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Simple Summary: Our research focuses on the franciscana dolphin, the most threatened dolphin in the southwestern Atlantic, mainly due to its frequent entanglement in artisanal gillnets. This has led to their classification as vulnerable. To better understand their sounds and communication, we recorded and analysed the sounds of both wild dolphins and those in a rehabilitation centre. We found that neonate dolphins emit sounds that differ from those of juveniles. Interestingly, the sounds made by juvenile dolphins are similar to those of wild dolphins. We also discovered patterns in the way dolphins produce clicks, sounds which are important for feeding and communication. Our findings highlight the need to protect calf dolphins and suggest that it might be possible to create tools to identify dolphins by their age, based on their sounds. This research is important for conservation efforts and could help in creating better protection strategies for these dolphins. The franciscana dolphin is a small, vulnerable species often caught in artisanal gillnets. This study aims to provide a comprehensive assessment of their acoustic capabilities by using advanced equipment to collect a large dataset of wideband, continuous recordings. We examined the detailed acoustic signals of franciscana dolphins, comparing the sounds from rehabilitated dolphins in captivity with those of wild dolphins near fishing nets. Significant differences in acoustic characteristics were found between neonates and older dolphins, with juvenile and wild dolphins showing similar features. For the first time, repetition patterns in click production were identified, highlighting the importance of understanding the context of these sounds in regards to feeding and communication. This study emphasizes the need for detecting neonates for species protection and suggests the potential for developing acoustic classifiers specific to different age groups. Our findings offer valuable insights for conservation efforts and the development of protection strategies for franciscana dolphins. [ABSTRACT FROM AUTHOR]

The F-POD is designed for passive acoustic monitoring of odontocetes. The offline classifiers can identify and separate porpoise-like sounds from dolphin-like sounds. We show that these two classifiers are not working independently. Run together, virtually no detections of both species were reported within the same minute, whereas 10% of the detection positive minutes were reported positive for both species when the two classifiers were run sequentially. This has important implications for interpretation of data in areas containing both species groups, and we call for reporting all analysis details in such studies and for further description and analysis of the classifiers. [ABSTRACT FROM AUTHOR]

The F-POD is designed for passive acoustic monitoring of odontocetes. The offline classifiers can identify and separate porpoise-like sounds from dolphin-like sounds. We show that these two classifiers are not working independently. Run together, virtually no detections of both species were reported within the same minute, whereas 10% of the detection positive minutes were reported positive for both species when the two classifiers were run sequentially. This has important implications for interpretation of data in areas containing both species groups, and we call for reporting all analysis details in such studies and for further description and analysis of the classifiers. [ABSTRACT FROM AUTHOR]

The Baltic Proper harbour porpoise population is listed as Critically Endangered by IUCN, and only a few hundred animals remain. One of the most serious threats to this population is bycatch in static net fisheries. To minimize bycatch, ICES has proposed that acoustic deterrent devices, pingers, should be used on static nets within the population's range.However, there have previously been indications that grey seals learn to associate the pinger sounds with the presence of nets with easily accessible prey, and that pinger use therefore can increase the risk of seal depredation in static net fisheries.In recent years, pingers operating at higher frequencies have been made commercially available, the idea being that harbour porpoises will still be able to hear the sound at 50–120 kHz while this will be above or at the limit of seal hearing. This would mean that such high‐frequency pingers would not induce this so‐called dinner‐bell effect.In this study, data were collected from active commercial static net fisheries in the Baltic Proper, using two types of high‐frequency pingers operating at 50–120 and 70 kHz, respectively. Pingers were attached to nets in accordance with manufacturers' guidelines, and fishers were asked to estimate the catch loss owing to seals in nets with and without pingers.Data were received from 646 deployments made between May 2019 and September 2020. Four generalized mixed effect models were developed with relevant variables.The results suggest using high‐frequency pingers does not increase seal depredation on static nets. It is concluded that pingers could be used as an interim measure to minimize bycatch of the Critically Endangered Baltic Proper harbour porpoise population. [ABSTRACT FROM AUTHOR]

Nature-based tourism activities are often sold as 'ecotourism', yet not all are educational, environmentally friendly, provide economic benefits to local communities, nor help achieve conservation goals. Whale-watching has the potential for ecotourism due to opportunities for supporting cetacean research, environmental education, and community engagement. Whalesafari, the first whale-watching company in the Arctic, is based in Norway and combines whale-watching with research, interpretation, and benefits for the local community. Researchers from around the world have carried out research on several aspects of sperm whales (the main target species), from abundance to diving behaviour, as well as other species. Tourists learn about cetaceans during a guided experience in the company's museum before the trip. This whale-watching model has attracted over 350,000 tourists over the years, benefiting the local community (e.g., hotels, restaurants, other attractions). Tourism and whale research can establish synergistic relationships, involving several agents and promoting research careers, while at the same time leading to innovative advances in the ecology and tourism fields. Here, we summarise over 30 years of whale-watching eco-tourism activities and research in Northern Norway, highlighting synergistic examples and the opportunities opened through linking marine tourism and research. [ABSTRACT FROM AUTHOR]

Harbour porpoises are well-suited for passive acoustic monitoring (PAM) as they produce highly stereotyped narrow-band high-frequency (NBHF) echolocation clicks. PAM systems must be coupled with a classification algorithm to identify the signals of interest. Here, the authors present a harbour porpoise click classifier (PorCC) developed in matlab, which uses the coefficients of two logistic regression models in a decision-making pathway to assign candidate signals to one of three categories: high-quality clicks (HQ), low-quality clicks (LQ), or high-frequency noise. The receiver operating characteristics of PorCC was compared to that of PAMGuard's Porpoise Click Detector/Classifier Module. PorCC outperformed PAMGuard's classifier achieving higher hit rates (correctly classified clicks) and lower false alarm levels (noise classified as HQ or LQ clicks). Additionally, the detectability index (d′) for HQ clicks for PAMGuard was 2.2 (overall d′ = 2.0) versus 4.1 for PorCC (overall d′ = 3.4). PorCC classification algorithm is a rapid and highly accurate method to classify NBHF clicks, which could be applied for real time monitoring, as well as to study harbour porpoises, and potentially other NBHF species, throughout their distribution range from data collected using towed hydrophones or static recorders. Moreover, PorCC is suitable for studies of acoustic communication of porpoises. [ABSTRACT FROM AUTHOR]