1,721,014 research outputs found
Modelli e misure di backscattering acustico di organismi marini pelagici ed applicazioni
No full textNegli ultimi decenni sono stati compiuti grandi passi avanti, sia dal punto
di vista sperimentale che teorico, nel campo dell'oceanografia e
dell'ecologia marina. Nonostante i progressi, molto rimane ancora da fare
per comprendere, ad esempio, come funziona l'ecosistema pelagico come
produttore di biomassa. Recenti progetti internazionali, hanno dimostrato
come oggi ci sia la necessità di un approccio interdisciplinare allo studio
delle Scienze Ambientali in generale e delle Scienze marine in
particolare e su come l'acustica marina sia destinata a svolgere un ruolo
importante per la parte sperimentale.
L'obbiettivo del progetto di Ricerca è stato lo studio del backscattering
acustico di organismi e tessuti, quali i Teleostei Clupeidi e il Sonar dei
Delfini, tramite l'utilizzo di modelli matematici e misure dirette e la
successiva applicazione.
Lo studio sul Sonar dei Delfini ha permesso di migliorare la
comprensione dei meccanismi di funzionamento e di selezionare una
serie di segnali acustici impiegati per la progettazione e la realizzazione
di un dispositivo elettroacustico in grado di allontanare, e quindi
salvaguardare, questi animali da zone di mare pericolose (aree di pesca,
zone militari, ecc).
Per quanto riguarda i Clupeidi, lo studio è stato fecalizzato sui seguenti
piccoli pelagici: larve di aringa (Clupea harengus) e giovanili e adulti di
sardina (Engraulis encrasicolus). Questa ricerca ha permesso di
individuarne il Target Strength di queste specie, cioè la stima dell'eco
prodotta dagli esemplari insonificati, che rappresenta uno strumento
fondamentale per la stima di biomassa con metodi acustici.
In questo lavoro di Ricerca è stato definito un approccio innovativo,
basato sull'applicazione di modelli matematici e di esperimenti in vasca
da usare come test di verifica. Questo approccio ha richiesto che
specialisti in discipline appartenenti alle Scienze Ambientali
(Bioacustica, Etologia, Ecologia marina, Fisiologia animale, Biologia,
ecc.) lavorassero insieme in modo tale da fornire contemporaneamente e
in maniera complementare la loro descrizione, analisi e sintesi dello
stesso problema per poi fonderle progettando ed eseguendo insieme
ricerche teoriche e sperimentali.
A great deal has been done in the fields of Oceanography and Marine
Ecology in the last decades, from both the experimental and the
theoretical standpoints. Much effort is still needed, however, to
understand, for example, how the pelagic ecosystem works as a biomass
producer. As new international projects have demonstrated, there is a
need today for an interdisciplinary approach to Environmental Sciences
in general, and to Marine Science studies in particular, and Marine
Acoustics is destined to have an important role in the experimental field.
The aim of this research project was to perform acoustic back-scattering
studies on pelagic organisms, e.g. Clupeid fish and Dolphin, through the
application of mathematical models and direct measurements.
Dolphin sonar studies have given us a better understanding of functional
mechanisms and enabled us to select a range of acoustic signals to use to
design and develop a pinger capable of keeping dolphins away from
dangerous areas (fishing areas, military zones, etc.).
The Clupeid studies focused on the target strength (TS) of herring larvae
(Clupea harengus) and juvenile and adult sardines (Engraulis
encrasicolus). TS evaluation enables biomass estimation based on an
acoustic method.
A new approach was defined in this research work, based on the
application of mathematical models validated by in situ measurements.
