Comparative study on lipid quality of distribution and abundance of Mnemiopsis leidyi in the eastern Iranian coasts of Caspian Sea

The alien ctenophore Mnemiopsis leidyi which was transported from the Black Sea into the Caspian Sea at the end of 1990s has been negatively affecting ecosystem in this new environment. In this study, spatial and temporal distribution of M.leidyi were studied from a total of stations located along three transects (Amirabad, Babolsar and Nowshar) in the Eeastern Iranian coasts of the Caspian Sea (Mazandaran province) during July 2001 to November 2002. M. leidyi acheived maximum biomass 1024.5 g/m^2 in August-October 2002. Minimum biomass (1.5 g/m^2 of ctenophore were measured in December-Jaunuary 2001. The highest biomass was at the stations with 10m bottom depth (570.7 g/m^2 in autumn and lowest biomass (75.9 g/m^2) was obtained at a station with a 50 m bottom depth in winter. The highest average biomass (641.2 g/m^2) were measured in ~irabad region and the lowest biomass (207.5 g/m^2) observed in Nowshar region. The young specimens (<5 mm) contributed about 90% to the total abundance of the population. The maximum length was 51-55mm which was measured in August. The factors affecting the distribution of M. leidyi in the study area were discussed

Reproduction of the ctenophore, Beroe ovata, in the Caspian Sea water

The experiments with Beroe ovata showed that this ctenophore can survive and reproduce in the Caspian Sea water, though at far lower rate than in the Black Sea; larval growth in the Caspian Sea water was also slower and mortality higher. Maximum fecundity of 2210 and 240 eggs recorded in laboratories of Turkey and Iran, respectively. About 34 to 100% of eggs in the Caspian Sea water could not develop and hatch. Larvae were at different stages of development, usually with size between 1.2 to 2mm. The highest number of eggs and larvae were obtained in tanks where Beroe individuals were together with Mnemiopsis leidyi. The poor reproduction of B. ovata in the Caspian Sea water could be due to both the acclimation stress to low salinity and possible damage of individuals during the transportation

Tuning gastropod locomotion: Modeling the influence of mucus rheology on the cost of crawling

Common gastropods such as snails crawl on a solid substrate by propagating muscular waves of shear stress on a viscoelastic mucus. Producing the mucus accounts for the largest component in the gastropod's energy budget, more than twenty times the amount of mechanical work used in crawling. Using a simple mechanical model, we show that the shear-thinning properties of the mucus favor a decrease in the amount of mucus necessary for crawling, thereby decreasing the overall energetic cost of locomotion.Comment: Corrected typo

Trophic Relationships and Food Supply of Heterotrophic Animals in the Pelagic Ecosystem of the Black Sea

