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This 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. [ABSTRACT FROM AUTHOR]

This study examined the effects of recorded boat noises on the behaviour and biochemistry of the common prawn ( Palaemon serratus ) in laboratory settings. The experiment was carried out in a tank equipped with a video-recording system using six groups (three control and three tested) of eight common prawns (48 animals in total). After habituation for 1 h, the behaviour of the prawns was monitored for 1 h. During the last 30 min, the animals in the test groups were exposed to noise resembling a marine area with high anthropogenic acoustic pollution. The exposure to noise produced significant changes in locomotor patterns, presence inside or outside a shelter, total protein concentrations in the haemolymph and brain, DNA integrity, and the expression protein levels of HSP 27 and 70 in brain tissues, revealing a stressful effect of noise on this crustacean species. This study clearly reveals that invertebrates are likely to be susceptible to acoustic stimuli from boat's noise and that they are potential valuable targets for further and detailed investigations into the effects of the anthropogenic noise pollution. [ABSTRACT FROM AUTHOR]

Marine crustaceans are influenced by numerous environmental factors. Environmental stress from pollutants seems to affect their metabolism, growth, moulting, survival, and immune defence. Recently, it has become clear that there is an impact of the global increase in sea noise levels due to shipping traffic on crustacean welfare. Considering the ecological and commercial importance of the European spiny lobster ( Palinurus elephas (Fabricius, 1787)) in most parts of the Mediterranean coastal area, in the present study we investigated whether shipping noise pollution contribute to changing the immune parameters of stress in the European spiny lobster. The animals were exposed to a mix of noises produced by different typologies of the boat played back in a tank, and the values of cellular and humeral parameters were evaluated. Total haemocyte count (THC), haemolymphatic protein concentration, phenoloxidase (PO) activity in cell-free haemolymph, and heat shock protein 27 (Hsp27) expression in haemocyte lysate were considered potential biomarkers of stress. THC and PO activity decreased significantly, whereas total protein and Hsp27 expression increased significantly. Overall, the results demonstrate that the stressful conditions investigated in this study affect both cellular and biochemical parameters in the European spiny lobster. [ABSTRACT FROM AUTHOR]

Abstract: The present study evaluated the impact of sea background noise (the acoustic environment of the offshore aquaculture system) and onshore aquaculture system's ambient noise on the welfare of gilthead sea bream juveniles (Sparus aurata) through primary, secondary (biochemical and haematological indexes) and tertiary (growth performances) stress responses. The experiment lasted 120days during which two different playlists of acoustic stimuli were projected inside six experimental tanks (each condition was replicated in three tanks). Offshore aquaculture noise conditions were recreated as the typical acoustic field in proximity of an offshore sea cage for fish farming using a random sequence of quiet sea background and boat noises. The acoustic field inside an onshore open concrete tank for fish farming represented the onshore aquaculture noise conditions. The other three tanks were used as a control condition without acoustic projection. The weights and lengths of fish exposed to offshore aquaculture noise were higher than the specimens in the control and onshore aquaculture groups. Moreover, higher levels of serum cortisol, glucose, red blood cell count, haematocrit value and haemoglobin content and lower levels of white blood cells were recorded in fish groups from the control and onshore treatments. These results allow us to hypothesise that offshore aquaculture noise and the sea soundscape in particular positively influence growth performance and could reduce stress and improve the welfare of the sea bream. [Copyright &y& Elsevier]

This study examined the effects of an acoustic stimulus on the haemolymph and agonistic behaviour of the red swamp crayfish, Procambarus clarkii. The experiment was conducted in a tank equipped with a video recording system using six groups (three control and three test groups) of five adult crayfish (30 specimens in total). After 1 h of habituation, the behaviour of the crayfish was monitored for 2h. During the second hour, the animals in the test groups were exposed to a linear sweep (frequency range 0.1-25kHz; peak amplitude l48dBrmsre. 1 μPa at 12kHz) acoustic stimulus for 30mm. Exposure to the noise produced significant variations in haemato-immunological parameters as well as a reduction in agonistic behaviour. Key words: acoustic stress. aaonistic behaviour. ohvsioloaical resoonse. red swamo crayfish [ABSTRACT FROM AUTHOR]

This study describes the underwater acoustic behavior of the red swamp crayfish Procambarus clarkii. The study was conducted both in a tank and in the natural environment. The tank was equipped with video and acoustic recording systems. Observations were conducted to identify the underwater acoustic signals produced and their association with behavioral events and the movement status of the animals. In a lake in a natural reserve, a remote acoustic recording station was used to study the circadian underwater acoustic activity of the crayfish and to assess the acoustic features of the signals. The red swamp crayfish produces irregular trains of wide-band pulses (duration 0.4 ms, SPLPK 128 dB re 1 μPa, peak frequency 28 kHz, bandwidthRMS 20 kHz). The production of signals is positively related to intraspecific interactions (encounter/approach, fighting and successive Tail Flips). In the natural environment, acoustic activity is almost absent during the day, increases abruptly at sunset and continues until dawn. This study reveals the previously unknown underwater acoustic signals of Procambarus clarkii and the potential of passive acoustic methods to monitor the presence, the abundance and the behavioral activities of this invasive species. [ABSTRACT FROM AUTHOR]

