Scientia Marina, Vol 75, No 2 (2011)

Ecosystem structure and trophic analysis of Angolan fishery landings

Ronaldo Angelini
Departamento de Engenharia Civil, Universidade Federal do Rio Grande do Norte - Marine Research Institute and Zoology Department, University of Cape Town , Brazil

Filomena Vaz-Velho
Instituto Nacional de Investigação Pesqueira , Angola


Information on the mean trophic level of fishery landings in Angola and the output from a preliminary Ecopath with Ecosim (EwE) model were used to examine the dynamics of the Angolan marine ecosystem. Results were compared with the nearby Namibian and South African ecosystems, which share some of the exploited fish populations. The results show that: (i) The mean trophic level of Angola’s fish landings has not decreased over the years; (ii) There are significant correlations between the landings of Angola, Namibia and South Africa; (iii) The ecosystem attributes calculated by the EwE models for the three ecosystems were similar, and the main differences were related to the magnitude of flows and biomass; (iv) The similarity among ecosystem trends for Namibia, South Africa and Angola re-emphasizes the need to continue collaborative regional studies on the fish stocks and their ecosystems. To improve the Angolan model it is necessary to gain a better understanding of plankton dynamics because plankton are essential for Sardinella spp. An expanded analysis of the gut contents of the fish species occupying Angola’s coastline is also necessary.


Ecopath with Ecosim; fishery management; marine ecosystem; Sardinella; trophic level

Full Text:



Aburto-Oropeza, O., L.G. López-Lemus, G. Paredes, M. Reza, A. Sáenz-Arroyo and E. Sala. – 2007. Letter to Editor. Fish. Res., 85: 233-234. doi:10.1016/j.fishres.2006.09.015

Arancibia, H. and S. Neira. – 2005. Long-term changes in the mean trophic level of central Chile fishery landings. Sci. Mar., 69(2): 295-300.

Baeta, F., M. J. Costa and H. Cabral. – 2009. Changes in the trophic level of Portuguese landings and fish market price variation in the last decades. Fish. Res., 97: 216-222. doi:10.1016/j.fishres.2009.02.006

Batty, M., M. Tjipute, M. Sowman, P. Cardoso and P. Fielding. – 2005. Overview and analysis of socio-economic and fisheries information to promote the management of artisanal fisheries in the BCLME region – Namibia. Final Report and Recommendations (Namibia). 40 pp.

Béné, C. and S. Heck. – 2005. Fish and food security in Africa. NAGA, WorldFish C. Quart., 28(3-4): 8-13.

Binet, D., B. Gobert and L. Maloueki. – 2001. El Niño-like warm events in the Eastern Atlantic (6•N, 20•S) and fish availability from Congo to Angola (1964-1999). Aquat. Liv. Res., 14: 99-113. doi:10.1016/S0990-7440(01)01105-6

Caddy, J.F. and K.L. Cochrane. – 2001. A review of fisheries management past and present and some future perspectives for the third millennium. Ocean Coast. Mgmt, 44: 653-682. doi:10.1016/S0964-5691(01)00074-6

Christensen, V. – 1995. Ecosystem maturity – towards quantification. Ecol. Mod., 77: 3–32. doi:10.1016/0304-3800(93)E0073-C

Christensen, V. and D. Pauly. – 1992. A guide to the ECOPATH II program (version 2.1). ICLARM Software, 6. 72 pp.

Christensen, V. and D. Pauly. – 1993. Trophic models of aquatic ecosystems. ICLARM, Manila. 390 pp.

Christensen, V. and D. Pauly. – 1995. Primary production required to sustain global fisheries. Nature, 374: 255-257. doi:10.1038/374255a0

Christensen, V. and C. Walters. – 2004. Ecopath with Ecosim: methods, capabilities and limitations. Ecol. Mod., 172: 109-139 doi:10.1016/j.ecolmodel.2003.09.003

Christensen, V., C.J. Walters and D. Pauly. – 2005. Ecopath with Ecosim: a user’s guide. Fisheries Centre, University of British Columbia, Vancouver, Canada. November 2005 version. 154 pp. (available online at

Coll, M., L.J. Shannon, C.L. Moloney, I. Palomera and S. Tudela. – 2006. Comparing trophic flows and fishing impacts of a NW Mediterranean ecosystem with upwelling systems by means of standardized models and indicators. Ecol. Mod., 198: 53-70. doi:10.1016/j.ecolmodel.2006.04.009

Duarte, A., P. Fielding, M. Sowman and M. Bergh. – 2005. Overview and analysis of socio-economic and fisheries information to promote the management of artisanal fisheries in the BCLME region- Angola. Final Report and Recommendations (Angola). 112 pp.