This approach involved experts in different fields of Environmental
Science (bio-acoustics, ethology, marine ecology, animal physiology,
biology, etc.), who worked together to produce a simultaneous,
complementary description, analysis and synthesis of the same problem,
subsequently combining all the information to design and perform joint
theoretical and experimental research
The Importance of Empirical Particle Motion Measurements for Monitoring Underwater Noise from Wave Energy Converters
No full textThe energy transition to achieve NetZero objectives by 2050 2050 needs a sharp increase of Marine Renewable Energies (MREs). This growth must ensure environmental sustainability while aligning with biodiversity conservation goals, as outlined in the EU Biodiversity Strategy. However, significant knowledge gaps persist regarding the impacts of MREs on marine ecosystems, leading to uncertainties in assessing cumulative effects on marine organisms. Comprehensive monitoring and data collection are crucial to enable the sustainable development of MREs. Underwater noise is a recognized stressor associated with MRE devices, including Wave Energy Converters (WECs). It is also classified as an environmental quality indicator under Descriptor 11 of the Marine Strategy Framework Directive (EU), mandating its monitoring during anthropogenic activities as a potential pollutant for marine ecosystems. Standards for MRE devices noise assessment are now available (IEC TS 62600-40). Traditionally, underwater noise monitoring has focused on scalar pressure measurements. However, particle motion, a vectorial measure representing the acceleration or velocity of water particles caused by sound waves, is equally significant, especially in shallow water environments where WECs and their mooring systems may influence soundscapes more through vibration than pressure. Many marine organisms perceive sounds predominantly as particle motion rather than pressure due to their physiological characteristics (i.e. fish and invertebrates). This highlights the need to broaden current noise monitoring frameworks, which primarily focus on pressure, to incorporate particle motion measurements.
This paper emphasizes the importance of particle motion as a critical component of underwater noise monitoring for WEC applications. We present initial findings from empirical measurements of both particle motion and pressure conducted at a pilot site in the Mediterranean Sea using an underwater acoustic vector sensor (M20-105 system, GTI Geospectrum Technologies Inc.). Acoustic data were collected near the ISWEC (Inertial Sea Wave Energy Converter) off the coast of Pantelleria, Italy, offering novel insights into the underwater noise characteristics generated by WECs and the role of particle motion in their assessment
Motility and acoustic signals of the decapod Cherax destructor
No full textThe present study examined for the first time the sound production and motility of the freshwater decapod crustacean Cherax destructor. An acoustic and video system was used to monitor the behavior of 10 individual (5 males and 5 females) in an experimental tank. Video data were used to analyze three motility variables (velocity, distance moved, and angular velocity). Acoustic data were analyzed to obtain abundance and these acoustic parameters: duration, 1st and 2nd peak frequency, sound pressure level (SPL) and the bandwidth. Both males and females produced short-duration pulses that could be grouped into three categories, high, medium, and low frequency. Males showed a higher rate of emission of mid-frequency sounds than females. The sounds emitted by females had significantly higher 1st and 2nd peak frequencies (Mean± DS: F1= 23±32 kHz; F2= 17±20 kHz) than males (F1= 10±15 kHz Mean± DS; F2= 11±16 kHz), sound duration was also higher in females (10±7 ms) than in males (8±4 ms), otherwise, SPL was higher in males (133±5 dB re 1μParms) than in females (132±7 dBre 1 μParms). Concerning the motility, there is no particular differences in velocity and distance moved, on the contrary, angular velocity was greater in males (21±39 deg/s) than in females (18±41 deg/s). This study is part of a wider one on the behaviour associated with the production of sounds by these animals observed both individually and in groups and on the behavioural and biochemical responses to potential sources of anthropogenic noise disturbance
Acoustic Detection of Franciscana Dolphins Near Artisanal Fishing Nets in Argentina
No full textThere is interest in the ability to detect the acoustic presence of franciscana dolphins in an area with active bycatch. To meet that objective, two-dolphin click detectors (F-PODs) were placed in two artisanal fishing gillnets in Claromecó (Buenos Aires Province, Argentina). Narrow band high frequency (NBHF) clicks were found near both gillnets, compatible with the description of the franciscana sound production. These preliminary results confirm that passive acoustic is a good tool to assess franciscana presences. Moreover, understanding the echolocation behavior around gillnets can lead to the design of better mitigation tools in order to reduce the bycatch.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: Cosentino, Melania. University Aarhus; DinamarcaFil: Buscaino, Giuseppa. Institute of Anthropic Impact and Sustainability in marine Environment; ItaliaFil: Bastida, Ricardo Oscar. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: 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; Argentin
