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At-sea abundance and spatial distribution of South American sea lion (Otaria byronia) in Chilean Northern Patagonia: How many are there?

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Abstract

The South American sea lion (Otaria byronia) (SSL) is a widespread opportunistic predator that inhabits waters ranging from Southern Ecuador to Southern Chile in the Pacific Ocean and from Southern Brazil to Southern Argentina in the Atlantic. SSL abundance estimates, as for many pinniped species, have relied on shore censuses, with the uncertainty that an indeterminate number of individuals at sea might remain uncounted. The proportion of the population that remains at sea during censuses and their distribution patterns are not clear and has been scarcely assessed. We used line transect sampling to gather information about at-sea abundance, density and spatial distribution of SSL in coastal waters off the Chilean Northern Patagonia. A total of 123 groups were sighted while on-effort, with an estimated density of 0.393 ind./km2 (95%CI = 0.262-0.591) and a total abundance, for the surveyed area, of 13,721 individuals (95%CI = 9127-20,627). Even when our survey was rather restricted in spatial range, generalized additive model results showed that depth, distance to SSL rockeries, coastline complexity and geographical coordinates had a significant influence on SSL spatial distribution. The results on abundance and spatial distribution of SSL at sea are discussed in terms of current population estimates. Our substantial at-sea abundance estimate suggests that shore censuses might have been historically biased. Several aspects should be taken into account in further research on SSL abundance, such as including pelagic waters and undertaking simultaneously on-rockery and marine SSL abundance estimates. The results presented here provide valuable insights for revisiting and possibly improve population estimates of SSL and other pinnipeds species worldwide. This is particularly relevant when management and conservation actions need to be taken on those species that have strong interactions with fisheries and aquaculture.

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References

  • Berkson, J.M., DeMaster, D.P., 1985. Use of pup counts in indexing population changes in pinnipeds. Can. J. Fish. Aquat. Sci. 42 (5), 873–879.

    Article  Google Scholar 

  • Beyer, H.L., 2012. Geospatial Modelling Environment (Version 0.7.2.0). https://doi.org/www.spatialecology.com/gme

  • Bjørge, A., Bekkby, T., Bakkestuen, V., Framstad, E., 2002. Interactions between harbour seals, Phoca vitulina, and fisheries in complex coastal waters explored by combined Geographic Information System (GIS) and energetics modelling. ICES J. Mar. Sci. 59 (1), 29–42.

    Article  Google Scholar 

  • Buckland, S.T., Anderson, D.R., Burnham, K.P., Laake, J.L., Borchers, D.L., Thomas, L, 2001. Introduction to Distance Sampling: Estimating Abundance of Biological Populations. Oxford University Press, Oxford.

    Google Scholar 

  • Calkins, D.G., Mallister, D.C., Pitcher, K.W., Pendleton, G.W., 1999. Stellersea lion status and trend in Southeast Alaska: 1979–1997. Mar. Mamm.Sci. 15(2), 462–477.

  • Call, K.A., Loughlin, T.R., 2005. An ecological classification of Alaskan Steller sea lion (Eumetopias jubatus) rookeries: a tool for conservation/management. Fish. Oceanogr. 14 (1), 212–222.

  • Campagna, C, Werner, R., Karesh, W., Marín, M.R., Koontz, F., Cook, R., Koontz, C, 2001. Movements and location at sea of South American sea lions (Otaria flavescens). J. Zool. 255 (2), 205–220.

    Article  Google Scholar 

  • Crespo, E.A., (Ph.D. dissertation) 1988. Dinámicapoblacionaldel lobomarinodelsur Otaria flavescens (Shaw, 1800). en el norte del litoral patagónico. University of Buenos Aires, Buenos Aires, Argentina.

  • Crespo, E.A., Pedraza, S.N., Dans, S.L., Alonso, M.K., Reyes, L.M., García, N.A., Coscarella, M., Schiavini, A.C., 1997. Direct and indirect effects of the high-seas fisheries on the marine mammal populations in the northern and central Patagonian coast. J. Northwest Atl. Fish. Soc. 22, 189–207.

