Climate change is a relevant threat on a global scale, leading to impacts on ecosystems and ocean biodiversity. A considerable fraction of marine life depends on sound. Marine mammals, in particular, exploit sound in all aspects of their life, including feeding and mating. This work explores the impact of climate change in sound propagation by computing the three‐dimensional global field of underwater sound speed. The computation was performed based on present conditions (2006–2016) and a “business‐as‐usual” future climate scenario (Representative Concentration Pathway 8.5), identifying two “acoustic hotspots” where larger sound speed variations are expected. Our results indicate that the identified acoustic hotspots will present substantial climate‐change‐induced sound speed variations toward the end of the century, potentially affecting the vital activities of species in the areas. Evidence is provided of the impact of such variation on underwater sound transmission. As an example of a species impacted by underwater transmission, we considered one marine mammal endangered species, the North Atlantic right whale (Eubalaena glacialis), in the northwestern Atlantic Ocean. To the best of our knowledge, this is the first global‐scale data set of climate‐induced sound speed changes expected under a future scenario. This study provides a starting point for policies oriented research to promote the conservation of marine ecosystems and, in particular, endangered marine mammals.

Among anthropogenic activities, marine seismic surveys are a fundamental tool for oil and gas explorations, geophysical research, environmental hazard, and risk analysis. This resulting noise may affect a range of species, eliciting masking, behavioral responses, and changes in acoustic repertoires. There is an urgency to understand in depth the potential effects of seismic surveys on marine ecosystems since the information available is still scarce. Using Scopus® and Web of Science™ 2023 Clarivate bibliographic databases, we systematically reviewed the scientific literature addressing seismic surveys’ effects on free-ranging marine fauna. The first selection of articles matching selected keywords yielded 680 articles from Scopus and 320 from Web of Science. Screening for research articles written in English investigating marine fauna in its natural environment and performing a quality assessment process resulted in selecting 31 articles since 2001. We found a trend of increasing research efforts in this field with a decrease after 2020 and a broad spectrum of journals that hosted the publications (31 papers published in 12 journals). Although several taxa are investigated, most studies focused on effects on marine mammals. There is a lack of research on diverse animal taxa, and no research papers compare the effects on different taxa along the food chain. Behavioral and physiological effects are the most found by authors in the field. However, observed behavioral changes cannot always be uniquely attributed to the exposure to seismic surveys, as many authors report the influence of other variables (e.g., environmental conditions) during the observations.

Policy makers require a knowledge-based support to identify effective interventions for the socio-economic sustainability of human activities at sea. When dealing with anthropogenic impacts on marine ecosystems, we deal with a complex and faceted system which has high variability in terms of environment, regulation, governance, industrial activities, and geo-political scenarios. We analyzed the conceptual scientific framework adopted to address underwater noise as a polluting component of the marine environment. We identified the scientific paths that can provide useful contributions towards comprehending the impacts on the native ecosystem. In order to furnish relevant clues towards the properties of the interconnection of signals, we briefly reviewed an example from a different discipline (helioseismology). We describe a new approach on how acoustic energy in the sea could be detected and analyzed to understand its role in the functioning of the ecosystem. We propose a change of perspective in the observation strategy of underwater noise, promoting a knowledge transfer from other disciplines, which in turn will enable a better understanding of the system. This will allow researchers and policy-makers to identify feasible and effective solutions to tackle the negative impacts of underwater noise and the conservation of the marine ecosystem.

Whale watching is considered a form of green tourism, but can affect marine ecosystems, impacting cetaceans’ behavior and potentially increasing acoustic pollution. A more sustainable whale-watching practice should employ a comprehensive approach involving all stakeholders, but whale-watching operators are rarely involved. We propose a method to assess whale–watching operators’ perceptions regarding the possible effects of their activity on marine fauna and preferred mitigation solutions, by means of online questionnaires and website communication strategies. Results from Canadian whale-watching operators show that they observe regulations regarding distance to whales but only partially perceive general vessels’ impacts on fauna. Three recognized whale-watching experts identify the need for continuous training targeted at operators, which should include the impacts on marine ecosystems. A continuous training framework is proposed that targets whale-watching operators in addition to tourists, and involves scientists in several steps of the approach. This study serves as a starting point to involve operators’ in order to advance towards a sustainable whale-watching tourism.

Marine seismic surveys contribute to acoustic pollution, and the sounds they produce may be audible by marine mammals at several hundred kilometers distance. To evaluate the potential effects of such sounds on fauna and translate them into effective policies and mitigation measures, stakeholders require quantitative estimations of acoustic fields. We compare simulations of airgun-array signals produced during the Upper LIthosphere Ship Subduction Exploration survey in the Ionian Sea with the signals recorded 650 kilometers away at the cabled seabed observatory NEMO-SN1. JASCO's Applied Sciences' Airgun Array Source Model was used to predict the sound levels for two configurations of 18-element airguns, and the signal was then propagated in a realistic environment utilizing JASCO's Full-Waveform Range dependent Acoustic Model from the source to the position of the receiver station. There is a qualitative agreement between the simulated, denoised, and recorded signals of the airgun arrivals. However, the signal simulated at 650 kilometers from the source stretches and shows fewer high-frequency components compared to the received one. Our study quantitatively shows that the peaks produced by a large airgun array during a scientific cruise, at 160–180 Hz are not masked by ambient noise even in busy shipping locations at a distance of 650 km.