Biomonitoring of the environmental contamination by organotins in the Gulf of Tunis: occurrence of imposex in Stramonita haemastoma (Linnaeus, 1767)

Abstract

Imposex has been observed in several regions of the world to affect many species of prosobranch gastropods such as Stramonita haemastoma (Linnaeus, 1767). This irreversible sexual anomaly is caused mainly by the accumulation of organotin compounds in tissues. The present study aimed to confirm the existence of imposex and to determine the different levels of infection in individuals of Stramonita haemastoma collected from different stations along the rocky coastline of the Gulf of Tunis. To do this, 10 stations covering the entire rocky coastline of the gulf were sampled during March-May 2012. Rates of occurrence of imposex suggest that sexual modifications occur to different degrees in this species in all sampled stations of the gulf. The most contaminated sites were harbour areas (Sidi Bou Said and La Goulette). In addition, an inverse relationship between the distances from potential sources of pollution and the occurrence of this sexual anomaly was observed. It should be noted that toxic effects induced by marine xenobiotics could cause the loss of biodiversity and the disruption of this ecosystem stability.

Integrated Biomarker Response for Environmental Assessment Using the Gastropod Phorcus turbinatus along the Northern and the Northeastern Coasts of Tunisia

“…In fact, the use of pesticides is increased in the north and northeast sector of the country where farms and agricultural lands are concentrated [49]. Moreover, this fringe is jointly contaminated by urban discharges and hydrocarbons evacuated in harbors by transiting ships [9]. In this context, [45,51,52] reported that CAT activity was often induced by exposure to PAHs, COs and PCBs.…”

“…This appears to reflect the presence of high stress suffered by these organisms. Indeed, these two zones are subject to several industrial and urban stressors and include large fishing ports with continuous maritime activity [9]. The maximal IBR values were synchronized with the minimal values of the Fulton condition factor (K), probably related to the reproductive activity of organisms during the summer and the autumn [30].…”

“…The rocky coasts of Tunisia are known to be strongly affected by organostannic compounds (tributyltin TBT) and heavy metals [9,10]. In addition, high total hydrocarbon concentrations were reported in the surface sediment of many areas of the Tunisian coasts, namely Bizerte Jarzouna (602-1270 µg/g) [11], Ghar el Melh lagoon (39.59-655.28 ng/g of Life 2021, 11, 529 2 of 13 dry weight) [12], Bizerta lagoon (83.3-447.08 ng/g of dry weight) [13], the Gulf of Tunis (14.7-618.1 ng/g) [14], Monastir Bay (25.6-576.8 ng/g of dry weight) [8] and the region of Khniss (between 2280 and 7700 µg/g) [15].…”