    Article  Google Scholar 

  • Dans, S.L., Crespo, E.A., Pedraza, S.N., Alonso, M.K., 2004. Recovery of the South American sea lion (Otaria flavescens) population in northern Patagonia. Can. J. Fish. Aquat. Sci. 61, 1681–1690, https://doi.org/10.1139/f04-105.

  • Dávila, P.M., Figueroa, D., Müller, E., 2002. Freshwater input into the coastal ocean and its relation with the salinity distribution off austral Chile (35-55 S). Cont. Shelf Res. 22 (3), 521–534.

  • Dawson, S.M., Wade, P., Slooten, E., Barlow, J., 2008. Design and field methods for sighting surveys of cetaceans in coastal and riverine habitats. Mamm. Rev. 38 (1), 19–49.

  • de laTorriente, A., Quinones, R.A., Miranda-Urbina, DA, Echevarría, F., 2010. South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia. ICES J. Mar. Sci. 67 (2), 294–303.

  • Drago, M., Crespo, E.A., Aguilar, A., Cardona, L, García, N., Dans, S.L., Goodall, N., 2009. Historic diet change of the South American sea lion in Patagonia as revealed by isotopic analysis. Mar. Ecol. Prog. Ser. 384, 273–286.

    Article  CAS  Google Scholar 

  • Drago, M., Cardona, L, Aguilar, A., Crespo, E.A., Ameghino, S., García, N., 2010. Diet of lactating South American sea lions, as inferred from stable isotopes, influences pup growth. Mar. Mamm. Sci. 26 (2), 309–323.

  • Félix, F., 2002. Una colonia de lobos marinos sudamericanos (Otaria flavescens) en Salinas, Ecuador. Acta Oceanogr. Pac. 11 (1), 181–184.

  • Fewster, R.M., Buckland, S.T., Burnham, K.P., Borchers, D.L., Jupp, P.E., Laake, J.L., Thomas, L, 2009. Estimating the encounter rate variance in distance sampling. Biome 65, 225–236.

    Google Scholar 

  • Friedlaender, A.S., Halpin, P.N., Qian, S.S., Lawson, G.L., Wiebe, P.H., Thiele, D., Read, A.J., 2006. Whale distribution in relation to prey abundance and oceanographic processes in shelf waters of the Western Antarctic Peninsula. Mar. Ecol. Prog. Ser. 317, 297–310.

    Article  Google Scholar 

  • George-Nascimento, M., Bustamante, R., Oyarzun, C, 1985. Feeding ecology of the South American sea lion Otaria flavescens: food contents and food selectivity. Mar. Ecol. Prog. Ser. 21, 135–143.

    Article  Google Scholar 

  • González, H.E., Castro, L, Daneri, G., Iriarte, J.L., Silva, N., Vargas, C.A., Giesecke, R., Sánchez, N., 2011. Seasonal plankton variability in Chilean Patagonia fjords: carbon flow through the pelagic food web of Aysen Fjord and plankton dynamics in the Moraleda Channel basin. Cont. Shelf Res. Fjord Oceanogr. Chil. Patagon. 31, 225–243, https://doi.org/10.1016/j.csr.2010.08.010.

  • Guinet, C, Dubroca, L, Lea, M.A., Goldsworthy, S., Cherel, Y., Duhamel, G., Bonadonna, F., Donnay, J.P., 2001. Spatial distribution of foraging in female Antarctic fur seals Arctocephalus gazella in relation to oceanographic variables: a scale-dependent approach using geographic information systems. Mar. Ecol. Prog. Ser. 219, 251–264.

    Article  Google Scholar 

  • Guisan, A., Zimmermann, N.E., 2000. Predictive habitat distribution models in ecology. Ecol. Model. 135, 147–186, https://doi.org/10.1016/S0304-3800(00)00354-9.

  • Harcourt, R., 1993. Individual variation in predation on fur seals by Southern sea lions (Otaria byronia). Can. J. Zool. 71, 1908–1911.

