USAP-DC

The Antarctic marine ecosystem is highly productive and supports a diverse range of ecologically and commercially important species. A key species in this ecosystem is Antarctic krill, which in addition to being commercially harvested, is the principle prey of a wide range of marine organisms including penguins, seals and whales. The aim of this study is to use penguins and other krill predators as sensitive indicators of past changes in the Antarctic marine food web resulting from climate variability and the historic harvesting of seals and whales by humans. Specifically this study will recover and analyze modern (<20 year old), historic (20-200 year old) and ancient (200-10,000 year old) penguin and other krill predator tissues to track their past diets and population movements relative to shifts in climate and the availability of Antarctic krill. Understanding how krill predators were affected by these factors in the past will allow us to better understand how these predators, the krill they depend on, and the Antarctic marine ecosystem as a whole will respond to current challenges such as global climate change and an expanding commercial fishery for Antarctic krill. The project will further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This project will support the cross-institutional training of undergraduate and graduate students in advanced analytical techniques in the fields of ecology and biogeochemistry. In addition, this project includes educational outreach aimed encouraging participation in science careers by engaging K-12 students in scientific issues related to Antarctica, penguins, marine ecology, biogeochemistry, and global climate change.

This research will help place recent ecological changes in the Southern Ocean into a larger historical context by examining decadal and millennial-scale shifts in the diets and population movements of Antarctic krill predators (penguins, seals, and squid) in concert with climate variability and commercial harvesting. This will be achieved by coupling advanced stable and radio isotope techniques, particularly compound-specific stable isotope analysis, with unprecedented access to modern, historical, and well-preserved paleo-archives of Antarctic predator tissues dating throughout the Holocene. This approach will allow the project to empirically test if observed shifts in Antarctic predator bulk tissue stable isotope values over the past millennia were caused by climate-driven shifts at the base of the food web in addition to, or rather than, shifts in predator diets due to a competitive release following the historic harvesting of krill eating whale and seals. In addition, this project will track the large-scale abandonment and reoccupation of penguin colonies around Antarctica in response to changes in climate and sea ice conditions over the past several millennia. These integrated field studies and laboratory analyses will provide new insights into the underlying mechanisms that influenced past shifts in the diets and population movements of charismatic krill predators such as penguins. This will allow for improved projections of the ecosystem consequences of future climate change and anthropogenic harvesting scenarios in the Antarctica that are likely to affect the availability of Antarctic krill.

Person	Role
Polito, Michael	Investigator and contact
Emslie, Steven	Investigator
Kelton, McMahon	Investigator
Patterson, William	Co-Investigator
Michelson, Chantel	Researcher
Hayat, Bennadji	Researcher
Kristan, Allyson	Researcher
McCarthy, Matthew	Co-Investigator

Antarctic Organisms and Ecosystems	Award # 1826712
Antarctic Organisms and Ecosystems	Award # 1443585
Antarctic Organisms and Ecosystems	Award # 1443424
Antarctic Organisms and Ecosystems	Award # 1443386

USAP-1443585_1

None in the Database

Repository	Title (link)	Format(s)	Status
NCBI BioProject	Receding ice drove parallel expansions in Southern Ocean penguin	Excel	exists
Figshare	SNP data from "Receding ice drove parallel expansions in Southern Ocean penguins".	Excel	exists
USAP-DC	Carbon and nitrogen stable isotope values of Antarctic Krill from the South Shetland Islands and the northern Antarctic Peninsula 2007 and 2009	Excel	exists
USAP-DC	Radiocarbon dates from pygoscelid penguin tissues excavated at Stranger Point, King George Island, Antarctic Peninsula	Excel	exists
USAP-DC	Amino acid nitrogen isotope values of penguins from the Antarctic Peninsula region 1930s to 2010s	Excel	exists
USAP-DC	Radioisotope dates and carbon (δ13C) and nitrogen (δ15N) stable isotope values from modern and mummified Adélie Penguin chick carcasses and tissue from the Ross Sea, Antarctica	Excel	exists
USAP-DC	The rise and fall of an ancient Adelie penguin 'supercolony' at Cape Adare, Antarctica	Excel	exists
USAP-DC	Radiocarbon dating and stable isotope values of penguin and seal tissues recovered from ornithogenic soils on Platter Island, Danger Islands Archipelago, Antarctic Peninsula in December 2015.	Excel	exists
USAP-DC	Ancient Adelie penguin colony revealed by snowmelt at Cape Irizar, Ross Sea, Antarctica	Excel	exists
USAP-DC	Stable isotope analysis of multiple tissues from chick carcasses of three pygoscelid penguins in Antarctica	Excel	exists
USAP-DC	Radiometric dating, geochemical proxies, and predator biological remains obtained from aquatic sediment cores on South Georgia Island.	Excel	exists
USAP-DC	Amino acid nitrogen isotope values of modern and ancient Adélie penguin eggshells from the Ross Sea and Antarctic Peninsula regions	Excel	exists

