Cetacean Diversity Research Articles

Isotopic niches reveal the trophic structure of the cetacean community in the oceanic waters around the Azores

IntroductionThe oceanic waters around the Azores host a high diversity of cetaceans, with 28 species of toothed and baleen whales present year-round or seasonally. This high cetacean biodiversity likely plays an important role in the structure, functioning and productivity of the ecosystem, and may increase trophic redundancy, thus contributing to food web resilience to disturbances.MethodsHere we used stable isotope (δ13C and δ15N) analysis to characterize trophic niches, assess niche overlap, describe the trophic structure and discuss potential redundancy in the cetacean community. Using 407 samples from 12 species, we estimated Standard Ellipse Areas and overlaps between species and used a hierarchical clustering analysis to identify trophic guilds.Results and discussionδ13C and δ15N values ranged from -20.53 to -15.46‰ and from 7.78 to 14.41‰ respectively, suggesting the use of diverse habitats and resources among cetacean species. Clustering analysis revealed that species were grouped into four trophic guilds, segregated mainly by trophic position (TP): a low-TP guild with three zooplanktivore baleen whales, a mid-TP guild with micronektivores, a high-TP guild with micronekton and nekton consumers, and a cluster with only Pseudorca crassidens. There was significant isotopic niche overlap between one pair of species within each guild, indicating some potential for trophic redundancy in the community. Yet, these pairs also showed some form of spatial or temporal partitioning, suggesting that mechanisms promoting species coexistence could play a key role in structuring the cetacean community in the region and in its ecological role.

Whales and dolphins of the Adriatic Sea

The Adriatic Sea is one of the Mediterranean areas most exposed to cumulative human stressors. This semienclosed and largely shallow basin has been subjected to intensive exploitation and destructive fishing practices for decades, resulting in biodiversity decline and poor ecosystem health. Diversity of cetaceans is lower than in other parts of the Mediterranean, and the extant dolphins and whales have been facing threats that include the combined effects of habitat loss and degradation, prey depletion, incidental mortality and injury caused by fisheries, anthropogenic noise, chemical contamination and climate change. Here, we report information for the nine cetacean species known to occur in the basin (classified as either regular, visitor or vagrant), plus three species characterized by a single record. For these species, we review evidence from field research and other studies – with a bias towards the common bottlenose dolphin Tursiops truncatus (by far the most intensively-studied cetacean in this area). We also describe and characterize the main threats to cetaceans in the Adriatic, relying on recent literature as well as historical information that helps frame the present status of cetaceans in the context of past human impacts (particularly the extensive killing campaigns conducted until the 1960s). Finally, we provide management recommendations to inform and guide the action that must be taken in compliance with extant legislation, marine conservation directives and international commitments to protect marine biodiversity.

Diversity and Conservation of Cetaceans in Pakistan

Diversity and Conservation of Cetaceans in Pakistan

Diversity and distribution of cetaceans in the Republic of Palau

Context Until recently, very little was known about the species diversity and occurrence of cetaceans in the Republic of Palau. A dedicated scientific investigation into the occurrence and distribution of island associated cetaceans in Palau was conducted in 2012 and 2013. Aims The aim of this project was to investigate the diversity and distribution of cetaceans in Palau to inform management and build local capacity in cetacean science. Methods Following a feasibility study in 2010, a vessel-based visual and acoustic line transect survey was conducted in 2012, covering a survey area of 4319 km2. The survey was repeated and expanded in 2013 using aerial methods. Additionally, small boat work was conducted in areas with high cetacean density to obtain genetic, acoustic, and photographic samples. In 2019, a vessel-based visual and acoustic survey of the Southwest Islands was conducted. Key results By combining the survey results with anecdotal sightings, a cetacean species inventory for Palau was established. The presence of 15 species was confirmed, while four species were identified as probably present and three as likely. Conclusions Survey results contributed to the management of cetaceans in the Palau Marine Mammal Sanctuary. The surveys raised local interest in cetaceans and, through public outreach and training, precipitated advancements in capacity building for cetacean management, along with a baseline for ongoing monitoring. Implications This study provided the first systematic, scientific investigation using multiple survey methods into the occurrence and distribution of cetaceans in Palau, highlighting the importance of conserving cetacean populations in this region.

