Abstract
Lake and coastal Tunisian areas are rich biodiversity habitats, although little information is available about the distribution of food sources for the inhabitant species. In this study, a fatty acid analysis was used to study the trophic ecology of Venerupis decussatac ommunities from 10 sites located along the Tunisian Coast. The richest population in fatty acids was found in S4 followed by S5 and S8, while that of S1, S3 and S10 were the least rich. Results from multivariate analysis confirmed the ecological position of the studied population based on their fatty acid composition. Our results divided the ten studied populations into three similar groups according to their ecological and geographical positions in relation to environmental parameters and food and trophic links. A principal component analysis revealed that diatoms and dinoflagellates were the predominate diets in all the sampling stations. Bacteria and urban discharge dominated the dietary source of clams from S10 and S9. Zooplankton were the preferred diet of V. decussata harvested from the two S2 and S3 lakes; although green algae, phytoplankton and detritus were absent from the dietary source of the two previous populations. Despite spatial differences, clams from the north and the south could be easily distinguished from each other, which indicates the utility of this method in the dietary analysis of different food chain links. This study proves that geographic, ecologic and abiotic factors as well as their mutual interaction should be properly investigated in studies focusing on the trophic chains of aquatic ecosystems.
Highlights
The littoral of Tunisia covers 1300 Km; it possesses an important particular biodiversity and is considered the richest ecosystem in the Mediterranean Sea (Hattour and Ben Mustapha, 2013)
Polyunsaturated fatty acids (PUFA) were present in the highest percentages in all the studied sites, with maximum values recorded in clams from S3 (40%) and S4 (60%) (Table 2)
This study revealed a significant geographical variation in the fatty acid composition of V. decussata related to environmental parameters of ten locations from the Tunisian Coast, revealing a good nutritional quality of the species marked by the abundance of PUFA especially DHA and EPA in all the sampled clams
Summary
The littoral of Tunisia covers 1300 Km; it possesses an important particular biodiversity and is considered the richest ecosystem in the Mediterranean Sea (Hattour and Ben Mustapha, 2013) This ecosystem is situated in the most productive area in the Mediterranean Sea, and its high productivity is maintained by a great level of nutrients in both sediment and water column. These transition zones between land and sea can offer unique ecosystem services ranging from trapping contaminants in their sediments to providing nursery areas for marine species and feeding grounds for migratory birds (McLusky and Elliot, 2004). FA analyses have been used extensively to study trophic relationships and as important determinants of ecosystem health and stability in marine food webs (Dalsgaard et al, 2003; Budge et al, 2006)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
