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    Coastal Plankton Assemblages in the Vicinity of Galindez Island and Neumayer Channel (Western Antarctic Peninsula) during the First Joint Turkish - Ukrainian Antarctic Research Expedition
    (Central Fisheries Research Inst, 2018) Yilmaz, Izzet Noyan; Ergul, Halim Aytekin; Mavruk, Sinan; Tas, Seyfettin; Aker, Halim Vedat; Yildiz, Melek; Ozturk, Bayram
    Western Antarctic Peninsula is one of the fastest warming areas on Earth and coastal areas of the region are foremost affected. Here we present the state of coastal plankton assemblages of the Galindez Island and Neumayer Channel, Western Antarctic Peninsula in austral autumn (April 2016). Surface water temperatures were ranged between -0.12 degrees C and -0.97 degrees C and average chlorophyll-a concentrations were 0.65 mu g/l. A total of 50 phytoplankton and 24 zooplankton taxa (15 copepods and 9 meroplanktonic species) were identified during the sampling period. Diatom species (78%) predominated phytoplankton and the highest abundance was 820 cells l(-1), while the highest number of phytoplankton species was 42. Zooplankton was prevailed by the dominance of copepods, except contribution of meroplankton at the Neumayer channel. Highest zooplankton abundance was 101 ind.m(-3). The sampling season was the transition period from the productive spring-summer to dormant winter conditions, which explains the low abundances registered, however, on contrary to low cell abundances, diversity was high within plankton.
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    Impacts of invasive alien marine species on ecosystem services and biodiversity: a pan-European review
    (Regional Euro-Asian Biological Invasions Centre-Reabic, 2014) Katsanevakis, Stelios; Wallentinus, Inger; Zenetos, Argyro; Leppakoski, Erkki; Cinar, Melih Ertan; Ozturk, Bayram; Grabowski, Michal; Golani, Daniel; Cardoso, Ana Cristina
    A good understanding of the mechanisms and magnitude of the impact of invasive alien species on ecosystem services and biodiversity is a prerequisite for the efficient prioritisation of actions to prevent new invasions or for developing mitigation measures. In this review, we identified alien marine species that have a high impact on ecosystem services and biodiversity in European seas, classified the mechanisms of impact, commented on the methods applied for assessing the impact and the related inferential strength, and reported on gaps in available information. Furthermore, we have proposed an updated inventory of 87 marine species in Europe, representing 13 phyla, which have a documented high impact on ecosystem services or biodiversity. Food provision was the ecosystem service that was impacted by the greatest number of alien species (in terms of both positive and negative impacts). Following food provision, the ecosystem services that were negatively affected by the highest number of alien species were ocean nourishment, recreation and tourism, and lifecycle maintenance, while the ecosystem services that were most often positively impacted were cognitive benefits, water purification, and climate regulation. In many cases, marine aliens were found to impact keystone/protected species and habitats. Thirty percent of the assessed species had an impact on entire ecosystem processes or wider ecosystem functioning, more often in a negative fashion. Forty-nine of the assessed species were reported as being ecosystem engineers, which fundamentally modify, create, or define habitats by altering their physical or chemical properties. The positive impacts of alien species are probably underestimated, as there is often a perception bias against alien species. Among the species herein assessed as high-impact species, 17 had only negative and 7 only positive impacts; for the majority (63 species), both negative and positive impacts were reported; the overall balance was often unknown. Although there is no doubt that invasive species have modified marine ecosystems, evidence for most of the reported impacts is weak, as it is based on expert judgement or dubious correlations, while only 13% of the reported impacts were inferred via manipulative or natural experiments. A need for stronger inference is evident, to improve our knowledge base of marine biological invasions and better inform environmental managers.
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    Wanted dead or alive: Corallium rubrum (Cnidaria: Anthozoa) on the coasts of Turkey
    (Cahiers De Biologie Marine, 2018) Cinar, Melih Ertan; Gonulal, Onur; Ozturk, Bayram
    The present paper deals with the occurrence of the red coral Corallium rubrum along the coasts of Turkey. Dead colonies of the species were found in the northern Aegean (one location in Gokceada) and Levantine Seas (three locations) between 45 and 110 m depths, and living colonies were only observed in the northern Aegean Sea (one location in Gokceada) at 50 m depth. The maximum height and basal diameter of dead skeletons of the specimens from Gokceada were measured as 9.6 cm and 8.4 mm, respectively. The present paper extended the distributional range of C. rubrum within the Mediterranean Sea to Anamur, the eastern point in its distribution.