Risultati del monitoraggio dei cetacei lungo il transetto Livorno-Bastia nel triennio 2013-2015 e confronto con le precedenti annualita'

Esistono otto specie di cetacei regolarmente presenti nel Mar Mediterraneo: un misticete (Balaenoptera physalus) e sette odontoceti (Physeter macrocephalus, Globicephala melas, Grampus griseus, Ziphius cavirostris, Tursiops truncatus, Stenella coeruleoalba e Delphinus delphis). I cetacei hanno pochi predatori naturali: la loro più grande minaccia è costituita dall’ uomo, che negli anni ha decimato intere popolazioni di questi mammiferi In questa situazione, la sopravvivenza dei cetacei appare legata all’attuazione di precise misure di conservazione volte alla protezione delle popolazioni, che dovrebbero essere costantemente monitorate in quanto la conoscenza su di esse è ancora scarsa ed in continua evoluzione. Grazie a una collaborazione tra ISPRA e altri enti è stato possibile sviluppare un ampio progetto di monitoraggio di cetacei e di altri grandi pelagici che consiste in una rete di 10 transetti trans-regionali distribuiti nel bacino del Mediterraneo. I dati sono ottenuti seguendo per tutte le tratte il medesimo protocollo e utilizzando i traghetti di linea come piattaforme d'osservazione per survey sistematici, cosa che abbatte notevolmente le spese da sostenere rendendo più accessibile il monitoraggio a lungo termine.Tra tutte le tratte facenti parte del progetto, l'unica ad essere attiva tutto l'anno dal 2008 fino ai giorni nostri è quella tra Livorno e Bastia, che si trova nel Mar Ligure orientale all'interno del Santuario Pelagos. La raccolta dati per questo elaborato di tesi è stata realizzata personalmente, durante tre anni completi di monitoraggio (2013-2014-2015). Lo scopo del lavoro è stato innanzitutto quello di determinare quali fossero le specie di cetacei presenti nell’area, e tra queste le più frequenti e abbondanti. Sono state poi create, tramite programmi di georeferenziazione, delle mappe di distribuzione e, una volta calcolato il tasso d’incontro, sono state messe in evidenza le zone in cui sono stati effettuati più avvistamenti. L'obiettivo è quello di verificare eventuali differenze significative a lungo termine nella composizione, nel tasso d'incontro e nella distribuzione dei cetacei in questo tratto di mare, nel corso degli anni e delle stagioni e mettere queste informazioni a confronto con i dati raccolti nel biennio Febbraio 2009 – Febbraio 2011 (Tesi di Anna Ruvolo, Università di Pisa)

Long-term monitoring for the surveillance of the conservation status of Tursiops truncatus in an EU Natura2000 site in the Mediterranean Sea. A pilot study in the Tuscan Archipelago

A pilot study, using the dataset from the research network ‘FLT Med Net’, which regularly monitors transborder regions in the Mediterranean Sea using ferries as platform for systematic surveys, was undertaken to assess common bottlenose dolphin range and population trends within the Natura 2000 EU marine site “Tutela del Tursiops truncatus”. The site was recently designated by the Tuscany Region (Italy) within the requirement of the EU Habitats Directive. In order to evaluate the conservation status of bottlenose dolphin according to the surveillance scheme of the Directive, two six-year periods (2007-2012; 2013-2018) were compared to assess trends in distribution-occurrence (range); Sightings Per Unit of Effort and Density (population). In total, 18146 NM were surveyed along two fixed transects, recording 90 sightings of Tursiops truncatus and a total of 268 specimens. Between the two periods, slight but not statistically significant differences were assessed, with decreasing trend in range and population  of the species; no variation was detected in mean group sizes. Travelling was the most common behaviour, and juveniles were present in 20% of the sightings, concentrated during spring and summer. The consistent FLT Med Net dataset was found to be appropriate to evaluate important parameters for the assessment of trends in the conservation status of Tursiops truncatus at the Natura2000 site scale.

