On the sperm whale (Physeter macrocephalus) ecology, sociality and behavior off Ischia Island (Italy): patterns of sound production and acoustically measured growth

The main goal of this research is to contribute to the overall knowledge of the sperm whales’ (Physeter macrocephalus) ecology, sociality, and behavior in the Mediterranean Sea. The combined use of visual and acoustic methods allows me to: 1) give a detailed outline of the encounters around Ischia Island (Tyrrhenian Sea, Italy) over 2002-2015 period; 2) provide insights into the acoustic repertoire in encounters with social units (females with immatures), clusters of presumed/confirmed males and solitary individuals; this information was then used to model habitat suitability and use via analysis of different vocalization types, analyze a type of social sound (i.e. coda), and investigate an unusual tonal sound (i.e. trumpet); 3) present acoustically derived estimates of individual whale growth. This involved the application of acoustic methods to groups or individual sperm whales located in the area. Using passive acoustics to study animal behaviour is a developing field. As such, many of the recent publications describe methods, models and algorithms that can be used to investigate cetaceans in the wild. In this thesis I attempt to apply these tools to a larger sample size than previous studies in the Mediterranean Sea, taking advantage of the long-term data set of audio recordings made around Ischia Island between 2004 and 2015. The thesis is organized in 6 chapters. - Chapters 1 and 2 describe sperm whale general biology and acoustics; - Goal 1 is addressed in Chapter 3; it provides fundamental background information on the study area, the distribution of sperm whale encounters around Ischia Island, the individual photoidentification and group composition, as well as new insights on the habitat suitability, and diving/resting at surface cycle; - Goal 2 is addressed in Chapter 4; - Goal 3 is addressed in Chapter 5; - The final Chapter (#6) provides conclusions and outlines directions for future research

First record of a hagfish anchored to a living bottlenose dolphin in the Mediterranean Sea

An unusual observation of a hagfish ( Myxine glutinosa ) anchored to a living bottlenose dolphin ( Tursiops truncatus ) was documented in an encounter with a group of about 80 dolphins during an ongoing long-term research program on cetaceans in the central Mediterranean Sea, Italy. The body of the hagfish was observed extruding from the blowhole of the bottlenose dolphin showing a stereotypical surfacing–breathing pattern. The observation lasted 2h; photo-identification, acoustic, and behavioral data were collected. Succorant behaviors (i.e., "standing by") from conspecifics and overlapping vocalizations during social phases were recorded. The dolphin was encountered again after 1 month in the same area without the hagfish, apparently in healthy conditions

High spatial resolution photo mosaicking for the monitoring of coralligenous reefs

AbstractCoralligenous reefs are characterized by large bathymetric and spatial distribution, as well as heterogeneity; in shallow environments, they develop mainly on vertical and sub-vertical rocky walls. Mainly diver-based techniques are carried out to gain detailed information on such habitats. Here, we propose a non-destructive and multi-purpose photo mosaicking method to study and monitor coralligenous reefs developing on vertical walls. High-pixel resolution images using three different commercial cameras were acquired on a 10 m2 reef, to compare the effectiveness of photomosaic method to the traditional photoquadrats technique in quantifying the coralligenous assemblage. Results showed very high spatial resolution and accuracy among the photomosaic acquired with different cameras and no significant differences with photoquadrats in assessing the assemblage composition. Despite the large difference in costs of each recording apparatus, little differences emerged from the assemblage characterization: through the analysis of the three photomosaics twelve taxa/morphological categories covered 97–99% of the sampled surface. Photo mosaicking represents a low-cost method that minimizes the time spent underwater by divers and capable of providing new opportunities for further studies on shallow coralligenous reefs

Personalized architectural documentation based on stakeholders' information needs

The stakeholders of a software system are, to a greater or lesser extent, concerned about its software architecture, as an essential artifact for capturing the key design decisions of the system. The architecture is normally documented in the Software Architecture Document (SAD), which tends to be a large and complex technical description, and does not always address the information needs of every stakeholder. Individual stakeholders are interested in dierent, sometimes overlapping, subsets of the SAD and they also require varying levels of detail. As a consequence, stakeholders are aected by an information overload problem, which in practice discourages the usage of the architectural knowledge and diminishes its value for the organization. Along this line, this work presents a semi-automated approach to recommend relevant contents of a given SAD to specific stakeholder profiles. Our approach assumes that SADs are hosted in Wikis, which not only favor communication and interactions among stakeholders, but also enable us to apply User Profiling techniques to infer stakeholders´ interests with respect to particular documents. We have built a recommendation tool implementing our approach, which was tested in two experiments with Wiki-based SADs. Although preliminary, the results have shown that the recommendations of the tool help to nd the architectural documents that best match the stakeholders´ interests.Fil: Tommasel, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; ArgentinaFil: Nicoletti, Matías Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; ArgentinaFil: Diaz Pace, Jorge Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; ArgentinaFil: Schiaffino, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; ArgentinaFil: Godoy, Daniela Lis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; Argentin

