scholarly journals Low diversity or poorly explored? Mesophotic molluscs highlight undersampling in the Eastern Mediterranean

2020 ◽  
Vol 29 (14) ◽  
pp. 4059-4072
Author(s):  
Paolo G. Albano ◽  
Michele Azzarone ◽  
Bruno Amati ◽  
Cesare Bogi ◽  
Bruno Sabelli ◽  
...  

Abstract Mesophotic assemblages are the next frontier of marine exploration in the Mediterranean Sea. Located below recreational scuba diving depths, they are difficult to access but host a diverse array of habitats structured by large invertebrate species. The Eastern Mediterranean has been much less explored than the western part of the basin and its mesophotic habitats are virtually unknown. We here describe two mesophotic (77–92 m depth) molluscan assemblages at a rocky reef and on a soft substrate off northern Israel. We record 172 species, of which 43 (25%) are first records for Israel and increase its overall marine molluscan diversity by 7%. Only five of these species have been reported in recent surveys of the nearby Lebanon, suggesting that our results are robust at a broader scale than our study area and that the reported west-to-east declining diversity gradient in the Mediterranean needs a reappraisal based on proper sampling of the eastern basin. We found only four (2%) non-indigenous species, represented by seven (0.5%) specimens. These results suggest that pristine native assemblages still thrive at this depth in Israel, in contrast to the shallow subtidal heavily affected by global warming and biological invasions, calling for strong conservation actions for these valuable but vulnerable habitats.

The Holocene ◽  
2020 ◽  
Vol 30 (10) ◽  
pp. 1438-1450
Author(s):  
Konstantina Agiadi ◽  
Paolo G Albano

The eastern Mediterranean marine ecosystem is undergoing massive modification due to biological invasions, overfishing, habitat deterioration, and climate warming. Our ability to quantify these changes is severely hindered by the lack of an appropriate baseline; most ecological datasets date back a few decades only and show already strong signatures of impact. Surficial death assemblages (DAs) offer an alternative data source that provides baseline information on community structure and composition. In this study, we reconstruct the marine fish fauna of the southern shallow Israeli shelf before the opening of the Suez Canal based on fish otoliths. We quantify the age of the otolith DAs by radiocarbon dating, and describe its taxonomic composition, geographic affinity, and trophic structure. Additionally, we test by radiocarbon dating the hypothesis that Bregmaceros, a presumed Lessepsian invader with continuous presence in the Mediterranean throughout the late Cenozoic, is a relict species. The otolith DA dates back to the mid-Holocene because 75% of the dated otoliths of the native species are older than the opening of the Suez Canal in 1869, suggesting that the DA is a proper baseline for quantifying modern impacts. Consistently, 97% of the otoliths and 88% of the species we collected belong to native Mediterranean species. The native anchovy Engraulis encrasicolus dominates the DAs, although gobiids are the most diverse group (14 species, 28%). The DAs show similar trophic structure to present-day pristine Mediterranean coastal fish assemblages. Two non-indigenous species are recorded here for the first time in the Mediterranean Sea, Amblygobius albimaculatus and Callogobius sp., highlighting the importance of DAs for detecting non-indigenous species. Finally, Bregmaceros otoliths are modern, not supporting the previous hypothesis that the taxon is a Pleistocene relict.


2016 ◽  
Vol 17 (2) ◽  
pp. 440 ◽  
Author(s):  
N. SOKOLOVER ◽  
P. D. TAYLOR ◽  
M. ILAN

The impact of global warming on the composition of marine biotas is increasing, underscoring the need for better baseline information on the species currently present in given areas. Little is known about the bryozoan fauna of Israel; the most recent publication concerning species from the Mediterranean coast was based on samples collected in the 1960s and 1970s. Since that time, not only have the species present in this region changed, but so too has our understanding of bryozoan taxonomy. Here we use samples collected during the last decade to identify 47 bryozoan species, of which 15 are first records for the Levantine basin. These include one new genus and species (Crenulatella levantinensis gen. et. sp. nov.), two new species (Licornia vieirai sp. nov. and Trematooecia mikeli sp. nov.), and two species that may be new but for which available material is inadequate for formal description (Reteporella sp. and Thalamoporella sp.). In addition, Conopeum ponticum is recorded for the first time from the Mediterranean Sea. Non-indigenous species make up almost one-quarter of the 47 species identified. All of the non-indigenous species are native to tropical and subtropical regions, implying a change of the Levant bryozoan biota from a temperate to a more tropical state, probably related to both higher temperature and salinity and to the opening of the Suez Canal connecting the Red Sea and the Eastern Mediterranean.  


Author(s):  
JOSÉ CASTELLÓ ◽  
GHAZI BITAR ◽  
HELMUT ZIBROWIUS

This study focuses on the isopod fauna of the eastern Mediterranean, mainly from the waters of Lebanon. Ninety-five samples containing isopods were obtained by scuba diving (depths 0 to 44 m) at 32 stations along the coast of Northern Cyprus, Syria, and Lebanon. The substrates most frequently sampled were caves, vertical walls, and calcareous algae crusts or build-ups. A total of 502 individuals were studied, belonging to 28 species, included in 20 genera, nine families, and three suborders. Four new species from this collection (Atarbolana beirutensis, Cirolana bitari, Cirolana zibrowiusi, Mesanthura pacoi) have already been published. Brief diagnoses and illustrations were included. The collection studied here consists mostly of Mediterranean species, some already known in the area. Ten (eleven, when cf. species is confirmed) are new records in the Levantine Sea (Apanthura addui, Cirolana manorae, Cymodoce fuscina, Cymodoce pilosa, Elaphognathia bacescoi, Gnathia illepidus, Gnathia inopinata, Heptanthura cryptobia, Kupellonura serritelson, Metacirolana rotunda, Pseudocerceis cf. seleneides). Of them, three (four, when cf. species is confirmed) are new records in the Mediterranean Sea (Apanthura addui, Cirolana manorae, Metacirolana rotunda, Pseudocerceis cf. seleneides). Eight species (28.5%) can be considered as non-indigenous (Apanthura addui, Cirolana manorae, Cymodoce fuscina, Metacirolana rotunda, Paracerceis sculpta, Paradella dianae, Pseudocerceis cf. seleneides, Sphaeroma walkeri). This manuscript also provides an inventory of the known Mediterranean isopod fauna (excluding Epicaridea, Oniscidea, and brackish water Aselloidea), which totals 295 species. The isopod fauna of various subregions of the Mediterranean, the Suez Canal, and the Red Sea / Gulf of Aden is compared, and the transit of species through the Suez Canal is discussed. The list of non-indigenous species in the Mediterranaean Sea is updated to 23.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3954 ◽  
Author(s):  
Aylin Ulman ◽  
Jasmine Ferrario ◽  
Anna Occhpinti-Ambrogi ◽  
Christos Arvanitidis ◽  
Ada Bandi ◽  
...  

The Mediterranean Sea is home to over 2/3 of the world’s charter boat traffic and hosts an estimated 1.5 million recreational boats. Studies elsewhere have demonstrated marinas as important hubs for the stepping-stone transfer of non-indigenous species (NIS), but these unique anthropogenic, and typically artificial habitats have largely gone overlooked in the Mediterranean as sources of NIS hot-spots. From April 2015 to November 2016, 34 marinas were sampled across the following Mediterranean countries: Spain, France, Italy, Malta, Greece, Turkey and Cyprus to investigate the NIS presence and richness in the specialized hard substrate material of these marina habitats. All macroinvertebrate taxa were collected and identified. Additionally, fouling samples were collected from approximately 600 boat-hulls from 25 of these marinas to determine if boats host diverse NIS not present in the marina. Here, we present data revealing that Mediterranean marinas indeed act as major hubs for the transfer of marine NIS, and we also provide evidence that recreational boats act as effective vectors of spread. From this wide-ranging geographical study, we report here numerous new NIS records at the basin, subregional, country and locality level. At the basin level, we report three NIS new to the Mediterranean Sea (Achelia sawayai sensu lato,Aorides longimerus,Cymodoceaff.fuscina), and the re-appearance of two NIS previously known but currently considered extinct in the Mediterranean (Bemlos leptocheirus, Saccostrea glomerata). We also compellingly update the distributions of many NIS in the Mediterranean Sea showing some recent spreading; we provide details for 11 new subregional records for NIS (Watersipora arcuata,Hydroides brachyacantha sensu latoandSaccostrea glomeratanow present in the Western Mediterranean;Symplegma brakenhielmi,Stenothoe georgiana,Spirobranchus tertaceros sensu lato,Dendostrea folium sensu latoandParasmittina egyptiacanow present in the Central Mediterranean, andW. arcuata,Bemlos leptocheirusandDyspanopeus sayiin the Eastern Mediterranean). We also report 51 new NIS country records from recreational marinas: 12 for Malta, 10 for Cyprus, nine for Greece, six for Spain and France, five for Turkey and three for Italy, representing 32 species. Finally, we report 20 new NIS records (representing 17 species) found on recreational boat-hulls (mobile habitats), not yet found in the same marina, or in most cases, even the country. For each new NIS record, their native origin and global and Mediterranean distributions are provided, along with details of the new record. Additionally, taxonomic characters used for identification and photos of the specimens are also provided. These new NIS records should now be added to the relevant NIS databases compiled by several entities. Records of uncertain identity are also discussed, to assess the probability of valid non-indigenous status.


