Oceanography The Official Magazine of
The Oceanography Society
Volume 31 Issue 04

View Issue TOC
Volume 31, No. 4
Pages 154 - 163


Composition, Spatial Distribution, and Trophic Structure of the Zooplankton Community in San Jorge Gulf, Southwestern Atlantic Ocean

Eloísa M. Giménez Gesche WinklerMónica HoffmeyerGustavo A. Ferreyra
Article Abstract

The goal of this study was to understand the zooplankton community composition and food web structure in San Jorge Gulf (45°–47°S, 65°30'W), a highly productive marine ecosystem in southern Argentina. A spatial grid of 14 stations was sampled in 2014. The sampled zooplankton community was composed of 30 taxa, with copepods accounting for 83% of the total abundance. Community composition was strongly related to surface temperature and water column stratification. Two distinct zooplankton assemblages were present. The zones designated North and Center were dominated by Ctenocalanus vanus; copepodite stages of C. vanus, Clausocalanus brevipes, and Paracalanus parvus; appendicularians; and Oithona helgolandica. The South zone was dominated by P. parvus, copepodites, Acartia tonsa, and Drepanopus forcipatus. The plankton food webs were increasingly enriched in carbon and nitrogen stable isotopes from the North to the South. Depleted δ13C signatures in the North may be explained by terrigenous inputs derived from strong westerly winds. The zooplankton taxa displayed a wide feeding range in the North, whereas the narrow trophic space of the South food web suggested similar feeding strategies among the taxa. Appendicularians were positioned at the base of the food webs, copepods were in the middle, and chaetognaths occupied high trophic positions.


Giménez, E.M., G. Winkler, M. Hoffmeyer, and G.A. Ferreyra. 2018. Composition, spatial distribution, and trophic structure of the zooplankton community in San Jorge Gulf, southwestern Atlantic Ocean. Oceanography 31(4):154–163, https://doi.org/10.5670/oceanog.2018.418.

Supplementary Materials

Acha, E.M., H.W. Mianzan, R.A. Guerrero, M. Favero, and J. Bava. 2004. Marine fronts at the continental shelves of austral South America: Physical and ecological processes. Journal of Marine Systems 44(1–2):83-105, https://doi.org/10.1016/​j.jmarsys.2003.09.005.

Akselman, R. 1996. Estudios Ecológicos en el Golfo San Jorge y Adyacencias (Atlántico Sudoccidental): Distribución, Abundancia y Variación Estacional del Fitoplancton en Relación a Factores Físico-Químicos y la Dinámica Hidrológica. PhD Thesis, Universidad de Buenos Aires, Facultad de Ciencias Exactas, Buenos Aires, Argentina.

Alemany, D., E.M. Acha, and O.O. Iribarne. 2014. Marine fronts are important fishing areas for demersal species at the Argentine Sea (Southwest Atlantic Ocean). Journal of Sea Research 87:56–67, https://doi.org/10.1016/j.seares.2013.12.006.

Alldredge, A.L., and M.W. Silver. 1988. Characteristics, dynamics and significance of marine snow. Progress in Oceanography 20(1):41–82, https://doi.org/​10.1016/0079-6611(88)90053-5.

Azam, F., T. Fenchel, J.G. Field, J.S. Gray, L.A. Meyer- Reil, and F. Thingstad. 1983. The ecological role of water-column microbes in the sea. Marine Ecology Progress Series 10(3):257–263, https://doi.org/​10.3354/meps010257.

Boltovskoy, D. 1981. Atlas del zooplancton del Atlántico Sudoccidental y métodos de trabajo con el zooplancton marino. Publicaciones especiales INIDEP, Mar del Plata, 936 pp.

Bray, J.R., and J.T. Curtis. 1957. An ordination of the upland forest communities of Southern Wisconsin. Ecological Monographs 27(4):325–349, https://doi.org/​10.2307/1942268.

Capitanio, F.L., and G.B. Esnal. 1998. Vertical distribution of maturity stages of Oikopleura dioica (Tunicata, Appendicularia) in the frontal system off Valdés Peninsula, Argentina. Bulletin of Marine Science 63(3):531–539.