The haematological parameters (RBC, Hb, PCV, WBC, TC, MCV, MCH, and MCHC) in farmed gilthead sea bream (Sparus aurata) were measured using an automatic method. We then compared the outcomes using the traditional manual method. After blood collection (T0), all samples were immediately analyzed using both the manual and automatic methods. The samples were successively divided into five different aliquots and stored at +4°C to evaluate the effect of the storage time on haematological parameters, measured with the automatic method, at 6, 24, 48, 72, and 96 h after collection. Paired t-tests were applied between the values obtained at T0 with the manual and automatic methods and no statistical difference was observed. One-way repeated measures analysis of variance (ANOVA) showed that parameters measured with the automatic system were significantly affected by the storage time (p < 0.0001). These results provide an innovative automatic method for the determination of haematological parameters in sea bream and suggest that the haematological profile can be accurately assessed within 6 h from blood collection. [ABSTRACT FROM PUBLISHER]

Abstract: The physiological responses of fish to underwater noise are poorly understood and further information is needed to evaluate any possible negative effects of sound exposure. We exposed European sea bass and gilthead sea bream to a 0.1–1kHz linear sweep (150dBrms re 1μPa). This band frequency is perceptible by many species of fish and is mainly produced by vessel traffic. We assessed the noise-induced motility reaction (analysing the movements) and the haematological responses (measuring blood glucose and lactate, and haematocrit levels). The noise exposure produced a significant increase in motility as well as an increase in lactate and haematocrit levels in sea bream and sea bass. A significant decrease of glucose was only observed in sea bream. A linear correlation between blood parameters and motility in fish exposed to the noise was observed. The acoustic stimulus produced intense muscle activity. [Copyright &y& Elsevier]

Biphonic signals are nonlinear phenomena (NLPs) occurring in the repertoire of several animal groups and widespread across mammalian species. Although the mechanism of production is unclear, an adaptive meaning was suggested by their communication function, such as group or individual recognition. We document the rare recording event of a biphonic whistle emitted within a free-ranging population of bottlenose dolphins in the waters of south-western Sicily, Italy. The whistle was recorded in 2 different years, always when a photo-identified individual was present. A quantitative description of the signal is provided. The signal presents some unique characteristics in its frequency modulation pattern which is stable for a long period. Furthermore, the synchronized beginning of the two fundamental frequencies, the signal repetition within few seconds and its emission in freely interacting contexts suggest that biphonation is neither temporary nor involuntary. Also, we propose that biphonation can be produced via multiple mechanisms in bottlenose dolphins and that NLPs could represent natural recognizing marks that play a role in communication between bottlenose dolphins. [ABSTRACT FROM AUTHOR]

Rough-toothed dolphin's abundance and distribution is largely unknown worldwide and evaluation of its conservation status in the Mediterranean Sea is necessary. A rough-toothed dolphin was sighted offshore Eastern Sicily (Mediterranean Sea) in July 2017 and acoustic data were acquired in the same area of Watkins, Tyack, Moore, and Notarbartolo di Sciara [(1987). Mar. Mamm. Sci. 3, 78–82]. An automatic detection algorithm was developed to identify the echolocation clicks recorded within both datasets and a recurrent inter-click interval value was identified during the new encounter. Distinctive whistle classes were also identified with similar contour shapes within both datasets. [ABSTRACT FROM AUTHOR]

We present a seabed map around Lampedusa, the largest island of the Pelagie Islands Marine Protected Area (Italy, western Mediterranean). The seafloor was mapped using bathymetry and backscatter multibeam systems along with an underwater camera for direct observations and ground truthing, from the coastal area to about 50 m depth. The map was produced to monitor the present-day distribution of thePosidonia oceanicameadows around the Island.P. oceanicais the most important endemic seagrass species of the Mediterranean Sea and it can form meadows or beds extending from the surface to 40–45 m depth. These meadows provide habitat for a large marine community, thus increasing biodiversity of the coastal zone, stabilizing sediments and reducing coastline erosion. The seagrass meadows are susceptible to regression in response to specific impacts, thus their presence and abundance is an indicator of the overall environmental quality of the coastal zone. Recently, within the Marine Strategy Framework Directive (2008/56/EC),P. oceanicahas been selected as an indicator of the Good Environmental Status for marine areas. Consequently, the Pelagie Islands Marine Protected Area launched a project to assess the conservation status and map the distribution ofP. oceanicameadows. The resulting 1:15,000 scale map includes information about the Mediterranean seagrass and the distribution of five acoustic facies reflecting hard lithologies and soft substrates. The Lampedusa seabed map provides new information, which contributes to the development of a detailed benthic habitat map and a more comprehensive maritime spatial planning of this Marine Protected Area. [ABSTRACT FROM AUTHOR]