Frekuensi Pemunculan, Tingkah laku, dan Diversitas Cetacea di Perairan sekitar Labuan Bajo, Flores, Nusa Tenggara Timur


 
 
 
 At least 30 cetaceans live in Indonesia, especially in the eastern waters of Indonesia, consisting of whales and dolphins. Cetaceans play an important role as a key species in determining the health of marine ecosystems. This study aims to determine the frequency of appearance, behavior, and diversity of cetaceans along Labuan Bajo, Flores, and East Nusa Tenggara. The study was conducted in October-November 2021, with four weeks to collect field data and interviews. The data involved a ship carrying a group of observers consisting of four people, with each task assigned to look for the appearance, species, and behavior of cetaceans. In the interview methods, interviews were conducted with fishermen regarding the presence of cetaceans. The data was then processed using the Microsoft Excel program and later plotted using the ArcView program as the outpour of the cetacean distribution. The results showed 19 occurrences of cetaceans, with six occurrences found in the field survey and 13 based on interviews with fishermen. Appearances were found to be evenly distributed in the study area, with a total of 7 species of cetaceans found, namely Stenella longirostris, Stenella attenuata, Tursiops truncates, Pseudorca crassidens, Grampus griseus, Kogia simus, and Physeter macrocephalus. In species composition and abundance, S. longirostris species had the highest value, and the P. crassidens species had the lowest composition value. A value of 1.06 was found in diversity, indicating that the cetaceans in Labuan Bajo were classified as moderate. Some behaviors include aerials, spy hopping, bow-riding, feeding, and avoidance.
 
 
 

Cetaceans of the Saya de Malha bank region, Indian Ocean: A candidate Important Marine Mammal Area

The banks of Saya de Malha and the surrounding Mascarene Plateau in the Indian Ocean are among the least studied shallow sea water regions in the world. The steep sloping bathymetry of this region is thought to drive high levels of primary productivity and support a diverse range of marine species. Until now, no surveys for cetaceans have been conducted in the waters surrounding Saya de Malha, and so the diversity of cetaceans is unknown. Opportunistic visual and acoustic surveys for cetaceans were conducted onboard a platform of opportunity, the MY Arctic Sunrise, which was involved in a wider project to document the marine life in the region. Survey effort was conducted over 7,700 km, with twelve species of cetacean encountered, including Bryde’s, sperm, beaked and killer whales, along with spinner, striped, pantropical spotted and bottlenose dolphins. A match of a sperm whale coda vocalisation to another, well-studied population off the coast of Mauritius suggests possible connectivity between these regions although further data would be required to confirm this. The banks of Saya de Malha appear to support a diverse range of cetacean species and further systematic surveys are required to increase our understanding of how different species utilise the banks. We provide whistle contours from visually confirmed acoustic detections to contribute towards building a region-specific whistle classifier. Given the diversity of species detected in the region, we suggest that the Saya de Malha bank area be designated, either as an Important Marine Mammal Area or as a marine protected area.

Acoustic Presence of Cetaceans in the Miaodao Archipelago, China.