Trumpet sounds emitted by male sperm whales in the Mediterranean Sea

Sperm whale trumpets are sounds only occasionally documented, with a well recognisable and stereotyped acoustic arrangement. This study investigated the acoustic features of the trumpets and the context in which these sounds were recorded, using acoustic data collected over 22 years, in the Pelagos Sanctuary area (North-Western Mediterranean Sea). Analysed trumpets (n = 230), recorded at the beginning of a dive after the whale fluke-up, comprised a series of acoustic units organized in short sequences. Acoustic parameters were derived for the entire trumpet and for each distinguishable unit in a trumpet. Overall, trumpet durations and their initial frequencies were higher in recordings collected when multiple whales were visually or acoustically detected in the observation area. The identity of 68 whales was assessed through photo-identification, with 29 individuals producing trumpets within and between years. The variability of the acoustic parameters appeared to be higher within the same individuals rather than between different individuals, suggesting an individual plasticity in composing and arranging units in a trumpet. Different click patterns were observed before and after the trumpets, with more complex sequences when (1) other whales were visually/acoustically detected, and (2) individuals were in suitable foraging sites (i.e., canyon areas). Trumpets were commonly followed or preceded by click patterns suited for communication, such as codas and/or slow clicks. Significant relations between the trumpet emission and the male-only long-range communication click pattern (i.e. slow clicks) emerged, supporting the hypothesis that a trumpet is a sound emitted by maturing/mature males in feeding grounds. This study provides the first evidence that trumpets were conserved in the sperm whale acoustic repertoire at the decadal timescale, persisting across years and individuals in the same area. This persistence may be functionally specific to foraging activities performed by males in a well-established feeding area

Finite mixtures in capture-recapture surveys for modelling residency patterns in marine wildlife populations

In this work, the goal is to estimate the abundance of an animal population using data coming from capture-recapture surveys. We leverage the prior knowledge about the population's structure to specify a parsimonious finite mixture model tailored to its behavioral pattern. Inference is carried out under the Bayesian framework, where we discuss suitable priors' specification that could alleviate label-switching and non-identifiability issues affecting finite mixtures. We conduct simulation experiments to show the competitive advantage of our proposal over less specific alternatives. Finally, the proposed model is used to estimate the common bottlenose dolphins' population size at the Tiber River estuary (Mediterranean Sea), using data collected via photo-identification from 2018 to 2020. Results provide novel insights on the population's size and structure, and shed light on some of the ecological processes governing the population dynamics

On the Radiative Impact of Biomass-Burning Aerosols in the Arctic: The August 2017 Case Study

Boreal fires have increased during the last years and are projected to become more intense and frequent as a consequence of climate change. Wildfires produce a wide range of effects on the Arctic climate and ecosystem, and understanding these effects is crucial for predicting the future evolution of the Arctic region. This study focuses on the impact of the long-range transport of biomass-burning aerosol into the atmosphere and the corresponding radiative perturbation in the shortwave frequency range. As a case study, we investigate an intense biomass-burning (BB) event which took place in summer 2017 in Canada and subsequent northeastward transport of gases and particles in the plume leading to exceptionally high values (0.86) of Aerosol Optical Depth (AOD) at 500 nm measured in northwestern Greenland on 21 August 2017. This work characterizes the BB plume measured at the Thule High Arctic Atmospheric Observatory (THAAO; 76.53° N, °68.74° W) in August 2017 by assessing the associated shortwave aerosol direct radiative impact over the THAAO and extending this evaluation over the broader region (60° N-80° N, 110° W-0° E). The radiative transfer simulations with MODTRAN6.0 estimated an aerosol heating rate of up to 0.5 K/day in the upper aerosol layer (8-12 km). The direct aerosol radiative effect (ARE) vertical profile shows a maximum negative value of -45.4 Wm-2 for a 78° solar zenith angle above THAAO at 3 km altitude. A cumulative surface ARE of -127.5 TW is estimated to have occurred on 21 August 2017 over a portion (3.1 10^6 km2) of the considered domain (60° N-80° N, 110° W-0° E). ARE regional mean daily values over the same portion of the domain vary between -65 and -25 Wm-2. Although this is a limited temporal event, this effect can have significant influence on the Arctic radiative budget, especially in the anticipated scenario of increasing wildfires

Biogenic Aerosol in the Artic from Eight Years of MSA Data from Ny Ålesund (Svalbard Islands) and Thule (Greenland)

In remote marine areas, biogenic productivity and atmospheric particulate are coupled through dimethylsulfide (DMS) emission by phytoplankton. Once in the atmosphere, the gaseous DMS is oxidized to produce H2SO4 and methanesulfonic acid (MSA); both species can a ect the formation of cloud condensation nuclei. This study analyses eight years of biogenic aerosol evolution and variability at two Arctic sites: Thule (76.5 N, 68.8 W) and Ny Ålesund (78.9 N, 11.9 E). Sea ice plays a key role in determining the MSA concentration in polar regions. At the beginning of the melting season, in April, up to June, the biogenic aerosol concentration appears inversely correlated with sea ice extent and area, and positively correlated with the extent of the ice-free area in the marginal ice zone (IF-MIZ). The upper ocean stratification induced by sea ice melting might have a role in these correlations, since the springtime formation of this surface layer regulates the accumulation of phytoplankton and nutrients, allowing the DMS to escape from the sea to the atmosphere. The multiyear analysis reveals a progressive decrease in MSA concentration in May at Thule and an increase in July August at Ny Ålesund. Therefore, while the MSA seasonal evolution is mainly related with the sea ice retreat in April, May, and June, the IF-MIZ extent appears as the main factor a ecting the longer-term behavior of MSA.MIUR PRIN 2007 and PRIN 2009, PNRA 2010-2012, PNRA 2015-2016, PNRA 2016-2018Publishedid 3495A. Ricerche polari e paleoclimaJCR Journa