scholarly journals The general specifications of the MEDITS surveys

2002 ◽  
Vol 66 (S2) ◽  
pp. 9 ◽  
Author(s):  
Jacques A. Bertrand ◽  
Luis Gil de Sola ◽  
Costas Papaconstantinou ◽  
Giulio Relini ◽  
Arnauld Souplet
Keyword(s):  
European Commission ◽  
Mediterranean Sea ◽  
Biological Data ◽  
Bottom Trawl ◽  
Trawl Survey ◽  
Bottom Trawl Survey ◽  
Mediterranean Countries ◽  
The Mediterranean

An international bottom trawl survey was designed from a European Commission´s initiative to produce biological data on the demersal resources in the Mediterranean Sea. Nine Mediterranean countries are associated in the programme, which covers all the trawlable areas along their coasts from 10 to 800 m depth. From 1994 to 2000, one survey was carried out each year, applying common standardized protocols. Seven yearly surveys have therefore been done, with a total of 7,500 stations prospected. This paper presents the methods adopted to carry out the surveys.

scholarly journals Depth trajectory and performance of a trawl used for an international bottom trawl survey in the Mediterranean

2002 ◽  
Vol 66 (S2) ◽  
pp. 169 ◽  
Author(s):  
Jacques Bertrand ◽  
Iole Leonori ◽  
Pierre Yves Dremière ◽  
Giulio Cosimi
Keyword(s):  
Bottom Trawl ◽  
Trawl Survey ◽  
A Posteriori ◽  
Sampling Protocol ◽  
Bottom Trawl Survey ◽  
Sampling Protocols ◽  
The Mediterranean ◽  
And Performance ◽  
Biological Assessments ◽  
Swept Area

An international bottom trawl survey (the MEDITS programme) has been carried out every year in the Mediterranean since 1994. During each survey, about 1000 hauls are done by a fleet of 8 to 11 vessels from 10 to 800 m depth, applying a unique standardized sampling protocol. This study analyses the trajectory and the performances of the sampling gear used for this survey, from records obtained during the surveys aboard some vessels in different geographical sub-areas and at different depth levels. Two kinds of sensors have been used, one to characterize a posteriori the vertical trajectory of the trawl from the beginning of shooting to the end of hauling (830 hauls), the other to describe in real time the stabilization of the trawl at its beginning (16 hauls) and its geometry during the tow (840 hauls). The results show the variability extent of these parameters linked with vessel, area, depth and period, illustrating their impact on the swept area estimates used for biological assessments. The results strongly suggest the inforcement of a quality strategy combining the use of rigourous sampling protocols and systematic controlling of the main parameters characterizing the trawl performance during routine surveys.

scholarly journals Spatio-temporal patterns of macrourid fish species in the northern Mediterranean Sea

2020 ◽  
Vol 83 (S1) ◽  
pp. 117
Author(s):  
Cristina García-Ruiz ◽  
Manuel Hidalgo ◽  
Paolo Carpentieri ◽  
Ulla Fernandez-Arcaya ◽  
Palma Gaudio ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Trawl Survey ◽  
Western Basin ◽  
Entire Study ◽  
Mediterranean Countries ◽  
The Mean ◽  
The Mediterranean ◽  
Spatio Temporal ◽  
First Time ◽  
Entire Study Area

The present study describes for the first time the spatial distribution of five macrourid species throughout the Mediterranean Sea and analyses depth, geographical and time-related trends regarding their abundance, biomass and mean fish weight. The data were collected as part of the MEDITS annual bottom trawl survey carried out by several European Mediterranean countries from 1994 to 2015, using the same standardized gear and sampling protocol. The most represented species in terms of abundance and biomass was Coelorinchus caelorhincus. The bathymetric trend was different for each species. The shallowest occurring species was C. caelorhincus, followed by Hymenocephalus italicus and Nezumia sclerorhynchus, while Nezumia aequalis and Trachyrincus scabrus were the deepest. Overall, the mean weight of all the species increased with depth. C. caelorhincus and H. italicus occurred in the entire study area: the first species showed relatively high catches in most areas, while the second was more abundant in the central and easternmost areas. N. aequalis and T. scabrus were mainly reported in the western basin, and N. sclerorhynchus in the central-eastern areas of the Mediterranean. An increasing inter-annual trend in abundance was only detected for C. caelorhincus and N. sclerorhynchus, while variable fluctuations were observed in the other species.

scholarly journals Decadal‐Scale Variation in Mean Trophic Level in Beibu Gulf Based on Bottom‐Trawl Survey Data

2021 ◽  
Vol 13 (3) ◽  
pp. 174-182
Author(s):  
Li Su ◽  
Zuozhi Chen ◽  
Kui Zhang ◽  
Youwei Xu ◽  
Shannan Xu ◽  
...  
Keyword(s):  
Survey Data ◽  
Trophic Level ◽  
Bottom Trawl ◽  
Beibu Gulf ◽  
Trawl Survey ◽  
Bottom Trawl Survey ◽  
Decadal Scale ◽  
Mean Trophic Level ◽  
Scale Variation

scholarly journals The influence of warp length on trawl dimension and catch of walleye pollock Theragra chalcogramma in a bottom trawl survey

2005 ◽  
Vol 71 (4) ◽  
pp. 738-747 ◽  
Author(s):  
Yasuzumi FUJIMORI ◽  
Kenji CHIBA ◽  
Tatsuki OSHIMA ◽  
Kazushi MIYASHITA ◽  
Satoshi HONDA
Keyword(s):  
Walleye Pollock ◽  
Bottom Trawl ◽  
Theragra Chalcogramma ◽  
Trawl Survey ◽  
Bottom Trawl Survey ◽  
Walleye Pollock Theragra Chalcogramma