During recent decades, the Black Sea has been affected by many negative factors that strongly changed the condition of its ecosystem. Especially trophic relationships in the Black Sea pelagic system became very vulnerable influencing the food supply, productivity and abundance of many species and populations of this marine basin. Food is one of most important link between biota and its environment. In this monograph, the role and variability of trophodynamic processes that effect the well-being (health) of main heterotrophic components of ecosystem were analysed in detail for a few key species as indicators for estimation of ecosystem condition in whole. These are most significant mass species of the Black Sea pelagic ecosystem. Among copepods this is Calanus euxinus that dominates the mesozooplankton which makes up the fodder base of planktivorous fishes. Among gelatinous these are medusa Aurelia aurita and the alien ctenophores Mnemiopsis leidyi and Beroe ovata which affected strongly mesozooplankton composition. Lastly among fishes the anchovy Engraulis encrasicolus ponticus and sprat Sprattus sprattus phalericus that dominate small pelagic fishery. We considered in this monograph: • Diel feeding behaviour, in situ feeding rate of Calanus euxinus and impact of mesozooplankton on primary production and phytoplankton biomass. • The effect of vertical migrations on energy budget and its components in C. euxinus; metabolic substrates used in catabolic processes under both aerobic and hypoxic conditions, the role of reserve lipids and effect of abiotic factors on individual growth and population structure of this species. • The intensity and efficiency of ingestion and energy transformation in three gelatinous species ( jellyfish Aurelia aurita, ctenophores Mnemiopsis leidyi and Beroe ovata) and their predatory impact on zooplankton community. • Nutritional condition and food supply of anchovy and sprat in the close interaction with natural biotic and abiotic and anthropogenic factors. • Tendencies in this interaction during long time space: since 1960 s till present years. • Estimation of population condition of these species and its long-term change. This monograph is the collective work of Ukrainian and Turkish scientists studying complex hydrobiological problems of the Black Sea. Its aim is to reveal the significance of nutritional factors on the ecology of Black Sea biota, including changes which have already occurred, as well as offering some insight into changes that may happen in the future. Our joint investigations started in the first half of the 1990s, when conditions for the close cooperation of researchers from the two countries were suitable after the collapse of the Soviet era. This spirit continues to the present day. Professor Ümit Unluata, Director of Erdemli Institute of Marine Sciences (Middle East Technical University, Ankara) was of paramount importance in organising and fostering the work undertaken. We would like to devote this monograph to the memory of him, who died so prematurely. We are also grateful to Academician Professor V. N. Eremeev, Director of the Sevastopol Institute of Biology of the Southern Sea (National Academy of Sciences of Ukraine), and to the directors of Erdemli Institute of Marine Sciences (Professor Ilkay Salihoglu, Professor Sukru Besiktepe and Professor Ferit Bingel) who also made significant contributions to the Ukrainian–Turkish collaboration. We are grateful to Dr Bill Parr from the Black Sea Ecosystem Recovery Project for his valuable efforts in improving earlier drafts. All these investigations were carried out within the framework of the following five NATO linkage-grants: • Pelagic animal food supply in the unstable Black Sea environment, • Will the new alien ctenophore Beroe ovata control the plankton community in the Black Sea? • Grazing, growth and production of Calanus euxinus in the Black Sea, • Bioindicators for assessment of Black Sea ecosystem recovery, • Adaptability and vulnerability of marine species in changing environments. And four TUBITAK - NASU joint projects: • Quantification of the recent ctenophore invader Beroe ovata impact in the Black Sea • Monitoring of the Black Sea anchovy and sprat, • Salinity tolerance as a key factor of invasion success of the copepods of Calanus genus into the Sea of Marmara, • Salinity tolerance as a key factor of invasion success of the mesozooplankton species into the Sea of Marmara. We hope that this publication will make a substantial contribution to future studies of the Black Sea ecosystem and offers further understanding of those features regulating biological processes in this unique marine basin

Early anthropogenic transformation of the Danube-Black Sea system

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 2 (2012): 582, doi:10.1038/srep00582.Over the last century humans have altered the export of fluvial materials leading to significant changes in morphology, chemistry, and biology of the coastal ocean. Here we present sedimentary, paleoenvironmental and paleogenetic evidence to show that the Black Sea, a nearly enclosed marine basin, was affected by land use long before the changes of the Industrial Era. Although watershed hydroclimate was spatially and temporally variable over the last ~3000 years, surface salinity dropped systematically in the Black Sea. Sediment loads delivered by Danube River, the main tributary of the Black Sea, significantly increased as land use intensified in the last two millennia, which led to a rapid expansion of its delta. Lastly, proliferation of diatoms and dinoflagellates over the last five to six centuries, when intensive deforestation occurred in Eastern Europe, points to an anthropogenic pulse of river-borne nutrients that radically transformed the food web structure in the Black Sea.This study was supported by grants OISE 0637108, EAR 0952146, OCE 0602423 and OCE 0825020 from the National Science Foundation and grants from the Woods Hole Oceanographic Institution

Comprehensive study on probability of controlling Caspian Sea invasive Ctenophora Activity 4: The laboratory study on probability of controlling Mnemiopsis leidyi by use of Beroe ovata (reproduction study of B. ovata in the Caspian Sea water)

