scholarly journals Shedding light on an East-Mediterranean mesophotic sponge ground community and the regional sponge fauna

2018 ◽  
Vol 19 (1) ◽  
pp. 84 ◽  
Author(s):  
TAL IDAN ◽  
SIGAL SHEFER ◽  
TAMAR FELDSTEIN ◽  
RUTH YAHEL ◽  
DOROTHEE HUCHON ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Mediterranean Coast ◽  
Shallow Waters ◽  
Depth Range ◽  
East Mediterranean ◽  
Remotely Operated Vehicle ◽  
Gas Drilling ◽  
Sponge Diversity ◽  
The Mediterranean ◽  
Levant Basin

Sponges are a diverse and abundant phylum, globally inhabiting many hard-bottom habitats. However, data on the East-Mediterranean sponge communities are scarce, outdated, and limited to the shallow waters. This study sought to expand the knowledge of the poriferan fauna along the Mediterranean shore of Israel. A newly-discovered mesophotic sponge ground at ~100 m depth was studied using a remotely-operated vehicle (ROV), in addition to shallow-water surveys conducted by scuba diving. In the mesophotic ecosystem, sponges, serving as environmental engineers, create complex 3D structures that attract invertebrates and fish. The results of the quantitative survey of this mesophotic sponge ground reveal that it maintains a rich and diverse community with an estimated 63 species, and a high sponge percent coverage (~35%). Several of the mesophotic species are documented for the first time from the Levant basin, while others might be novel species. Here we identified over 100 sponge species along the Mediterranean coast of Israel, 33 of which were sampled from the mesophotic sponge ground. The updated sponge list supports the hypothesis that the Levantine sponge diversity is not as species-poor, compared to other parts of the Mediterranean Sea, as has previously been considered. In addition, shallow and mesophotic sponge community compositions were found to only partially overlap.  Moreover, the latter harbors some species that have disappeared from the shallow habitats, and only a few species thrive along the entire depth range. We suggest that mesophotic sponge grounds may serve as refugia for species stressed by the rising temperatures in shallow waters and should be protected from anthropogenic influences such as oil and gas drilling.

scholarly journals An updated overview of the geographic and bathymetric distribution of Savalia savaglia

2014 ◽  
Vol 16 (1) ◽  
pp. 128 ◽  
Author(s):  
Mi. GIUSTI ◽  
C. CERRANO ◽  
M. ANGIOLILLO ◽  
L. TUNESI ◽  
S. CANESE
Keyword(s):  
Mediterranean Sea ◽  
Depth Range ◽  
Remotely Operated Vehicle ◽  
Protection Measure ◽  
The Past ◽  
Scuba Divers ◽  
Occurrence Data ◽  
The Mediterranean ◽  
Recent Occurrence ◽  
Barcelona Convention

The distribution of gold coral Savalia savaglia is modified on the basis of bibliographic information and recent occurrence data, collected using a ROV (Remotely Operated Vehicle) and SCUBA divers. The species is long-lived, rare and has been exploited in the past by divers for collection purposes. S. savaglia is listed in Annex II of the SPA/BD Protocol of the Barcelona Convention and has a wider distribution than previously thought, including both the Mediterranean Sea and the Atlantic Ocean. Our results highlighted that specimens mainly live at a depth range of 15-90 m, but may reach as deep as 900 m in the Mediterranean Sea. This species can form monospecific facies of hundreds of colonies, as observed in Montenegro (Adriatic Sea), between 10 and 20 m, and in the Canary Islands, at a depth range of 27-70 m. Recent data highlighted numerous cases of specimens that were endangered by lost fishing gear, which exposed this species to further threats. Considering its longevity and structural role, it is urgent to develop an effective protection measure for S. savaglia, thereby increasing research efforts and implementing protection areas for this species.

scholarly journals Design and Fabrication of Under Water Remotely Operated Vehicle

2021 ◽  
Vol 82 (1) ◽  
pp. 133-144
Author(s):  
Roman Kalvin ◽  
Juntakan Taweekun ◽  
Muhammad Waqas Mustafa ◽  
Faisla Ishfaq ◽  
Saba Arif
Keyword(s):  
Homeland Security ◽  
High Speed ◽  
Oil And Gas ◽  
Low Cost ◽  
Sea Turtle ◽  
Low Flow ◽  
Remotely Operated Vehicle ◽  
Gas Drilling ◽  
Hydrodynamic Efficiency ◽  
Mobile Vehicle

Underwater Remotely Operated vehicle is a tethered mobile vehicle most often used to monitor underwater oil and gas drilling inspection, telecommunications and homeland security. The main focus of this research is to design a vehicle at low cost which is safe, portable, and easy to use while increasing the maneuverability and efficiency to reach a depth of 5 meters. While conducting research a unique design is selected based on a novel fin propulsion mechanism rather than propellers. Propellers though have high speed but cannot work on low flow rates and their blades can be damaged if jelly fish or other material is struck in its shaft. Two shapes have been considered to remove above difficulties i.e. Fish and Turtle. Due to higher stability, larger area and greater hydrodynamic efficiency Sea Turtle has been selected, as it can easily overcome the forces like buoyancy, pressure and thrust force. The results extracted from this research shows that the underwater vehicles based on the biological locomotion principle can perform very well than other propeller counterparts. The research concludes with the performance of a working system that validates motion capabilities related to speed, depth and hydrodynamic efficiency which can be further improved by using sophisticated control systems, outer shell and highly integrated processors.

Geographic distribution of Astroides calycularis (Scleractinia: Dendrophylliidae) as a baseline to assess future human impacts on the Southern Iberian Peninsula

2015 ◽  
Vol 96 (5) ◽  
pp. 1181-1189 ◽  
Author(s):  
Alejandro Terrón-Sigler ◽  
David León-Muez ◽  
Patricio Peñalver-Duque ◽  
Rafael Gálvez-César ◽  
Free Espinosa Torre
Keyword(s):  
Iberian Peninsula ◽  
Human Activities ◽  
Human Impacts ◽  
Mediterranean Coast ◽  
Marine Biodiversity ◽  
Depth Range ◽  
The South ◽  
Bioindicator Species ◽  
Two Factors ◽  
The Mediterranean

Human activities have increasingly affected biodiversity in the Mediterranean Sea. Data on the distribution and abundance of species allows researchers to assess the possible degradation of wild populations. These data could act as a baseline to assess the magnitude of the effects of human activities on a bioindicator species. The distribution and relative abundance of the south-western populations of the endemic Astroides calycularis in the South Iberian Peninsula were studied to establish a baseline for future studies. The rocky shoreline was studied at a depth range of 0–12 m, including more than 650 km of Spain's Andalusian coastline. The species was present in 135 of the 585 dive points sampled. ANOVA analysis showed differences in depth in the four provinces studied, and there was no interaction between the two factors. As human activities on the Mediterranean coast are reducing the A. calycularis populations, a baseline on marine populations is greatly recommended for monitoring, assessment, and management studies, especially for endangered or bioindicator species. This baseline could be useful as a reference tool to assess the effects of human activities on marine biodiversity, including global change.

scholarly journals Macrofauna Inhabiting Massive Demosponges From Shallow and Mesophotic Habitats Along the Israeli Mediterranean Coast

2021 ◽  
Vol 7 ◽  
Author(s):  
Liron Goren ◽  
Tal Idan ◽  
Sigal Shefer ◽  
Micha Ilan
Keyword(s):  
Benthic Communities ◽  
Mediterranean Coast ◽  
Ecosystem Engineers ◽  
Limiting Factor ◽  
Associated Fauna ◽  
Remotely Operated Vehicle ◽  
Shallow Habitat ◽  
Sponge Diversity ◽  
Clear Differentiation ◽  
Taxonomic Groups

Sponges have long been considered as “living hotels” due to the great diversity and abundance of other taxonomic groups often found in association with them. Sponges are the dominant components of benthic communities in the Levant Sea; and especially in the recently discovered mesophotic sponge grounds off the coast of Israel. However, almost no data exist regarding their associated macrofauna. The current study sought to identify the macrofauna associated with massive sponges along the Israeli Mediterranean coast; and to compare the role of sponges, as ecosystem engineers, or “living hotels,” in both the shallow-water and mesophotic habitats. Sixty-four massive sponge specimens, from 10 different species, were collected from shallow and mesophotic habitats by SCUBA diving and Remotely Operated Vehicle, respectively. Sponge volume was estimated, specimens were dissected, and the associated macrofauna were identified. Our results reveal that the sponges supported a diverse assemblage of associated macrofauna. A total of 61 associated taxa were found, including species reported for the first time in Israel. A clear, differentiation existed in the structure of the associated assemblage between the two habitats, which is mainly attributed to four species (two polychaetes, a crustacean, and a brittle star). The trophic composition remained stable across the two habitats. No correlation was found between sponge volume and the associated fauna community parameters. The highest richness of associated fauna was found in the mesophotic habitat, where sponge diversity is also higher. In contrast, a greater endobiont abundance and density were recorded in the shallow habitat, where massive sponges may be a limiting factor due to their lower richness and abundance. Our findings emphasize the importance of sponges as ecosystem engineers, and suggest that sponge diversity may be an important factor that contribute to benthic biodiversity in these regions.

Genetic Diversity and Structure of the Nile Soft-Shelled Turtle (Trionyx triunguis) Along the Mediterranean coast of Turkey

2020 ◽  
Vol 27 (6) ◽  
pp. 307-315
Author(s):  
Özgür Güçlü ◽  
Bülent Bozdoğan
Keyword(s):  
Microsatellite Loci ◽  
Geographic Distance ◽  
Iucn Red List ◽  
Genetic Variations ◽  
Mediterranean Coast ◽  
Critically Endangered ◽  
Mediterranean Populations ◽  
Genetic Diversity And Structure ◽  
Polymorphic Microsatellite ◽  
The Mediterranean

The Nile soft-shelled turtle (Trionyx triunguis) is distributed between Dalyan and Samandağ throughout the Mediterranean coast in Turkey. The Mediterranean subpopulation of the Nile soft-shelled turtle is listed as critically endangered in the IUCN Red List Categories. This investigation aimed to determinate levels of genetic variations and patterns of genetic structures among Mediterranean populations in Turkey by using T. triunguis-specific microsatellite primers. A total of 13 polymorphic microsatellite loci were studied among samples of 121 individuals collected from five populations in Turkey. Of 13 polymorphic microsatellite loci used, 3 new were identified in this study. The genetic differentiation among the 5 studied populations of T. triunguis was significant (p 0.001). The analysis of molecular variance (AMOVA) indicated that genetic variations occurred mainly within populations (89.7%) rather than among populations (10.3%). Structure analysis showed presence of two main groups among the Mediterranean T. triunguis populations. However genetic variations among populations were not correlated with geographic distance between the locations. Analysis of data showed that one of the populations (Dalyan) had undergone a bottleneck effect. Migration analysis indicates that T. triunguis migrates between five Mediterranean populations in Turkey. We concluded that based on our results the status of ‘critically endangered’ of T. triunguis should be maintained. Long term population genetic survey studies should be undertaken and changes in habitats of T. triunguis populations, as well as their population size and structure should be monitored for each population to be able to establish a clear strategy for protection of T. triunguis.

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