Rapporto Finale del Progetto di alta formazione: “Esperti di Idroacustica, Analisi Dati, ICT e Tutela della Biodiversità Marina” (BLU-DATA-BIO)

Questo rapporto di fine progetto presenta i dati relativi al corso di formazione riportato nel titolo e rivolto a giovani laureati in scienze MM.FF.NN., chimiche, biologiche, ma anche ambientali, ingegneristiche e socio-economiche. Il corso è stato concepito come una prima di tappa di chi volesse intraprendere una carriera di ricerca presso Enti di Ricerca, oppure una carriera imprenditoriale nel settore della RS&I applicata alle scienze marine ed in particolare al concetto di “Crescita Blu”. L’ambiente marino con le sue risorse ha costituito il minimo comun denominatore di un’articolata offerta formativa finalizzata a creare nuove professionalità ad alta specializzazione all’interno di 2 macro-ambiti che costituiscono il “core business” del soggetto attuatore e che rappresentato i 2 Profili (A e B) del Progetto: 1. L’acustica marina attiva e passiva, connessa all’analisi dati e alle soluzioni ICT; 2. La tutela della biodiversità marina, connessa alla diffusione della cultura scientifica (Science Communication), collegata all’Osservatorio Regionale delle Biodiversità Siciliana Marina e Terrestre (D.D.G. del Dipartimento Ambiente della Regione Siciliana n. 342 del 10 giugno 2011)

Acoustic Presence of Dolphins through Whistles Detection in Mediterranean Shallow Waters

The evaluation of acoustic temporal rhythms in wide-ranging cetaceans can reveal patterns in animal spatial presence and the occurrence of periodical phenomena. Here, we aimed at assessing the temporal patterns of dolphin’s acoustic presence in a shallow-water area in the Sicily Strait (Mediterranean Sea). Whistles were collected continuously for 14 months from an acoustic monitoring station installed aboard of an elastic seamark. Over a total of 6955 h of recording, 14,048 signals were identified using both automatic and visual methods. Three parameters were analyzed: hourly presence (HP), used as a proxy of the presence of dolphins in the area; detection rate (DR), indicating the acoustic activity rate of dolphins measured per hour in the entire dataset; and detection rate in presence of dolphins (DRD), indicating the acoustic activity rate of dolphins considering only the hours when whistles were recorded. The highest values of both HP and DR were reached during the night, and the Autumn and Winter months, suggesting an increase in the dolphin’s occurrence and a possible moving away and towards the monitoring station potentially following prey. DRD, instead, showed an almost uniform distribution throughout the day implying that when the animals are close to the monitoring station, the acoustic activity does not show any pattern. However, possible changes in the communication exchange along the seasons were suggested. This study complements other work on this subject, improving the knowledge of dolphins’ acoustic activity in the area

The final call: evidence for signature whistle of dying common dolphin in Argentina (South America)

Signature whistles are stereotyped and individually distinctive acoustic signals emitted by T.truncatus in isolated captive conditions. They are used as individual recognition signals, for maintaining group cohesion and during stressful situations (Janik and Sayigh, 2010). However, little information was reported for other species (reviewed in Janik and Sayigh, 2013). Here, we tested the hypothesis of the occurrence of signature whistles in an isolated short-beaked common dolphin (Delphinus delphis) kept in a rehab circular tank (13m diameter, 1.35m deep) at Mundo Marino Aquarium (San Clemente del Tuyú). The dolphin, an adult female, was found ashore in Villa Gesell, Argentina, on 19th January 2019. During its maintaining, a hydrophone (model Benthowave BII-7017) with a flat sensitivity response of -174.5 (± 2) dB re V/µPa from 0.1 to 100 kHz connected to digital analogical converter C5535 DSP (TMS320C5535), was deployed in the tank. Twenty-three hours of continuous recordings were collected, starting after 12 hours from the beginning of the dolphin´s rehab until their death for hepatitis. Data were visually screened and the number of whistles was noted. Six parameters (peak, maximum and minimum frequencies, duration, frequency contour and the number of harmonics) were measured from the recorded whistles by using Raven Pro (Cornell University). A total of 59 whistles were analyzed and only one type of frequency contour was detected (ascending-descending). They showed an averaged peak frequency of 9. 04 ±2.33kHz; an averaged maximum frequency value of 13.28 ±1.81 and a minimum of kHz; a 5.99 ±1.58; the average duration was 0.72 ±0.29 seconds and harmonic´s number ranging from 1 to 4. The CV values of all parameters were lower than 0.4. The low variability of whistles parameters and the only whistle contour found in an isolated and stressed dolphin support the hypothesis that they produce signature whistles. It is the first evidence of the use of this signal in D.delphis in Southwester Ocean. Dolphins produce many non-stereotyped whistles but detecting the presence of signature whistles can provide us new info on socio-behavioral aspects and on the use of vocalizations. Our work is the first step to understanding Latin American common dolphin sound production, which the majority of the ecological aspects are unknown.Fil: Giardino, Gisela Vanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Papale, Elena. Consiglio Nazionale delle Ricerche; ItaliaFil: Gregorietti, Martina. Consiglio Nazionale delle Ricerche; ItaliaFil: Ceraulo, Maria. Consiglio Nazionale delle Ricerche; ItaliaFil: Loureiro, Juán Pablo. Fundación Mundo Marino (fmm);Fil: Rodriguez Heredia, Sergio. Fundación Mundo Marino (fmm);Fil: Alvarez, Karina. Fundación Mundo Marino (fmm);Fil: Rodriguez, Diego Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Mazzola, Salvatore. Consiglio Nazionale delle Ricerche; ItaliaFil: Buscaino, Giuseppa. Consiglio Nazionale delle Ricerche; Italia5th International Conference on The Effects of Noise on Aquatic LifePaíses BajosAcoustical Society of Americ

