Scientia Marina, Vol 77, No 1 (2013)

Distribution of intertidal macrobenthic assemblages in relation to environmental factors in the Tagus estuary, western Portugal

Anxo Conde
IBB-Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico (IST) - Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo , Spain

Júlio M. Novais
IBB-Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico (IST) , Portugal

Jorge Domínguez
Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo , Spain


Fourteen intertidal sites from the eastern mid-region of the Tagus estuary were considered in order to study their macrobenthic assemblages in relation to environmental factors. The salinity gradient was displayed in an ordination of the assemblages by non-metric multidimensional scaling (NMDS). However, salinity was not found to be a significant environmental factor to explain the distribution of the assemblages. Conversely, a lateral gradient characterized three clusters of sites identified in relation to their outer, intermediate and inner location also related to organic matter content, oxygen concentration and redox potential values. Although the hydrodynamic factor was not investigated it is thought to be an important environmental factor for characterizing the lateral gradient. As a general trend, there was a transition between the groups of assemblages from the lower estuary towards the inner and upstream locations. The polychaetes Lanice conchilega and Hediste diversicolor and the gastropod Hydrobia ulvae were the characteristic species in the outer, inner and intermediate groups of sites, respectively. It was concluded that the lateral gradient is the main environmental driver that explains the distribution of the intertidal macrobenthic assemblages in the Tagus estuary when the salinity gradient is not find to be a significant environmental factor.


community transition; salinity gradient; lateral gradient; static factors; indicative species; estuarine zones

Full Text:



Anderson M.J. 2001. A new method for non-parametric multivariate analysis of variance. Austral Ecol. 26: 32-46.

Anderson M.J. 2005. PERMANOVA: a FORTRAN computer program for permutational multivariate analysis of variance. Depart. Stat., Univ. Auckland, New Zealand, 24 pp.

Attrill M.J., Rundle S.D. 2002. Ecotone or ecocline: ecological boundaries in estuaries. Estuar. Coast. Shelf Sci. 55: 929-936.

Barnes R.S.K. 1989. What, if any, is a brackish water fauna? Trans. Roy. Soc. Edinburgh, Earth Sci. 80: 235-240.

Blanchet F.G., Legendre P., Borcard D. 2008. Forward selection of explanatory variables. Ecology 89: 2623-2632. PMid:18831183

Bocher P., Piersma T., Dekinga A., Kraan C., Yates M.G., Guyot T., Folmer E.O., Radenac G. 2007. Site and species-specific distribution patterns of molluscs at five intertidal soft sediment areas in northwest Europe during a single winter. Mar. Biol. 151: 577-594.

Borcard D., Gillet F., Legendre P. 2011. Numerical ecology with R. Springer, New York, 306 pp

Borja A., Muxika I., Franco J. 2006. Long-term soft-bottom benthos recovery, following urban and industrial sewage treatment in the Nervión estuary (southern Bay of Biscay). Mar. Ecol. Prog. Ser. 313: 43-55.

Calvário J. 1982. Estudo ambiental do estuário do Tejo: povoamentos bentónicos intertidais (substratos móveis). CNA TEJO 19, Rel 18, Comissão Nacional do Ambiente, Lisboa, Portugal.

Calvário J. 2001. Characterization of the Tagus estuary macrobenthic communities. Bol. Mus. Mun. Funchal 6: 313-330.

Carvalho S., Moura A., Gaspar M.B., Pereira P., Cancela da Fonseca L., Falcão M., Drago T., Leitão F., Regala J. 2005. Spatial and inter-annual variability of the macrobenthic communities within a coastal lagoon (Óbidos lagoon) and its relationship with environmental parameters. Acta Oecol. 27: 143-159.

Clarke K.R., Warwick R.M. 1994. Change in marine communities: an approach to statistical analysis and interpretation. Plymouth Marine Laboratory, Plymouth, 144 pp.

Conde A., Novais J., Domínguez J. 2010. Southern limit of distribution of the soft-shell clam Mya arenaria on the Atlantic East Coast. Biol. Invasions 12: 429-432.

Crawley, M.J. 2007. The R book. Wiley, Chichester, 942 pp.

Dufrêne M., Legendre P. 1997. Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol. Monogr. 67: 345-366.

Elliott M., McLusky D.S. 2002. The need for definitions in understanding estuaries. Estuar. Coast. Shelf Sci. 55: 815-827.

França S., Vinagre C., Pardal M.A., Cabral H.N. 2009. Spatial and temporal patterns of benthic invertebrates in the Tagus estuary, Portugal: comparison between subtidal and an intertidal mudflat. Sci. Mar. 73: 307-318.

Gamito S., Chainho P., Costa J.L., Medeiros J.P., Costa M.J., Marques, J.C. 2010. Modelling the effects of extreme events on the dynamics of the amphipod Corophium orientale. Ecol. Model. 221: 459-466.

García-Arberas L., Rallo A. 2002. The intertidal soft-bottom infaunal macrobenthos in three Basque estuaries (Gulf of Biscay): a feeding guild approach. Hydrobiologia 475/476: 457-468.

Gaudêncio M.J., Cabral H.N. 2007. Trophic structure of macrobenthos in the Tagus estuary and adjacent coastal shelf. Hydrobiologia 587: 241-251.

Jansen J.M., Pronker A.E., Bonga S.W., Hummel H. 2007. Macoma balthica in Spain, a few decades back in climate history. J. Exp. Mar. Biol. Ecol. 344: 161-169.

