A proteomic analysis of the statocyst endolymph in common cuttlefish (Sepia officinalis): an assessment of acoustic trauma after exposure to sound

Here, the proteomic analysis of the endolymph was performed before and after sound exposure to assess the efects of exposure to low intensity, low frequency sounds on the statocyst endolymph of the Mediterranean common cuttlefsh (Sepia ofcinalis), determining changes in the protein composition of the statocyst endolymph immediately and 24h after sound exposure. Signifcant diferences in protein expression were observed, especially 24h after exposure. A total of 37 spots were signifcantly diferent in exposed specimens, 17 of which were mostly related to stress and cytoskeletal structure. Among the stress proteins eight spots corresponding to eight hemocyanin isoforms were under-expressed possible due to lower oxygen consumption. In addition, cytoskeletal proteins such as tubulin alpha chain and intermediate flament protein were also down-regulated after exposure. Thus, endolymph analysis in the context of acoustic stress allowed us to establish the efects at the proteome level and identify the proteins that are particularly sensitive to this type of trauma.Postprint (published version

Imaging techniques to study the effects of low frequency sounds on cephalopods spp.

The introduction of artificial sound sources in the marine environment has shown to have negative effects on marine organisms. While marine mammals have attracted most of the attention of the research conducted in that area, invertebrates are also suspected to be negatively affected after an exposure to loud low frequency noise. An ongoing study from the Laboratory of Applied Bioacoustics of the Technical University of Catalonia is studying through imaging techniques (routine histology and SEM) the possible lesions in the statocysts of three cephalopod species (Sepia officinalis, Loligo vulgaris and Octopus vulgaris) as the likely most sensitive organ to high intensity noise.Peer Reviewe

Evidence of Cnidarians sensitivity to sound after exposure to low frequency underwater sources

Jellyfishes represent a group of species that play an important role in oceans, particularly as a food source for different taxa and as a predator of fish larvae and planktonic prey. The massive introduction of artificial sound sources in the oceans has become a concern to science and society. While we are only beginning to understand that non-hearing specialists like cephalopods can be affected by anthropogenic noises and regulation is underway to measure European water noise levels, we still don’t know yet if the impact of sound may be extended to other lower level taxa of the food web. Here we exposed two species of Mediterranean Scyphozoan medusa, Cotylorhiza tuberculata and Rhizostoma pulmo to a sweep of low frequency sounds. Scanning electron microscopy (SEM) revealed injuries in the statocyst sensory epithelium of both species after exposure to sound, that are consistent with the manifestation of a massive acoustic trauma observed in other species. The presence of acoustic trauma in marine species that are not hearing specialists, like medusa, shows the magnitude of the problem of noise pollution and the complexity of the task to determine threshold values that would help building up regulation to prevent permanent damage of the ecosystems.Postprint (published version

Artificial sound impact could put at risk hermit crabs and their symbiont anemones

The sea anemone Calliactis parasitica, which is found in the East Atlantic (Portugal to Senegal) and the Mediterranean Sea, forms a symbiotic relationship with the red hermit crab, Dardanus calidus, in which the anemone provides protection from predators such as the octopus while it gains mobility, and possibly food scraps, from the hermit crab. Acoustic pollution is recognised by the scientific community as a growing threat to ocean inhabitants. Recent findings on marine invertebrates showed that exposure to artificial sound had direct behavioural, physiological and ultrastructural consequences. In this study we assess the impact of artificial sound (received level 157 ± 5 dB re 1 µPa2 with peak levels up to 175 dB re 1 µPa2) on the red hermit crab and its symbiotic sea anemone. Scanning electron microscopy analyses revealed lesions in the statocyst of the red hermit crab and in the tentacle sensory epithelia of its anemone when exposed to low-intensity, low-frequency sounds. These ultrastructural changes under situations of acoustic stress in symbiotic partners belonging to different phyla is a new issue that may limit their survival capacity, and a new challenge in assessing the effects of acoustic disturbance in the oceanic ecosystem. Despite the lesions found in the red hermit crab, its righting reflex time was not as strongly affected showing only an increase in the range of righting times. Given that low-frequency sound levels in the ocean are increasing and that reliable bioacoustic data on invertebrates is very scarce, in light of the results of the present study, we argue that anthropogenic sound effects on invertebrates species may have direct consequences in the entire ecosystem.Author J.-M. Fortuño acknowledges the institutional support of the “Severo Ochoa Centre of Excellence” accreditation (CEX 2019-000928-S).Peer ReviewedPostprint (published version

Offshore exposure experiments on cuttlefish indicate received sound pressure and particle motion levels associated with acoustic trauma

