Temperature effects on sinking velocity of different Emiliania huxleyi strains

The sinking properties of three strains of Emiliania huxleyi in response to temperature changes were examined. We used a recently proposed approach to calculate sinking velocities from coccosphere architecture, which has the advantage to be applicable not only to culture samples, but also to field samples including fossil material. Our data show that temperature in the sub-optimal range impacts sinking velocity of E. huxleyi. This response is widespread among strains isolated in different locations and moreover comparatively predictable, as indicated by the similar slopes of the linear regressions. Sinking velocity was positively correlated to temperature as well as individual cell PIC/POC over the sub-optimum to optimum temperature range in all strains. In the context of climate change our data point to an important influence of global warming on sinking velocities. It has recently been shown that seawater acidification has no effect on sinking velocity of a Mediterranean E. huxleyi strain, while nutrient limitation seems to have a small negative effect on sinking velocity. Given that warming, acidification, and lowered nutrient availability will occur simultaneously under climate change scenarios, the question is what the net effect of different influential factors will be. For example, will the effects of warming and nutrient limitation cancel? This question cannot be answered conclusively but analyses of field samples in addition to laboratory culture studies will improve predictions because in field samples multi factor influences and even evolutionary changes are not excluded. As mentioned above, the approach of determining sinking rate followed here is applicable to field samples. Future studies could use it to analyse not only seasonal and geographic patterns but also changes in sinking velocity over geological time scales

Historical record of Corallium rubrum and its changing carbon sequestration capacity: A meta-analysis from the North Western Mediterranean

Background There is a scarcity of long time-span and geographically wide research on the health status of Corallium rubrum, including limited research on its historical ecology and carbon sequestration capacity. Objectives To reconstruct the temporal trends of the most reported C. rubrum population parameters in the Northwestern Mediterranean Sea and to determine the changes in total carbon sequestration by this species. Data sources Quantitative and qualitative, academic and grey documents were collected from scientific web browsers, scientific libraries, and requests to scientists. Study eligibility criteria Documents with original information of basal diameter, height and/or weight per colony, with a depth limit of 60 m in the Catalan and Ligurian Seas were analyzed. Synthesis methods We calculated yearly average values of C. rubrum biometric parameters, as well as estimated total weight, carbon flux, and carbon fixation in the structures of C. rubrum's colonies. Results In both study areas, the values of the selected morphometric parameters for C. rubrum decreased until the 1990s, then increased from the 2000s, with average values surpassing the levels of the 1960s (Ligurian Sea) or reaching levels slightly lower than those of the 1980s (Catalan Sea). The difference in carbon sequestered between the oldest (1960s: Ligurian Sea; 1970s: Catalan Sea) and the lowest (1990s) biomass value of colonies is nearly double. Limitations Quantitative data previous to the 1990s are very limited. Information on recent recovery trends in C. rubrum parameters is concentrated in a few areas and biased towards colonies in marine protected areas, with scarce quantitative information from colonies in other areas. Conclusions The halt in the C. rubrum decreasing trend coincided with the exhaustion of tree-like colonies and the first recovery response due to effective protection measures in some areas. Nevertheless, C. rubrum climate change mitigation capacity through carbon sequestration can be drastically reduced from its potential in only a few decades

Local and tourist perceptions of coastal marine habitats in Cap de Creus (NE Spain)

Direct human pressure on Marine Protected Areas (MPAs) adds to climate change impacts on marine habitats, especially in coastal biodiversity hot spots. Understanding MPA user perception towards the Coastal marine Habitats (CMHs) could improve awareness of the challenges that such areas have to face, eventually providing insights for the design of conservation and tourism management plans. We studied perception of ecosystem services, impacts and threats of CMHs by locals and tourists (n = 624) of Cap de Creus MPA (NW Mediterranean Sea). Overall, we found that perceptions of tourists and locals are similar. Respondents perceived that CMHs provide valuable regulating services, and they assigned less value to cultural services. Locals valued the food provision ecosystem service of CMHs significantly more than tourists, probably because of the historical importance of fisheries for subsistence. Respondents ranked marine pollution of inland origin, climate change and people’s behaviour towards nature as the most impactful and threatening to CMHs, and invasive marine species as the least. Respondents also perceived that climate change impacts would increase soon, whilst the impact of people’s behaviour towards nature would decrease. Tourists perceived mass tourism as significantly more impactful and threatening to CMHs than locals did. Overall, our study shows that conservation of CMHs is highly valued, so more effort needs to be directed toward this goal

Hot, Sour and Breathless – Ocean under Stress.