FAO. – 2000. FishStat Plus. Universal software for fisheries statistical time series. Version 2.3. FAO, Rome.

FAO. – 2006. Fishery and Aquaculture Statistics. Yearbook 2006. FAO, Rome. 81 pp.

Freire, K.M.F., V. Christensen and D. Pauly. – 2008. Description of the East Brazil large marine ecosystem using a trophic model. Sci. Mar., 72(3): 477-491.

Froese, R. and D. Pauly (eds.). – 2007. FishBase. World Wide Web electronic publication., version (02/2007).

Griffis, R.B. and K.W. Kimball. – 1996. Ecosystem approaches to coastal and ocean stewardship. Ecol. Appl., 6(3): 708-712. doi:10.2307/2269467

Heymans, J.J. and U.R. Sumaila. – 2007. Update ecosystem model for the northern Benguela ecosystem, Namibia. In: W.J.F. Le Quesne, F. Arreguín-Sánchez and J.J. Heymans (eds.), INCOFISH Ecosystem models: Transiting from Ecopath to Ecospace. Fisheries Centre Research Reports, pp. 25–70. Fisheries Centre, Vancouver, Canada.

Heymans, J.J., L.J. Shannon and A. Jarre. – 2004. Changes in the northern Benguela ecosystem over three decades: 1970s, 1980s and 1990s. Ecol. Mod., 172: 175–195. doi:10.1016/j.ecolmodel.2003.09.006

Heymans, J. J., U. R. Sumaila and V. Christensen. – 2009. Policy options for the northern Benguela ecosystem using a multispecies, multifleet ecosystem model. Prog. Oceanogr., 83: 417–425. doi:10.1016/j.pocean.2009.07.013

Milessi, A.C., H. Arancibia, S. Neira and O. Defeo. 2005. The mean trophic level of Uruguayan landings during the period 1990-2001. Fish. Res., 74: 223-231. doi:10.1016/j.fishres.2005.02.002

Moloney, C.L., A. Jarre, H. Arancibia, Y.M. Bozec, S. Neira, J-P. Roux and L.J. Shannon. – 2005. Comparing the Benguela and Humboldt marine upwelling ecosystems with indicators derived from inter-calibrated models. ICES J. Mar. Sci., 62: 493-502. doi:10.1016/j.icesjms.2004.11.009

Odum, E.P. – 1969. The strategy of ecosystem development. Science, 104: 262–270. doi:10.1126/science.164.3877.262 PMid:5776636

Pauly, D., V. Christensen, S. Guenette, T.J. Pitcher, U.R. Sumaila, C.J. Walters, R. Watson and D. Zeller. – 2002. Towards sustainability in world fisheries. Nature, 418: 689-695. doi:10.1038/nature01017 PMid:12167876

Pauly D., V. Christensen, J. Dalsgaard, R. Froese and F. Torres. – 1998. Fishing down marine food webs. Science, 279: 860-863. doi:10.1126/science.279.5352.860 PMid:9452385

Pérez-España, H., L.G. Abarca-Arenas and M.L. Jiménez-Badillo. – 2006. Is fishing-down trophic web a generalized phenomenon? The case of Mexican fisheries. Fish. Res., 79: 349-352. doi:10.1016/j.fishres.2006.03.027

Pichevin, L., M. Cremer, J. Giraudeau and P. Bertrand. – 2005. A 190 ky record of lithogenic grain-size on the Namibian slope: forging a tight link between past wind-strength and coastal upwelling dynamics. Mar. Geog., 218: 81-96. doi:10.1016/j.margeo.2005.04.003

Polovina, J.J. – 1984. Model of a coral reef ecosystem. 1. The ECOPATH model and its application to French Frigate Shoals. Cor. Reefs, 3: 1-11. doi:10.1007/BF00306135