2016 ◽  
Vol 17 (2) ◽  
pp. 417 ◽  
Author(s):  
J. G. HARMELIN ◽  
G. BITAR ◽  
H. ZIBROWIUS

Because of its location in the warmest corner of the Mediterranean, its proximity to the northern entrance of the Suez Canal, i.e. the gateway for massive exotic biota introduction into the Mediterranean, the occurrence of high shipping activity and strong human pressure, the Lebanese coastal zone is an area that is exceptionally well-suited for investigating the effects of these extreme conditions on Mediterranean biodiversity. Bryozoans, which are among the main components of sessile communities, reflect dramatically the impact of these particular conditions. Their assemblages, sampled by diving along the whole coast of Lebanon during a pluriannual programme, mainly between 1999 and 2003, consist of 93 species (12 Cyclostomata, 2 Ctenostomata, 79 Cheilostomata). The native part of this bryozoan fauna exhibits low diversity, with an unexpected absence of many taxa, from family to species level, which are very common in the rest of the Mediterranean. It is also characterized by a high proportion of endemic species, in contrast with the general eastward trend of decreasing endemicity observed in the Mediterranean, and by the strong presence of 'southern' thermophilic species. With 27 non-indigenous species, xenodiversity is exceptionally high, particularly in the cheilostome pool (26 species), but was likely undersampled. Moreover, one may assume that new non-indigenous bryozoans (NIB) are now established along the Levantine coasts. This trend is expected to increase in the near future with the intensification of surface water warming and boost of shipping activity and propagule flux generated by the expansion of the Suez Canal.


NeoBiota ◽  
2021 ◽  
Vol 70 ◽  
pp. 151-165
Author(s):  
Francesco Zangaro ◽  
Benedetta Saccomanno ◽  
Eftychia Tzafesta ◽  
Fabio Bozzeda ◽  
Valeria Specchia ◽  
...  

The biodiversity of the Mediterranean Sea is currently threatened by the introduction of Non-Indigenous Species (NIS). Therefore, monitoring the distribution of NIS is of utmost importance to preserve the ecosystems. A promising approach for the identification of species and the assessment of biodiversity is the use of DNA barcoding, as well as DNA and eDNA metabarcoding. Currently, the main limitation in the use of genomic data for species identification is the incompleteness of the DNA barcode databases. In this research, we assessed the availability of DNA barcodes in the main reference libraries for the most updated inventory of 665 confirmed NIS in the Mediterranean Sea, with a special focus on the cytochrome oxidase I (COI) barcode and primers. The results of this study show that there are no barcodes for 33.18% of the species in question, and that 45.30% of the 382 species with COI barcode, have no primers publicly available. This highlights the importance of directing scientific efforts to fill the barcode gap of specific taxonomic groups in order to help in the effective application of the eDNA technique for investigating the occurrence and the distribution of NIS in the Mediterranean Sea.


Diversity ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 57
Author(s):  
Marika Galanidi ◽  
Argyro Zenetos

In the present work, we analysed time series data on the introduction of new non-indigenous species (NIS) in the Mediterranean between 1970 and 2017, aiming to arrive at recommendations concerning the reference period and provisional threshold values for the NIS trend indicator. We employed regression analysis and breakpoint structural analysis. Our results confirm earlier findings that the reference conditions differ for the four Mediterranean subregions, and support a shortening of the reporting cycle from six to three years, with a two-year time lag for the ensuing assessment. Excluding Lessepsian fishes and parasites, the reference period, defined as the most recent time segment with stable mean new NIS values, was estimated as 1997–2017 for the eastern Mediterranean, 2012–2017 for the central Mediterranean, 2000–2017 for the Adriatic and 1970–2017 for the western Mediterranean. These findings are interpreted primarily on the basis of a basin scale temperature regime shift in the late 1990s, shifts in driving forces such as shellfish culture, and as a result of intensified research efforts and citizen scientist initiatives targeting NIS in the last decade. The threshold values, i.e., the three-year average new NIS values during the reference period, are indicative and will ultimately depend on the choice of species and pathways to be used in the calculations. This is discussed through the prism of target setting in alignment with specific management objectives.


Author(s):  
HOUSSEIN ELBARAASI ◽  
BAHRIA ELABAR ◽  
SALAMA ELAABIDI ◽  
ASMA BASHIR ◽  
OSAMA ELSILINI ◽  
...  

 Here we provide an updated review of both native and non-indigenous ichthyofauna occurring in the waters of Libya, one of the largest and less studied marine areas of the Mediterranean basin. With respect to the most recent information, the list of Libyan bony fishes was updated with 104 species for a total of 304 listed taxa. Out of these species, 271 are native, 6 endemic to the Mediterranean, 22 non indigenous of Lessepsian origin and 5 range expanding taxa from Gibraltar. Information on the distribution and abundance of Lessepsian fishes along the Libyan coasts was gained through both field surveys and interviews with local small-scale fishermen, which contributed in filling large information gaps in the area. This combined approach allowed to gather a more complete representation of non indigenous species along the Libyan coasts and indicated three assessment areas, corresponding to the eastern, central and western sectors of the country, which should be considered in future monitoring programs.


2015 ◽  
Vol 24 (2) ◽  
pp. 43-45 ◽  
Author(s):  
Bella Galil ◽  
Ferdinando Boero ◽  
Simona Fraschetti ◽  
Stefano Piraino ◽  
Marnie Campbell ◽  
...  

Author(s):  
Carlo Nike Bianchi ◽  
Francesco Caroli ◽  
Paolo Guidetti ◽  
Carla Morri

Global warming is facilitating the poleward range expansion of plant and animal species. In the Mediterranean Sea, the concurrent temperature increase and abundance of (sub)tropical non-indigenous species (NIS) is leading to the so-called ‘tropicalization’ of the Mediterranean Sea, which is dramatically evident in the south-eastern sectors of the basin. At the same time, the colder north-western sectors of the basin have been said to undergo a process of ‘meridionalization’, that is the establishment of warm-water native species (WWN) previously restricted to the southern sectors. The Gulf of Genoa (Ligurian Sea) is the north-western reach for southern species of whatever origin in the Mediterranean. Recent (up to 2015) observations of NIS and WWN by diving have been collated to update previous similar inventories. In addition, the relative occurrences of both groups of southern species have been monitored by snorkelling between 2009 and 2015 in shallow rocky reefs at Genoa, and compared with the trend in air and sea surface temperatures. A total of 20 southern species (11 NIS and 9 WWN) was found. Two WWN (the zebra seabream Diplodus cervinus and the parrotfish Sparisoma cretense) and three NIS (the SW Atlantic sponge Paraleucilla magna, the Red Sea polychaete Branchiomma luctuosum, and the amphi-American and amphi-Atlantic crab Percnon gibbesi) are new records for the Ligurian Sea, whereas juveniles of the Indo-Pacific bluespotted cornetfish Fistularia commersonii have been found for the first time. While temperature has kept on increasing for the whole period, with 2014 and 2015 being the warmest years since at least 1950, the number of WWN increased linearly, that of NIS increased exponentially, contradicting the idea of meridionalization and supporting that of tropicalization even in the northern sectors of the Mediterranean basin.


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