Scientia Marina, Vol 73, No 2 (2009)

The effect of sewage discharge on Melarhaphe neritoides (Gastropoda: Littorinidae) population dynamics

Joana Cabral-Oliveira
IMAR - Institute of Marine Research, Department of Zoology, University of Coimbra , Portugal

Paulo Maranhão
IMAR - Institute of Marine Research, Department of Zoology, University of Coimbra , Portugal

GIRM – Marine Resources Research Group, School of Maritime Technology. Portugal

Miguel Ângelo Pardal
IMAR - Institute of Marine Research, Department of Zoology, University of Coimbra , Portugal


The discharges of sewage effluent treatment plants has a major impact on coastal communities. In our study area (western coast of Portugal) Melarhaphe neritoides (L. 1758) is the dominant high-shore gastropod. Two populations of M. neritoides were studied in order to understand the impact of sewage discharges on intertidal communities: one population in an impacted area and the other in a similar but unimpacted area (reference site). Environmental data and abundance, biomass, population structure and annual growth production of M. neritoides were estimated in the two areas. The results showed that M. neritoides density is higher in the impacted area as a result of massive settlement. The sewage discharge increases the nutrient concentrations in the water, which causes more microalgae to grow on the rocky surfaces. This higher availability of food may promote recruitment. However, we found high mortality in the juveniles in the impacted area, which affected density values on the upper shore levels (where we found the adults) of both areas. Moreover, the adults were bigger in the unimpacted area, which suggests that individuals grow more or live longer in this area.


Melarhaphe neritoides; abundance; biomass; secondary production; sewage; nutrient enrichment; rocky shore

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Arévalo, R., S. Pinedo and E. Ballesteros. – 2007. Changes in the composition and structure of Mediterranean rocky-shore communities following a gradient of nutrient enrichment: Descriptive study and test of proposed methods to assess water quality regarding macroalgae. Mar. Pollut. Bull., 55: 104-113. doi:10.1016/j.marpolbul.2006.08.023 PMid:17045305

Bacelar-Nicolau, P., L.B. Nicolau, J.C. Marques, F. Morgado, R. Pastorinho and U.M. Azeiteiro. – 2003. Bacterioplankton dynamics in the Mondego estuary (Portugal). Acta Oecol., 24: S67-S75. doi:10.1016/S1146-609X(03)00016-X

Benke, A.C. – 1979. A modification of the Hynes method for estimating secondary production with particular significance for multivoltine populations. Limnol. Oceanogr., 24(1): 168-171.

Bishop, M.J., A.J. Underwood and P. Archambault. – 2002. Sewage and environmental impacts on rocky shores: necessity of identifying relevant spatial scales. Mar. Ecol. Prog. Ser., 236: 121-128. doi:10.3354/meps236121

Bosh, M. and I. Moreno. – 1986. Spatial distribution of Littorina neritoides (L. 1758) (Mollusca, Gastropoda) in the supralitoral zone in the Balearic Islands. Cah. Biol. Mar., 42: 53-62.

Chen, Y.S. and A.M.M. Richardson. – 1987. Factors affecting the size structure of two populations of the intertidal periwinkle Nodilittorina unifasciata (Gray, 1839) in the Derwent River, Tasmania. J. Molluscan Stud., 53: 69-78. doi:10.1093/mollus/53.1.69

Cronin, M.A., A.A. Myers and R.M. O’Riordan. – 2000. The reproductive cycle of the intertidal gastropod Melarhaphe neritoides on the west and south coasts of Ireland. In: Bruce Osborne (ed.), Environ. Proc. R. Ir. Acad., 100B(2): 97-106. Dublin, Ireland.

Ferskvandsbiologisk Laboratorium – 1985. Limnologisk Metodik. Kobenhawns Universitet (ed.), Akademisk Forlag, København.

Fraschetti, S., C. Gambi, A, Giangrande, L. Musco, A. Terlizzi and R. Danovaro. – 2006. Structural and functional response of meiofauna rocky assemblages to sewage pollution. Mar. Pollut. Bull., 52: 540-548. doi:10.1016/j.marpolbul.2005.10.001 PMid:16289572

Fretter, V. and A. Graham. – 1980. The prosobranch molluscs of Britain and Denmark. Part 5 – Marine Littorinacea. J. Molluscan Stud., 7: 243-284.

Fretter, V. and R. Manly. – 1977. Settlement and early benthic life of Melarhaphe neritoides (L) at Wembury, S Devon. J. Molluscan Stud., 43: 255-262.

Gappa, J.L., A. Tablado and N.H. Magaldi. – 1990. Influence of sewage pollution on a rocky intertidal community dominated by the mytilid Brachidontes rodriguezi. Mar. Ecol. Prog. Ser., 63: 163-175. doi:10.3354/meps063163

Hughes, R.N. and D.J. Roberts. – 1981. Comparative demography of Littorina rudis, L. nigrolineata and L. neritoides on three contrasted shores in North Wales. J. Anim. Ecol., 50: 251-268. doi:10.2307/4043

Lebour, M.V. – 1935. The breeding of Littorina neritoides. J. Mar. Biol. Ass. U.K., 20: 373-378.

Little, C. and J.A. Kitching. – 1996. The biology of rocky shores. Oxford University Press, New York.

Lysaght, A. – 1941. The biology and trematode parasites of the gastropod Littorina neritoides (L.) on the Plymouth Breakwater. J. Mar. Biol. Ass. U.K., 25: 41-67.

Newell, R.C. – 1979. Biology of intertidal animals. Marine Ecological Surveys, Ltd. Faversham.

Nogueira, A.J. – 1992. ANAMOD — Extracção dos componentes modais de distribuições de frequências de variáveis biométricas. Provas de aptidão pedagógica e capacidade científica. University of Coimbra, Coimbra.

Nybakken, J.W. – 2000. Marine Biology: An Ecological Approach. Benjamin Cummings. USA.

Palant, B. and L. Fishelson. – 1968. Littorina punctata and M. neritoides from Israel: ecology and annual cycle of the genital system. Isr. J. Zool., 17: 145-60.

Raffaelli, D.G. and R.N. Hughes. – 1978. The effect of crevice size and availability on populations of Littorina rudis and Littorina neritoides. J. Anim. Ecol., 47: 71-83. doi:10.2307/3923

Stafford R. and M.S. Davies. – 2005. Examining refuge location mechanisms in intertidal snails using artificial life simulation techniques. In: M. Capcarrere et al. (eds.), Lecture Notes in Artificial Intelligence. Proc. VIIth Eur. Conf. Art. Life, 3630: 520-529. Springer Berlin, Heidelberg.

Strickland, J.D.H. and T.R. Parsons. – 1968. A practical handbook of seawater analysis. Bull. Fish Res. Board Can., 167: 1-311.

Tablado, A. and J.L. Gappa – 2001. Morphometric diversity of the pulmonate limpet Siphonaria lessoni in different coastal environments. Sci. Mar., 65(1): 33-41. doi:10.3989/scimar.2001.65n133

Terlizzi A., D. Scuderi, S. Fraschetti and M.J. Anderson. – 2005. Quantifying effects of pollution on biodiversity: a case study of highly diverse molluscan assemblages in the Mediterranean. Mar. Biol., 148: 293-305. doi:10.1007/s00227-005-0080-8

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