Cepeda, G.D., M.E. Sabatini, C.L. Scioscia, F.C. Ramírez, and M.D. Viñas. 2016. On the uncertainty beneath the name Oithona similis Claus, 1866 (Copepoda, Cyclopoida). ZooKeys 552:1–15, https://doi.org/10.3897/zookeys.552.6083.

Chew, L.L., V.C. Chong, K. Tanaka, and A. Sasekumar. 2012. Phytoplankton fuel the energy flow from zooplankton to small nekton in turbid mangrove waters. Marine Ecology Progress Series 469:7–24, https://doi.org/10.3354/meps09997.

Clarke, K.R., and R.M. Warwick. 1994. Change in Marine Communities: An Approach to Statistical Analysis and Interpretation. Natural Environment Research Council, Plymouth, UK, 144 pp.

Clarke, K.R., and R.N. Gorley. 2006. PRIMER V6: User Manual/Tutorial (Plymouth routines in multivariate ecological research). PRIMER-E: Plymouth, UK.

Coronato, A.M., F. Coronato, E. Mazzoni, and M. Vázquez. 2008. The physical geography of Patagonia and Tierra del Fuego. Developments in Quaternary Sciences 11:13–55, https://doi.org/​10.1016/S1571-0866(07)10003-8.

Cucchi Colleoni, D., and J.I. Carreto. 2001. Variación estacional de la biomasa fitoplanctónica en el Golfo San Jorge: Resultados de las campañas de investigación OB-01/00, OB-03/00, OB-07/00, OB-10/00 y OB-12/00. Technical report DNI-INIDEP 49, Mar del Plata, Argentina, 30 pp.

De Ruiter, P.C., V. Wolters, and J.C. Moore. 2005. Dynamic food webs. Pp. 3–9 in Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development and Environmental Change, vol. 3. P.C. De Ruiter, V. Wolters, and J.C. Moore, eds, Academic Press.

Durán, A., H. Morrás, G. Studdert, and X. Liu. 2011. Distribution, properties, land use and management of mollisols in South America. Chinese Geographical Science 21(5):511, https://doi.org/​10.1007/s11769-011-0491-z.

Favier, J.B. 2013. Détermination de la niche écologique du complexe d’espèces Eurytemora affinis dans la zone de transition estuarienne du Saint-Laurent. MSc Thesis, Université du Québec à Rimouski, Québec, Canada.

Fofonoff, N.P., and R.C.J. Millard. 1983. Algorithms for computation of fundamental properties of seawater. UNESCO Technical Papers in Marine Science 44:53.

Fry, B., and E.B. Sherr. 1989. δ13C measurements as indicators of carbon flow in marine and freshwater ecosystems. Pp. 196–229 in Stable Isotopes in Ecological Research. Springer, New York.

Fry, B., and S.C. Wainright. 1991. Diatom sources of 13C-rich carbon in marine food webs. Marine Ecology Progress Series 76:149–157, https://doi.org/​10.3354/meps076149.

Gearing, J.N., P.J. Gearing, D.T. Rudnick, A.G. Requejo, and M.J. Hutchins. 1984. Isotopic variability of organic carbon in a phytoplankton-​based, temperate estuary. Geochimica et Cosmochimica Acta 48(5):1,089–1,098, https://doi.org/​10.1016/​0016-7037(84)90199-6.

Giesecke, R., and H.E. González. 2004. Feeding of Sagitta enflata and vertical distribution of chaetognaths in relation to low oxygen concentrations. Journal of Plankton Research 26(4):475–486, https://doi.org/10.1093/plankt/fbh039.

Glembocki, N.G., G.N. Williams, M.E. Góngora, D.A. Gagliardini, and J.M.L. Orensanz. 2015. Synoptic oceanography of San Jorge Gulf (Argentina): A template for Patagonian red shrimp (Pleoticus muelleri) spatial dynamics. Journal of Sea Research 95:22–35, https://doi.org/10.1016/​j.seares.2014.10.011.

Góngora, M.E., D. González-Zevallos, A. Pettovello, and L. Mendía. 2012. Caracterización de las principales pesquerías del Golfo San Jorge Patagonia, Argentina. Latin American Journal of Aquatic Research 40(1):1–11.