The Social Role of Vocal Complexity in Striped Dolphins

Many gregarious species require complex patterns of communication for maintaining coordinated behaviors, articulated social structure and group cohesion. In mammal species, social complexity has been considered the driving force for the development of advanced acoustic communication systems. Striped dolphins are highly social, showing large group size with females maintaining strong bonds with kin. Here, we tested the hypothesis that more complex acoustic pattern plays a key role in social activity in the striped dolphins. The production rate of clicks, whistles and burst pulses, and the acoustic features of whistles have been related to the activity context (feeding, traveling, resting, and socializing). Furthermore, complex calls, consisting of a combination of frequency-modulated, and/or pulsed components were detected. Higher whistles and burst pulses production rates were recorded during socializing. Also, the social activity can be discriminated basing on the modulation of the whistle contour. Biphonic calls were especially recorded during social interaction events, suggesting that these phenomena can encode information about individual or group identity to conspecifics. Outcomes indicate the pivotal role of vocal complexity during social context and elicit further investigations of the communication system of small odontocetes from local to wider spatial scale

Effects of waterg gun on echinoderms: biochemical changes on sea urchin (Arbacia lixula) and sea cucumber (Holothuria tubulosa)

Sources Airguns and Waterguns are used in seismic exploration the marine seafloor for different purposes such as oil and gas search, or geological-geodynamic reconstruction. In this technique a bubble of compressed air is produced with a consequently production of loud sound wave penetrating the ocean floor. The impact of seismic Airguns was assessed in some cetaceans (Kyhn et al. 2019), fish species and invertebrate (Carroll et al. 2017), but we need to know more. In this study we evaluate the biochemical changes in sea urchin (Arbacia lixula) and sea cucumber (Holothuria tubulosa) exposed to a 20 minutes of watergun noise (1 pulse each 10 s) at a distance of 50 m. For each species 40 individuals were captured and caged in the sea in groups of 10. After four days of acclimation we started the experimental test that previewed these 4 samplings phases: T0-control group before the Watergun sound exposition; T1-post group soon after the end of sound exposition; T2-post group after 3 hour of exposition; T3- post group after 24 hour of exposition. Watergun pulse was characterized by measuring pressure (SM2U, Wildlife Acoustics) and particle speed (M20- 105, Geospectrum) in the three dimensions at the same position of the caged animals. Watergun pulses Power Spectral Density for pressure and particle speed showed respectively a peak of 122 dB re1μPa2/Hz at 850 Hz and a peak of 207 dB re(1nm/s)2 at 550 Hz for x component (direction parallel to the sea surface and forward the caged animals). The coelomatic fluid was extracted by each animal for the following successive analysis: total volume withdrawn, Total Hemocytes Counts (THC), total protein, phosphatase, esterase and peroxidase activity. In the sea urchin we observed significant differences in esterase (T0 < T2 and T3), and peroxidase (T0 < T2 and T3). Concerning sea cucumber we found significant differences for THC (T0 T2; T1 < T2). This is the first attempt to study the effects of a short loud low frequencies sound exposition in echinoderms species and results show that these animals reacted to the noise with an alteration of some coelomic fluid parameters indicators of stress