The accumulation of the five trace metals (TMs) cadmium, copper, lead, nickel and zinc was measured in Posidonia oceanica leaves. Shoots were seasonally sampled at 8-10-m depth from four stations located in Port El Kantaoui area, Tunisia, during four campaigns performed in 2012. Levels of the five TMs were analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES) in three compartments of P. oceanica shoots: blades and sheaths of adult leaves and intermediate leaves. Results showed a preferential accumulation of Cd, Pb, Ni and Zn in adult leaf blades. Therefore, we focus on the study of this compartment. TM levels of blades of adult leaves decreased in the following order: Zn > Ni > Cu > Pb > Cd, irrespective of the season. Levels of the five TMs significantly differed between seasons (p < 0.01). Levels of Cd and Cu showed a seasonal pattern: Cd decreased from spring to winter while Cu increased during that same period of time. A significant correlation (p < 0.01) was found between Cd-Cu and Cd-Pb. A significant correlation (p < 0.05) was also noted between Cd-Ni in the adult leaf blades. A relationship was recorded between the foliar surface of the adult leaf blades and Zn accumulation. This survey allowed to highlight the annual variation of TM accumulation in adult leaf blades of P. oceanica, in relation with ecophysiology of this seagrass. Therefore, this study reinforces the usefulness and the relevance of this compartment of P. oceanica, easy to sample without destruction of whole shoot, as a bioindicator of Zn, Ni, Cd and Pb contamination.
The Indo-Pacifics pecies Avrainvillea amadelpha (Montagne) A. Gepp &E .S. Gepp is reported for the first time from the Mediterranean Sea (Kerkennah Islands, Tunisia). The species is considered as introduced and invasive in the Hawaiian Archipelago. The Mediterranean specimens are studied and the reproductive structures are described and illustrated here for the first time.The possible origins and vectors of this introduction and the risk of propagation of the species in the MediterraneanS ea are discussed. Avrainvillea amadelpha /U lvophyceae /T unisia /M editerranean /I ntroduced species / Invasive species Résumé-L'espèce Indo-Pacifique Avrainvillea amadelpha (Montagne) A. Gepp &E.S. Gepp, est signaléep our la première fois en Méditerranée(Iles Kerkennah, Tunisie). L'espèce est considéréec omme introduite et invasive dans l'archipel Hawaiien. Les spécimens méditerranéens sont étudiése tl es organes reproducteurs sont décrits et illustrésp our la première fois. Les origines et les vecteurs possibles de cette introduction sont discutés, ainsi que les risques de propagation de l'espèce en Méditerranée.
The loggerhead sea turtle (Caretta caretta), has the broadest distribution among sea turtle species in the Mediterranean and requires regional and international collaborations in addition to local efforts to better inform conservation actions. Molecular techniques are powerful tools to assess population dynamics at large scales, especially by determining the connectivity among different nesting and foraging sites, and genetic diversity. In this study, a large sample was collected synchronously in the nesting areas located in the north, south and east of the Mediterranean. Recently described nesting sites from Albania and other nesting sites represented by lower sample size were also included in order to fully assess the genetic composition of the region's rookeries. Samples from 710 individuals were collected and the longer (815 bp) mtDNA D-loop fragment of these samples was ampli ed. We recorded 15 haplotypes, three of which were novel. In addition, our results show that some haplotypes, considered of Atlantic origin, have a wider dispersal in the Mediterranean than previously thought, albeit with low levels of representation. Our results, which also contribute to determining the likely origin of haplotypes that were previously known only from foraging sites, highlight the utility of broad-scale sampling, with increased sample number and longer mtDNA sequence to determine genetic diversity and connectivity. This study also demonstrates that it is important to continue to monitor the contribution of Atlantic origin haplotypes to the Mediterranean population, and the resident Mediterranean population, which is expected to expand its geographical range for reproduction with the effect of climate change and climate change in the long term. This work is important for, among other things, mixed stock analyses (MSA) that seek to localize the origin of stranded or accidentally caught sea turtles or those purposefully obtained from foraging sites to better understand the migratory distribution for conservation purposes.
In this paper, we propose a secure semi-fragile self-authentication watermarking technique based on embedding of perceptual hash derived from discrete wavelet transformation of jpeg2000 encoder. The original image is transformed on wavelet domain using JPEG2000 encoder. Then, we extract LL sub-band coefficients in order to perform perceptual hash. This hash will be embedded back into the same sub-band as a watermark using QIM approach. The experimental results show that the proposed scheme is capable to detect the authenticity of watermarked image while preserving the visual quality.
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