Recent findings on cephalopods in laboratory conditions showed that exposure to artificial noise had a direct consequence on the statocyst, sensory organs, which are responsible for their equilibrium and movements in the water column. The question remained about the contribution of the consequent near-field particle motion influence from the tank walls, to the triggering of the trauma. Offshore noise controlled exposure experiments (CEE) on common cuttlefish (Sepia officinalis), were conducted at three different depths and distances from the source and particle motion and sound pressure measurements were performed at each location. Scanning electron microscopy (SEM) revealed injuries in statocysts, which severity was quantified and found to be proportional to the distance to the transducer. These findings are the first evidence of cephalopods sensitivity to anthropogenic noise sources in their natural habitat. From the measured received power spectrum of the sweep, it was possible to determine that the animals were exposed at levels ranging from 139 to 142¿dB re 1¿µPa2 and from 139 to 141 dB re 1¿µPa2, at 1/3 octave bands centred at 315¿Hz and 400¿Hz, respectively. These results could therefore be considered a coherent threshold estimation of noise levels that can trigger acoustic trauma in cephalopods.Postprint (published version

A critical period of susceptibility to sound in the sensory cells of cephalopod hatchlings

The cephalopod statocyst and lateral line systems are sensory organs involved in orientation and balance. Lateral lines allow cephalopods to detect particle motion and are used for locating prey or predators in low light conditions. Here, we show the first analysis of damaged sensory epithelia in three species of cephalopod hatchlings (Sepia officinalis, Loligo vulgaris and Illex coindetii) after sound exposure. Our results indicate lesions in the statocyst sensory epithelia, similar to what was found in adult specimens. The novelty is that the severity of the lesions advanced more rapidly in hatchlings than in adult animals; i.e. the degree of lesions seen in hatchlings immediately after noise exposure would develop within 48 h in adults. This feature suggests a critical period of increased sensitivity to acoustic trauma in those species as has been described in developing mammalian cochlea and avian basilar papilla. The hair cells in the lateral lines of S. officinalis followed the same pattern of damage occurrence, while those of L. vulgaris and I. coindetii displayed a decreasing severity of damage after 24 h. These differences could be due to dissimilarities in size and life stages between the three species.Peer ReviewedPostprint (published version

Marine mammal acoustic detections in the Greenland and Barents Sea, 2013 – 2014 seasons

While the Greenland and Barents Seas are known habitats for several cetacean and pinniped species there is a lack of long-term monitoring data in this rapidly changing environment. Moreover, little is known of the ambient soundscapes, and increasing of-shore anthropogenic activities can infuence the ecosystem and marine life. Baseline acoustic data is needed to better assess current and future soundscape and ecosystem conditions. The analysis of a year of continuous data from three passive acoustic monitoring devices revealed species-dependent seasonal and spatial variation of a large variety of marine mammals in the Greenland and Barents Seas. Sampling rates were 39 and 78kHz in the respective locations, and all systems were operational at a duty cycle of 2min on, 30min of. The research presents a description of cetacean and pinniped acoustic detections along with a variety of unknown low-frequency tonal sounds, and ambient sound level measurements that fall within the scope of the European Marine Strategy Framework (MSFD). The presented data shows the importance of monitoring Arctic underwater biodiversity for assessing the ecological changes under the scope of climate changePeer ReviewedPostprint (published version

Modeling the underwater noise associated to the construction and operation of offshore wind turbines

The operation and in particular the construction of offshore wind converters induce considerable underwater noise emissions. It is assumed that small whales and seals can be affected by noise from machines and vessels, piling and installation of the wind turbines. Piling, in particular using hydraulic hammers creates impulsive noise with considerable high energy levels. Currently, only little knowledge about the effects of different noises to marine life is available. Here, we present the objectives of the ongoing project of the Laboratory of Applied Bioacoustics (Technical University of Catalonia): to simulate the generation, radiation and propagation of underwater noise; to develop forecasting hydro sound models of offshore wind converters and future noise reduction methods during pile driving; to determine the impact area of offshore wind farms; to allow the formulation of recommendations for acoustic emission thresholds; and to develop standard procedures for the determination and assessment of noise emissions.Peer Reviewe

Best practices in management, assessment and control of underwater noise pollution

The origin of this work can be found in the project ‘Effects and Control of Anthropogenic Noise in Marine Ecosystems’ in the part relative to legal initiatives. In the first phase of the Report on this Project (December 2008) it was concluded that the level of complexity of marine issues, united by the fact that wide scientific gaps and difficulties still need to be covered and resolved, counseled against the immediate drawing up of legal projects concerning underwater acoustic pollution. Nevertheless, it was suggested that a document of ‘Best Practices’ be elaborated to focus on the ‘state of the art’ of this issue, and that it be used by public administrations and promoters of projects that will cause acoustic pollution, as much within the framework of environmental impact assessments as in management development plans in protected marine areas. It is of vital importance that activities, which generate acoustic pollution in the oceans, be monitored. Accordingly, this document could derive, in the short term, a Protocol of Applications which will in its own time open the way for the preparation of, if necessary, legislative initiatives within their own right.Preprin

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation