USAP-DC

Intellectual Merit: Pleuragramma antarcticum, the Antarctic silverfish, play a key role in the trophic pyramid of the Antarctic coastal ecosystem, acting as food for larger fishes, flying and non-flying seabirds, pinnipeds, and whales. In turn, they are predators on coastal euphausiids, including both Euphausia superba and crystallorophias. Historically, Pleuragramma have been an important food source for Adélie Penguins of the Western Antarctic Peninsula (WAP), but during the last decade Pleuragramma have disappeared from the Adélie diet. We suggest that Pleuragramma?s absence from the diets of top predators is linked to the declining sea ice canopy, which serves as a nursery for eggs and larvae during the austral spring. The research will investigate four hydrographic regimes over the WAP continental shelf with the following features: (1) persistent gyral flows that act to retain locally spawned larvae, (2) spring sea ice that has declined in recent years (3) the prevalence of adult silverfish, and (4) the presence of breeding Adélie penguins whose diets vary in the proportions of silverfish consumed. The research will evaluate the importance of local reproduction versus larval advection, and the extent to which populations in the subregions of study are genetically distinct, via analysis of population structure, otolith microchemistry and molecular genetics of fish. The Pleuragramma data will be compared with penguin diet samples taken synoptically.

Broader Impacts: The proposed research brings together an international group of scientists with highly complimentary suites of skills to address the fate of Pleuragramma on the WAP shelf. Graduate students will use the data acquired as part of their Ph.D research, and will receive cross-training in ornithological field techniques, molecular genetic methods and otolith isotope chemistry. The PIs will work actively with the St. Petersburg Times to produce a blog in real time with pictures and text, which will be used to interact with local schools while we are at sea and after our return. The investigators also will collaborate with the COSEE center at USF and at local schools and museums to disseminate results to the K-12 community throughout the region.

Person	Role
Torres, Joseph	Investigator

Antarctic Organisms and Ecosystems

Award # 0741348

Deployment	Type
NBP1002	ship expedition

None in the Database

Repository	Title (link)	Format(s)	Status
R2R	Expedition data of NBP1002	None	exists

1. Brooks, C. M., Caccavo, J. A., Ashford, J., Dunbar, R., Goetz, K., La Mesa, M., & Zane, L. (2018). Early life history connectivity of Antarctic silverfish (Pleuragramma antarctica ) in the Ross Sea. Fisheries Oceanography, 27(3), 274–287. (doi:10.1111/fog.12251)
2. Parker, M. L., Fraser, W. R., Ashford, J., Patarnello, T., Zane, L., & Torres, J. J. (2015). Assemblages of micronektonic fishes and invertebrates in a gradient of regional warming along the Western Antarctic Peninsula. Journal of Marine Systems, 152, 18–41. (doi:10.1016/j.jmarsys.2015.07.005)
3. Agostini, C., Patarnello, T., Ashford, J. R., Torres, J. J., Zane, L., & Papetti, C. (2015). Genetic differentiation in the ice-dependent fishPleuragramma antarcticaalong the Antarctic Peninsula. Journal of Biogeography, 42(6), 1103–1113. (doi:10.1111/jbi.12497)
4. La Mesa, M., Riginella, E., Mazzoldi, C., & Ashford, J. (2014). Reproductive resilience of ice-dependent Antarctic silverfish in a rapidly changing system along the Western Antarctic Peninsula. Marine Ecology, 36(2), 235–245. (doi:10.1111/maec.12140)
5. Henry, L. V., & Torres, J. J. (2013). Metabolism of an Antarctic solitary coral, Flabellum impensum. Journal of Experimental Marine Biology and Ecology, 449, 17–21. (doi:10.1016/j.jembe.2013.08.010)