Sponge diversity gradients in marine caves of the eastern Mediterranean

Although sponges constitute the dominant animal group in marine caves globally, few studies have investigated quantitatively their diversity patterns in this habitat. Regarding Mediterranean marine caves, data describing the structure and diversity gradients of sponge assemblages are available for the north-western basin, while information for the eastern Mediterranean is almost inexistent. In this study, the sponge assemblages in two Aegean marine caves (eastern Mediterranean Sea) with different topography were examined using a non-destructive method. In each cave, three quadrats (25 × 25 cm) were photographed at 5 m intervals, along three transects: one along the ceiling and two along the opposite walls. Per cent coverage for each sponge species was calculated using advanced image processing software. Our analyses revealed a rich sponge assemblage, which consisted of 50 species assigned to eight growth forms. Resemblance analysis for the surveyed caves revealed two major groups of samples corresponding to the shadowy outer and the darker internal cave sectors. However, differences in species composition as well as divergent spatial patterns of species richness, Shannon–Wiener diversity and morphological diversity were found not only between the caves but also between different transects within each cave. Sponge morphological diversity presented significant positive correlation with species richness and Shannon–Wiener diversity in both caves, suggesting that it could possibly be used as a surrogate measure for describing sponge diversity gradients in Mediterranean caves. Cave topography was found to have a significant effect on the observed diversity patterns and assemblage structure, highlighting the high level of individuality in these unique habitats.

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Global gradients in intertidal species richness and functional groups

eLife ◽

10.7554/elife.64541 ◽

2021 ◽

Vol 10 ◽

Author(s):

Jakob Thyrring ◽

Lloyd S Peck

Keyword(s):

Functional Groups ◽

Global Scale ◽

Local Scale ◽

Rocky Intertidal ◽

Marine Biodiversity ◽

Diversity Patterns ◽

The North ◽

Discernible Effect ◽

Diversity Gradients ◽

Α Diversity

Whether global latitudinal diversity gradients exist in rocky intertidal a-diversity and across functional groups remains unknown. Using literature data from 433 intertidal sites, we investigated α-diversity patterns across 155° of latitude, and whether local-scale or global-scale structuring processes control α-diversity. We, furthermore, investigated how the relative composition of functional groups changes with latitude. α-diversity differed among hemispheres with a mid-latitudinal peak in the north, and a non-significant unimodal pattern in the south, but there was no support for a tropical-to-polar decrease in α-diversity. Although global-scale drivers had no discernible effect, the local-scale drivers significantly affected α-diversity, and our results reveal that latitudinal diversity gradients are outweighed by local-processes. In contrast to α-diversity patterns, three functional groups: predators, grazers and suspension-feeders diversity declined with latitude, coinciding with an inverse gradient in algae. Polar and tropical intertidal data were sparse, and more sampling is required to improve knowledge of marine biodiversity.

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Lithistid Demosponges of Deep-Water Origin in Marine Caves of the North-Eastern Mediterranean Sea

Frontiers in Marine Science ◽

10.3389/fmars.2021.630900 ◽

2021 ◽

Vol 8 ◽

Author(s):

Andrzej Pisera ◽

Vasilis Gerovasileiou

Keyword(s):

Deep Water ◽

Eastern Mediterranean ◽

Aegean Sea ◽

Western Mediterranean ◽

Elevated Concentration ◽

The North ◽

Deep Waters ◽

Marine Caves ◽

North Eastern ◽

Tropical Areas

Desmas-bearing demosponges known as lithistids have heavily silicified skeleton and occur typically in bathyal environments of warm and tropical areas but may be found in certain shallow marine caves. Here we report, for the first time two lithistid species, i.e., Neophrissospongia endoumensis, and N. cf. nana, that were earlier known from Western Mediterranean marine caves, from four marine caves in the north-eastern Mediterranean, and their congener Neophrissospongia nolitangere from deep waters (ca. 300 m) of the Aegean Sea. All marine caves, and sections within these caves, where lithistids occur, have freshwater springs. We interpret this surprising association between lithistids and freshwater input by elevated concentration of silica in water in cave sections where such springs occur, being 8–11 times higher in comparison with shallow water outside caves, and comparable to that of deep waters, that promoted lithistids’ development. One of the studied caves harbored an abundant population of N. endoumensis which formed large masses. The age estimation of these lithistids, based on known growth rate of related deep-water sponges, suggest that they could be approximately 769–909 years old in the case of the largest specimen observed, about 100 cm large. These sponges could have colonized the caves from adjacent deep-water areas not earlier than 7,000–3,000 years ago, after the last glaciation, because earlier they were emerged. High variability of spicules, especially microscleres, and underdevelopment of megascleres may be related to silicic acid concentration.

