Size in Square Kilometres
1 749 716 km2
Qualifying Species and Criteria
Southern right whales – Eubalaena australis
Criterion C (2)
Southern elephant seal – Mirounga leonina
Criterion C (2)
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The Argentine Basin IMMA is used as a foraging area by both southern right whale (Eubalaena australis) mothers and calves and adult southern elephant seal (Mirounga leonina) females. Both species have primary breeding grounds in the waters or coastal areas of Península Valdés (Argentina), and perform recurrent foraging trips to this cIMMA. Although there is no direct overlap between the epipelagic foraging of whales and the deep diving of seals, the area is critically important for the survival of reproductive females of both species.
Description of Qualifying Criteria
Criterion C: Key Life Cycle Activities
Sub-criterion C2: Feeding Areas
Satellite tracking information was used to infer habitat use of southern right whales (Eubalaena australis) and southern elephant seals (Mirounga leonina) (Zerbini et al., 2016; 2018; unpublished data; Campagna et al., 2021; McGovern et al., 2019). Southern right whales migrate from their calving grounds in the northern Patagonian gulfs, including Golfo Nuevo near Peninsula Valdes, Argentina, into the Patagonian shelf and the Argentine Basin. Animals moving into the basin comprise primarily females that were accompanied by a calf at the time of instrumentation. Movement models suggest that when they are in the basin these whales engage in area-restricted search behavior, which has been linked to feeding by marine vertebrates, including baleen whales (Jonsen et al., 2007; Bailey et al., 2009). This type of behavior is frequently associated with cyclonic, cold-water eddies (Zerbini et al., 2016), where it is believed southern right whales forage on zooplankton at the epipelagic zone.
Male elephant seals from the population that originates in colonies on Península Valdés forage in shallow water along the continental shelf or slope. In contrast, most adult females forage in the deeper waters of the Argentine Basin (Campagna et al. 1999, 2007, Lewis et al. 2006; McGovern et al., 2019; Campagna et al., 2021), although some may forage over the continental shelf (Eder et al. 2019). Approximately 17% of recorded adult female foraging dives occurred on the continental shelf, while 80% occurred over the continental slope and Argentine Basin (McGovern et al., 2019). Fishes of the families Microstomatidae and Myctophidae (Lampadena sp.) were recorded as the main prey, and captures were mainly on the mesopelagic system, with prey encounter depth being significantly deeper during the day (603 ± 202 m) than during dusk, night, and dawn (462 ± 193, 336 ± 217, and 327 ± 201 m, respectively). There was a clear association with deep water masses in the Argentine Basin, as females made most of their foraging dives (68%), and had the most prey encounters (67%) in Antarctic Intermediate Water followed by the Upper Circumpolar Deep Water, with 20% of dives and prey encounters (McGovern et al., 2021).
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Campagna, C., Fedak, M. A., & McConnell, B. J. (1999). Post-breeding distribution and diving behavior of adult male southern elephant seals from Patagonia. Journal of Mammalogy, 80(4), 1341-1352.
Campagna, C., Piola, A. R., Marin, M. R., Lewis, M., Zajaczkovski, U., & Fernández, T. (2007). Deep divers in shallow seas: Southern elephant seals on the Patagonian shelf. Deep Sea Research Part I: Oceanographic Research Papers, 54(10), 1792-1814.
Campagna, J., Lewis, M. N., González Carman, V., Campagna, C., Guinet, C., Johnson, M., … & Hindell, M. A. (2021). Ontogenetic niche partitioning in southern elephant seals from Argentine Patagonia. Marine Mammal Science, 37(2), 631-651.
Eder, E. B., Lewis, M. N., Campagna, C., & Koch, P. L. (2010). Evidence of demersal foraging from stable isotope analysis of juvenile elephant seals from Patagonia. Marine Mammal Science, 26(2), 430-442.
Fontela, M., Velo, A., Gilcoto, M., & Pérez, F. F. (2021). Anthropogenic CO2 and ocean acidification in Argentine Basin Water Masses over almost five decades of observations. Science of The Total Environment, 779, 146570.
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Lewis, R., O’Connell, T. C., Lewis, M., Campagna, C., & Hoelzel, A. R. (2006). Sex-specific foraging strategies and resource partitioning in the southern elephant seal (Mirounga leonina). Proceedings of the Royal Society B: Biological Sciences, 273(1603), 2901-2907.
McGovern, K. A., Rodriguez, D. H., Lewis, M. N., & Davis, R. W. (2019). Diving classification and behavior of free-ranging female southern elephant seals based on three-dimensional movements and video-recorded observations. Marine Ecology Progress Series, 620, 215-232.
McGovern, K. A., Rodríguez, D. H., Lewis, M. N., Eder, E. B., Piola, A. R., & Davis, R. W. (2022). Habitat associations of post-breeding female southern elephant seals (Mirounga leonina) from Península Valdés, Argentina. Deep Sea Research Part I: Oceanographic Research Papers, 185, 103789.
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Piola, A. R., Matano, R. P., Steele, J. H., Thorpe, S. A., & Turekian, K. K. (2001). Brazil and Falklands (Malvinas) currents. Ocean currents, 35-43.
Smythe‐Wright, D., & Boswell, S. (1998). Abyssal circulation in the Argentine Basin. Journal of Geophysical Research: Oceans, 103(C8), 15845-15851.
Zerbini, A.N., Rosenbaum, H., Mendez, M., Sucunza, F., Andriolo, A., Harris, G., Clapham, P.J., Sironi, M., Uhart, M. and Ajó, A.F. 2016. Tracking southern right whales through the southwest Atlantic: an update on movements, migratory routes and feeding destinations. Paper SC/66b/BRG26 presented to the IWC Scientific Committee, June 2016, Bled, Slovenia (unpublished), 16pp.
Zerbini, A.N., Ajo, A.F., Andriolo, A., Clapham, P.J., Crespo, E., Gonzalez, R., Harris, G., Mendez, M., Rosenbaum, H., Sironi, M., Sucunza, F. and Uhart, M. 2018. Satellite tracking of Southern right whales (Eubalaena australis) from Golfo San Matías, Rio Negro Province, Argentina. Paper SC/67B/CMP/17 presented to the IWC Scientific Committee, Bled, Slovenia, 23 April-6 May 2018, 10pp.