scholarly journals DISTRIBUTION OF SPAWNING AND NURSERY GROUNDS FOR DEEP–WATER RED SHRIMPS IN THE CENTRAL WESTERN MEDITERRANEAN SEA

2014 ◽  
Vol 16 (1) ◽  
pp. 117 ◽  
Author(s):  
F. PALMAS ◽  
P. ADDIS ◽  
S. CABIDDU ◽  
D. CUCCU ◽  
M. C. FOLLESA ◽  
...  

The presence of spawning and nursery grounds of Aristeids in the central western Mediterranean Sea were investigated using fishery-independent data (trawl surveys, 1994–2012). Spatial distributions were generated for mature animals and recruits, for both spring/summer and autumn data, using an inverse distance weighted deterministic interpolation. The persistence index was used to identify stable spawning and nursery grounds in the Sardinian slope region for Aristaeomorpha foliacea and Aristeus antennatus. Areas of aggregation for recruits and mature females appear connected with important physical habitat features. The analysis also suggests a seasonal bathymetric distribution for nursery areas. The recruits of A. foliacea are located in the upper part of the continental slope (377-450 m) in spring-summer and reach greater depths (468-628 m) in autumn. For A. antennatus, for which nursery areas only emerge in autumn, there is presumably an opposite ontogenic migration, from deep sea to upper slope, during the summer (575-681 m). Results indicate also a partial overlap between the nursery and spawning grounds of both species. In this particular areas, local environmental conditions such as upwelling events or the presence of canyons and seamounts seem to play an important role in their distribution. This study generated also relevant information on the spatial and temporal distribution of seasonal or persistent aggregations of spawners and recruits, providing scientific elements to suggest the feasibility of protecting these important resources.

Author(s):  
SKANDER SETITI ◽  
BOUALEM HAMDI ◽  
SAFIA CHERNAI ◽  
FOUZIA HOUMA BACHARI ◽  
SAMIR BACHOUCHE ◽  
...  

Coastal waters worldwide are widely contaminated with various-size plastics, whose presence in aquatic ecosystems has been shown to produce a wide range of economic and social impacts and harmful effects on marine ecosystems. While microplastics have been reported from many regions of the Mediterranean Sea, very few data exist regarding microplastics concentration in Algerian waters. In this study, we used a Manta trawl (330 µm) at six sampling stations in Bou-Ismail Bay, Algeria (South-West Mediterranean Sea) in order to provide novel information about the occurrence and composition of microplastics along the Algerian coast. Sampling was performed seasonally at six different sampling stations in 2018, providing additional information about the spatio-temporal variability of microplastics concentrations at the sea surface. Microplastics were found in all collected samples, with highly variable concentrations of 0.95, 0.88, 1.26, and 0.36 items/m3 in Autumn, Winter, Spring and Summer, respectively, and an overall mean concentration of 0.86 ± 0.35 items/m3. A classification based on the shape and appearance of microplastics indicated the predominance of fibers (32%), followed by fragments (27%), films (16%), foams (13%), and granules (12%). A qualitative microplastics analysis through Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) revealed that microplastics were mainly composed of polyethylene (68.2%), polypropylene (24.7%), polystyrene (4.1%) and other polymers (3%). These data provide an initial overview of the quantity, characteristics, and spatio-temporal distribution of floating microplastics in Bou-Ismail Bay (Algeria).


2014 ◽  
Vol 59 (1) ◽  
Author(s):  
Salvatore Mele ◽  
Maria Pennino ◽  
Maria Piras ◽  
José Bellido ◽  
Giovanni Garippa ◽  
...  

AbstractThe metazoan parasite assemblage of the head of 30 specimens of the Atlantic chub mackerel (Scomber colias) from the western Mediterranean Sea was analysed. Eight species of parasites were found, four mazocraeid monogeneans: Grubea cochlear (prevalence = 10%), Kuhnia scombercolias (59%), K. scombri (52%), Pseudokuhnia minor (86%); three didymozoid trematodes: Nematobothrium cf. faciale (21%), N. filiforme (41%), N. scombri (7%); and one laerneopodid copepod: Clavelissa scombri (7%). Results were compared with previously published data from 14 localities of the eastern Mediterranean Sea and the Atlantic Ocean, using non-parametric univariate and multivariate analyses, and the whole parasite fauna of S. colias was compared with that of the congeners (S. australasicus, S. japonicus and S. scombrus). Parasites showed to reflect the biogeographical and phylogenetic history of host. From a methodological point of view, the use of both non-parametric univariate and multivariate techniques proved to be effective tools to detect dissimilarities between parasite assemblages.


2021 ◽  
Vol 9 (2) ◽  
pp. 208
Author(s):  
Valentina Vannucchi ◽  
Stefano Taddei ◽  
Valerio Capecchi ◽  
Michele Bendoni ◽  
Carlo Brandini

A 29-year wind/wave hindcast is produced over the Mediterranean Sea for the period 1990–2018. The dataset is obtained by downscaling the ERA5 global atmospheric reanalyses, which provide the initial and boundary conditions for a numerical chain based on limited-area weather and wave models: the BOLAM, MOLOCH and WaveWatch III (WW3) models. In the WW3 computational domain, an unstructured mesh is used. The variable resolutions reach up to 500 m along the coasts of the Ligurian and Tyrrhenian seas (Italy), the main objects of the study. The wind/wave hindcast is validated using observations from coastal weather stations and buoys. The wind validation provides velocity correlations between 0.45 and 0.76, while significant wave height correlations are much higher—between 0.89 and 0.96. The results are also compared to the original low-resolution ERA5 dataset, based on assimilated models. The comparison shows that the downscaling improves the hindcast reliability, particularly in the coastal regions, and especially with regard to wind and wave directions.


2007 ◽  
Vol 105 (1-2) ◽  
pp. 101-117 ◽  
Author(s):  
Tommaso Tesi ◽  
Stefano Miserocchi ◽  
Miguel A. Goñi ◽  
Leonardo Langone

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