Concern about the spread of the invader seaweed Caulerpa taxifolia var. distichophylla (Chlorophyta: Caulerpales) towards the West Mediterranean

The new Australian alien seaweed Caulerpa taxifolia var. distichophylla, after being established along the Turkish Mediterranean coast in 2006, was recorded in Southern Sicily in 2007. Since then local fishermen claimed support to counteract the effects of entanglement of large amounts of the alien strain wrack in their trammel nets, causing the gear to become ineffective. The further northward and westward spread of the new alien strain is supposed to be limited by winter temperature. We present novel data confirming that the new alien strain is fully naturalized in Central Mediterranean and is expanding its range beyond such limit (i.e. the 15°C February isotherm), thus becoming potentially able to colonize the western basin. By means of a preliminary estimation of effects on native polychaete assemblages, and considering some peculiarities of Sicily (mostly linked to its geographical position in the Mediterranean Sea), the risk linked to the increasing range of distribution of the invasive algae is highlighted.

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Migration, residency, and homing of bluefin tuna in the western Mediterranean Sea

ICES Journal of Marine Science ◽

10.1093/icesjms/fst157 ◽

2013 ◽

Vol 71 (3) ◽

pp. 510-518 ◽

Cited By ~ 24

Author(s):

Jean-Marc Fromentin ◽

Daniel Lopuszanski

Keyword(s):

Mediterranean Sea ◽

Spatial Dynamics ◽

Bluefin Tuna ◽

Western Mediterranean ◽

Careful Consideration ◽

Mediterranean Coast ◽

Central Mediterranean ◽

The North ◽

Western Mediterranean Sea ◽

Local Enrichment

Abstract This study presents the results of an electronic tagging programme on mature Atlantic bluefin tuna (ABFT) that has been conducted since 2007 offshore of the French Mediterranean Coast. The spatial distributions of ABFT showed little year-to-year variation and the fish concentrated in a small area of the central northwestern Mediterranean, where they may stay for several months. The individual tracks display sinuous trajectories in this area, indicating the possibility of feeding behaviour. No fish went out to the North Atlantic, but several fish displayed some migration to the southern western Mediterranean Sea during winter and the central Mediterranean during the spawning season. The homing behaviour of one fish after a full year as well as the back and forth of several fish further indicates that this restricted feeding area is probably persistent from year to year. We hypothesize that this area could result from local enrichment due to permanent mesoscale oceanographic features related to the North Mediterranean Current and the North Balearic front. The option of a spatial management, through marine protected areas, for a highly migratory species, such as ABFT, thus deserves more careful consideration because those species displayed complex spatial dynamics (e.g. homing), and population structure (e.g. several subpopulations of different sizes).

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Occurrence of Bluntnose Sixgill Shark Hexanchus griseus (Bonnaterre, 1788) in Yeşilovacık Bay, Northeastern Mediterranean

Asian Journal of Biology ◽

10.9734/ajob/2018/v7i230050 ◽

2019 ◽

pp. 1-7

Author(s):

Deniz Ayas ◽

Deniz Ergüden ◽

Nuray Çiftçi ◽

Mısra Bakan

Keyword(s):

Mediterranean Sea ◽

Eastern Mediterranean ◽

Mediterranean Coast ◽

Shark Species ◽

Female Specimen ◽

The West ◽

Protection Measures ◽

Total Length ◽

Iskenderun Bay ◽

Specific Conservation

Aims: In this study, an individual of H. griseus was caught from the Mersin Bay and this ichthyologic note presents a new female record of H. griseus for Mersin Bay, Mediterranean coast of Turkey. This study aims to contribute to the chronological records of the species in the Mediterranean Sea. Place and Duration of Study: Yeşilovacık bay is a small bay in the west of Mersin Bay. Yeşilovacık bay which lies at approximately 36°07’n latitude, 33°37’e, longitude and about 143 km Western of in Mersin province, Turkey. Sample: On 19 March 2018 blunthose sixgill shark specimen was measured and then deposited in the Museum of the Systematic, Faculty of Fisheries, University of Mersin. Methodology: A female specimen of H. griseus with a total length (TL) of 350 cm (400 kg) was captured by a commercial trawl at a depth around of 280 m of the Yeşilovacık Bay (Northeastern Mediterranean Sea), Turkey. Total length was measured to the nearest 1 mm and the weight of the specimen was determined to the nearest kilogram. Results: Measurements of the specimen are presented and compared with the previous records of H. griseus in the Eastern Mediterranean coast of Turkey (Iskenderun Bay), which are given in Table. The identification was carried out according to the previous report. Conclusion: To date specific conservation measures are not known for this species for the Northeastern Mediterranean coast of Turkey. Thus, the effect of coastal fishery for sharks should be regularly monitored and protection measures should be taken in this region in order for this shark species to continue their conservation for the next generation.

