The effect of sewage discharge on Melarhaphe neritoides (Gastropoda: Littorinidae) population dynamics
Cabral-Oliveira, J.; Maranhão, P.; Pardal, M.A. (2009). The effect of sewage discharge on Melarhaphe neritoides (Gastropoda: Littorinidae) population dynamics. Sci. Mar. (Barc.) 73(2): 259-267. https://dx.doi.org/10.3989/scimar.2009.73n2259
In: Scientia Marina (Barcelona). Consejo Superior de Investigaciones Científicas. Institut de Ciènces del Mar: Barcelona. ISSN 0214-8358; e-ISSN 1886-8134, meer
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Trefwoorden |
Abundance Biological production > Secondary production Enrichment Population characteristics > Biomass Sewage Topographic features > Landforms > Coastal landforms > Rocky shores Melarhaphe neritoides (Linnaeus, 1758) [WoRMS] Marien/Kust |
Author keywords |
Melarhaphe neritoides; abundance; biomass; secondary production; sewage;nutrient enrichment; rocky shore |
Auteurs | | Top |
- Cabral-Oliveira, J.
- Maranhão, P.
- Pardal, M.A.
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Abstract |
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. |
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