González, H.E., and V. Smetacek. 1994. The possible role of the cyclopoid copepod Oithona in retarding vertical flux of zooplankton faecal material. Marine Ecology Progress Series 113(3):233–246, https://doi.org/​10.3354/​meps113233.

Grigor, J.J., A.E. Marais, S. Falk-Petersen, and Ø. Varpe. 2015. Polar night ecology of a pelagic predator, the chaetognath Parasagitta elegans. Polar Biology 38(1):87–98, https://doi.org/10.1007/s00300-014-1577-8.

Guerrero, R.A., and A.R. Piola. 1997. Masas de agua de la Plataforma Continental Argentina. Pp. 107–118 in El Mar Argentino y sus recursos pesqueros; Tomo 1: Antecedentes históricos de las exploraciones en el mar y características ambientales. E. Boschi, ed., Instituto Nacional de Investigación y Desarrollo Pesquero.

Guglielmo, L., T. Antezana, N. Crescenti, and A. Granata. 1997. Atlas of Marine Zooplankton, Straits of Magellan: Amphipods, Mysids, Euphausiids, Ostracods, Chaetognaths. L. Guglielmo and A. Ianora, eds, Springer-Verlag, Berlin, 279 pp.

Hamame, M., and T. Antezana. 2010. Vertical diel migration and feeding of Euphausia vallentini within Southern Chilean fjords. Deep Sea Research Part II 57(7):642–651, https://doi.org/10.1016/​j.dsr2.2009.10.013.

Hawke, D.J., and J.M. Clark. 2010. Isotopic signatures (13C/12C; 15N/14N) of blue penguin burrow soil invertebrates: Carbon sources and trophic relationships. New Zealand Journal of Zoology 37(4):313–321, https://doi.org/10.1080/03014223.2010.519036.

Hopcroft, R.R., and J.C. Roff. 1998. Production of tropical larvaceans in Kingston Harbour, Jamaica: Are we ignoring an important secondary producer? Journal of Plankton Research 20(3):557–569, https://doi.org/10.1093/plankt/20.3.557.

Hulsemann, K. 1991. The copepodid stages of Drepanopus forcipatus Giesbrecht, with notes on the genus and a comparison with other members of the family Clausocalanidae (Copepoda Calanoida). Helgoländer Meeresuntersuchungen 45(1):199–224, https://doi.org/​10.1007/BF02365642.

Jia, Z., K.M. Swadling, K.M. Meiners, S. Kawaguchi, and P. Virtue. 2016. The zooplankton food web under East Antarctic pack ice: A stable isotope study. Deep Sea Research Part II 131:189–202, https://doi.org/10.1016/j.dsr2.2015.10.010.

Kiørboe, T. 1993. Turbulence, phytoplankton cell size, and the structure of pelagic food webs. Advances in Marine Biology 29:1–72, https://doi.org/10.1016/S0065-2881(08)60129-7.

Koppelmann, R., R. Böttger-Schnack, J. Möbius, and H. Weikert, H. 2009. Trophic relationships of zooplankton in the eastern Mediterranean based on stable isotope measurements. Journal of Plankton Research 31(6):669–686, https://doi.org/10.1093/plankt/fbp013.

Lampitt, R.S., and J.C. Gamble. 1982. Diet and respiration of the small planktonic marine copepod Oithona nana. Marine Biology 66(2):185–190, https://doi.org/10.1007/BF00397192.

Latorre, M.P., I.R. Schloss, G.O. Almandoz, K. Lemarchand, X. Flores-Melo, V. Massé-Beaulne, and G.A. Ferreyra. 2018. Mixing processes at the pycnocline and vertical nitrate supply: Consequences for the microbial food web in San Jorge Gulf, Argentina. Oceanography 31(4):50–59, https://doi.org/10.5670/oceanog.2018.410.

Legendre, L., and F. Rassoulzadegan. 1995. Plankton and nutrient dynamics in marine waters. Ophelia 41(1):153–172, https://doi.org/10.1080/​00785236.​1995.10422042.