On a saddled snake eel Pisodonophis semicinctus (Osteichthyes: Ophichthidae) trawled in the Strait of Sicily (Mediterranean Sea)

2000 ◽  
Vol 80 (5) ◽  
pp. 951-952 ◽  
Author(s):  
Sergio Ragonese ◽  
Giovan Battista Giusto
Keyword(s):  
Body Weight ◽  
Mediterranean Sea ◽  
Bottom Trawl ◽  
Northern Coast ◽  
Rare Finding ◽  
Strait Of Sicily ◽  
Total Length ◽  
The Mediterranean

The occurrence in the Strait of Sicily of the saddled snake eel, Pisodonophis semicinctus (Osteichthyes: Ophichthidae), a rare finding for the Mediterranean Sea, is confirmed on the basis of one specimen caught off the northern coast of Tunisia in 1991. The specimen, 800 mm in total length and 457 g in body weight (preserved condition), was captured during a commercial bottom trawl hauled at 30 m next to Cape Bon (north of Tunisia). This represents the second and fourth documented record of this Atlantic intruder within the Strait of Sicily and the Mediterranean Sea, respectively.

scholarly journals Protocols of the EU bottom trawl survey of Flemish Cap

2014 ◽  
Vol 46 ◽  
pp. 3-51
Author(s):  
A Vazquez ◽  
J M Casas ◽  
A Alpoim
Keyword(s):  
Bottom Trawl ◽  
Trawl Survey ◽  
Bottom Trawl Survey ◽  
The Eu

scholarly journals Bottom trawl catch comparison in the Mediterranean Sea: Flexible Turtle Excluder Device (TED) vs traditional gear

PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0216023
Author(s):  
Claudio Vasapollo ◽  
Massimo Virgili ◽  
Andrea Petetta ◽  
Giada Bargione ◽  
Antonello Sala ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Bottom Trawl ◽  
Trawl Catch ◽  
The Mediterranean

scholarly journals Characterizing the Evolution of the Container Traffic Share in the Mediterranean Sea Using Hierarchical Clustering

2018 ◽  
Vol 6 (4) ◽  
pp. 121 ◽  
Author(s):  
Manel Grifoll ◽  
Thanassis Karlis ◽  
M. Ortego
Keyword(s):  
Mediterranean Sea ◽  
Hierarchical Clustering ◽  
System Analysis ◽  
Compositional Data ◽  
Eastern Mediterranean ◽  
Compositional Data Analysis ◽  
Mediterranean Countries ◽  
The Mediterranean ◽  
Combination Of Methods ◽  
Port Infrastructure

This research investigates the traffic share evolution of the container throughput in the Mediterranean ports from 2000 to 2015 considering hierarchical clustering and concentration indexes. Compositional Data analysis techniques are used to illustrate periods with similar traffic share composition. Two different regions (East and West) in the Mediterranean Sea (Med) are selected in the function of the long haul services. The standard concentration indexes (i.e., concentration ratio, Gini coefficient, and Normalized Herfindahl-Hirschman) reveal a gentle decreasing of the concentration with relevant fluctuations mainly in the East region. This is due to the investment in port infrastructure in the area resulting from privatization initiatives in many Eastern Mediterranean countries. The periods obtained from the hierarchical clustering show a differentiated pattern in traffic share composition. For these periods, the shift-share results are consistent with traffic fluctuations and in line with the evolution of the concentration indexes. The combination of methods has allowed a good interpretation of the spatial and temporal evolution of the Med ports’ traffic being the methodology applicable elsewhere in the context of port system analysis.

Total Mercury and Methylmercury Content in Edible Fish from the Mediterranean Sea

2003 ◽  
Vol 66 (2) ◽  
pp. 300-303 ◽  
Author(s):  
M. M. STORELLI ◽  
R. GIACOMINELLI STUFFLER ◽  
A. STORELLI ◽  
G. O. MARCOTRIGIANO
Keyword(s):  
European Commission ◽  
Mediterranean Sea ◽  
Total Mercury ◽  
Food Additives ◽  
World Health ◽  
Expert Committee ◽  
Blue Whiting ◽  
Commission Decision ◽  
Wet Weight ◽  
The Mediterranean

The objective of this study was to determine the current levels of total mercury and methyl mercury in the muscle tissues of different fish species caught in the Mediterranean Sea to ascertain whether these concentrations exceed the maximum level stipulated by the European Commission Decision. Total mercury concentrations in the muscles of skates ranged from 0.18 to 1.85 mg/kg (wet weight) (average, 1.00 mg/kg) while levels of 0.11 to 1.92 mg/kg (wet weight) (average, 0.70 mg/kg) and 0.21 to 1.74 mg/kg (wet weight) (average, 0.70 mg/kg) were recorded for blue whiting and red mullet, respectively. For 66.7% of long nose skate samples, 61.4% of thornback ray samples, 42.8% of winter skate samples, and 38% of starry ray samples, the total mercury concentrations exceeded the prescribed legal limit (1.0 mg/kg [wet weight]). Concentrations exceeding the maximum total mercury level stipulated by the European Commission Decision (0.5 mg/kg [wet weight]) were observed in 63.6 and 40% of blue whiting and striped mullet samples, respectively. Mercury was present in the different species almost completely in the methylated form at 55 to 100%. Weekly intakes were estimated and compared with the provisional tolerable weekly intake recommended by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives.

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