A jellyfish diet for the herbivorous green turtle Chelonia mydas in the temperate SW Atlantic

Feeding ecology of juvenile green turtles (Chelonia mydas) was studied from 2008 to 2011 at Samborombón Bay (35°30′–36°30′S, Argentina), combining data on digestive tract examination and stable isotope analysis through a Bayesian mixing model. We found that animal matter, in particular gelatinous plankton, was consumed in large proportions compared to herbivorous food items such as terrestrial plants and macroalgae. This diet is facilitated by the high abundance of gelatinous plankton in the region, thus confirming the adaptive foraging behaviour of the juveniles according to prey abundance in the SW Atlantic. To our knowledge, this is the first study to employ this combination of techniques and to conclusively demonstrate that animal matter, in particular gelatinous plankton, is important in the diet of the neritic green sea turtles.     

Short- and long-term importance of small sharks in the diet of the rare deep-sea shark Dalatias licha

Knowing the trophic ecology of marine predators is essential to develop an understanding of their ecological role in ecosystems. Research conducted on deep-sea and threatened shark species is limited. Here, by combining analyses of individual stomach contents and stable isotope values, we examined the trophic ecology (dietary composition and trophic position) of the kitefin shark Dalatias licha, a deep-sea shark considered as near threatened globally and as data deficient in the Mediterranean Sea. Results revealed the importance of small sharks in the diet of the kitefin shark at short- and long-term scales, although fin-fish, crustaceans and cephalopods were also found. Predation on sharks reveals the high trophic position of the kitefin shark within the food web of the western Mediterranean Sea. Stable isotope values from liver and muscle tissues confirmed our results from stomach content analysis and the high trophic position.     

Relevant scales of variability of the benthic allochthonous microalga Chrysophaeum taylorii

Chrysophaeum taylorii (Pelagophyceae) is an allochthonous benthic microalga recently recorded in the Mediterranean Sea. During summer, the occurrence of C. taylorii is usually visible to the naked eye due to the large amount of mucilage this species produces. Information on the spatio-temporal variability of this species and on the predictability of massive mucilage events is still scarce and requires to define ad hoc managing strategies of major bloom events. The aim of this work was to identify the relevant scales of variation in the abundance of C. taylorii abundance and to estimate the relative recurrence of its blooms, testing the hypothesis that mucilage was dependent on the cell density. The first approach was the identification of the most appropriate sampling procedure to estimate benthic cell abundance of C. taylorii. The second one was the estimation of the magnitude of variation in C. taylorii cell abundance attributable to each of several spatial (areas, sites, zones and replicates) and temporal scales (fortnights and years) in the Marine Protected Area of Tavolara Punta Coda Cavallo (Western Mediterranean Sea). The results indicate fortnight and year as the most relevant scales of variability in the cell abundance of C. taylorii and highlight the unimportance of small spatial scales (zone and replicates) to the species variability. The collected data also evidence the absence of a direct relationship between the cell density of C. taylorii and the production of mucilage. In conclusion, these results indicate that patterns in the cell abundance of C. taylorii vary notably depending on the considered scale and that future investigations on processes affecting its performance will need to consider the relevant scales of variation evidenced.     

Optimization of the electrocoagulation process for the removal of copper, lead and cadmium in natural waters and simulated wastewater

Chemical, electrochemical and flow variables were optimized to examine the effectiveness of the electrocoagulation process for the removal of copper, lead and cadmium. The electrochemical process, which uses electrodes of commercial laminate steel, was applied to simulated wastewater containing 12 mg dm(-3) of copper, 4 mg dm(-3) of lead and 4 mg dm(-3) of cadmium. The optimum conditions for the process were identified as pH=7, flow rate=6.3 cm(3) min(-1) and a current density between 31 and 54 A m(-2). When the electrode geometric area and time of electrolysis reached critical values, the copper removal reached a maximum value of 80%. A linear relationship was identified between the current density and the mass of generated sludge. In addition, a linear relationship was found between specific energy consumption and current density. The results of this investigation provide important data for the development of an industrial-scale electrolytic reactor.     

Comparing methods to estimate the proportion of turbine-induced bird and bat mortality in the search area under a road and pad search protocol

Environmental and Ecological Statistics - Estimating bird and bat mortality at wind facilities typically involves searching for carcasses on the ground near turbines. Some fraction of carcasses...     

Lichens as an integrating tool for monitoring PAH atmospheric deposition: A comparison with soil, air and pine needles

The aim of this study was to validate lichens as biomonitors of PAH atmospheric deposition; for that, an inter-comparison between the PAH profile and concentrations intercepted in lichens with those of air, soil and pine needles was performed. The study was conducted in a petro-industrial area and the results showed that PAH profiles in lichens were similar to those of the air and pine needles, but completely different from those of soils. Lichens accumulated higher PAH concentrations when compared to the other environmental compartments and its concentrations were significantly and linearly correlated with concentrations of PAHs in soil; we showed that a translation of the lichen PAHs concentrations into regulatory standards is possible, fulfilling one of the most important requirements of using lichens as biomonitors. With lichens we were then able to characterize the air PAHs profile of urban, petro-industrial and background areas.     

Reconstruction of the environmental evolution of a Sicilian saltmarsh (Italy)

The present study deals with the reconstruction of the environmental evolution of a Trapani saltmarsh (southwestern Sicily, Italy) by combining different analytical approaches such as metal content evaluation, low-field nuclear magnetic resonance (NMR) relaxometry, and benthic foraminifera identification. A 41 cm core was collected in the sediments of a Trapani saltmarsh (southwestern Sicily, Italy) at a water depth of about 50 cm. Different time intervals were recognized, each characterized by peculiar features that testify different environmental conditions. In particular, the bottom layers of the sediment core (41–28 cm) comprised the lowest amount of mud fraction, only some selected metals, and the lowest foraminiferal density. Here, co-occurrence of abundant microcrystals of gypsum and Ammonia tepida is indicative of hyper-saline conditions. In the sediments from 28 to 6 cm, mud fraction and number of metal elements resulted higher due to the increase of the anthropogenic pressure. The sediments in the last time interval, corresponding to the environmental recovery of the saltmarsh, showed an increase of foraminiferal density, a decrease of the mud fraction, and a trend in the metal concentration attributable to the protection policy applied since 1990. NMR relaxometry parameters highlighted the changes of sediment chemical–physical heterogeneity going from the bottom to the top of the core. These heterogeneities have been related to the different intervals recognized as aforementioned. The present study highlights how the anthropogenic pressure modifies the environmental conditions of a transitional ecosystem like saltmarshes.