Louge, E.B., R. Reta, B.A. Santos, and D.R. Hernández. 2004. Variaciones interanuales (1995–2000) de la temperatura y la salinidad registradas en los meses de enero en el Golfo San Jorge y aguas adyacentes (43°S–47°S). Revista de Investigación y Desarrollo Pesquero 16:27–42.

Mackas, D.L., M. Tsurumi, M.D. Galbraith, and D.R. Yelland. 2005. Zooplankton distribution and dynamics in a North Pacific Eddy of coastal origin: Part II. Mechanisms of eddy colonization by and retention of offshore species. Deep Sea Research Part II 52(7):1,011–1,035, https://doi.org/10.1016/​j.dsr2.2005.02.008.

Mann, K.H., and J.R. Lazier. 2013. Dynamics of Marine Ecosystems: Biological-Physical Interactions in the Oceans. John Wiley & Sons.

Marrari, M., M.D. Viñas, P. Martos, and D. Hernández. 2004. Spatial patterns of mesozooplankton distribution in the Southwestern Atlantic Ocean (34–41°S) during austral spring: Relationship with the hydrographic conditions. ICES Journal of Marine Science: Journal du Conseil 61(4):667–679, https://doi.org/10.1016/j.icesjms.2004.03.025.

Martineau, C., W.F. Vincent, J.J. Frenette, and J.J. Dodson. 2004. Primary consumers and particulate organic matter: Isotopic evidence of strong selectivity in the estuarine transition zone. Limnology and Oceanography 49(5):1,679–1,686, https://doi.org/10.4319/lo.2004.49.5.1679.

Mazzocchi, M.G., G. Zagami, A. Ianora, L. Guglielmo, N. Crescenti, and J. Hure. 1995. Atlas of Marine Zooplankton, Straits of Magellan: Copepods. Pp. 279. G. Letterio and A. Ianora, series eds, Springer-Verlag, Heidelberg, 279 pp.

McCutchan, J.H., W.M. Lewis, C. Kendall, and C.C. McGrath. 2003. Variation in trophic shift for stable isotope ratios of carbon, nitrogen, and sulfur. Oikos 102(2):378–390, https://doi.org/​10.1034/j.1600-0706.2003.12098.x.

Minagawa, M., and E. Wada. 1984. Stepwise enrichment of 15°N along food chains: Further evidence and the relation between δ15N and animal age. Geochimica et Cosmochimica Acta 48(5):1,135–1,140, https://doi.org/​10.1016/​0016-7037(84)90204-7.

Molinero, J.C., F. Ibanez, S. Souissi, E. Bosc, and P. Nival. 2008. Surface patterns of zooplankton spatial variability detected by high frequency sampling in the NW Mediterranean: Role of density fronts. Journal of Marine Systems 69(3):271–282, https://doi.org/10.1016/j.jmarsys.2005.11.023.

Palma, E.D., and R.P Matano. 2012. A numerical study of the Magellan Plume. Journal of Geophysical Research 117(C5), https://doi.org/​10.1029/​2011JC007750.

Parsons, T.R., Y. Maita, and C.M. Lalli. 1984. A Manual of Chemical and Biological Methods for Seawater Analysis, vol. 395. Pergamon Press, 173 pp.

Pérez Seijas, G.M., F.C. Ramírez, and M.D. Viñas. 1987. Variaciones de la abundancia numérica y biomasa del zooplancton de red en el golfo San Jorge (Año 1985). Revista de Investigación y Desarrollo Pesquero 7:5–20.

Peterson, B.J., and B. Fry. 1987. Stable isotopes in ecosystem studies. Annual Review of Ecology and Systematics 18(1):293–320, https://doi.org/10.1146/annurev.es.18.110187.001453.

Post, D.M. 2002. Using stable isotopes to estimate trophic position: Models, methods, and assumptions. Ecology 83(3):703–718, https://doi.org/10.1890/0012-9658(2002)083​[0703:USITET]2.0.CO;2.

Price, H.J., K.R. Boyd, and C.M. Boyd. 1988. Omnivorous feeding behavior of the Antarctic krill Euphausia superba. Marine Biology 97(1):67–77, https://doi.org/10.1007/BF00391246.