    Article  Google Scholar 

  • Hastie, T.J., Tibshirani, R., 1990. Generalized Additive Models. Chapman and Hall/CRC, London.

  • Hucke-Gaete, R., Osman, L.P., Moreno, C.A., Torres, D., 2004. Examining natural population growth from near extinction: the case of the Antarctic fur seal at the South Shetlands, Antarctica. Polar Biol. 27, 304–311, https://doi.org/10.1007/s00300-003-0587-8.

  • Hucke-Gaete, R., 2004. (Ph.D. dissertation). In: Distribución, preferencia de hábitat y dinámica espacial de la ballena azul en Chile: 1997–2004. Universidad Austral de Chile, Valdivia, Chile.

  • Hückstädt, LA, Antezana, T., 2003. Behaviour of the southern sea lion (Otaria flavescens) and consumption of the catch during purse-seining for jack mackerel (Trachurus symmetricus) off central Chile. ICES J. Mar. Sci. 60, 1003–1011, https://doi.org/10.1016/S1054-3139(03)00100-0.

  • Hückstädt, LA., Krautz, M.C., 2004. Interaction between southern sea lions Otaria flavescens and jack mackerel Trachurus symmetricus commercial fishery off central Chile: ageostatistical approach. Mar. Ecol. Prog. Ser. 282, 285–294.

    Article  Google Scholar 

  • Hückstädt, LA., Rojas, C.P., Antezana, T., 2007. Stable isotope analysis reveals pelagic foraging by the Southern sea lion in central Chile. J. Exp. Mar. Biol. Ecol. 347 (1), 123–133.

  • Hückstädt, L.A., Quiñones, RA, Sepúlveda, M., Costa, D.P., 2013. Movement and diving patterns of juvenile male South American sea lions off the coast of central Chile. Mar. Mamm. Sci., https://doi.org/10.1111/mms.12085.

  • Iriarte, J.L., González, H.E., Liu, K.K., Rivas, C, Valenzuela, C, 2007. Spatial and temporal variability of chlorophyll and primary productivity in surface waters of southern Chile (41.5–43 S). Estuar. Coast. Shelf Sci. 74 (3), 471–480.

  • King, J., 1983. Seals of the World. British Museum (Natural History), London.

  • Koen Alonso, M., Crespo, E.A., Pedraza, S.N., GarcãÂa, N.A., Coscarella, MA, 2000. Food habits of the South American sea lion, Otaria flavescens, off Patagonia, Argentina. Fish. Bull. 98, 250–263.

    Google Scholar 

  • Longhurst, A.R., 1998. Ecological Geography of the Sea. Academic Press, San Diego, CA.

    Google Scholar 

  • Muck, P., Fuentes, H., 1987. Sea lion and fur seal predation on the Peruvian anchoveta, 1953 to 1982. In: Pauly, D., Tsukayama, I. (Eds.), The Peruvian anchoveta and its upwelling ecosystem: three decades of change. Instituto del Mar del Peru (IMARPE)/Deutsche Gesellshaft für Technische Zusammenarbeit (GTZ)/International Center for living Aquatic Resources Management, Callao, Peru/GmbH, Eschbom, Federal Republic of Germany/Manila, Philippines, pp. 234–247, ICLARM Studies and Reviews 15, 351p.

  • Oksanen,J., Minchin, P.R., 2002. Continuum theory revisited: what shape are species responses along ecological gradients? Ecol. Model. 157, 119–129.

    Article  Google Scholar 

  • Oliva, D., Sielfeld, W., Sepúlveda, M., Pérez, M.J., Moraga, R., Urra, A., Schrader, D., Pavés, H., Buscaglia, M., 2008. Plan de acción para disminuir y mitigar los efectos de las interacciones del lobo marino común (Otaria flavescens) con las actividades de pesca y acuicultura. Informe final Proyecto FIP 2006-34, 323 pp. https://doi.org/10www.fip.cl/proyectos/2006/2006-34.htm

  • Oliva, D., Crespo, E.A., Dans, S.L., Sepúlveda, M., 2009. Report of the Workshop on the Status of South American Sea Lions Along the Distribution Range. https://doi.org/www.yaqupacha.org/fileadmin/user_upload/pdf/workshop_sealions_2009_report.pdf

  • Palma, S., Silva, N., 2004. Distribution of siphonophores, chaetognaths, euphausiids and oceanographic conditions in the fjords and channels of southern Chile. Deep-Sea Res. II 51 (6), 513–535.