Schwartzlose, R.A., J. Alheit, A. Bakun, T.R. Baumgartner, R. Cloete, R.J.M. Crawford, W.J. Fletcher, Y. Green-Ruiz, E. Hagen, T. Kawasaki, D. Lluch-Belda, S.E. Lluch-Cota, A.D. MacCall, Y. Matsuura, M.O. Nevárez-Martínez, R.H. Parrish, C. Roy, R. Serra, K.V. Shust, M.N. Ward and J.Z. Zuzunanga. – 1999. Worldwide large-scale fluctuations of sardine and anchovy populations. S. Afr. J. Mar. Sci., 21: 289-347. doi:10.2989/025776199784125962

Shannon, L.J. and C. van der Lingen. – 2006. Ecosystem states, ecosystem changes and changes in ecosystem functioning of the southern and northern Benguela ecosystem. EAF Project Regional Meeting, Cape Town (SA). Document 3a. 15 pp.

Shannon, L.J., C.L. Moloney, A. Jarre and J.G. Field. – 2003. Trophic flows in the southern Benguela during the 1980s and 1990s. J. Mar. Sys., 39(1–2): 83–116. doi:10.1016/S0924-7963(02)00250-6

Shannon, L.J., K.L. Cochrane, C.L. Moloney and P. Fréon. – 2004a. Ecosystem approach to fisheries management in the southern Benguela: a workshop overview. Afr. J. Mar. Sci., 26: 1–8. doi:10.2989/18142320409504046

Shannon, L.J., V. Christensen and C. Walters. – 2004b. Modelling stock dynamics in the southern Benguela ecosystem for the period 1978-2002. In: L.J. Shannon, K.L. Cochrane and S.C. Pillar (eds.), Ecosystem Approaches to Fisheries in the Southern Benguela. Afr. J. Mar. Sci. 26: 179-196.

Shannon, L.J., S. Neira and M. Taylor. – 2008. Comparing internal and external drivers in the southern Benguela and the southern and northern Humboldt upwelling ecosystems. Afr. J. Mar. Sci., 30(1): 63-84. doi:10.2989/AJMS.2008.

Shannon, L.J., M. Coll and S. Neira. – 2009. Exploring the dynamics of ecological indicators using food web models fitted to time series of abundance and catch data. Ecol. Ind., 9: 1078-1095. doi:10.1016/j.ecolind.2008.12.007

Strømme, T., G. Søtersdal, O. Alvheim and H. Ullebust. – 1986. Report on surveys of Angola’s marine fish resources. January 1985 – June 1986. http:/

Sumaila, U.R., G. Munro and H. Keith. – 2005. Benguela Current Comission. Economic Study. Report of the United Nations Office for Projects Services (UNOPS) and Benguela Current Large Marine Ecosystem (BCLME) Programme. Vancouver, Canada.

Thurstan, R.H., S. Brockington and C.M. Roberts. – 2010. The effects of 118 years of industrial fishing on UK bottom trawl fisheries. Nature Comms,.

Ulanowicz, R.E. – 1986. Growth and Development: Ecosystem Phenomenology. Springer, New York.

Vaz-Velho, F., B.E. Axelsen, P. Barros and G. Bauleth-D’Almeida. – 2006 Identification of acoustic targets off Angola using general discriminant analysis. Afr. J. Mar. Sc. 28(3-4): 525-533. doi:10.2989/18142320609504203

Vosloo, M.C. – 2004. A comparative assessment of the impact of recreational and subsistence fishing on selected Eastern Cape estuarine ecosystems using the Ecopath modeling approach. MSc thesis, Univ. Port Elizabeth.

Walters, C., V. Christensen and D. Pauly. – 1997. Structuring dynamic models of exploited ecosystems from trophic mass–balance assessments. Rev. Fish Biol. Fish., 7: 139-172. doi:10.1023/A:1018479526149

Worm, B., E.B. Barbier, N. Beaumont, J.E. Duffy, C. Folke, B.S. Halpern, J.B.C. Jackson, H.K. Lotze, F. Micheli, S.R. Palumbi, E. Sala, K.A. Selkoe, J.J. Stachowicz and R. Watson. – 2006. Impacts of biodiversity loss on ocean ecosystems service. Science, 314: 787-790. doi:10.1126/science.1132294 PMid:17082450

Copyright (c) 2011 Consejo Superior de Investigaciones Científicas (CSIC)

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Contact us

Technical support