In 1999 Mnemiopsis leidyi was introduced to the Caspian Sea from the Black Sea with ballast waters from the ships. The comprehensive study on probability of controlling Caspian Sea invasive Ctenophora planned after a remarkable of decreeing in Kilka fish catches stocks and fisheris community problems. This study focus on reproduction experiments of Beroe ovata as the best candidate for control of Mnemiopsis population size in the Caspian Sea that was performed in Turkey and Iran during 2002-2003. At 2002, 87 specimens of B. ovata, 10-50 mm transferred to Caspian sea ecology research center from Marmareh sea where acclimated with Caspian sea water gradually. At 2003, experiments were performed near to Black sea (at Sinop) with freshly collected Beroe ovata, 40-65 mm size in three salinity level treatment, the Black sea water 18 , Mixed water 15 and Caspian water 12 . 130 individuals of Beroe ovata were brought from Sinop (Turkey) to Iran during 2003. A number of Beroe specimens were sent to Guilan province for reproduction studies and another part were sent to Mazandaran province for both reproduction and mesocosem studies. For control we had 1 Beroe, length 30 mm in the Black Sea water that was alive during of study in Iran. The Jars were examined each day for ova and larvae and they were collected and put into glass container of Caspian water for hatching and developing survey, some of them were left without any handling for larvae developing. Also in another experiment the eggs collected from jars were placed in the same three treatments for studying of growth and survival. The results were unsuccessful on propagation experiments at 2002 since the spawning and hatching rates were very low (20 ova) and, none of the larvae developed into adults in Caspian Sea water. The spawning was more in Marmareh sea water with 138 ova where only 7 larvae was hatched. Results showed that Beroe specimens is able to survive and reproduce in Caspian water but was not as well as Black Sea also the Beroe larvae growth rate is low in the Caspian Sea water. Maximum fecundity of Beroe individual was 2212 and 235 ovae in Caspian Sea water in site Sinop and Iran respectively. Results showed 34-100% eggs in Caspian Sea water were destroyed and did not develop. In Iran we obtained only one larvae with 5 mm length, other larvae were at different stages of development but most of them were 1.2 2 mm. The results of mesocosm survey showed most of ova and larvae have been obtained from the tanks where individuals B. ovata were with Mnemiopsis. Fecundity of Beroe in the control with Black Sea water were between 17 to 1879 with average of 828 ± 112 ova. The poor results of B. ovata reproduction obtained in this survey in Caspian Sea may be due to transportation and acclimation stress and low salinity of Caspian Sea water

The Mediterranean Sea Regime Shift at the End of the 1980s, and Intriguing Parallelisms with Other European Basins

Background: Regime shifts are abrupt changes encompassing a multitude of physical properties and ecosystem variables, which lead to new regime conditions. Recent investigations focus on the changes in ecosystem diversity and functioning associated to such shifts. Of particular interest, because of the implication on climate drivers, are shifts that occur synchronously in separated basins. Principal Findings: In this work we analyze and review long-term records of Mediterranean ecological and hydro-climate variables and find that all point to a synchronous change in the late 1980s. A quantitative synthesis of the literature (including observed oceanic data, models and satellite analyses) shows that these years mark a major change in Mediterranean hydrographic properties, surface circulation, and deep water convection (the Eastern Mediterranean Transient). We provide novel analyses that link local, regional and basin scale hydrological properties with two major indicators of large scale climate, the North Atlantic Oscillation index and the Northern Hemisphere Temperature index, suggesting that the Mediterranean shift is part of a large scale change in the Northern Hemisphere. We provide a simplified scheme of the different effects of climate vs. temperature on pelagic ecosystems. Conclusions: Our results show that the Mediterranean Sea underwent a major change at the end of the 1980s that encompassed atmospheric, hydrological, and ecological systems, for which it can be considered a regime shift. We further provide evidence that the local hydrography is linked to the larger scale, northern hemisphere climate. These results suggest that the shifts that affected the North, Baltic, Black and Mediterranean (this work) Seas at the end of the 1980s, that have been so far only partly associated, are likely linked as part a northern hemisphere change. These findings bear wide implications for the development of climate change scenarios, as synchronous shifts may provide the key for distinguishing local (i.e., basin) anthropogenic drivers, such as eutrophication or fishing, from larger scale (hemispheric) climate drivers

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

Resolving structure and function of metaorganisms through a holistic framework combining reductionist and integrative approaches

Current research highlights the importance of associated microbes in contributing to the functioning, health, and even adaptation of their animal, plant, and fungal hosts. As such, we are witnessing a shift in research that moves away from focusing on the eukaryotic host sensu stricto to research into the complex conglomerate of the host and its associated microorganisms (i.e., microbial eukaryotes, archaea, bacteria, and viruses), the so-called metaorganism, as the biological entity. While recent research supports and encourages the adoption of such an integrative view, it must be understood that microorganisms are not involved in all host processes and not all associated microorganisms are functionally important. As such, our intention here is to provide a critical review and evaluation of perspectives and limitations relevant to studying organisms in a metaorganism framework and the functional toolbox available to do so. We note that marker gene-guided approaches that primarily characterize microbial diversity are a first step in delineating associated microbes but are not sufficient to establish proof of their functional relevance. More sophisticated tools and experiments are necessary to reveal the specific functions of associated microbes. This can be accomplished through the study of metaorganisms in less complex environments, the targeted manipulation of microbial associates, or work at the mechanistic level with the toolbox available in model systems. We conclude that the metaorganism framework is a powerful new concept to help provide answers to longstanding biological questions such as the evolution and ecology of organismal complexity and the importance of organismal symbioses to ecosystem functioning. The intricacy of the metaorganism requires a holistic framework combining reductionist and integrative approaches to resolve metaorganism identities and to disclose the various roles that microorganisms play in the biology of their hosts