  • Pavés, H.J., Schlatter, R.P., Espinoza, C.I., 2005. Patrones reproductivos del lobo marino común, Otaria flavescens (Shaw 1800), en el centro-sur de Chile. Rev. Chil. Hist. Nat. 78 (4), 673–686.

  • R Development Core Team, 2009. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Available at https://doi.org/10www.R-project.org

  • Reyes, L.M., Crespo, EA, Szapkievich, V., 1999. Distribution and population size of the southern sea lion (Otaria flavescens) in Central and Southern Chubut, Patagonia, Argentina. Mar. Mamm. Sci. 15, 478–493, https://doi.org/10.1111/j.1748-7692.1999.tb00814.x.

  • Reyes, P., Hucke-Gaete, R.,Torres-Florez,J.P., 2013. First observations of operational interactions between bottom-trawling fisheries and South American sea lion, Otaria flavescens in south-central Chile. J. Mar. Biol. Assoc. U. K. 93 (2), 489–494.

  • Riet-Sapriza, F.G., Costa, D.P., Franco-Trecu, V., Marín, Y., Chocca, J., González, B., Beathyate, G., Chilvers, B.L., Hückstadt, LA, 2013. Foraging behaviour of lactating South American sea lions (Otaria flavescens) and spatial-temporal resource overlap with the Uruguayan fisheries. Deep-Sea Res. II 88, 106–119.

    Article  Google Scholar 

  • Rodríguez, D.H., Dassis, M., Ponce de León, A., Barreiro, C, Farenga, M., Bastida, R.O., Davis, R.W., 2013. Foraging strategies of Southern sea lion females in the La Plata River Estuary (Argentina-Uruguay). Fourth International Symposium on Bio-logging Science, vols. 88–89. Deep-Sea Res. II: Top. Stud. Oceanogr., 120–130, https://doi.org/10.1016/j.dsr2.2012.07.012.

  • Sepúlveda, M., Oliva, D.P., Palma, F.J., 2001. Daily and annual circarhythms activity in the South American sea lion Otaria flavescens (Carnivora: Otariidae) at the central zone of Chile. Rev Biol Mar Oceanogr 36, 181–188.

    Article  Google Scholar 

  • Sepúlveda, M., Oliva, D., 2005. Interactions between South American sea lions Otaria flavescens (Shaw) and salmon farms in southern Chile. Aquac. Res. 36, 1062–1068.

    Article  Google Scholar 

  • Sepúlveda, M., Pérez, M.J., Sielfeld, W., Oliva, D., Durán, L.R., Rodríguez, L., Araos, V., Buscaglia, M., 2007. Operational interaction between South American sea lions Otaria flavescens and artisanal (small-scale) fishing in Chile: results from interview surveys and onboard observations. Fish. Res. 83 (2), 332–340.

  • Sepúlveda, M., Oliva, D., Urra, A., Pérez-Álvarez, M.J., Moraga, R., Schrader, D., Inos-troza, P., Melo, A., Díaz, H., Sielfeld, W., 2011. Distribution and abundance of the South American sea lion Otaria flavescens (Carnivora: otariidae) along the central coast off Chile. Rev. Chil. Hist. Nat. 84, 97–106.

    Article  Google Scholar 

  • Soto, K.H., Trites, A.W., Arias-Schreiber, M., 2006. Changes in diet and maternal attendance of South American sea lions indicate changes in the marine environment and prey abundance. Mar. Ecol. Prog. Ser. 312, 277–290.

