-Helmholtz Centre, Potsdam, 14473, Germany, (8)Institute for Geophysics, University of Texas, J.J. Pickle Research Campus, Building 196, 10100 Burnet Rd., Austin, TX 78758, (9)Department of Geology, University of Tunis El Manar, Faculty of Sciences of Tunis, Campus universitaire, 2092 Manar II, Tunis, Tunisia, (10)Geological Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, 450 UCB, Boulder, CO 80309, (11)Department of Earth and Environmental Sciences, University of Leuven, Naamsestraat 22, 3000, Leuven, 3000, Belgium
The Cretaceous-Paleogene (K-Pg) mass extinction event (~66 Ma) led to the eradication of >75% of marine species on Earth. One of the biggest consequences of the mass extinction was the apparent weakening of the biological pump: the mechanism whereby organic matter is exported from the surface to deep ocean and is eventually sequestered in deep-sea sediments. Although there was only a transient reduction in the strength of the biological pump immediately after the K-Pg extinction, several records have shown that the efficiency of the biological pump took >2 million years to recover. In addition, its complete restoration was temporally heterogeneous, perhaps due to paleoceanographic differences between ocean basins and marine environments.
Previous research indicates that planktic foraminiferal feeding strategies and adaptations changed in tandem with stages in the recovery of the biological pump, with symbiont-bearing forms only becoming dominant once pump efficiency was high and nutrient availability in shallow waters was low. Less work has been conducted to determine whether similar evolutionary patterns can be recognized in the phytoplankton, which are a keystone at the base of the marine food web. Here, we use the extensive and globally distributed record of calcareous nannoplankton (unicellular, golden-brown algae) at two geographically-disparate K-Pg sites (El Kef; Tunisia and the Chicxulub impact crater; Gulf of Mexico), to show that switchovers in low diversity, high abundance paleo-blooms (“boom-bust successions”) were also a direct response to the restoration of biological pump efficiency. Possible boom-bust successions are also recognized in other taxonomic groups such as the planktic foraminifera, benthic foraminifera, bivalves, and gastropods during the early Danian, suggesting that the biological pump was key in driving the restoration of the entire marine ecosystem following the mass extinction event. As the recovery of multiple taxonomic groups appear to be intrinsically linked, future work should focus on combining these disparate paleoecological datasets to gain a more holistic understanding of how entire marine ecosystems recover following extreme environmental perturbation.
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