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Particulate biogenic barium tracer of mesopelagic carbon remineralization in the Mediterranean Sea (PEACETIME project)

10.5194/bg-2020-271 ◽

2020 ◽

Author(s):

Stéphanie H. M. Jacquet ◽

Christian Tamburini ◽

Marc Garel ◽

Aurélie Dufour ◽

France Van-Vambeke ◽

...

Keyword(s):

Mediterranean Sea ◽

Western Mediterranean ◽

Central Mediterranean ◽

Particle Injection ◽

Western Basin ◽

Western Mediterranean Sea ◽

Winter Convection ◽

Carbon Remineralization ◽

The Mediterranean ◽

Heterotrophic Production

Abstract. We report on the sub-basins variability of particulate organic carbon (POC) remineralization in the central and western Mediterranean Sea during a late spring period (PEACETIME cruise). POC remineralization rates (MR) were estimated using the excess non-lithogenic particulate barium (Baxs) inventories in mesopelagic waters (100–1000 m) and compared with prokaryotic heterotrophic production (PHP). MR range from 25 ± 2 to 306 ± 70 mg C m−2 d−1. Results reveal larger MR processes in the Algerian (ALG) basin compared to the Tyrrhenian (TYR) and Ionian (ION) basins. Baxs inventories and PHP also indicates that significant remineralization occurs over the whole mesopelagic layers in the ALG basin in contrast to the ION and TYR basins where remineralization is mainly located in the upper 500 m horizon. We propose that this may be due to particle injection pumps likely driven by strong winter convection in the Western basin of the Mediterranean Sea. This implies significant differences in the remineralization length scale of POC in the central Mediterranean Sea relative to the western region.

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Phytoplankton assemblage Characterization along the Mediterranean coast of Morocco during autumn

Proceedings e report - Eighth International Symposium “Monitoring of Mediterranean Coastal Areas. Problems and Measurement Techniques” ◽

10.36253/978-88-5518-147-1.55 ◽

2020 ◽

pp. 547-556

Author(s):

Hajar IDMOUSSI ◽

Laila SOMOUE ◽

Karim HILMI ◽

Omar Ettahiri ◽

Tarik BAIBAI ◽

...

Keyword(s):

Mediterranean Sea ◽

Mediterranean Coast ◽

Phytoplankton Assemblage ◽

The West ◽

The Mediterranean ◽

Abundance And Diversity

The present study aimed to assess the composition, abundance and diversity of phytoplankton assemblage along the Moroccan Mediterranean Coast. Phytoplankton samples were collected in October 2018 at 48 stations from M’diq bay in the West to Saïdia in the East. 92 taxa have been inventoried, belonging to five groups. Diatoms dominate qualitatively and quantitatively (85.5%), followed by dinoflagellates (12%). Phytoplanktonic diversity and abundance was pronounced in the western part of Moroccan Mediterranean Sea, especially (from Jebha to M’diq) because of the influence of the Atlantic flow.

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Diet of the Deep-Sea Shark Galeus melastomus Rafinesque, 1810, in the Mediterranean Sea: What We Know and What We Should Know

Sustainability ◽

10.3390/su13073962 ◽

2021 ◽

Vol 13 (7) ◽

pp. 3962

Author(s):

Claudio D’Iglio ◽

Serena Savoca ◽

Paola Rinelli ◽

Nunziacarla Spanò ◽

Gioele Capillo

Keyword(s):

Mediterranean Sea ◽

Prey Availability ◽

Trophic Position ◽

Feeding Habits ◽

Ontogenetic Development ◽

Central Mediterranean ◽

Western Basin ◽

Important Prey ◽

Environment Adaptation ◽

The Mediterranean

We reviewed literature on the diet of the Galeus melastomus Rafinesque, 1810, from the Mediterranean Sea. Specific keywords (“Galeus melastomus diet”, “feeding habits”, “trophic position”, “biology”, “deep environment adaptation”) in the principal data sources, such as Web of Science, PubMed, and Google Scholar were used. Seventeen studies conducted on the diet and trophic position of G. melastomus have been considered for Mediterranean Sea regions. The feeding habits have been analyzed in many areas of the western basin; instead, for the Tyrrhenian, Adriatic, and central Mediterranean Seas, information is outdated and fragmentary. In all investigated sub areas, the data showed that G. melastomus is an opportunistic demersal supra benthic predator, benthic feeder, and scavenger, that adapts its diet to the seasonal and geographical fluctuations of the prey availability. It occupies a generalist niche showing individual specialization. In all reviewed Mediterranean sub areas, the most important prey groups were crustaceans, cephalopods, and teleost fishes. Taxa percentage in its diet composition can vary depending on different habitats with ontogenetic development of individuals, depth (that is correlated with the ontogenetic development), seasonal availability, and distribution of different prey groups. Widening knowledge of G. melastomus feeding habits is a fundamental tool for better understand meso and bathy-pelagic ecosystems.

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eastern and western med Messinian salinity crisis : comparison scenarii and propositions

10.5194/egusphere-egu2020-19209 ◽

2020 ◽

Author(s):

Christian Gorini ◽

Romain Pellen ◽

jean-loup Rubino ◽

Benoit Didier ◽

Lucien Montader ◽

...

Keyword(s):

Mediterranean Sea ◽

Nile Delta ◽

Eastern Mediterranean ◽

Phase 1 ◽

Threshold Effect ◽

Western Mediterranean ◽

Messinian Salinity Crisis ◽

Central Mediterranean ◽

Western Basin ◽

The Mediterranean

<p>The partial sequestration of the Mediterranean Sea from adjacent oceans at the end of the Miocene caused an evaporation surfeit that increased the water salinity above the seafloor of the deep basins and peripheral basins. As a result, an up to 2-3 km-thick sequence of evaporites was deposited in the center of the deep basins. This coincided with the concomitantly intense subaerial erosion of the adjacent margins and important Mass transport deposit events all around the peri- Mediterranean slopes. The volume of evaporites deposited in the deep basins implies a periodic connection with the world oceans concomitant with a huge evaporation during all the MSC. &#8220;Deep basins&#8221; refers to their position in the deep central parts of the extant Messinian basins in the western basin, the central basins (Ionian) and the eastern basins. The configuration of these basins and the distribution and thickness of the evaporites were very different 6 Myr ago due to the Africa Europe convergence. Evaporites deposition at the edge of the evaporites basins was affected by the geodynamic nature of the margins: Tertiary or Mesozoic passive or transform margins (North Africa), strike slip margins (northern and eastern Levant), convergent margins in the North of the East Mediterranean with evaporites subducted or stacked in a fore arc position. We propose a kinematic reconstruction of the central Mediterranean sea to discuss the connections between the Atlantic waters and the eastern Mediterranean Sea. In this presentation, we show that: (1) There is no opposition between the deposition of the first deep water evaporites and a sea level fall of more than 1000 m. (2) by a threshold effect the eastern Mediterranean could have been more restricted than the western Mediterranean during the phase 1 of the MSC, which could explain the two major incisions observed in the Nile delta (3). At the end of the MSC, this threshold effect could have been maximal with an accommodation space almost filled up and a bathymetry probably not exceeding 50 m in the western Mediterranean and in the Central Mediterranean with deposition of K and Mg evaporates, and almost zero in the Eastern Mediterranean as shown by the fluvial network developed on a wide-spread erosional surface on top of the Levant basin salt. (4) The Messinian salinity crisis (MSC) ended with the rapid re-flooding of the Mediterranean sea. A two-step flooding in the western Mediterranean could find its origin in this threshold effect.</p>

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