• Energy Research

CASCADE is a global dataset for 139 extant coccolithophore taxonomic units. CASCADE includes a trait database (size and cellular organic and inorganic carbon contents) and taxonomic-specific global spatiotemporal distributions (Lat/Lon/Depth/Month/Year) of coccolithophore abundance and organic and inorganic carbon stocks. CASCADE covers all ocean basins over the upper 275 meters, spans the years 1964-2019 and includes 33,119 taxonomic-specific abundance observations. Within CASCADE, we characterise the underlying uncertainties due to measurement errors by propagating error estimates between the different studies. Full details of the data set are provided in the associated Scientific Data manuscript. The repository contains five main folders: 1) "Classification", which contains YAML files with synonyms, family-level classifications, and life cycle phase associations and definitions; 2) "Concatenated literature", which contains the merged datasets of size, PIC and POC and which were corrected for taxonomic unit synonyms; 3) "Resampled cellular datasets", which contains the resampled datasets of size, PIC and POC in long format as well as a summary table; 4) "Gridded data sets", which contains gridded datasets of abundance, PIC and POC; 5) "Species lists", which contains spreadsheets of the "common" (>20 obs) and "rare" (<20 obs) species and their number of observations. The CASCADE data set can be easily reproduced using the scripts and data provided in the associated github repository: https://github.com/nanophyto/CASCADE/ (zenodo.12797197) Correspondence to: Joost de Vries, joost.devries@bristol.ac.uk v.0.1.2 has some fixes: 1. The wrongly specified S. neapolitana was removed from synonyms.yml (this species is now S. nana)2. Longitudes were corrected for Guerreiro et al., 20233. A double entry for Dimizia et al., 2015 was fixed4. Units in Sal et al., 2013 were correct to cells/L (previously cells/ml)5. Data from Sal et al., 2013 was re-done, as some species were missing6. Duplicate entries from Baumann et al., 2000 were dropped

Mesocosm experiments have been fundamental to investigate the effects of elevated CO2 and ocean acidification (OA) on planktic communities. However, few of these experiments have been conducted using naturally nutrient-limited waters and/or considering the combined effects of OA and ocean warming (OW). Coccolithophores are a group of calcifying phytoplankton that can reach high abundances in the Mediterranean Sea, and whose responses to OA are modulated by temperature and nutrients. We present the results of the first land-based mesocosm experiment testing the effects of combined OA and OW on an oligotrophic Eastern Mediterranean coccolithophore community. Coccolithophore cell abundance drastically decreased under OW and combined OA and OW (greenhouse, GH) conditions. Emiliania huxleyi calcite mass decreased consistently only in the GH treatment; moreover, anomalous calcifications (i.e. coccolith malformations) were particularly common in the perturbed treatments, especially under OA. Overall, these data suggest that the projected increase in sea surface temperatures, including marine heatwaves, will cause rapid changes in Eastern Mediterranean coccolithophore communities, and that these effects will be exacerbated by OA. In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2021) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2021-05-11.

&lt;p&gt;With a coastal population of nearly 150 million inhabitants, the influx of freshwater from densely populated river catchments and a contribution to 30% of the global shipping activity, the Mediterranean Sea has been recognized as one of the world most affected areas by marine litter. Moreover, the countries surrounding the region yearly attract about one third of the world tourism. Taken together, these pressures make this semi-enclosed sea an accumulation zone for marine litter. This high contamination goes hand to hand with a stream of adverse effects to marine ecosystems, public health or socio-economic costs. The beaches are one of the main land-based sources for litter to enter the oceans. The Mediterranean Sea is not an exception as during the summer, the beaches are a hotspot for leisure. This is particularly true for the Mediterranean islands, which due to their attractiveness will host a far greater population during the summer. In this study we evaluate the seasonal variation of marine litter as an effect of tourism on sandy beaches of Mediterranean islands and we assess the effectiveness of pilot actions in order to reduce the amount of marine litter.&lt;/p&gt;&lt;p&gt;147 surveys were conducted in 2017 during both the low and high touristic season. For each of the eight participating islands (Mallorca, Sicily, Rab, Malta, Crete, Mykonos, Rhodes and Cyprus), three different beaches were selected: a touristic beach, a beach mainly used by locals and a remote beach. For each beach, a periodic monitoring was performed on the same fixed 100m portion. Here, any item found was collected, characterized and properly disposed of. We included the mesoplastics (0.5 &amp;#8211; 2.5cm), large microplastics (0.1 &amp;#8211; 0.5cm) and pellets (raw plastic material). In 2019, a monitoring of 11 of the selected beaches was conducted following the implementation of pilot actions (mainly awareness campaigns). To test their effectiveness, the results are compared to those of 2017.&lt;/p&gt;&lt;p&gt;Our results show that tourism in Mediterranean island beaches is a main driver of marine litter generation. Popular beaches (touristic and locals) are clearly the most impacted sites. Every day, during the high touristic season peak (July-August), visitors will leave (i.e.: cigarette butts, drink can, etc.) or generate (i.e.: MePs and MPs) 950 &amp;#8211; 1190 items on every 100m of beach. This amount falls to 60 items for the remote beaches. At the region scale, we estimated that during July-August, visitors could be responsible for the accumulation of about 47.5 10&lt;sup&gt;6&lt;/sup&gt; &amp;#177; 13.5 10&lt;sup&gt;6&lt;/sup&gt; items/day on the beaches of the Mediterranean islands.&lt;/p&gt;&lt;p&gt;The awareness campaigns is an efficient tool to reduce the amount of litter generated by visitors on the beaches. We observed an average decrease of 52.5% of the accumulation of the items abandoned by the visitors after the implementation of the pilot actions. These encouraging results probably benefit from the growing attention of the public to the plastic pollution issue. However, this reduction has a price: the average cost of the pilot actions for the whole high season would be of 111.6 k&amp;#8364; per km of beach.&lt;/p&gt;

AbstractThe mean predicted decrease of 0.3–0.4 pHunits in the global surface ocean by the end of the century has prompted urgent research to assess the potential effects of ocean acidification on the marine environment, with strong emphasis on calcifying organisms. Among them, the Mediterranean red coral (Corallium rubrum) is expected to be particularly susceptible to acidification effects, due to the elevated solubility of its Mg‐calcite skeleton. This, together with the large overexploitation of this species, depicts a bleak future for this organism over the next decades. In this study, we evaluated the effects of lowpHon the species from aquaria experiments. Several colonies ofC. rubrumwere long‐term maintained for 314 days in aquaria at two differentpHlevels (8.10 and 7.81,pHT). Calcification rate, spicule morphology, major biochemical constituents (protein, carbohydrates and lipids) and fatty acids composition were measured periodically. Exposure to lowerpHconditions caused a significant decrease in the skeletal growth rate in comparison with the control treatment. Similarly, the spicule morphology clearly differed between both treatments at the end of the experiment, with aberrant shapes being observed only under the acidified conditions. On the other hand, while total organic matter was significantly higher under lowpHconditions, no significant differences were detected between treatments regarding total carbohydrate, lipid, protein and fatty acid composition. However, the lower variability found among samples maintained in acidified conditions relative to controls, suggests a possible effect ofpHdecrease on the metabolism of the colonies. Our results show, for the first time, evidence of detrimental ocean acidification effects on this valuable and endangered coral species.

To understand the response of marine calcifying organisms under high CO2 scenarios, it is critical to study their calcification patterns in the natural environment. This paper focuses on a major calcifying phytoplankton group, the coccolithophores, through the analysis of water samples collected along a W-E Mediterranean transect during two research cruises, in April 2011 (Meteor cruise M84/3) and May 2013 (MedSeA cruise 2013). The Mediterranean Sea is a marginal sea characterized by large biogeochemical gradients. Currently, it is undergoing both warming and ocean acidification, processes which are rapidly modifying species distribution and calcification. The species Emiliania huxleyi largely dominates the total coccolithophore production in present day oceans and marine basins, including the Mediterranean Sea. A series of morphometric measurements were performed on the coccoliths of this species to estimate their mass, length and calculate a calcification index (proxy for the size-normalized calcification degree). The most abundant morphotype of E. huxleyi in the Mediterranean Sea is Type A. Coccoliths of this morphotype were additionally analyzed based on scanning electron microscopy images: four calcification varieties were quantified, according to the relationship between slit length-tube width, and the state of the central area (open or closed). The average E. huxleyi coccolith mass along the Mediterranean oceanographic transect depended strongly on both the average coccolith length and calcification index. The variability in average coccolith length and calcification index across samples reflected oscillations in the relative abundance of the calcification varieties. We also demonstrated that the distribution of the calcification varieties followed the main environmental gradients (carbonate chemistry, salinity, temperature, nutrient concentrations). Hence, shifts in the distribution of the calcification varieties and of the average E. huxleyi coccolith mass are to be expected in the Mediterranean Sea under climate change. These physiological and ecological responses will modulate the net coccolithophore calcification and, ultimately, the regional carbonate export to the seafloor.

Unidad de excelencia María de Maeztu CEX2019-000940-M Altres ajuts: acords transformatius de la UAB Climate change poses severe threats to coastal social-ecological systems (SES) worldwide. Recent calls recognize the importance of including Indigenous and local knowledge (ILK) in research on climate change impacts. Yet studies that have attempted to weave ILK and scientific knowledge have seldom considered the gendered nature of climate change impacts. Building on the literature on gender and climate change and knowledge pluralism, this study contributes to addressing this research gap by exploring local knowledge on climate change impacts and its relation to scientific knowledge through a gendered approach and focusing on the Western Indian Ocean region, and more specifically on Kenya. We adopted a mixed methodology combining qualitative and quantitative approaches. We found evidence of pronounced climate change impacts on coastal SES both in the scientific literature and in local reports. Our findings highlight that there is an extensive overlap between information derived from scientific and local knowledge systems. Importantly, our study revealed reports of change that were only provided by SSF communities, namely changes in coastal dynamics, a decrease in rainfall, and a decrease in the abundance of green algae. Although we found gendered variations in changes reported by SSF communities, gendered differences of climate change impacts on SSF were not detected in the reviewed literature. Overall, our results suggest that knowledge cross-fertilization generates a holistic, relational, and place-based view of climate change impacts, which may support sound and gender-inclusive adaptive policies.

The Mediterranean Sea and its coastal systems are threatened by intense anthropogenic pressures including rapid accumulation of marine litter by diverse human activities. The region, which is the world's leading touristic destination, has to face a seasonal increase of waste generation due to the seasonal influx of visitors. The beaches, extremely crowded during the summer, are particularly vulnerable since they are proven to be concentrated accumulation zones and one of the main gateways of litter to enter the marine system. We found that the accumulation rates of marine litter on Mediterranean island beaches follow a seasonal pattern, increasing up to 4.7 times during the high season, representing a daily load of 40.6 10⁶ ± 11.5 10⁶ items/day extrapolated to all the islands of the region. We developed an accumulation index to assess the dynamics of marine litter and support efficient mitigation strategies by local authorities. To limit marine litter production attributable to recreational activities, a series of pilot actions implemented during the high touristic season, demonstrated a substantial reduction (up to 52.5%). The implementation towards an efficient and sustainable tourism business model is urgently required.