First occurrence of the Indo-Pacific polychaete species Glycinde bonhourei Gravier, 1904 in the Hellenic seas (Northern Evvoikos Gulf)

A specimen of Glycinde bonhourei Gravier, 1904, an Indo-Pacific species, was found at a station near the metalliferous waste disposal in the Northern Evvoikos Gulf (Aegean Sea, eastern Mediterranean). This is the second report of this species in the Mediterranean Sea after its first finding in the Levantine basin (Israel and Egypt). This paper provides new information on its distributional range in the Mediterranean Sea

An overlooked alien species present on the coasts of Greece (Eastern Mediterranean): the polychaete Polycirrus twisti Potts (Polychaeta: Terebellidae)

The Terebellidae polychaete Polycirrus twisti Potts, 1928 had been confused in several previous records the Eastern Mediterranean with the co-generic species Polycirrus plumosusWollebaeck, 1912, because of incomplete specimens or unclear descriptions; therefore its presence in Greek seas had been overlooked. Specimens of Polycirrus twisti were currently identified from the Korinthiakos Gulf (Greece, Eastern Mediterranean), while older records from the Hellenic marine area, erroneously assigned toPolycirrus plumosus and recorded since 1983 (Rhodos island, Dodekanesse) were emended. Polycirrus twisti is an alien species, most likely introduced to the Mediterranean from the Suez Canal, while it was recently reported from the Southern coasts of Turkey (Levantine Sea). Its identification and report in Greek Seas increases the number of alien polychaete species in this area to 37 and offers a further evidence and link of its introduction and dispersion dynamics from the Suez Canal to the Levantine and Aegean Sea. The presence of the previously reported species Polycirrus plumosus in the Mediterranean Sea is therefore strongly questionable

Benthic indicators to use in Ecological Quality classification of Mediterranean soft bottom marine ecosystems, including a new Biotic Index

A general scheme for approaching the objective of Ecological Quality Status (EcoQ) classification of zoobenthic marine ecosystems is presented. A system based on soft bottom benthic indicator species and related habitat types is suggested to be used for testing the typological definition of a given water body in the Mediterranean. Benthic indices including the Shannon-Wiener diversity index and the species richness are re-evaluated for use in classification. Ranges of values and of ecological quality categories are given for the diversity and species richness in different habitat types. A new biotic index (BENTIX) is proposed based on the relative percentages of three ecological groups of species grouped according to their sensitivity or tolerance to disturbance factors and weighted proportionately to obtain a formula rendering a five step numerical scale of ecological quality classification. Its advantage against former biotic indices lies in the fact that it reduces the number of the ecological groups involved which makes it simpler and easier in its use. The Bentix index proposed is tested and validated with data from Greek and western Mediterranean ecosystems and examples are presented. Indicator species associated with specific habitat types and pollution indicator species, scored according to their degree of tolerance to pollution, are listed in a table. The Bentix index is compared and evaluated against the indices of diversity and species richness for use in classification. The advantages of the BENTIX index as a classification tool for ECoQ include independence from habitat type, sample size and taxonomic effort, high discriminative power and simplicity in its use which make it a robust, simple and effective tool for application in the Mediterranean Sea

Increasing Polychaete diversity as a consequence of increasing research effort in Greek waters: new records and exotic species

The increasing diversity of the Greek Polychaete fauna over the last seven decades, as illustrated graphically, shows an increasing trend which is proportionately related to the research effort exerted. Ongoing research activities mainly in the depths of the N. Aegean Sea, as a result of which 13 new records have been added to the Greek Polychaete fauna, confirming the above statement. The new species records are presented along with their geographical distribution and habitat. According to the latest checklist of the Greek Polychaeta, 753 species of Polychaetes have been recorded in Greek waters. Finally, it should be noted that 6 Lessepsian migrants and 16 species have been recorded in the Mediterranean for the first time. Their distribution within Greece and worldwide is given and their presence in Greek waters is discussed

First occurrence of the invasive alien species Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae) on the coast of Greece (Elefsis Bay; Aegean Sea)

The present study reports on the occurrence of two specimens of the alien species Polydora cornutaBosc, 1802, in Elefsis Bay, the Saronikos Gulf (Aegean Sea, eastern Mediterranean). This is the firstrecord of this invasive alien species on the coast of Greece and the second report in the eastern MediterraneanSea after its first finding in Izmir Bay (on the Turkish Aegean coast). This finding enhances its distributionalpattern within the Mediterranea

Indicators for the Sea-floor Integrity of the Hellenic Seas under the European Marine Strategy Framework Directive: establishing the thresholds and standards for Good Environmental Status