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Recent findings of Ommastrephes bartramii (Cephalopoda: Ommastrephidae) in the eastern Mediterranean and the implication on its range expansion

Mediterranean Marine Science ◽

10.12681/mms.41 ◽

2011 ◽

Vol 12 (2) ◽

pp. 413 ◽

Cited By ~ 1

Author(s):

E. LEFKADITOU ◽

P. PERISTERAKI ◽

N. CHARTOSIA ◽

A. SALMAN

Keyword(s):

Mediterranean Sea ◽

Species Distribution ◽

Eastern Mediterranean ◽

Aegean Sea ◽

Intermediate Water ◽

Ommastrephes Bartramii ◽

Western Basin ◽

The North ◽

Lower Beak ◽

The Mediterranean

The neon flying squid Ommastrephes bartramii is found circumglobally in subtropical, temperate waters and sustains important fisheries in the North Pacific, but it is rarely encountered in the Mediterranean Sea. During the last decade, and particularly since 2004, the frequency of its presence in the Aegean Sea and nearby regions has increased, raising a question about a change in the species distribution and abundance in this area. In this study, we reviewed the literature on O. bartramii findings in the Mediterranean Sea and present new data describing body and beak morphometry, diet and the maturity of specimens recently collected from the easternmost basins. According to data from the entire Mediterranean Sea, collected individuals reached 66 cm in mantle length (ML), wherein only females were larger than 32 cm in ML. An isometric growth in body weight (BW) was shown, whereas the lower beak rostral length (LRL) was allometrically positive in relation to the ML. Occasional catches by jigs during experimental cruises provided most of the individuals recorded in the period from 1982-1992. In contrast, the most recent records are primarily comprised of mature females collected on or near the shore in the eastern basin and of predominantly smaller individuals from the western basin caught by professional jigging fisheries. The distribution of the specimen recorded from the Aegean Sea indicates an association between the species distribution and the circulation of the warm Levantine Intermediate Water. The more frequent observations of moribund spawning females at the periphery of the Cretan Sea are indicative of a spawning ground at this area. The suspected recent increase of O. bartramii abundance in both the northeastern and northwestern basins might be due to the warming of upper sea layers, which has been observed since the mid-1980s and is considered to be the main factor driving the northward expansion of the warm-water species’ range within the Mediterranean Sea.

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Census of biodiversity in marine caves of the eastern Mediterranean Sea

Mediterranean Marine Science ◽

10.12681/mms.1069 ◽

2015 ◽

Vol 16 (1) ◽

pp. 245 ◽

Cited By ~ 29

Author(s):

V. GEROVASILEIOU ◽

C. CHINTIROGLOU ◽

D. VAFIDIS ◽

D. KOUTSOUBAS ◽

M. SINI ◽

...

Keyword(s):

Alien Species ◽

Current Knowledge ◽

Eastern Mediterranean ◽

Scientific Information ◽

Species Number ◽

Sampling Effort ◽

Central Mediterranean ◽

The North ◽

Marine Caves ◽

Cave Habitat

Scientific information on the biodiversity of marine caves in the eastern Mediterranean is limited, especially when considering the extensively studied caves of the north-western and central Mediterranean. Aiming to enhance current knowledge regarding cave communities, this study represents a first assessment of the marine cave biota of the eastern Mediterranean, as this has been defined by the European Union’s Marine Strategy Framework Directive (MSFD). Information retrieved from an extensive overview of relevant scientific documents was combined with original data recorded from 23 marine caves of the north-eastern Mediterranean. Our results report a total of 520 taxa recorded in eastern Mediterranean marine caves to date, the majority of which are sponges, polychaetes, rhodophytes, bivalves, fishes, and gastropods. These include several protected, endemic, and alien species. However, not all taxonomic groups have been equally studied among different areas and future studies are expected to raise the number of endemic and alien species. The overall observed trend is that the reported species number is generally related to sampling effort and scientific expertise. The most well-studied marine cave communities of the eastern Mediterranean are those of the Aegean Sea (especially its northern sector), which presented the highest number of species, followed by those of the Levantine. Furthermore, our research in Aegean caves revealed numerous new records for the marine cave fauna of the eastern basin, while several species are reported for the first time in the marine cave habitat. The critical need for further scientific research, monitoring, and conservation of this unique ecosystem was highlighted by (i) the presence of certain species endemic to the eastern Mediterranean coupled with a high proportion of alien species, especially in the Levantine, and (ii) the marine cave habitat availability in isolated insular areas of the eastern Mediterranean.