This study examined the effects of lab-generated acoustic signals on the behaviour and biochemistry of Mediterranean mussels ( Mytilus galloprovincialis ). The experiment was carried out in a tank equipped with a video-recording system using six groups of five mussels exposed to five acoustic treatments (each treatment was replicated three times) for 30 min. The acoustic signals, with a maximum sound pressure level of 150 dB rms re 1 μPa, differed in frequency range as follows: low (0.1–5 kHz), mid-low (5–10 kHz), mid (10–20 kHz), mid-high (20–40 kHz) and high (40–60 kHz). The exposure to sweeps did not produce any significant changes in the mussels' behaviour. Conversely, the specimens exposed to the low frequency band treatment showed significantly higher values of the following biochemical stress parameters measured in their plasma and tissues: glucose, total proteins, total haemocyte number (THC), heat shock protein 70 (Hsp70) expression, and Acetylcholinesterase (AChE) activity. The responses observed in the mussels exposed to low frequency sweeps enable us to suppose a biological and ecological role for this sound, which contains the main frequencies produced by both shipping traffic and the acoustic emissions of fish. [ABSTRACT FROM AUTHOR]

Simple Summary: There is some evidence that the presence of dolphins in fishing areas represents a concrete economic loss for fishermen due to their depredation activities on the entangled fish on the nets. Bycatch events are one of the major sources of anthropogenic mortality of species of conservation interest in the world. T. truncatus is a plastic species and the more frequently observed species in the Adriatic Sea owing to the natural tendency to interact with the fishing activities in the area. This case report describes the acoustic parameters detected in whistle spectral contours associated with low-frequency signals recorded with a passive acoustic monitoring device in an exceptional event of bycatch that involved three individuals during a midwater commercial trawling in the Adriatic Sea. Marine mammal vocal elements have been investigated for decades to assess whether they correlate with stress levels or stress indicators. Due to their acoustic plasticity, the interpretation of dolphins' acoustic signals of has been studied most extensively. This work describes the acoustic parameters detected in whistle spectral contours, collected using passive acoustic monitoring (PAM), in a bycatch event that involved three Bottlenose dolphins during midwater commercial trawling. The results indicate a total number of 23 upsweep whistles recorded during the bycatch event, that were analyzed based on the acoustic parameters as follows: (Median; 25th percentile; 75th percentile) Dr (second), total duration (1.09; 0.88; 1.24); fmin (HZ), minimum frequency (5836.4; 5635.3; 5967.1); fmax (HZ), maximum frequency, (11,610 ± 11,293; 11,810); fc (HZ), central frequency; (8665.2; 8492.9; 8982.8); BW (HZ), bandwidth (5836.4; 5635.3; 5967.1); Step, number of step (5; 4; 6). Furthermore, our data show that vocal production during the capture event was characterized by an undescribed to date combination of two signals, an ascending whistle (upsweep), and a pulsed signal that we called "low-frequency signal" in the frequency band between 4.5 and 7 kHz. This capture event reveals a novel aspect of T. truncatus acoustic communication, it confirms their acoustic plasticity, and suggests that states of discomfort are conveyed through their acoustic repertoire. [ABSTRACT FROM AUTHOR]

Simple Summary: To date there is not much information regard the role that sounds may play in the life of elasmobranchs. This gains particular importance if we consider the current understanding about noise pollution at sea. In fact, in the past few years, the effects of anthropogenic noise on marine fauna have received increasing attentions considering the plethora of repercussions deriving from the expansion of this type of pollution. Here, we exposed small-spotted catshark specimens kept in an aquarium, to different acoustic conditions to analyse the possible changes in swimming behaviour. Four different acoustic conditions consisted of biological sounds and anthropogenic noises. Moreover, the amplitude levels were differentiated among them, to analyse the effects caused by different signal-to-noise ratios. The results highlighted both a tendency of the animals to increase the overall time spent swimming and to avoid the noisiest section of the aquarium when subjected to higher amplitude levels of noise. Despite the growing interest in human-made noise effects on marine wildlife, few studies have investigated the potential role of underwater noise on elasmobranch species. In this study, twelve specimens of small-spotted catshark (Scyliorhinus canicula) were exposed to biological and anthropogenic sounds in order to assess their behavioural changes in response to prey acoustic stimuli and to different amplitude levels of shipping noise. The sharks, individually held in aquariums, were exposed to four experimental acoustic conditions characterized by different spectral (Hz) components and amplitude (dB re 1 µPa) levels. The swimming behaviour and spatial distribution of sharks were observed. The results highlighted significant differences in swimming time and in the spatial use of the aquarium among the experimental conditions. When the amplitude levels of biological sources were higher than those of anthropogenic sources, the sharks' swimming behaviour was concentrated in the bottom sections of the aquarium; when the amplitude levels of anthropogenic sources were higher than biological ones, the specimens increased the time spent swimming. Moreover, their spatial distribution highlighted a tendency to occupy the least noisy sections of the aquarium. In conclusion, this study highlighted that anthropogenic noise is able to affect behaviour of catshark specimens and the impact depends on acoustic amplitude levels. [ABSTRACT FROM AUTHOR]