Ramírez, F.C. 1971. Eufáusidos de algunos sectores del Atlántico Sudoccidental. Physis 30(81):385–405.

Rau, G.H., T.L. Hopkins, and J.J. Torres. 1991. 15N/14N and 13C/12C in Weddell Sea invertebrates: Implications for feeding diversity. Marine Ecology Progress Series 77(1):1–6.

Sabatini, M.E., R. Reta, and R.P. Matano. 2004. Circulation and zooplankton biomass distribution over the Southern Patagonian shelf during late summer. Continental Shelf Research 24(12):1,359–1,373, https://doi.org/​10.1016/j.csr.2004.03.014.

Spinelli, M.L., M. Pájaro, P. Martos, G.B. Esnal, M.E. Sabatini, and F.L. Capitanio. 2012. Potential zooplankton preys (Copepoda and Appendicularia) for Engraulis anchoita in relation to early larval and spawning distributions in the Patagonian frontal system (SW Atlantic Ocean). Scientia Marina 76(1):39–47.

Temperoni, B., and M.D. Viñas. 2013. Food and feeding of Argentine hake (Merluccius hubbsi) larvae in the Patagonian nursery ground. Fisheries Research 148:47–55, https://doi.org/10.1016/​j.fishres.2013.08.008.

Temperoni, B., M.D. Viñas, P. Martos, and M. Marrari. 2014. Spatial patterns of copepod biodiversity in relation to a tidal front system in the main spawning and nursery area of the Argentine hake Merluccius hubbsi. Journal of Marine Systems 139:433–445, https://doi.org/10.1016/j.jmarsys.2014.08.015.

Thompson, G.A., E.O. Dinofrio, and V.A. Alder. 2013. Structure, abundance and biomass size spectra of copepods and other zooplankton communities in upper waters of the Southwestern Atlantic Ocean during summer. Journal of Plankton Research 35(3):610–629, https://doi.org/10.1093/plankt/fbt014.

Thornton, S.F., and J. McManus. 1994. Application of organic carbon and nitrogen stable isotope and C/N ratios as source indicators of organic matter provenance in estuarine systems: Evidence from the Tay Estuary, Scotland. Estuarine, Coastal and Shelf Science 38(3):219–233, https://doi.org/​10.1006/ecss.1994.1015.

Tonini, M., E.D. Palma, and A. Rivas. 2006. Modelo de alta resolución de los Golfos Patagónicos. Mecánica Computacional 25:1,441–1,460.

Turner, J.T. 1984. The Feeding Ecology of Some Zooplankters That Are Important Prey of Larval Fish. Technical Report NMFS 7, National Oceanic and Atmospheric Administration, 28 pp.

Turner, J.T. 1991. Zooplankton feeding ecology: Do co-occurring copepods compete for the same food? Reviews in Aquatic Sciences 5:101–195.

Turner, J.T. 2004. The importance of small planktonic copepods and their roles in pelagic marine food webs. Zoological Studies 43(2):255–266.

Turner, J.T., and E. Granéli. 1992. Zooplankton feeding ecology: Grazing during enclosure studies of phytoplankton blooms from the west coast of Sweden. Journal of Experimental Marine Biology and Ecology 157(1):19–31, https://doi.org/​10.1016/0022-0981(92)90071-H.

Viñas, M.D., F.C. Ramírez, B.A. Santos, and G.M. Pérez Seijas. 1992. Zooplankton distributed in the North Patagonian nursery and spawning ground of the hake (Merluccius hubbsi). Frente Marítimo 11:105–113.

Yorio, P. 2009. Marine protected areas, spatial scales, and governance: Implications for the conservation of breeding seabirds. Conservation Letters 2(4):171–178, https://doi.org/​10.1111/​j.1755-​263X.2009.00062.x.

Copyright & Usage

This is an open access article made available under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution, and reproduction in any medium or format as long as users cite the materials appropriately, provide a link to the Creative Commons license, and indicate the changes that were made to the original content. Images, animations, videos, or other third-party material used in articles are included in the Creative Commons license unless indicated otherwise in a credit line to the material. If the material is not included in the article’s Creative Commons license, users will need to obtain permission directly from the license holder to reproduce the material.