Macrozoobenthic species composition and distribution in the Northern lagoon of Tunis
Abstract
1 - The macrobenthic community and abiotic parameters of a Méditerranean lagoon (Norhern lagoon of Tunis) was studied on automnal season during 1995, 1996 and 1997.
2 - Analysis of abiotic parametters revealed significant differences between stations. Variations of temperaturs and salinity reported in this studie show a gradient increasing in the direction circulating currents. Tidally driven marine waters cause a contnuous refreshment of lagoon waters, thus promoting oxygenation and nutrient loading.
3 - In total, 61 species were recognized, divided into seven zoo-goups with Molluscs always dominant. A noticeable increase in specific richness occured due to hydrologic and environmental improvement after sanitation in 1984-1988.
4 - Comparison of ecological indexes (specific richness, abundances, density, Shannon- Weaver indexes and evenesses) indicate significant variations in the spatial distribution and structure of benthic community, area A subjected to marine refreshment having a more deversified benthic fauna. In contrast, stations (B and C) remote from the sea display a neat faunal disturbance.
5 - Multivariate analysis help characterize hetergeneity in the benthic community structure of stations; thus, Echinodermata and Porifera phyla represent a great heterogeneity in species abundances.
6 - Physico-chemical properties of lagoon waters and macrobenthic faunal characters help identify three main sectors: i) a northeastern sector near the lagoon entrance, with newly introduced marine species (as Pinctada radiata); ii) a transitional sector which suffered pollution earlier to lagoon sanitation; iii) a sector with confinement and typically lagoonal, eurythermal and euryhaline species
DOI Code:
10.1285/i1825229Xv2n2p1
Keywords:
community; macrozoobenthos; Northern lagoon Tunis; diversity; pollution; sewedge
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