    Article  Google Scholar 

  • Suarez, A.A., Sanfelice, D., Cassini, M.H., Cappozzo, H.L., 2005. Composition and seasonal variation in the diet of the South American sea lion (Otaria flavescens) from Quequén, Argentina. LAJAM 4(2), 163–174.

  • Szteren, D., Páez, E., 2003. Predation by southern sea lions (Otaria flavescens) on artisanal fishing catches in Uruguay. Mar. Freshw. Res. 53 (8), 1161–1167.

  • Szteren, D., Naya, D.E., Arim, M., 2004. Overlap between pinniped summer diet and artisanal fishery catches in Uruguay. LAJAM 3 (2), 119–125.

  • Thomas, L, Williams, R., Sandilands, D., 2007. Designing line transect surveys for complex survey regions. J. Cetacean Res. Manage. 9 (1), 1–13.

  • Thomas, L, Laake, J.L., Rexstad, E., Strindberg, S., Marques, F.F.C., Buckland, S.T., Borchers, D.L., Anderson, D.R., Burnham, K.P., Burt, M.L., Hedley, S.L., Pollard, J.H., Bishop, J.R.B., Marques, T.A., 2006. Distance 6.0, Beta 5. Research Unit for Wildlife Population Assessment. University of St. Andrews, UK https://doi.org/10www.ruwpa.st-and.ac.uk/distance/

  • Thomas, L, Laake, J.L., Rexstad, E., Strindberg, S., Marques, F.F.C., Buckland, S.T., Borchers, D.L., Anderson, D.R., Burnham, K.P., Burt, M.L., Hedley, S.L., Pollard, J.H., Bishop, J.R.B., Marques, T.A., 2009. Distance 6.0. Release 2. Research Unit for Wildlife Population Assessment. University of St. Andrews, UK https://doi.org/10www.ruwpa.st-and.ac.uk/distance/

  • Thompson, D., Duck, CD., McConnell, B.J., Garrett, J., 1998. Foraging behaviour and diet of lactating female southern sea lions (Otaria flavescens) in the Falkland Islands. J. Zool. 246, 135–146, https://doi.org/10.1111/j.1469-7998.1998.tb00142.x.

  • Williams, R., Thomas, L., 2009. Cost-effective abundance estimation of rare animals: testing performance of small-boat surveys for killer whales in British Columbia. Biol. Conserv. 142,1542–1547.

    Article  Google Scholar 

  • Williams, R., Thomas, L, 2007. Distribution and abundance of marine mammals in the coastal waters of BC, Canada. J. Cetacean Res. Manage. 9 (1), 15–28.

    Google Scholar 

  • Williams, R., Leaper, R., Zerbini, A., Hammond, P.S., 2007. Methods for investigating measurement error in cetacean line transect surveys. J. Mar. Biol. Assoc. U. K. 87, 313–320.

    Article  Google Scholar 

  • Wood, S., 2006. Generalized Additive Models: an introduction with R. Chapman and Hall/CRC Press, Boca Raton.

  • Yodzis, P., 2001. Must top predators be culled forthe sake of fisheries? Trends Ecol. Evolut. 16, 78–84, https://doi.org/10.1016/S0169-5347(00)02062-0.

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  1. Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile

    L. Bedriñana-Romano, F. A. Viddi, J. Ruiz & R. Hucke-Gaete

  2. NGO Centro Ballena Azul, c/o ICML, UACh, Casilla 567, Valdivia, Chile

    L. Bedriñana-Romano, F. A. Viddi, J. P. Torres-Florez, J. Ruiz, M. F. Nery, D. Haro, Y. Montecinos & R. Hucke-Gaete

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  1. L. Bedriñana-Romano
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Bedriñana-Romano, L., Viddi, F.A., Torres-Florez, J.P. et al. At-sea abundance and spatial distribution of South American sea lion (Otaria byronia) in Chilean Northern Patagonia: How many are there?. Mamm Biol 79, 384–392 (2014). https://doi.org/10.1016/j.mambio.2014.07.002

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