1. Polito, M. J., Trivelpiece, W. Z., Reiss, C. S., Trivelpiece, S. G., Hinke, J. T., Patterson, W. P., & Emslie, S. D. (2019). Intraspecific variation in a dominant prey species can bias marine predator dietary estimates derived from stable isotope analysis. Limnology and Oceanography: Methods, 17(4), 292-303. (doi:10.1002/lom3.10314)
2. Kristan, A. K., Emslie, S. D., & Patterson, W. P. (2019). Stable isotope analyses of ancient and modern Adélie Penguin (Pygoscelis adeliae) mummies from the Ross Sea Region, Antarctica. Polar Biology, 1-10. (doi:10.1007/s00300-019-02513-4)
3. Emslie, S. D., McKenzie, A., Marti, L. J., & Santos, M. (2018). Recent occupation by Adelie penguins (Pygoscelis adeliae) at Hope Bay and Seymour Island and the ‘northern enigma’in the Antarctic Peninsula. Polar Biology, 41(1), 71-77. (doi:10.1007/s00300-017-2170-8)
4. Emslie, S.D., M. Romero, M. Juáres, & Argota M. (2019) Holocene occupation history of pygoscelid penguins at Stranger Point, King George (25 de Mayo) Island, northern Antarctic Peninsula. The Holocene 1-7. (doi:10.1177/0959683619875814)
5. McMahon, K. W., Michelson, C. I., Hart, T., McCarthy, M. D., Patterson, W. P., & Polito, M. J. (2019). Divergent trophic responses of sympatric penguin species to historic anthropogenic exploitation and recent climate change. Proceedings of the National Academy of Sciences Dec 2019, 201913093 (doi:10.1073/pnas.1913093116)
6. Wang, X., Liu, X., Fang, Y., Jin, J., Wu, L., Fu, P., … Emslie, S. D. (2020). Application of δ15N to trace the impact of penguin guano on terrestrial and aquatic nitrogen cycles in Victoria Land, Ross Sea region, Antarctica. Science of The Total Environment, 709, 134496. (doi:10.1016/j.scitotenv.2019.134496)
7. Emslie, S.D., A. McKenzie and W. P. Patterson (2018). The rise and fall of an ancient Adélie penguin ‘supercolony’ at Cape Adare, Antarctica. R. Soc. open sci., 5172032 (doi:10.1098/rsos.172032)
8. Emslie, S.D. (2020). Ancient Adelie penguin colony revealed by snowmelt at Cape Irizar, Ross Sea, Antarctica. Geology (doi:10.1130/G48230.1)
9. Kalvakaalva, R., Clucas, G., Herman, R. W., and Polito, M. J. (2020). Late Holocene variation in the hard prey remains and stable isotope values of penguin and seal tissues from the Danger Islands, Antarctica. Polar Biology, 43(10), 1571-1582. (doi:10.1007/s00300-020-02728-w)
10. Cole, T. L., Dutoit, L., Dussex, N., Hart, T., Alexander, A., Younger, J. L., Clucas, G.V., Frugone, M.J., Cherel, Y., Cuthbert, R., Ellenberg, U., Fiddaman, S.R., Hiscock, J., Houston D., Jouventin, P., Mattern, T., Miller, G., Miskelly, C., Nolan, P., Polito, M.J., Quillfeldt, P., Ryan, P.G., Smith, A., Tennyson, A.J.D., Thompson, D., Wienecke, B., Vianna, JA., and Ellenberg, U., (2019). Receding ice drove parallel expansions in Southern Ocean penguins. Proceedings of the National Academy of Sciences. 116 (52), 26690 (doi:10.1073/pnas.1904048116)
11. Ramirez, M. D., Besser, A. C., Newsome, S. D., & McMahon, K. W. (2021). Meta‐analysis of primary producer amino acid δ15N values and their influence on trophic position estimation. Methods in Ecology and Evolution, 12(10), 1750–1767. (doi:10.1111/2041-210x.13678)
12. Michelson, C.I. (2021) Penguin Proxies: Disentangling Historical and Millennial-Scale Ecosystem Shifts in the Antarctic Food Web. Louisiana State University, Doctoral Dissertation. 5442. https://digitalcommons.lsu.edu/gradschool_dissertations/5442
13. Kristan, A. K. (2021). Penguins past and present: Trace elements, stable isotopes, and population dynamics in Antarctic and sub-Antarctic penguins and seals. Louisiana State University, Masters Thesis. 5351. https://digitalcommons.lsu.edu/gradschool_theses/5351
14. Kristan, A. K., Maiti, K., McMahon, K. W., Dance, M. A., & Polito, M. J. (2022). Biological and geochemical proxies in sediment cores reveal shifts in marine predator population dynamics relative to historic anthropogenic exploitation and recent climate change at South Georgia Island sub-Antarctic. Polar Biology, 1-11. (doi:https://doi.org/10.1007/s00300-022-03067-8)
15. Kristan, A. K., Maiti, K., McMahon, K. W., Dance, M. A., & Polito, M. J. (2022). Biological and geochemical proxies in sediment cores reveal shifts in marine predator population dynamics relative to historic anthropogenic exploitation and recent climate change at South Georgia Island sub-Antarctic. Polar Biology. 45(8), 1379-1389. (doi:10.1007/s00300-022-03067-8)
16. Stahl, A. R., Rynearson, T. A., & McMahon, K. W. (2023). Amino acid carbon isotope fingerprints are unique among eukaryotic microalgal taxonomic groups. Limnology and Oceanography. Portico. (doi:10.1002/lno.12350)
17. Michelson, C. I., Polito, M. J., Wunder, M. B., Emslie, S. D., McCarthy, M. D., Patterson, W. P., & McMahon, K. W. (2023). Holocene climate change shifted Southern Ocean biogeochemical cycling and predator trophic dynamics. Limnology and Oceanography. 68, 2642–2653. (doi:10.1002/lno.12446)