Junoy J., Viéitez J.M. 1990. Macrozoobenthic community structure in the Ria de Foz, an intertidal estuary (Galicia, Northwest Spain). Mar. Biol. 107: 329-339.

Lacy J.R., Stacey M.T., Burau J.R., Monismith S.G. 2003. Interaction of lateral baroclinic forcing and turbulence in an estuary. J. Geophys. Res. 108.

Legendre P., Gallagher E.D. 2001. Ecologically meaningful transformations for ordination of species data. Oecologia 129: 271-280.

Legendre P., Legendre L. 1998. Numerical ecology. Elsevier, Amsterdam, 853 pp. PMCid:107859

Little C. 2000. The Biology of Soft Shores and Estuaries. Oxford Univ. Press, Oxford, 252 pp.

McLusky D.S. 1993. Marine and Estuarine Grandients – an overview. Neth. J. Aquat. Ecol. 27: 489-493.

McLusky D.S., Elliott M. 2004. The Estuarine Ecosystem: ecology, threats and management. Oxford Univ. Press Inc., New York, 216 pp.

Moreira M.H., Queiroga H., Machado M.M., Cunha M.R. 1993. Environmental gradients in a southern Europe estuarine system: Ria de Aveiro, Portugal. Implications for soft bottom macrofauna colonization. Neth. J. Aquat. Ecol. 27: 465-482.

Mucha A.P., Costa M.H. 1999. Macrozoobenthic community structure in two Portuguese estuaries: Relationship with organic enrichment and nutrient gradients. Acta Oecol. 20: 363-376.

Nixon S.W. 1988. Physical energy inputs and the comparative ecology of lake and marine ecosystems. Limnol. Oceanogr. 33: 1005-1025.

Oksanen J. 2011. Multivariate Analysis of Ecological Communities in R: VEGAN Tutorial,

Oksanen J., Kindt R., Legendre P., O'Hara R.B. 2006. VEGAN: Community Ecology Package Version 1.8-2. URL:

Pielou, E.C. 1969. An introduction to mathematical ecology. Wiley & Sons, New York, 286 pp.

Queiroga H. 1990. Corophium multisetosum (Amphipoda: Corophiidae) in Canal de Mira, Portugal: some factors that affect its distribution. Mar. Biol. 104: 397-402.

R Development Core Team. 2009. R: a Language and Environment for Statistical Computing. R Foundation for Statistical Computing. Available from:

Ralston D.K., Geyer W.R. 2009. Episodic and long-term sediment transport capacity in The Hudson River estuary. Estuar. Coast 32: 1130-1151.

Rodrigues A.M., Meireles S., Pereira T., Gama A., Quintino V. 2006. Spatial Patterns of Benthic Macroinvertebrates in Intertidal Areas of a Southern European Estuary: The Tagus, Portugal. Hydrobiologia 555: 99-113.

Rodrigues A.M., Quintino V., Sampaio L., Freitas R., Neves R. 2011. Benthic biodiversity patterns in Ria de Aveiro, Western Portugal: Environmental biological relationships. Estuar. Coast. Shelf Sci. 95: 338-348.

Salgado J.P., Cabral H.N., Costa M.J. 2007. Spatial and temporal distribution patterns of the macrozoobenthos assemblage in the salt marshes of Tejo estuary (Portugal). Hydrobiologia 587: 225-239.

Silva G., Costa J.L., Raposo de Almeida P., Costa M.J. 2006. Structure and dynamics of a benthic invertebrate community in an intertidal area of the Tagus estuary, Western Portugal: a six year data series. Hydrobiologia 555: 115-128.

Shannon C., Weaver W. 1963. The mathematical theory of communication. Urbana Univ. Press, Illinois, 127 pp.

Sousa R., Dias S., Antunes C. 2006. Spatial subtidal macrobenthic distribution in relation to abiotic conditions in the Lima Estuary, NW of Portugal. Hydrobiologia 559: 135-148.

Sousa R., Dias S., Freitas V., Antunes C. 2008. Subtidal macrozoobenthic assemblages along the River Minho estuarine gradient (NW of Iberian Peninsula). Aquat. Conserv.: Mar. Freshw. Ecosyst. 18: 1063-1077.

Vale C., Canário J., Caetano M., Lavrado J., Brito P. 2008. Estimation of the anthropogenic fraction of elements in surface sediments of the Tagus Estuary (Portugal). Mar. Pollut. Bull. 56: 1353-1376. PMid:18501386

Viéitez J.M. 1976. Ecología de Poliquetos y Moluscos de la playa de Meira (Ría de Vigo). Inv. Pesq. 40: 223-248.

Warwick R.M., Goss-Custard J.D., Kirby R., George C.L., Pope N.D., Rowden A.A. 1991. Static and dynamic environmental factors determining the community structure of estuarine macrobenthos in SW Britain: why is the Severn estuary different? J. Appl. Ecol. 28: 1004-1026.

Ysebaert T., Herman P.M.J., Meire P., Craeymeersch J., Verbeek H., Heip C.H.R. 2003. Large-scale spatial patterns in estuaries: estuarine macrobenthic communities in the Schelde estuary, NW Europe. Estuar. Coast. Shelf Sci. 57: 335-355.

Ysebaert T., Meire P., Coosen J., Essink K. 1998. Zonation of intertidal macrobenthos in the estuaries of Schelde and Ems. Aquat. Ecol. 32: 53-71.

Copyright (c) 2013 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