Once an important cetacean habitat, the Miaodao Archipelago has been altered by human-induced disturbances over several decades. While cetacean diversity is known to have decreased, no recent data on species diversity around Miaodao are known to exist. Capitalizing on the high vocal activity of cetaceans, three passive acoustic surveys, including towed and stationary types, were undertaken to detect the presence of species-specific vocalizations in May 2021, October 2021, and July 2022, as most cetacean sightings occurred during May and August in recent years. The results revealed that the East Asian finless porpoise is the sole cetacean species that can be reliably observed around the archipelago, as no other species were detected. The acoustic data also revealed potentially clumped distributions of finless porpoises with some seasonal variation. While not acoustically detected during any of the surveys, humpback whales, minke whales, and killer whales have been visually sighted in the region. The lack of acoustic detection of these species suggests that they are likely to be temporary visitors to the region, or at least exhibit strong seasonality in their presence within the region. These new data provide the latest snapshot of cetacean presence around the Miaodao Archipelago that can help inform future research and conservation.

Fall distribution and diversity of cetaceans along the southern and eastern coasts of Hokkaido, Japan

The southern and eastern coasts of Hokkaido, part of the western North Pacific and the southern Sea of Okhotsk, are productive regions with a high degree of biodiversity and human activity. This area is an important habitat for cetaceans. However, only a few studies have been conducted on comprehensive species co-inhabiting the study area at the same time. Information regarding cetacean distribution patterns is necessary for ecosystem management and marine conservation. The objective of this study was to investigate the distribution patterns and environmental variables affecting the distribution of cetaceans in coastal Hokkaido using sighting surveys. Five baleen and seven toothed whale species were observed during the study period. The maximum entropy model used to map the distribution of 11 selected cetacean species showed a heterogeneous distribution, which may reflect a potentially suitable habitat for each species. In the North Pacific region, there are differences in water temperature between east and west of Cape Erimo, which is possibly the reason why some species are only distributed in the eastern side. In the Nemuro Strait, the distribution differs from north to south, likely influenced by seafloor topography. Our results will help to clarify the habitat of various cetacean species in coastal Hokkaido and provide essential information for their conservation.

Cetacean diversity around the Mozambique Channel island of Mayotte (Comoros archipelago)

The Indian Ocean was designated as a whale sanctuary in 1979. While cetacean research has been conducted throughout the sanctuary, few studies have been conducted to assess the diversity, distribution and abundance of cetaceans inhabiting the waters surrounding the islands in the northern Mozambique Channel. In order to contribute to management and conservation efforts in this area, a series of small boatbased surveys were undertaken around the island of Mayotte from July 2004 to August 2005 to assess the diversity of cetaceans in the lagoon and surrounding waters, i.e. external barrier reef slope, insular slope (200-1,000m) and oceanic (>1,000m) waters. During this period, more than 284 hours were spent at sea on-effort and 17 cetacean species were recorded around Mayotte (n=286 sightings). One mysticete (1 Balaenopterid) and sixteen odontocetes (1 Kogid, 1 Physeterid, 13 Delphinids and 2 Ziphiids) were observed: spinner dolphin, n=118; pantropical spotted dolphin, n=61; Indo-Pacific bottlenose dolphin, n=44; humpback whale, n=37; melon-headed whale, n=5; Blainville’s beaked whale, n=4; Indo-Pacific humpback dolphin, n=4; common bottlenose dolphin, n=2; Risso’s dolphin, n=2; false killer whale, n=2; dwarf sperm whale, n=2; sperm whale, n=1; pygmy killer whale, n=1; short-finned pilot whale, n=1; Fraser’s dolphin, n=1; and Longman’s beaked whale, n=1. In addition to these 17 species recorded during dedicated surveys, two other cetacean species were observed opportunistically and subsequently identified as the Ginkgo-toothed beaked whale and the blue whale. The relatively large diversity of cetaceans around Mayotte is attributed to the wide range of marine habitats, such as coastal, reef-associated and oceanic, within close proximity to one another.