Sound effect on the maternal care behavior of a crab
No full textMaternal care in marine decapods encompasses eggs caring until larvae hatching, ensuring healthy embryonic development. The effect of different sound sources (anthropogenic and biologic) and temporal patterns (low- and high- rate) was studied on the maternal care of the key crab species, Neohelice granulata, through laboratory experiments. Three acoustic stimuli were emitted, two anthropogenic: an artificial white noise and motorboat passes obtained from the crabs´ natural habitat; and one biologic: signals from a crabs’ predator (fish). Behavioral variables quantified included: duration of still position and maternal care behaviors. Preliminary findings showed that the high-rate anthropogenic stimuli increased the still position and diminished maternal care behaviors. The predatory stimulus did not affect the still position; although the high- rate temporal emission pattern reduced the maternal care behaviors. The fact that all stimuli affected the maternal care behaviors indicate a negative effect that potentially could affect offspring survival. This is important to consider given the ecosystem engineering function (e.g., burrowing) of the studied key crab species.Fil: Sal Moyano, María Paz. 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: Ceraulo, Maria. Consiglio Nazionale delle Ricerche; ItaliaFil: Luppi, Tomas Atilio. 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: Gavio, Maria Andrea. 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: Buscaino, Giuseppa. Consiglio Nazionale delle Ricerche; Itali
Impact of aquatic acoustic noise on oxidative status and some immune parameters in gilthead sea bream Sparus aurata (Linnaeus, 1758) juveniles
No full textThis study evaluated the ambient noise effect of onshore and offshore aquaculture systems on oxidative status and on some immune parameters in gilthead sea bream (Sparus aurata) juveniles. The experiment was performed for 40 days, projecting two different playlists of acoustic stimuli: offshore aquaculture noise condition that created the typical acoustic field in proximity of an offshore sea cage for fish farming, using a random sequence of quite sea background and boat noises; and onshore aquaculture noise condition that represented the acoustic field inside an open concrete tank for fish farming. A third group without any acoustic projection was used as a control. After 40 days from the beginning of acoustic noise, fish exposed to the offshore aquaculture condition showed significantly higher levels of total oxidant status, lysozyme activity, antiprotease activity and white blood cells together with a lower albumin/globulin ratio in comparison to fish from the control group; whereas fish exposed to the onshore condition showed analytical data placed between the other groups, though never significantly different. These results demonstrate that the offshore aquaculture noise, and in particular the sea soundscape, adversely influences the oxidative status and the immune function of gilthead sea bream determining a mild stress condition that could affect the sea bream welfare
Noise accelerates embryonic development in a key crab species: Morphological and physiological carryover effects on early life stages
No full textAnthropogenic noise is considered one important global pollutant. The impact of noise on marine invertebrates has been less assessed. The present study evaluated the chronic effect of the motorboat noise obtained from a lagoon´s soundscape, the natural habitat of the key crab Neohelice granulata, on its whole embryonic development, considering morphological and physiological carryover effects on embryos and hatched larvae. Results demonstrated that embryonic development was shortened under noise exposure. The effects on advanced embryos, larvae and adult females were: increased heartbeats and non-viable eggs, and decreased fecundity. Biochemical responses showed lipid peroxidation in embryos while antioxidant enzymes were activated in larvae and adults, indicating a counteracting effect related to the life stage. The negative effects on fitness offspring may imply ecological consequences at the population level. Results are discussed in terms of the ecosystem engineer species studied and the habitat, a MAB UNESCO Reserve lagoon, suggesting the urgent need to develop mitigation plans.Fil: Sal Moyano, María Paz. 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: Mitton, Francesca María. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Luppi, Tomas Atilio. 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: Snitman, Solana Morena. 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: Nuñez, Jesus Dario. 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: Lorusso, Martin Ignacio. 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: Ceraulo, Maria. Consiglio Nazionale delle Ricerche; ItaliaFil: Gavio, Maria Andrea. 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: Buscaino, Giuseppa. Consiglio Nazionale delle Ricerche; Itali
The soundscape of Mediterranean shallow water
No full textIn the marine environment, acoustic signals are source of information, crucial for inter and intra specific communication, i.e. during territorial and reproductive activities, orientation and habitat recognition. Soundscape analysis highlights the coexistence and the interconnection of all acoustic components, revealing different ecosystem processes.