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Westward Palaearctic range expansion of Papilio demoleus Linnaeus, 1758 (Lepidoptera: Papilionidae) and its arrival at Mediterranean coastal regions of Turkey and Syria

Entomologist s Gazette ◽

10.31184/g00138894.714.1776 ◽

2020 ◽

Vol 71 (4) ◽

pp. 257-272

Author(s):

Onat Başbay ◽

Mudar Salimeh ◽

Eddie John

Keyword(s):

Eastern Mediterranean ◽

Economic Importance ◽

Invasive Pest ◽

Pest Species ◽

Coastal Regions ◽

The North ◽

North Eastern ◽

The World ◽

Invasive Pest Species ◽

Papilio Demoleus

We review the continuing and extensive spread of Papilio demoleus in south-eastern Turkey and in regions of Turkey and Syria adjacent to the north-eastern Mediterranean. Since the authors documented the arrival of this attractive but potentially destructive papilionid species at coastal areas of Syria in 2019, regular monitoring has confirmed successful overwintering there, as well as in Turkey. As previously indicated, P. demoleus is widely recognized as an invasive pest species in Citrus-growing areas of the world and hence its arrival is of potential economic importance to a region in which citrus is widely grown.

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Spatial Distribution of Lichens in Metrosideros excelsa in Northern New Zealand Urban Forests

Diversity ◽

10.3390/d13040170 ◽

2021 ◽

Vol 13 (4) ◽

pp. 170

Author(s):

Gladys N. Benitez ◽

Glenn D. Aguilar ◽

Dan Blanchon

Keyword(s):

Spatial Distribution ◽

Species Richness ◽

New Zealand ◽

Lichen Species ◽

Positive Correlation ◽

Breast Height ◽

Lichen Community ◽

The North ◽

The City ◽

Lichen Flora

The spatial distribution of corticolous lichens on the iconic New Zealand pōhutukawa (Metrosideros excelsa) tree was investigated from a survey of urban parks and forests across the city of Auckland in the North Island of New Zealand. Lichens were identified from ten randomly selected trees at 20 sampling sites, with 10 sites classified as coastal and another 10 as inland sites. Lichen data were correlated with distance from sea, distance from major roads, distance from native forests, mean tree DBH (diameter at breast height) and the seven-year average of measured NO2 over the area. A total of 33 lichen species were found with coastal sites harboring significantly higher average lichen species per tree as well as higher site species richness. We found mild hotspots in two sites for average lichen species per tree and another two separate sites for species richness, with all hotspots at the coast. A positive correlation between lichen species richness and DBH was found. Sites in coastal locations were more similar to each other in terms of lichen community composition than they were to adjacent inland sites and some species were only found at coastal sites. The average number of lichen species per tree was negatively correlated with distance from the coast, suggesting that the characteristic lichen flora found on pōhutukawa may be reliant on coastal microclimates. There were no correlations with distance from major roads, and a slight positive correlation between NO2 levels and average lichen species per tree.

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Atmospheric circulation over Europe during the Younger Dryas

Science Advances ◽

10.1126/sciadv.aba4844 ◽

2020 ◽

Vol 6 (50) ◽

pp. eaba4844

Author(s):

Brice R. Rea ◽

Ramón Pellitero ◽

Matteo Spagnolo ◽

Philip Hughes ◽

Susan Ivy-Ochs ◽

...

Keyword(s):

Eastern Mediterranean ◽

Storm Track ◽

Younger Dryas ◽

Jet Stream ◽

The North ◽

Blocking High ◽

Last Glaciation ◽

The Alps ◽

Precipitation Anomalies ◽

Climate Cooling

The Younger Dryas (YD) was a period of rapid climate cooling that occurred at the end of the last glaciation. Here, we present the first palaeoglacier-derived reconstruction of YD precipitation across Europe, determined from 122 reconstructed glaciers and proxy atmospheric temperatures. Positive precipitation anomalies (YD versus modern) are found along much of the western seaboard of Europe and across the Mediterranean. Negative precipitation anomalies occur over the Fennoscandian ice sheet, the North European Plain, and as far south as the Alps. This is consistent with a more southerly and zonal storm track, which is linked to a concomitant southern location of the Polar Frontal Jet Stream, generating cold air outbreaks and enhanced cyclogenesis, especially over the eastern Mediterranean. This atmospheric configuration resembles the modern Scandinavian (SCAND) circulation over Europe (a blocking high pressure over Scandinavia pushing storm tracks south and east), and by analogy, a seasonally varying palaeoprecipitation pattern is interpreted.