Cetaceans in the Mediterranean Sea: Encounter Rate, Dominant Species, and Diversity Hotspots

We investigated the presence and diversity of cetaceans in the Mediterranean Sea, analysing the data collected by 32 different research units, over a period of 15 years (2004–2018), and shared on the common web-GIS platform named Intercet. We used the encounter rate, the species prevalence, and the Shannon diversity index as parameters for data analysis. The results show that cetacean diversity, in the context of the Mediterranean basin, is generally quite low when compared with the eastern Atlantic, as few species, namely the striped dolphin, the bottlenose dolphin, the fin whale, and the sperm whale, dominate over all the others. However, some areas, such as the Alboran Sea or the north-western Mediterranean Sea, which includes the Pelagos Sanctuary (the Specially Protected Area of Mediterranean Interest located in the northern portion of the western basin), show higher levels of diversity and should be considered hotspots to be preserved. Primary production and seabed profile seem to be the two main drivers influencing the presence and distribution of cetaceans, with the highest levels of diversity observed in areas characterized by high levels of primary production and high bathymetric variability and gradient. This collective work underlines the importance of data sharing to deepen our knowledge on marine fauna at the scale of the whole Mediterranean Sea and encourages greater efforts in the networking process, also to accomplish the requirements of the Marine Strategy Framework Directive, with particular reference to Descriptor 1: biological diversity is maintained.

A note on observations on cetaceans in the western Indian sector of the Southern Ocean (20-56°S and 45-57°30’E), January to March 2004

A multi-disciplinary and multi-institutional pilot expedition was organised by the National Centre for Antarctic and Ocean Research (NCAOR) to the ice-free areas of the Western Indian Ocean sector of the Southern Ocean onboard ORV Sagar Kanya during the austral summer of 2004 (January-March). This survey, conducted by the Central Marine Fisheries Research Institute (CMFRI), is the first Indian attempt to survey for cetacean diversity in the Southern Ocean. The ultimate objective is to determine distribution, relative abundance, migration patterns and critical habitat parameters. 68% of a total of 13 sightings (22 individuals) were positively identified and species observed included Antarctic minke whales (Balaenoptera bonaerensis), fin whales (B. physalus), sei whales (B. borealis) and blue whales (B. musculus). The blue whales were not identified to the sub-species level. The highest concentration of cetaceans was between 35° and 37°S (along 45°E) and between 48° and 53°S (along 45°E). Relatively small numbers of cetaceans were observed during the present cruise, possibly because most of the cetacean sighting effort was made during inclement sea conditions. Results on the sighting characteristics and occurrence patterns of the cetaceans in relation to the region and hydrographical parameters are discussed briefly vis a vis published information from the Southern Ocean.

Habitat and abundance of cetaceans in Atlantic Ocean continental slope waters off the eastern USA

This study quantifies the abundance and spatial distribution of the cetacean community occupying continental shelf edge and inner continental slope waters along the US southeast Atlantic coast. A shipboard visual line-transect survey was conducted between June and August of 2004 that included effort in waters >50m deep encompassing the shelf break and inner continental slope off the US east coast between 28°N and 38°N latitude. The abundance of nine cetacean taxa was estimated using line-transect distance analysis and an independent observer approach to correct for visibility bias. Canonical correspondence analysis was used to examine the spatial distribution of the cetaceans encountered during the survey as a function of surface temperature, surface salinity, surface fluorescence, bottom depth, and bottom slope. The abundance estimates for most species were much higher than those from a study of the area conducted in 1998. This is primarily due to increased coverage of the shelf-break region and correction for visibility bias. The multivariate analysis indicated four distinct groups of cetaceans that partitioned habitat as a function of salinity, depth, and a latitudinal gradient. These groups were associated with specific water masses and hydrographic features including mid-Atlantic shelf waters (Group I), the shelf break (Group II), mid-Atlantic slope waters (Group III), and south Atlantic slope water (Group IV). Areas where water masses converge such as the continental shelf break along the mid-Atlantic and near Cape Hatteras, North Carolina are therefore areas of both high diversity and density of cetaceans.

Cetaceans and cetacean research in India

The diversity of cetacean species in Indian waters is high, with 25 species recorded so far. Records of cetaceans from India during the last 200 years have provided insights into their spatiotemporal distribution, behaviour, feeding, reproduction, fishery interaction and pollution. The cetacean fauna is dominated by pantropical species, with a relatively high abundance of spinner dolphins, which is similar to other areas studied within the northern Indian Ocean. Historical records were analysed to propose an inventory of cetaceans. Cetacean diversity was highest in the Gulf of Mannar on the southeast coast of India, which with 14 species recorded from a small area can be considered a ‘hot spot’ for further research. Fishery interactions, domestic consumption, pollution and lack of quality information to inform management are the main threats for successful survival of cetaceans. The status of information regarding cetaceans in India could be classified based on this study as: six species with adequate data; five species where data is restricted to a few geographic locations; four species for which data collection is being initiated; five species with sparse data; and six species which are difficult to observe.

Cetacean diversity of the eastern South Atlantic Ocean and Vema Seamount detected during a visual and passive acoustic survey, 2019

Abstract Cetaceans in the eastern South Atlantic Ocean are poorly studied. We present results from a 2 week ship-based survey from Cape Town to Vema Seamount (980 km to the west) during October–November 2019, including visual and towed-hydrophone observations from the vessel, and 10 days of acoustic monitoring on the seamount. Fifty-two hours of visual surveys resulted in 39 encounters of whale groups including seven of humpback, six of fin and one sei whale, as well as four unidentified baleen whales, 18 unidentified balaenopterid whales and four unidentified odontocetes. Two humpback whales at the seamount were engaged in possible feeding behaviour. A large aggregation of mostly fin whales was observed near the continental shelf edge (22 encounters over a 70 × 50 km2 area, six fin, one sei whale, 15 not confirmed to species), an historic whaling ground for both fin and sei whales. Towed-hydrophone data (78.7 h) detected five groups of sperm whales, 45 of delphinids, one beaked whale and no Kogiids. Acoustic data from the seamount detected calls from several baleen whale species including humpback whale non-song calls, Antarctic minke ‘bioduck’ calls, sei whale down-sweep calls and a likely Bryde's whale call. Two call types could not be assigned to species, including the most detected – a simple frequency-modulated call with peak power around 130 Hz. This study contributes to an improved understanding of cetacean occurrence in the eastern South Atlantic Ocean and highlights the need for more research to improve identification of cetacean vocalizations in the region.

A new squaloziphiid-like odontocete from the Early Miocene of Patagonia expands the cetacean diversity in the southwestern Atlantic Ocean

ABSTRACT The Early Miocene Gaiman Formation, from Argentina, houses a taxonomic variety of odontocetes, mainly dominated by platanistoids and physeteroids. In this work, we describe a new medium-sized odontocete, Crisocetus lydekkeri gen. et sp. nov., based on a partial skull, which expands the diversity of odontocetes in the Early Miocene beds of Patagonia (Argentina). The phylogenetic analyses placed C. lydekkeri within the crown Odontoceti, stemward to delphinidans, ziphiids, and physeteroids. Crisocetus lydekkeri displays a set of characters that are shared with the members of the Squaloziphiidae family (i.e., Squaloziphius emlongi and Yaquinacetus meadi), such as a massive postglenoid process of the squamosal, ventrally longer than the posttympanic process and the exoccipital; apex of postglenoid process anteroposteriorly longer than transversely thick; presence of a deep emargination by a neck muscle fossa on the posterior end of the zygomatic process; basioccipital crests forming an angle of circa 70–90°; and a basioccipital width wider than 51% of the skull width in ventral view. Thus, we recognize a squaloziphiid-like morphology shared by C. lydekkeri, S. emlongi, Y. meadi, and even Dolgopolis kinchikafiforo. Our phylogenetic analyses partially support the inclusion of C. lydekkeri within Squaloziphiidae, however this family is recovered with low support. Finally, the presence of C. lydekkeri and even D. kinchikafiforo in the Early Miocene of Patagonia expands the paleogeographic distribution of squaloziphiid-like forms to the southwest coast of the Atlantic Ocean, suggesting that these taxa had an almost antitropical distribution.

Spatial mismatch in diversity facets reveals contrasting protection for New Zealand's cetacean biodiversity

Cetaceans play key roles in the world's ecosystems and provide important economic and social benefits. New Zealand's Exclusive Economic Zone is a global biodiversity hotspot for cetaceans and benefits from a system of marine protected areas (MPAs). However, spatial patterns of cetacean biodiversity and their overlap with MPAs have never been assessed.We quantify this overlap by using a comprehensive cetacean at-sea sightings database, high-resolution environmental data layers, and information on ecological and evolutionary characteristics of each species to model spatial patterns of taxonomic, functional, and phylogenetic diversity of cetaceans. We examine areas of congruence among hotspots of richness and uniqueness components of biodiversity and measure the contribution of species to biodiversity.We find that cetacean taxonomic and phylogenetic diversity are spatially mismatched with MPAs, but this is less true for functional diversity. Hotspots of congruence among richness indices are located on the continental shelf break, whereas hotspots of uniqueness indices are located closer to shore on the continental shelf. Seven species have high contributions to biodiversity, with blue whale being the only species being evolutionarily distinct, functionally unique, specialised and globally endangered.Our results underline the potential of multicomponent biodiversity indices, their spatial congruence, and the contribution of species to biodiversity to be used as guides for a strategic placement and expansion of MPAs to protect biodiversity.

A Genetic Perspective on Cetacean Evolution

Studies of cetacean evolution using genetics and other biomolecules have come a long way—from the use of allozymes and short sequences of mitochondrial or nuclear DNA to the assembly of full nuclear genomes and characterization of proteins and lipids. Cetacean research has also advanced from using only contemporary samples to analyzing samples dating back thousands of years, and to retrieving data from indirect environmental sources, including water or sediments. Combined, these studies have profoundly deepened our understanding of the origin of cetaceans; their adaptation and speciation processes; and of the past population change, migration, and admixture events that gave rise to the diversity of cetaceans found today.

Cetacean stranding records along the Pacific coastline of Guatemala, 2007–2021: Implications for management, conservation and research

Cetacean strandings constitute one of the most important sources of information for studying cetacean diversity and obtaining basic biological data. The Guatemalan Pacific Ocean supports a high diversity of cetaceans, with at least 19 confirmed species records. However, little is known about cetacean strandings in Guatemala and their association with anthropogenic activities. We reviewed the occurrence of cetacean strandings on the Pacific coastline of Guatemala between 2007 and 2021. Stranding records were obtained from publications and citizen science such as sporadic reports from third parties, local and social media. In total, 39 stranding events from 12 species were recorded over the 15-year period examined. Stranded species belong to five families: Delphinidae, Kogiidae, Ziphiidae, Balaenopteridae and Eschrichtiidae. The striped dolphin (Stenella coeruleoalba, n = 6), bottlenose dolphin (Tursiops truncatus, n = 6), spinner dolphin (S. longirostris, n = 5), spotted dolphin (S. attenuata, n = 4), and humpback whale (Megaptera novaeangliae, n = 4) were the most frequently stranded species. For three of the stranded species, the melon-headed whale (Peponocephala electra), Blainville's beaked whale (Mesoplodon densirostris), and gray whale (Eschrichtius robustus), these stranding records represent the first confirmed report of the species in Guatemalan waters. Although we could not determine the cause of stranding in most cases, at least 15% of stranded individuals presented marks or injuries that could be associated with anthropogenic activities, such as fisheries or vessel strikes. This study highlights the importance of stranding data and the need to create a national network to allow timely response to stranding events and to enable improved data collection protocols. A well-curated cetacean stranding database is crucial for scientific research as well as to implement management and conservation measures to protect these species in the region.

Cetacean community off French Guiana

Although human activities are developing in French Guiana Exclusive Economic Zone (EEZ) and surrounding countries, knowledge on diversity and ecology of cetaceans in the region is scarce. This study aimed to collect new information on the cetacean species occurring year-round in the entire French Guiana EEZ by combining visual and acoustic data obtained from three boat-based campaigns conducted by local NGOs. The GEPOG campaign was conducted from July 2011 to June 2012, four days every two months; the COHABYS campaign was performed five days per month from January to May 2018; the OSL campaign consisted in four 10-day surveys conducted in June, July, September and October 2018. The visual observation effort conducted when Beaufort sea state < 5 was 1,961 km, 1,491 km and 3,243 km respectively. Acoustic records were done when Beaufort sea state < 5 during daylight and/or nighttime, depending on the survey. A total of 132 cetacean sightings were done. Five cetacean families and 15 species were identified. Delphinidae was the family most frequently sighted (91% to 100% of groups and 99% to 100% of individuals per campaign). The most frequent species in the area were identified, along with their distribution and phenology: Guiana dolphin (Sotalia guianensis) was found in the coastal area (0-20 m), the long-beaked common dolphin (Delphinus delphis) was sighted on the shelf (20-100 m), along with the bottlenose dolphin (Tursiops truncatus) and the Atlantic spotted dolphin (Stenella frontalis) that were also common on the upper slope (100-1,500 m). Finally, the spinner dolphin (Stenella longirostris), the melon-headed whale (Peponocephala electra) and the pantropical spotted dolphin (Stenella attenuata) were frequent on the slope (100-3,500 m). The results suggest these species may be found in French Guiana waters all year round and mother and calf pairs, as indicator of reproduction, were observed for all of them except the long-beaked common dolphin and the Guiana dolphin. Mother and calf pairs of humpback whales (Megaptera novaeangliae), that potentially belong to the “A” stock, were also sighted twice, as well as two groups of sperm whales (Physeter macrocephalus) with calves. Hence, these results showed that French Guiana bears a particular responsibility for the conservation of cetacean biodiversity, but a lot remains to be done to strengthen knowledge and conservation of these species in the territory.

Citizen science as a tool to assess cetacean diversity in the Atacama Desert coast

An understanding of the fine-scale distribution, diversity, and population trends of endangered cetacean species threatened by anthropogenic activities is key for their conservation. In remote places such as the coastline of the Atacama Desert in Northern Chile, research focused on cetacean species is often limited by funding, and personnel. However, scientific interest from local citizens could be an alternative and useful tool to obtain valuable information on cetaceans. Here, we assess the power of citizen science as a tool to determine cetacean species richness, group size, behaviour, seasonality and conservation threats in Northern Chile by undertaking training workshops for local citizens on cetacean species identification and data gathering. A total of 24 citizen scientists reported 495 cetacean sightings during the period between 2013 and 2020, with a total of 19 cetacean species observed (6 mysticetes and 13 odontocetes). One bay (Mejillones Bay) dominated most cetacean sightings (73%) in the study area (Antofagasta region). Seven cetacean species were more frequently observed year-round: Balaenoptera physalus, Megaptera novaeangliae, Grampus griseus, Tursiops truncatus, Lagenorhynchus obscurus, Delphinus capensis and Phocoena spinipinnis. Other species were either opportunistically observed or were rare stranded species. Four species of cetaceans, B. physalus, D. capensis, L. obscurus, and P. spinipinnis were observed mostly traveling (43%) and feeding (37%), indicating that the study region is an important feeding area. Twelve cetacean species were reported stranded, and citizen scientists identified 3 species of cetaceans entangled in fishing nets. This study shows the potential of citizen science for providing information on cetacean richness and threats in remote locations such as the South East Pacific. This approach may improve knowledge on fine-scale cetacean distribution for regions that are sparsely populated and have limited research activity.