Advanced Research Techniques for Cetacean Conservation

Cetaceans are an important component of marine biodiversity, essential for the preservation of marine ecosystems and the overall health of the oceans. As top predators, they play a crucial role in maintaining the balance of food chains, influencing the structure of lower trophic levels in the food web. They are often designated as sentinels or indicators for the state of marine ecosystems, since changes in their presence and abundance can signal environmental problems such as pollution, climate change, or overexploitation of marine resources. Cetaceans are also iconic and charismatic flagship taxa useful for capturing public and media attention as well as generating public interest, which then translates into support for conservation efforts [1].

Beyond their ecological functions, cetaceans are increasingly recognized as key allies in addressing the climate and biodiversity crises. As ecosystem engineers, they contribute to the structure and productivity of marine habitats, enhancing species richness and maintaining the health of the environments they inhabit [2]. Large whales, in particular, play a central role in biogeochemical cycling through the “whale pump”—the vertical transport of nutrients that stimulates primary productivity [3]. Throughout their lives, they accumulate significant amounts of carbon, which is sequestered on the seafloor after their natural death, making them important contributors to natural carbon sinks [4]. Small cetaceans, deep-divers and baleen whales play different roles in nutrient biological cycling at both global and local scales, and diversity in the cetacean community may be important locally in shaping patterns of productivity and diversity in their ecosystems [5]. Cetacean protection has thus become a priority not only for the conservation of biodiversity, but also for the mitigation of climate change.

This growing ecological awareness has been increasingly reflected in the development of international environmental policies and agreements. Cetaceans are now explicitly included in major conservation frameworks, such as the Convention on the Conservation of Migratory Species of Wild Animals (CMS) and its regional agreement ACCOBAMS, which promote coordinated action for the protection of cetaceans in the Mediterranean and Black Seas. In addition, their role in maintaining ocean health is aligned with global sustainability goals, particularly Sustainable Development Goal 14 of the United Nations 2030 Agenda [6], which calls for the conservation and sustainable use of the oceans, seas, and marine resources.

As sentinels of marine ecosystem health, cetaceans are currently exposed to multiple anthropogenic threats and provide early warning signs of environmental degradation [7]. Changes in their populations or behaviors can reflect broader ecological disturbances, including those caused by climate change, ocean acidification, chemical contamination, and underwater noise. Monitoring cetacean populations thus represents a strategic tool to evaluate the effectiveness of marine conservation measures and to support adaptive policy responses. However, cetacean populations worldwide continue to face cumulative threats, reinforcing the urgent need for interdisciplinary, transboundary, and policy-integrated conservation strategies.

Effective cetacean conservation management primarily depends on accurate and timely data on their health, abundance and distribution obtained through monitoring techniques that use a variety of visual and acoustic research platforms. Moreover, non-invasive research methods such as satellite tagging and genetic analysis allow researchers to obtain more in-depth information on cetacean behavior and habitat use while minimizing the stressful effect of monitoring practices on the species studied. The integrated use of all these technologies strengthens the development of conservation strategies and improves the long-term survival prospects of cetaceans. In this evolving context, researchers have also begun to adopt very high-resolution satellite imagery, cloud computing, and artificial intelligence as complementary tools to traditional monitoring platforms. These technologies have enormous potential and enable large-scale, automated data collection in remote or inaccessible marine regions, further expanding our capacity to track and understand cetacean populations [8,9].

While each method presents specific strengths and limitations, it is increasingly evident that collaboration among scientists and the open sharing of data are crucial to maximize the effectiveness of these tools and to develop integrated, scalable approaches for cetacean conservation in the years to come.

The purpose of the invited Special Issue was to publish the most recent research focused on the application of innovative approaches for the conservation of cetaceans. This Special Issue includes seven papers that explore a wide array of methodologies—ranging from traditional techniques to cutting-edge technologies such as passive acoustic monitoring, satellite imagery, artificial intelligence, and ecological modeling. These contributions provide new insights into the spatial distribution, behavior, social structure, and threats affecting cetacean populations across different regions. Taken together, the articles highlight the importance of interdisciplinary research and technological advancement in improving the effectiveness and precision of cetacean conservation efforts.

The contributions in this Special Issue encompass a range of traditional and advanced methodologies applied to cetacean research, providing both technological innovation and ecological insight.

Sanguineti et al. present an overview of real-time passive acoustic monitoring systems in the Mediterranean Sea, highlighting two main platforms: surface buoys equipped with hydrophones and deep-sea observatories integrated into submarine neutrino telescopes. Their work illustrates the potential of continuous, non-invasive acoustic monitoring to study cetaceans across multiple depths and spatial scales.

Ranù et al. apply species distribution modeling (MaxEnt) to identify a biodiversity hotspot for bottlenose dolphins and seabirds in western Sicilian waters. Their integration of environmental and anthropogenic variables—such as fishing activity—demonstrates the value of predictive modeling for spatially explicit conservation planning-

Terranova et al. explore the acoustic behavior of a bottlenose dolphin pod during a fatal bycatch event in the Gulf of Catania. Their findings reveal intense vocal activity, suggesting that bioacoustic signals could serve as real-time indicators of entanglement and support the development of early-warning detection systems.

Gnone et al. conduct a large-scale meta-analysis involving 15 research groups across the Mediterranean to examine how physiographic features of the continental shelf influence dolphin group structure and home range size. Their study underscores the relevance of shared data and regional collaboration in identifying habitat-based population differences.

Schall and Parcerisas introduce robust algorithms for the automatic detection of fin whale choruses and pulses from extensive passive acoustic datasets. Their approach addresses challenges of data volume and signal variability, offering scalable solutions for monitoring elusive species like fin whales.

Cipriano et al. investigate the residency patterns and social structure of bottlenose dolphins in the Gulf of Taranto using photo-identification and social network analysis. The identification of both stable and fluid associations, as well as socially segregated units, calls for management plans tailored to subpopulation dynamics.

Finally, Khan et al. showcase the GAIA (Geospatial Artificial Intelligence for Animals) initiative, leveraging very high-resolution satellite imagery, cloud computing, and artificial intelligence to detect marine mammals from space. Their work represents a major advancement in remote monitoring, particularly in challenging or data-poor environments.

Together, these studies reflect the evolving landscape of cetacean research, in which traditional ecological methods are increasingly complemented by remote sensing, automation, and machine learning. This integration enhances our ability to monitor cetaceans more effectively and to inform evidence-based conservation strategies across spatial and technological scales.