Βenthic hydrozoan assemblages as potential indicators of environmental health in a Μediterranean Μarine protected area

The comparative study of marine benthic hydrozoan assemblages can improve our understanding of environmental and ecological conditions in marine protected areas (MPAs) such as the large Mediterranean MPA of Datça-Bozburun, where important prospects for future intensive tourism development exist. The analysis of such assemblages may help managers detect changes in important parameters of ecosystem health within this MPA. In this study we compared the hydrozoan assemblages occurring on hard (rocky) and soft (Posidonia meadows) bottoms from stations belonging to three different conditions: i) small marinas (medium anthropogenic impact), ii) yacht stopovers (low impact), and iii) unspoiled sites (no impact) in the southern part of the Datça Peninsula during summer and winter 2015 and 2016. Significant differences in the structure, species composition and richness of benthic hydrozoans among the sampling sites were detected. In both seasons, hydroid assemblages in medium-impact sites significantly differed from little-impact and no-impact sites in terms of qualitative composition. Large structural species were widely represented in all hard-bottomed sampling sites, but small inconspicuous taxa with diverse life histories were much less abundant at the medium impacted sites. Species richness and diversity in Posidonia meadows was much higher in little- and no-impact sites, where highly specific hydroid epibionts were abundant

A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe

Saros Körfezi Gorgon Topluluklarının Demografik Yapıları

The aim of this study was to scientifically record the current status of gorgonian populations in Saros Bay, an important part within the Saros Specially Protected Area, and to provide data for future monitoring of changes. Twenty-five scuba dives were effectuated between 0- 40 m depth along southern, northern and three islands coast of the bay in order to determine the species and locate sites of highest density. Four sites that can be evaluated as gorgonian facies were determined and were quantitatively studied by transect or quadrat techniques. According to our results, the white gorgonian Eunicella singularis is distributed along the northern coasts, particularly around thrice locality and has a density of 2-3 colonies.m(-2) where colonies are densest. Both white and yellow (E. cavolini) gorgonians can be found along southern coasts. The white gorgonian has a density between 1-5 colonies.m 2 where densest, while the yellow gorgonian can reach around 10 colonies.m(-2). The yellow gorgonian population has a symmetrical size frequency distribution and the abundance of large size classes is conspicuous, particularly in comparison to populations in the Western Mediterranean. However, small size classes are at low numbers, which might be a sign of limited recruitment

Demographic Structure of Gorgonian (Anthozoa, Octocorallia, Holaxonia) Assemblages in the Bay of Saros

The aim of this study was to scientifically record the current status of gorgonian populations in Saros Bay, an important part within the Saros Specially Protected Area, and to provide data for future monitoring of changes. Twenty-five scuba dives were effectuated between 0- 40 m depth along southern, northern and three islands coast of the bay in order to determine the species and locate sites of highest density. Four sites that can be evaluated as gorgonian facies were determined and were quantitatively studied by transect or quadrat techniques. According to our results, the white gorgonian Eunicella singularis is distributed along the northern coasts, particularly around thrice locality and has a density of 2-3 colonies.m(-2) where colonies are densest. Both white and yellow (E. cavolini) gorgonians can be found along southern coasts. The white gorgonian has a density between 1-5 colonies.m 2 where densest, while the yellow gorgonian can reach around 10 colonies.m(-2). The yellow gorgonian population has a symmetrical size frequency distribution and the abundance of large size classes is conspicuous, particularly in comparison to populations in the Western Mediterranean. However, small size classes are at low numbers, which might be a sign of limited recruitment

First insights into the demography of the rare gorgonian Spinimuricea klavereni in the Mediterranean Sea

We present the results of the first study to highlight the demography, morphometry and growth rates of Spinimuricea klavereni, a rare Mediterranean endemic gorgonian exceptionally common in shallow depths of the Northeast Marmara Sea. In the study area, this species forms vast populations on rocks, boulders and attached to pebbles/stones/shells on soft substrates between 20 and 45m depth, with a total average density of 0.3coloniesm(-2) but comprising patches up to 3coloniesm(-2). Colonies, which are on average 42.9 (+/- 20.1) cm in height, can reach up to 110cm. Unlike other Mediterranean gorgonians, the colonies studied here showed fast growth rates that decreased with increasing colony height, between 1.5-11.1 and 4.96 +/- 3.01 cmyear(-1) on average. The low necrosis and high growth rates displayed by this species in the Northeast Marmara Sea confirm the previously hypothesized opportunistic behaviour of the species. The unique community consisting of S. klavereni and other rare gorgonian/soft corals has limited distribution in this area and should be considered to be a vulnerable marine ecosystem. Therefore we recommend that some conservation measures are taken, including the prohibition of all fisheries and anchoring over these assemblages

Reproduction in the Mediterranean endemic gorgonian Spinimuricea klavereni (Anthozoa, Octocorallia, Plexauridae)

Spinimuricea klavereni is a Mediterranean endemic gorgonian that is rarely encountered, probably because it typically occurs at depths below 50m. It is exceptionally common in the northern Marmara Sea, with an unusually shallow upper depth limit of similar to 20m. The reproductive biology of this species was studied during a one year period off Buyukada, in the northeastern Marmara Sea. Spinimuricea klavereni is a gonochoric broadcast spawner with an almost even sex ratio. Colonies were similar to 15cm in height at first reproduction. Gametogenesis was continuous, characterized by high male and female fecundities year-round. Oocytes and sperm sacs of all developmental stages were found throughout the year, with small-sized oocytes and sperm sacs dominant throughout the year. The reproduction of S. klavereni did not seem to exhibit any marked seasonal pattern, unlike most other studied Mediterranean octocorals. Modest variation in gamete output was probably related to slight alterations in food availability and temperature. The non-seasonal reproductive pattern we observed may be related to the low intra-annual variation in temperature in the Marmara Sea, and the fact that the mesotrophic-eutrophic level of productivity in the Marmara Sea can support the energetic requirements of continuous gametogenesis in this gorgonian. Whether these patterns are local adaptations or intrinsic characteristics for this Mediterranean endemic species remains to be studied

Abundance and composition of solid waste materials on the western part of the Turkish Black Sea seabed

Accumulation of marine litter is a worldwide growing problem of pollution in seas. Although it is recognized as one of the major pollution types for the Black Sea, very few studies can provide quantitative data and there are no data at all on solid wastes of the Black Sea seabed. This study was therefore aimed at investigating the abundance and composition of solid wastes in the southwestern Black Sea. Litter items were collected by trawling in October 2007, and in February and April 2008, at depths ranging from 25 m to 100 m. The solid waste concentration on the seabed showed a large variability ( with zones ranging from 128-1320 items km(-2) and 8-217 kg km(-2)). Marine litter concentrations were higher than in the Mediterranean Sea, consisting mainly of plastic materials. Most items were fragmented, which indicated that they had spent a long time at sea, and this made their identification difficult. Only 8 items had legible labels, 2 of them being Turkish and 6 foreign. This suggested that marine litter is a trans-boundary problem, not only in the oceans, but also for enclosed seas like the Black Sea. The situation needs to be monitored all over the basin using standardised methods in order to develop regionally valid and effective solutions

Distribution and mortality of the Mediterranean Stony Coral (Cladocora caespitosa Linnaeus, 1767) around Gokceada Island (Northern Aegean Sea)

Cladocora caespitosa colonies around Gokceada Island had discrete and scattered distribution with regional density of 0.12 colonies.m(-2) and a mean cover of 0.27%. The size frequency distribution of the colonies showed a prevalence of small sizes, possibly related to frequent storm events. About 15% of the colonies were affected by mortality, of which 67% were recently dead, probably due to positive thermal anomalies. This is the first report of mortality of this species from the Aegean Sea and from the Turkish coasts. Considering the vulnerability of the species to climate change and harvesting in the island, we suggest that C. caespitosa should be included in the list of species completely prohibited to harvest according to the statements 2012/66 and 2012/65 of Turkish law

A multispecific accumulation of gelatinous organisms in the central Aegean Sea as a case of biological evidence for unnoticed offshore events

An exceptionally high density of gelatinous organisms was observed in May 2015, off the coasts of Doganbey, central Aegean Sea. Eight gelatinous species were found in the accumulation, with salps being the main component. The hydromedusae Solmaris corona and Aequorea forskalea, the siphonophore Nanomia bijuga and the ctenophore Leucothea sp. are recorded for the first time from the Aegean Sea. The hydromedusa S. corona, the siphonophores Hippopodius hippopus and N. bijuga, the salp Salpa maxima and the ctenophore Leucothea sp. are first records for the Turkish coasts. We suggest that the various life histories and different ecological traits of the gelatinous components in the accumulation are indicators of an apparent bloom, i.e., the organisms bloomed/increased their abundances in response to different processes and were aggregated only subsequently at the coast, due to strong southwesterly winds and north-eastward currents originating a few days prior to our observations. The offshore area facing Doganbey is characterized by a large gyre coupled with one of the most vigorous upwelling zones in the Mediterranean Sea, therefore creating favourable conditions for the aggregation of salps and the presence of siphonophores

Benthic hydrozoan assemblages as potential indicators of environmental health in a mediterranean marine protected area

The comparative study of marine benthic hydrozoan assemblages can improve our understanding of environmental and ecological conditions in marine protected areas (MPAs) such as the large Mediterranean MPA of Datca-Bozburun, where important prospects for future intensive tourism development exist. The analysis of such assemblages may help managers detect changes in important parameters of ecosystem health within this MPA. In this study we compared the hydrozoan assemblages occurring on hard (rocky) and soft (Posidonia meadows) bottoms from stations belonging to three different conditions: i) small marinas (medium anthropogenic impact), ii) yacht stopovers (low impact), and iii) unspoiled sites (no impact) in the southern part of the Datea Peninsula during summer and winter 2015 and 2016. Significant differences in the structure, species composition and richness of benthic hydrozoans among the sampling sites were detected. In both seasons, hydroid assemblages in medium-impact sites significantly differed from little-impact and no-impact sites in terms of qualitative composition. Large structural species were widely represented in all hard-bottomed sampling sites, but small inconspicuous taxa with diverse life histories were much less abundant at the medium impacted sites. Species richness and diversity in Posidonia meadows was much higher in little- and no-impact sites, where highly specific hydroid epibionts were abundant