• Publicationsclose
• Other research productsclose
• 2014-2023close
• Archivio istituzionale della ricerca - Università degli Studi di Venezia Ca' Foscari close
• EUTOPIA Alliance close

Rano Raraku, the crater lake constrained by basaltic tuff that served as the primary quarry used to construct themoaistatues on Rapa Nui (Easter Island), has experienced fluctuations in lake level over the past centuries. As one of the only freshwater sources on the island, understanding the present and past geochemical characteristics of the lake water is critical to understand if the lake could have been a viable freshwater source for Rapa Nui. At the time of sampling in September 2017, the maximum lake depth was ~1 m. The lake level has substantially declined in the subsequent years, with the lake drying almost completely in January 2018. The lake is currently characterized by highly anoxic conditions, with a predominance of ammonium ions on nitrates, a high concentration of organic carbon in the water-sediment interface and reducing conditions of the lake, as evidenced by Mn/Fe and Cr/V ratios. Our estimates of past salinity inferred from the chloride mass balance indicates that it was unlikely that Rano Raraku provided a viable freshwater source for early Rapa Nui people. The installation of an outlet pipe around 1950 that was active until the late 1970s, as well as grazing of horses on the lake margins appear to have significantly impacted the geochemical conditions of Rano Raraku sediments and lake water in recent decades. Such impacts are distinct from natural environmental changes and highlight the need to consider the sensitivity of the lake geochemistry to human activities.

Statistics is assuming an increasing rule in the administration of justice. Scientific evidence is mostly presented at trial in terms of probabilities as measure of uncertainty. Handling probabilities may be an involving task, in particular with reference to complex cases that are characterized by multiple sources of uncertainty. The computation, presentation and interpretation of the probative value of the scientific evidence at trial may give rise to wrong considerations that might influence the final decision of a court. This has originated a large debate and this paper offers a general discussion about these aspects.

We determined the specific biomass burning biomarker levoglucosan in an ice core from the TALos Dome Ice CorE drilling project (TALDICE) during the mid- to late Holocene (6000–750 BP). The levoglucosan record is characterized by a long-term increase with higher rates starting at ∼ 4000 BP and peaks between 2500 and 1500 BP. The anomalous increase in levoglucosan centered at ∼ 2000 BP is consistent with other Antarctic biomass burning records. Multiple atmospheric phenomena affect the coastal Antarctic Talos Dome drilling site, where the Southern Annular Mode (SAM) is the most prominent as the Southern Annular Mode Index (SAMA) correlates with stable isotopes in precipitation throughout the most recent 1000 years of the ice core. If this connection remains throughout the mid- to late Holocene, then our results demonstrate that changes in biomass burning, rather than changes in atmospheric transport, are the major influence on the TALDICE levoglucosan record. Comparisons with charcoal syntheses help evaluate fire sources, showing a greater contribution from southern South American fires than from Australian biomass burning. The levoglucosan peak centered at ∼ 2000 BP occurs during a cool period throughout the Southern Hemisphere, yet during a time of increased fire activity in both northern and southern Patagonia. This peak in biomass burning is influenced by increased vegetation in southern South America from a preceding humid period, in which the vegetation desiccated during the following cool, dry period. The Talos Dome ice core record from 6000 to ∼ 750 BP currently does not provide clear evidence that the fire record may be strongly affected by anthropogenic activities during the mid- to late Holocene, although we cannot exclude at least a partial influence.

Fish consumption analysis involves public and commercial interests. Many studies have focused on this issue over the last few decades. Researchers rarely consider the heterogeneity of these products, while we believe there are at least five reasons why it should always be taken into account: (i) health factors; (ii) environmental drawbacks regarding the consumption of particular species; (iii) the importance of species and how the fish are presented to consumers; (iv) the perceived differences between species are of prime importance for marketing strategies; and finally (v) being able to identify different species helps prevent fraud. Through perceptual mapping we studied the perceived differences between European anchovies (Engraulis encrasicholus), European sardines (Sardina pilchardus) and mackerel (Sgomber spp.), wild-caught cod and sole, and farmed sea bream and sea bass. We checked for the influence of gender, age, education and residence in how consumers perceive seafood. We found that the gender, age and education of consumers do not usually affect their perception of blue fish as being cheap, flavorsome and traditional, cod and sole as nutritional, and farmed sea bream and bass as natural. A slight difference was found in central/southern Italian residents, who perceive farmed sea bream and bass as cheap and flavorful. The results validate the idea that consumers recognize the different attributes of each species or type of fish for sale, but some issues remain unresolved and further studies are recommended.