A data set of 625 samples of benthic macroinvertebrates collected from the Hellenic Seas (Ionian and Aegean) was used to establish thresholds and reference standards for two of the indicators addressing the descriptors of Sea-floor Integrity under the Marine Strategy Framework Directive (MSFD): species diversity and richness and the ratio of sensitive species to tolerant species. The dataset was categorised according to the baseline ecological status assessment of the respective water bodies under the Water Framework Directive (WFD). Species diversity and richness were characterised using the Shannon diversity and species richness indices, respectively, and were analysed for three pre-defined substrate types, three depth zones and three sample-size categories, and the significant categories were statistically validated. Good Environmental Status (GEnS) threshold and reference values were established for the valid combinations of categories denoted as ‘ecotypes’ through the use of a boxplot and an analysis of variance. The limitations and specifications for an overall GEnS assessment using the above indices are highlighted based on the WFD experience. For the ratio of sensitive species to tolerant species, the BENTIX index classification scale is proposed for GEnS assessment, and an integrated approach to the assessment of diversity and species richness is suggested. Finally, the regionality of the tested indices in relation to the two Mediterranean sub-regions, including the Hellenic area, was tested

On the Occurrence and Established Populations of the Alien Polychaete Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae) in the Sea of Marmara and the Bosphorus Strait (Turkey)

The present paper reports the first occurrence of Polydora cornuta in the Bosphorus Strait and its finding in a new locality in the Sea of Marmara, providing a link with its Aegean and Black Sea populations. The probable vector for the introduction of P. cornuta into the Sea of Marmara is shipping through the Dardanelles Strait. Both soft and hard-bottom populations were examined and the importance and prevalence of this species within the native macrozoobenthic communities were elucidated. Its abundance ranged between 40 and 3390 ind.m-2 (mean:1320 ±1199.45 SD) and its percent contribution to the total faunal populations ranged between 3.31 and 75.56 (mean:27.79 ±25.00 SD) in the Sea of Marmara softbottom community. During the sampling period, P. cornuta contributed little to the total faunal abundance of the hard-bottom communities in the Bosphorus Strait. Its mean abundance in the hard substrate ranged between 8.33 and 1000 ind.m-2 (mean:117.36 ±279.73 SD) and its percent contribution to the total faunal populations ranged between 0.02 and 21.86 (mean:2.07 ±6.25 SD). The role of this invasive species in the soft-bottom macrobenthic community at an organically enriched site examined in the Sea of Marmara is highlighted, and a comparison with Aegean Sea populations of the species is also included

Application of the bentix index in assessing ecological quality of hard substrata: a case study from the Bosphorus Strait, Turkey

In this paper, a biotic index (Bentix) has been used for the assessment of ecological quality status of shallow water hard substrate benthic ecosystems affected by coastal sewage discharges in the Bosphorus Strait. A significant difference was observed between the control and the discharge stations with regard to Bentix values (Mann-Whitney U Test, p=0.002) and ecological quality status of the discharge stations was worse than that of controls. The index values revealed that sewage discharges caused serious disturbance in macrozoobenthic communities in the area investigated. Although so far it has been used for soft bottom communities, Bentix (with some species scoring modifications) also appeared to work successfully in hard substrates, at least for the present study

Coastal benthic diversity in the Black and Aegean Seas

Quantitative data pertaining to the composition of macrobenthic communities of soft bottoms along the coastal zones of the Black and Aegean Seas are reviewed. The study area includes one site in the Russian coastal zone, four sites in Ukraine (at depths 3-125 m), four sites in Bulgaria (at depths 12-83 m), and four sites in Greece (at depths 9-90 m). The species variety, population density and community diversity are compared between Seas, among regions and among stations. The fluctuation of these parameters in connection to anthropogenic impact (ranging from open undisturbed sites to those receiving heavy organic and chemical effluent) are discussed. The low species number of benthic fauna in the Black Sea, as opposed to the richness of the Aegean Sea (three times higher) a ratio well established for other marine groups, is not reflected in the overall abundance. Thus, the average population density of benthic organisms may reach 12352 ind per m2 in the Black Sea (Cocketrice sandy bank) while in the Aegean it did not exceed 4,000 ind per m2 (Saronikos Gulf). Community diversity was always lower in the Black Sea than similar sites in the Aegean Sea. Within the various regions examined, the protected areas exhibited the most complex community structure

Flabelliderma cinari (Polychaeta: Flabelligeridae), a new species from the Eastern Mediterranean

A new species of flabelligerid polychaete, Flabelliderma cinari, is described from the Turkish coast of the Eastern MediterraneanSea. This represents the first occurrence of the genus Flabelliderma in the Mediterranean. Flabelliderma cinari sp. nov. isclosely allied to F. claparedei in having dorsal tubercles of two different sizes; however, these species differ in the relative shapeand number of dorsal tubercles, the number of capillaries per fascicle in the notopodia and the shape of the curved distal articlesin the neuropodial hooks