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The species richness of Miocene browsers, and implications for habitat type and primary productivity in the North American grassland biome

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2003.09.032 ◽

2004 ◽

Vol 207 (3-4) ◽

pp. 371-398 ◽

Cited By ~ 66

Author(s):

C JANIS

Keyword(s):

Species Richness ◽

Primary Productivity ◽

North American ◽

Habitat Type ◽

The North ◽

Grassland Biome

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Coastal inundation in the north-eastern mediterranean coastal zone due to storm surge events

Journal of Coastal Conservation ◽

10.1007/s11852-010-0090-7 ◽

2010 ◽

Vol 15 (3) ◽

pp. 353-368 ◽

Cited By ~ 21

Author(s):

Yannis N. Krestenitis ◽

Yannis S. Androulidakis ◽

Yannis N. Kontos ◽

George Georgakopoulos

Keyword(s):

Storm Surge ◽

Coastal Zone ◽

Eastern Mediterranean ◽

Coastal Inundation ◽

The North ◽

North Eastern

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Upper-plate structural controls on the segmentation of the Kefalonia Fault (Ionian Sea, Greece)

10.5194/egusphere-egu21-15736 ◽

2021 ◽

Author(s):

Emmanuel Skourtsos ◽

Haralambos Kranis ◽

Spyridon Mavroulis ◽

Efthimios Lekkas

Keyword(s):

Eastern Mediterranean ◽

Source Parameters ◽

Plate Boundary ◽

Temporal Distribution ◽

Western Coast ◽

African Plate ◽

Plate Structure ◽

The North ◽

Macroseismic Effects ◽

Spatio Temporal

The NNE-SSW, right-lateral Kefalonia Transform Fault (KTF) marks the western termination of the subducting Hellenic slab, which is a part of the oceanic remnant of the African plate. The inception of the KTF, described as a STEP fault, is placed in the Pliocene. KTF is considered to be the most active earthquake source in the Eastern Mediterranean. During the last two decades, four significant earthquakes (M>6.0) have been associated with the KTF. These events are attributed to the reactivation of different segments of the KTF, which are (from North to South) the North Lefkada, South Lefkada, Fiskardo, Paliki and Zakynthos segments: the North Lefkada segment ruptured in the 2003 earthquake, the 2014 Kefalonia events are associated with the Paliki segment and the 2015 Lefkada earthquake with the South Lefkada (and possibly the Fiskardo) segments.The upper plate structure in the islands of Lefkada and Kefalonia is characterized by the Ionian Unit, thrusted over the Paxi (or Pre-Apulian) Unit. The Ionian Thrust, which brings the Ionian over the Paxi Unit, is a main upper-plate NNW-SSE, NE-dipping structure. It runs through the island of Lefkada, to be mapped onshore again at the western coast of Ithaki and at SE Kefalonia. Two other major thrusts are mapped on this island: the Aenos thrust, which has a WNW-ESE strike at the southern part of the island and gradually curves towards NNW-SSE in the west and the Kalo Fault in the northern part. These Pliocene (and still active) structures developed during the late-most stages of thrusting in the Hellenides, strike obliquely to the KTF and appear to abut against it.We suggest that these thrusts control not only the deformation within the upper plate, but also the earthquake segmentation of the KTF. This suggestion is corroborated by the spatio-temporal distribution and source parameters of the recent, well-documented earthquake events and by the macroseismic effects of these earthquakes. The abutment of the Ionian thrust against the KTF marks the southern termination of the Lefkada earthquake segment, which ruptured in the 2003 earthquake, while the Aenos, (or the Kalo) thrust mark the southern end of the Fiskardo segment. The spatial distribution of the Earthquake Environmental Effects related to the four significant events in the last 20 years displays a good correlation with our interpretation: most of the 2003 macroseismic effects are located in the northern part of Lefkada, which belongs to the upper block of the Ionian thrust; similarly, the effects of the 2014 earthquakes of Kefalonia are distributed mainly in the Paliki Peninsula and the southern part of the island that belong to the footwall of the Aenos thrust and the 2015 effects are found in SW Lefkada, which is part of the footwall of the Ionian thrust.We suggest that correlation between upper-plate structure and plate boundary faulting can provide insights in the understanding of faulting pattern in convergent settings, therefore contributing to earthquake management plans.

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