The Mediterranean Sea comprises a plurality of ecosystems and shows a high degree of biological diversity. However, poor studies have been carried out to investigate if this ecological richness is reflected in the acoustic environment.
Objective of this work is to investigate the soundscape of Mediterranean coastal habitats in protected and impacted areas, with the aim of improving knowledge for the conservation of shallow waters habitats. Biological signals were described, together with their temporal and spatial patterns, and the impact of anthropogenic noise was estimated. Furthermore, the efficiency of the Acoustic Complexity Index (ACI), developed to study the acoustic complexity of terrestrial environment, was tested for Mediterranean coastal habitats.
In order to obtain a baseline of the Mediterranean coastal soundscape, the marine protected area of Lampedusa Island was monitored one year long. The soundscape is dominated over 2 kHz by snapping shrimps activity along all the year, following daily and seasonal patterns. The fish choruses characterize the frequencies below 2 kHz during the summer season. Results show that the presence of a protected zone does not preserve the acoustic space of species, since the boat noise masks during 46% of time sampled the frequency band used by soniferous fish. Moreover, the acoustic complexity index (ACI), applied in this Mediterranean shallow waters, was recognized as a good indicator for biological emissions, even if a major adjustment was needed to be applied to the marine environment.
In order to overcome this issue, I tested how ACI efficiency varies by adjusting its temporal resolution, applied during ACI computation, in relation to the different biological signals considered. Compared to terrestrial habitats, the soundscape of marine environment is characterized by manifold biophonical component in terms of type of signals (impulsive, tonal) and of frequency extent (from few Hz to hundreds kHz), that could influence index response. I found that higher temporal resolution was required for pulsed signals than for tonal sounds, while ACI efficiency for boat noise and geophonies did not change when a different temporal resolution was selected.
After to have demonstrated the functioning of the acoustic metrics in marine coastal environment, I applied them to study a high impacted area made up of the typical Posidonia oceanica meadow and sandy patches. Results showed that these two different habitats are characterized at the high and medium frequencies by distinct soundscapes and, the meadows have a more complex soundscape. New biological signals have been described for the first time and potentially attributed to both endemic and alien fish species.
Finally, a new approach to analyze the impact of noise in a shallow water environment has been carried out. The propagation of particle velocity generated by pile driving in an enclosed and simulated shallow sandy habitat resulted complexly related to the sound pressure transmission.
This thesis represents a base study for the future Mediterranean soundscape analysis, describing and characterizing different acoustic environments and their components. This first contribution paves the way for new questions and studies through different approaches. For example, the connection between the health status of the habitat and its soundscape complexity is poorly analyzed, and nowadays totally unknown in the Mediterranean marine system. The full comprehension of this relationship, mostly in key habitats, such as Posidonia oceanica meadows, could make the soundscape approach one of the most powerful tool to monitor of habitat changes under a growing human impact
(Brachyura, Varunidae)
Full text linkVery few studies of sound production in the Brachyura have simultaneously identified the type of individuals (e.g. sex) producing acoustic signals, the structures involved in making sound and the social context. The emission and type of sound signals in Neohelice granulata were previously characterized, but the sex and the body structures involved in the sound production mechanism were not determined. In the present study, experiments conducted in the laboratory demonstrated that acoustic signals were produced by males through an up-down movement of the cheliped by rubbing the merus against the pterygostomial area of the carapace. The micromorphology of the merus showed that it has a ridge of tubercles which may act as a plectrum, while the pterygostomial area bears tubercles and might function as the pars stridens. Acoustic signals were displayed more frequently in the presence of receptive females. Agonistic encounters among males also occurred more often in the presence of receptive females. We propose that Neohelice granulata males use their chelipeds to produce sound signals in a mating context, probably to attract the receptive female and/or to repel other males when a receptive female is present. Thus, the display might have a reproductive function influencing mate choice.Fil: Sal Moyano, María Paz. 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: Ceraulo, Maria. Consiglio Nazionale delle Ricerche; ItaliaFil: Mazzola, Salvatore. Consiglio Nazionale delle Ricerche; ItaliaFil: Buscaino, Giuseppa. Consiglio Nazionale delle Ricerche; ItaliaFil: Gavio, Maria Andrea. 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; Argentin
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