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The impact of geographical habitat and soil types on morphological aspect, phytochemical composition and enzymes activity of Erodium glaucophyllum was assessed. Different soil textures were identified including sandy loam, clay and sandy clay loam. The plants exhibiting the highest degree of morphological development were identified in the Gabes region. The best nutrient composition value was recorded for the Gafsa and the Gabes regions. Among the mineral elements detected, the highest amounts of Mg and Ca were found in the Sidi Bouzid region with 29.61 and 50.07 mg kg−1, respectively. They depended on geographical location, altitude, average rainfall and the physiological condition of the plant. Plants from the Gafsa region exhibited the highest levels of phenolic and flavonoid contents measuring 187.47 mg GAE/g and 29.76 mg QE/g, respectively. Antioxidant activity was in accordance with total phenols of the three localities and the lowest IC50 values for DPPH scavenging and FRAP assay was recorded for the Gafsa region. The findings demonstrated that the studied species has the potential to serve as a valuable ecological natural source for bioactive antioxidant compounds. Furthermore, it shows promise as an alternative source for the production of β-amylase, L-asparaginase and lipoxygenase. [ABSTRACT FROM AUTHOR]

Harbours are one of the most disturbed coastal ecosystems due to intensive anthropogenic pressures. This study aimed for the first time to compare anthropogenic impacts in three harbours from the central coast of Tunisia (Mediterranean Sea) employing analysis of heavy metal contamination and ecological quality status (EcoQS). Sampling was carried out in spring 2019 in the fishing harbour of Teboulba, the marina of Monastir, and the commercial harbour of Sousse. The high levels of concentration in heavy metals and organic matter were closely related to the fine-grained fraction of the sediment in the fishing and commercial harbours. A total of 94 macrobenthic species, including five nonindigenous species, were identified belonging to six zoological groups. Multivariate analyses highlighted a strong influence of the harbour activity on the diversity of macrozoobenthic communities. Three benthic assemblages were identified according to their environmental characteristics such as sediment type, organic matter content, and heavy metal contamination. Benthic and biotic indices (H′, J′, AMBI, and BO2A) showed that the EcoQS varied from poor (commercial harbour) to good (marina), and was significantly influenced by harbour activity, organic matter, and heavy metal contamination of the sediment. The present work could be considered as providing important baseline data for the implementation of national environmental policies and management plans in the future. [ABSTRACT FROM AUTHOR]

The structure, diversity, spatial and seasonal distributions of amphipod assemblages associated with intertidal Zostera (Zosterella) noltei meadows were studied around the Kneiss Islands (central Mediterranean Sea). This site represents a site of international interest in terms of its ornithological diversity (Important Bird Area, Ramsar Site and SPAMI). The amphipod fauna was sampled at 32 stations in spring 2014. A total of 6,482 individuals belonging to 78 species and 22 families were identified; among these taxa, Lysianassa ceratina is new for the Tunisian amphipod inventory, whereas 25 species are identified for the first time in the Gulf of Gabès. The dominant species are Cymadusa filosa, Microdeutopus gryllotalpa, Gammarus insensibilis, Dexamine spiniventris, Monocorophium insidiosum, Elasmopus rapax, Melita palmata and Leucothoe incisa. Four amphipod assemblages are identified using MDS analysis. The distribution of amphipod assemblages is linked to several environmental factors, such as sediment type, organic matter content and distance from the shore, which is itself associated with a clear inshore–offshore gradient. Seasonal variations of the amphipod assemblage patterns at eight stations, sampled between April 2014 and January 2015, show a maximum abundance and diversity during summer and autumn, with a minimum in winter. These seasonal fluctuations may be related to many factors such as variations of climatic factors (e.g. temperature, salinity), the growth and production rates of Zostera noltei meadows and seasonal patterns in the life cycle of dominant species. [ABSTRACT FROM AUTHOR]

Skhira Bay located in the Gulf of Gabès, on the southeastern coast of Tunisia, is an important area in terms of its dense vegetation coverage, wide continental shelf, and fisheries resources. However, this area with a typically micro-tidal range is subject to intensive anthropogenic pressures: soft bottom trawling, chemical pollution from phosphoric acid production, and shipping activity. The present study is the first investigation of the structure of the benthic macrofauna on this part of the Tunisian coast. In April 2010, 28 stations were sampled along four transects from the phosphogypsum outfall on an inshore-offshore gradient. A total of 239 macrobenthos taxa, belonging to nine zoological groups and 140 families, were identified with a dominance of polychaetes (33.5%), crustaceans (29.4%), and mollusks (19.6%). Results show that the stations facing the phosphogypsum discharges are the most disturbed and characterized by a poorly diversified macrofauna. The macrofauna is dominated by carnivores, suspension feeders, and selective deposit feeders, and seems to be linked more to the availability of trophic resources than to disturbance. Four benthic assemblages are identified using Cluster and MDS analyses linked to edaphic factors, such as sediment structure, organic matter content, inshore/offshore gradient, and the proximity of the phosphogypsum outfall. The biotic indices (AMBI and BO2A) calculated from macrofauna data show that the ecological status of Skhira Bay varies overall from moderate to good. This study suggests initiating a long-term monitoring program to improve our understanding of the temporal changes of this ecosystem, to recommend the necessary conservation measures in this area of high-value natural heritage. [ABSTRACT FROM AUTHOR]

In the Gulf of Gabès (South-eastern Tunisia), polychaete bait digging is widely practiced for recreational and commercial fishing and is an economically significant activity. The present study aims to assess the short-term effects of intertidal bait digging on macrobenthic communities from the Kneiss Islands. Following a protocol with a control station (not impacted) and three impacted stations for polychaete collection, the study was conducted during March and April 2015 at spring tides. After digging, immediate significant decreases were observed in the abundance of total macrofauna as well in numerous families of polychaetes. Control of this activity should be proposed for the future to protect the biodiversity of this intertidal area of high heritage interest. [ABSTRACT FROM AUTHOR]