ISBN 978-0-9519618-6-

The specificities of the feasibility study of the ANUBiH project General Encyclopedia of Bosnia and Herzegovina

Objavljivanje prvih dvaju tomova, u nacionalnom ili teritorijalnom smislu, partikularnih enciklopedija, Hrvatske enciklopedije Bosne i Hercegovine i Enciklopedije Republike Srpske, u intelektualnoj je javnosti otvorila pitanje stvaranja Opće enciklopedije Bosne i Hercegovine. Ta bi enciklopedija morala posmatrati BiH kao cjelovitu, jedinstvenu i zasebnu historijsku, socijalnu i državnu tvorevinu isključivo na osnovu naučno utvrđenih činjenica. Predsjedništvo je odlučilo da se ANUBiH angažuje na ovom projektu. Nakon faze pripremnih radnji Akademija je zaključila da se u postojećim društvenim uslovima najprije mora sačiniti iscrpna studija izvodljivosti za cijeli izdavački poduhvat državne opće enciklopedije. Ovaj rad je prvi odgovor na taj zahtjev. U njemu se na bazi postojećih saznanja o studijama izvodljivosti i enciklopedistici, te sadašnjih i predvidljivih društveno-političkih prilika, utvrđuju najvažniji elementi buduće studije izvodljivosti projekta ANUBiH Opća enciklopedija Bosne i Hercegovine.The first two volumes of ethnically or territorially specific encyclopedias, the Croatian Encyclopedia of Bosnia and Herzegovina and Encyclopedia of the Republika Srpska, opened the issue of creating a General Encyclopedia of Bosnia and Herzegovina among the intellectual public. This encyclopedia should observe B&H as a complete, unique, and separate historical, social, and state entity based solely on scientifically established facts. The Presidency decided to engage ANUBiH in this project. After a phase of preparatory activities, the Academy concluded that existing socio-political conditions require a comprehensive feasibility study for the entire publishing endeavour, focused on the national general encyclopedia. This paper is the first response to that request. Based on the existing knowledge on feasibility studies and encyclopedistics and the current and anticipated social circumstances, the study determines the most important elements of the future feasibility study for the ANUBiH project General Encyclopedia of Bosnia and Herzegovina

Sensitivity of Mediterranean bivalve mollusc aquaculture to climate change, ocean acidification, and other environmental pressures: findings from a producer survey

Human-induced climate change and ocean acidification are global environmental phenomena with a common driver: anthropogenic emissions of carbon dioxide. Both processes potentially threaten the Mediterranean bivalve mollusc aquaculture sector, which is economically relevant to several regions and countries. Detrimental effects on bivalve mollusc species might arise from the associated increase in sea surface temperature, pH reduction, higher frequency of extreme climatic events, and possible synergies with other nonclimatic stressors, such as harmful algal blooms and mollusc diseases. This paper presents the results of a questionnaire-based study of Mediterranean bivalve mollusc producers from 12 coastal regions and six countries, the latter including those with the highest production share in the Mediterranean region. This study aims to assess knowledge and perception of threat of climatic and nonclimatic environmental stressors within the Mediterranean aquaculture industry. Furthermore, it collects information about the (geographical) impacts of summer heat waves and ocean acidification. The results suggest that ocean acidification is still a relatively unknown phenomenon and generally poorly understood. Moreover, it is considered a secondary threat compared with other pressures. Summer heat waves are presently perceived as the highest threat, having been observed in a majority of the studied production sites in past years, with effects on seed (spat), adult mortality, and byssus attachment

Climatological variations of total alkalinity and total dissolved inorganic carbon in the Mediterranean Sea surface waters

Abstract. A compilation of data from several cruises between 1998 and 2013 was used to derive polynomial fits that estimate total alkalinity (AT) and total dissolved inorganic carbon (CT) from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross-validation results and revealed that second- and third-order polynomials fit the AT and CT data respectively. The AT surface fit yielded a root mean square error (RMSE) of ± 10.6 μmol kg−1, and salinity and temperature contribute to 96 % of the variability. Furthermore, we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ± 14.3 μmol kg−1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The identified empirical equations were applied on the 0.25° climatologies of temperature and salinity, available from the World Ocean Atlas 2013. The 7-year averages (2005–2012) showed that AT and CT have similar patterns with an increasing eastward gradient. The variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer–winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations