Rui Prieto

• PhD
• Senior Research Associate at University of the Azores

Biologging and biotelemetry are essential tools to better understand marine species and consequently contribute to increasing our knowledge of marine ecosystems as a whole. Assessing marine megafauna trajectories is traditionally performed with significantly high cost and labor, without guaranteeing the equipment recapture, where quick georeferenci...

Photo-identification is a staple tool used in cetacean conservation studies since the 1970s to monitor individuals on a regional and ocean basin-wide scale to infer critical information about habitat use, suitability, and shifts. This technique has been extensively used on sperm whales globally since it was developed in 1982, initially using the ta...

How animals navigate during long-distance migration remains a mystery. Many theories have been proposed ¹ (Keeton, 1979), with the Earth’s magnetic field emerging as a clear potential source of orientational information for navigational decision-making across diverse taxa ² (Putman, 2022). Yet, the mechanics involved in magnetic navigation remain u...

Introduction The 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...

Determining how animals allocate energy, and how external factors influence this allocation, is crucial to understand species' life history requirements and response to disturbance. This response is driven in part by individuals' energy balance, prey characteristics, foraging behaviour and energy required for essential functions. We developed a bio...

Animal songs can change within and between populations as the result of different evolutionary processes. When these processes include cultural transmission, the social learning of information or behaviours from conspecifics, songs can undergo rapid evolutions because cultural novelties can emerge more frequently than genetic mutations. Understandi...

Background High-resolution sound and movement recording tags offer unprecedented insights into the fine-scale foraging behaviour of cetaceans, especially echolocating odontocetes, enabling the estimation of a series of foraging metrics. However, these tags are expensive, making them inaccessible to most researchers. Time-Depth Recorders (TDRs), whi...

Highly polymorphic single tandem repeat loci (STR, also known as microsatellite loci) remain a familiar, cost efficient class of markers for genetic analyses in ecology, behavior and conservation. We characterize a new universal set of ten STR loci (from 28 potential candidate loci) in seven baleen whale species, which are optimized for PCR amplifi...

Disturbance from whale watching can induce a wide range of behavioral responses in cetaceans, some of which can affect their energetic balance and, ultimately, their long-term fitness. However, assessing disturbance effects on deep-diving cetaceans remains challenging, as the majority of their activities occurs underwater and are difficult to monit...

Dolphins play a key role in marine food webs as predators of mid-trophic-level consumers. Because of their mobility and relatively long life span, they can be used as indicators of large-scale changes in the ecosystem. In this study, we calculated the trophic position (TP) of 5 dolphin species from the Canary, Madeira and Azores Islands using bulk...

Mechanisms driving song learning and conformity are still poorly known yet fundamental to understand the behavioural ecology of animals. Broadening the taxonomic range of these studies and interpreting song variation under the scope of cultural evolution will increase our knowledge on vocal learning strategies. Here, we analysed changes in fin whal...

Efficient use of the energy budget is of fundamental importance for long-distance migrants, which must cope with seasonal energy demands and environmental conditions. Time-activity budgets can provide information on how animals balance energy use and acquisition over their annual cycle, and on the costs and benefits of different migratory strategie...

Global warming is affecting the population dynamics and trophic interactions across a wide range of ecosystems and habitats. Translating these real-time effects into their long-term consequences remains a challenge. The rapid and extreme warming period that occurred after the Last Glacial Maximum (LGM) during the Pleistocene–Holocene transition (7–...

Large baleen and toothed whales play crucial ecological roles in oceans; nonetheless, very little is known about their intestinal microbiomes. Based on striking differences in natural history and thus in feeding behaviours, it can be expected that intestinal microbiomes of large baleen whales and toothed whales are different. To test this hypothesi...

Background Prioritizing groupings of organisms or ‘units’ below the species level is a critical issue for conservation purposes. Several techniques encompassing different time-frames, from genetics to ecological markers, have been considered to evaluate existing biological diversity at a sufficient temporal resolution to define conservation units....

Cetaceans are considered ecosystem engineers and useful bioindicators of the health of marine environments. The Eastern North Atlantic is an area of great geographical and oceanographic complexity that favours ecosystem richness and, consequently, cetacean occurrence. Although this occurrence has led to relevant scientific research on this taxon, i...

Community ecology based on biological and/or functional traits rather than taxonomic criteria informs general ecological patterns through the study of ecological niches, function, and resistance and resilience to perturbations. There are no repositories for diverse species traits from non-chemosynthetic deep-sea ridges and associated seamounts, whe...

Community ecology based on biological and/or functional traits rather than taxonomic criteria informs general ecological patterns through the study of ecological niches, function, and resistance and resilience to perturbations. There are no repositories for species traits from non-chemosynthetic deep-sea ridges and associated seamounts, where the i...

The Arctic is entering a new ecological state, with alarming consequences for humanity. Animal-borne sensors offer a window into these changes. Although substantial animal tracking data from the Arctic and subarctic exist, most are difficult to discover and access. Here, we present the new Arctic Animal Movement Archive (AAMA), a growing collection...

Ecological “big data” Human activities are rapidly altering the natural world. Nowhere is this more evident, perhaps, than in the Arctic, yet this region remains one of the most remote and difficult to study. Researchers have increasingly relied on animal tracking data in these regions to understand individual species' responses, but if we want to...

Aim Understanding the environmental drivers of movement and habitat use of highly migratory marine species is crucial to implement appropriate management and conservation measures. However, this requires quantitative information on their spatial and temporal presence, which is limited in the high seas. Here, we aimed to gain insights of the essenti...

Highly migratory marine species pose a challenge for the identification of management units due to the absence of clear oceanographic barriers. The population structure of North Atlantic fin whales has been investigated since the start of whaling operations but is still the subject of an ongoing scientific debate. Here we measured stable isotopes o...

Several seamounts have been identified as hotspots of marine life in the Azores, acting as feeding stations for top predators, including cetaceans. Passive acoustic monitoring is an efficient tool to study temporal variations in the occurrence and behaviour of vocalizing cetacean species. We deployed bottom-moored Ecological Acoustic Recorders (EAR...

Close‐range photogrammetry (CRP) is a well‐established technique to retrieve quantitative information from objects using photography. CRP is often used in morphology studies when the direct handling of individuals is unpractical or unethical, or to reduce processing costs and time. Although multiple software to extract quantitative information from...

The increasing public perception that marine megafauna is under threat is an outstanding incentive to investigate their essential habitats (EMH), their responses to human and climate change pressures, and to better understand their largely unexplained behaviors and physiology. Yet, this poses serious challenges such as the elusiveness and remotenes...

The GNSS Science Support Centre (GSSC), led by ESA’s Galileo Science Office at ESAC (Spain), aims to consolidate a world-wide GNSS Preservation and Exploitation platform through the provision of products and services to foster research in Europe, and notably the use of Galileo by the scientific community. Announced at the Galileo Colloquium 2017 i...

Knowing the migratory movements and behaviour of baleen whales is fundamental to understanding their ecology. We compared δ 15 N and δ 13 C values in the skin of blue (Balaenoptera musculus), fin (Balaenoptera physalus) and sei (Balaenoptera borealis) whales sighted in the Azores in spring with the values of potential prey from different regions wi...

The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collec...

Capture-mark-recapture methods have been extensively used to estimate abundance, demography, and life history parameters of populations of several taxa. However, the high mobility of many species means that dedicated surveys are logistically complicated and expensive. Use of opportunis-tic data may be an alternative, if modeling takes into account...

The demography of baleen whales and their prey during the past 30 thousand years was assessed to understand the effects of past rapid global warming on marine ecosystems. Mitochondrial and genome-wide DNA sequence variation in eight baleen whale and seven prey species revealed strong, ocean-wide demographic changes that were correlated with changes...

Aim The knowledge of a species biogeographical patterns greatly enhances our understanding of geographical ecology, which can improve identifying key conservation needs. Yet, this knowledge is still scarce for many marine top predators. Here, we aim to analyse movement patterns and spatial structuring of a large predator, the short‐finned pilot wha...

Highlights Mitochondrial monophyly is commonly employed to define evolutionary significant units. Monophyly may be caused by insufficient sampling or a recent common ancestor. Mitogenomic studies are generally based on few samples and prone to sampling issues. Expanded mitogenome sampling negates previous monophyly in fin whales. Abstract The adve...

Biologging technology has provided scientists with unprecedented tools to investigate the ecology and behaviour of marine animals, but tag deployment and attachment methods have lagged behind. Electronic tagging of elasmobranchs still essentially involves implanting anchors or drilling the fins of restrained animals. On the other hand, most biologg...

Currently, three stocks of sei whales (Balaenoptera borealis) are defined in the North Atlantic; the Nova Scotian, Iceland-Denmark Strait and Eastern North Atlantic stocks, which are mainly based upon historical catch and sighting data. We analyzed mitochondrial control region DNA (mtDNA) sequences and genotypes from 7 to 11 microsatellite loci in...

Ziphiids or beaked whales, are deep-diving, echolocation-user odontocetes. They are the second most species-rich modern cetacean family with a diverse fossil record, with around fifty skulls recovered from Portuguese and Spanish (Asturias and Galicia) coastal waters. The mid-Atlantic Portuguese Archipelago of Azores is well-renowned for its rich fa...

Information on abundance and demography is essential to assess the status of populations, inform conservation and management measures and evaluate effectiveness of those measures. Application of capture-mark-recapture (CMR) methods to photo-identification data has been extensively used to estimate abundance and life history parameters of cetacean p...

ABSTRACT: The International Whaling Commission currently recognizes 3 stocks of sei whales (Balaenoptera borealis) in the North Atlantic, mainly based upon historical catch and sighting data. In this study, we evaluated the validity of this division into stocks by analyzing 87 samples collected from 3 different sites in the North Atlantic; Iceland,...

Biologging technology has provided scientists with unprecedented tools to investigate the ecology and behaviour of marine animals, but tag deployment and attachment methods have lagged behind. Electronic tagging of elasmobranchs still essentially involves implanting anchors or drilling the fins of restrained animals. Here, we present two new non-in...

Biophysical coupling at seamounts may lead to the formation of pelagic foraging hotspots, which can attract predators like cetaceans. Spatial and temporal dynamics of prey has a strong effect on the foraging success and performance of predators. Dolphins change their distribution and foraging strategy in response to changes in micronekton prey abun...

We present two alternative solutions for short term deployments of external tags and sensors on two species of elasmobranchs

Marine spatial planning and ecological research call for high-resolution species distribution data. However, those data are still not available for most marine large vertebrates. The dynamic nature of oceanographic processes and the wide-ranging behavior of many marine vertebrates create further difficulties, as distribution data must incorporate b...

In July 2016, started “EcoDiveAz”, a 3 years project from IMAR-MARE & the University of the Azores, funded by the regional government through the Açores2020-FEDER program. This project was designed to contribute to the sustainable growth and management of blue sharks (Prionace glauca) and mobula rays (Mobula tarapacana) diving in the Azores. This f...

The Azores supported a sperm whaling industry for over one century and presently host a growing whale watching industry that mainly targets this species. Despite the lower productivity in relation to other coastal areas, the waters around the Azores are one important feeding ground for the species in the North Atlantic. Yet, very little is known ab...

Marine spatial planning and ecological research call for high-resolution species distribution data. However, those data are still not available for most marine large vertebrates. The dynamic nature of oceanographic processes and the wide-ranging behavior of many marine vertebrates create further difficulties, as distribution data must incorporate b...

A number of parasitic diseases have gained importance as neozoan opportunistic infections in the marine environment. Here, we report on the gastrointestinal endoparasite fauna of three baleen whale species and one toothed whale: blue (Balaenoptera musculus), fin (Balaenoptera physalus), and sei whales (Balaenoptera borealis) and sperm whales (Physe...

Baleen and sperm whales, belonging to the Order Cetartiodactyla, are the largest and heaviest existent mammals in the world, collectively known as large whales. Large whales have been subjected to a variety of conservation means, which could be better monitored and managed if physiological and pathophysiological information, such as pathogen infect...

A relação do Homem com os cetáceos poderá ter mais de 150 mil anos, como atestam registos fósseis. Deverá ter-se iniciado com o aproveitamento de carcaças de animais arrojadas na costa. As carcaças destes seres estranhos, vindos de um mundo aquático também misterioso, devem ter alimentado não só os corpos como também a imaginação dos nossos ancestr...

The stock structure of the sei whale Balaenoptera borealis in the North Atlantic is unknown, despite years of commercial hunting. New and up-to-date data on distribution and movements are essential for the creation of plausible hypotheses about the stock structure of this species. Between 2008 and 2009 satellite tracks of 8 sei whales were obtained...

Genetic studies have shown that there are small but significant differences between the short-beaked common dolphin populations in the Atlantic Ocean and those in the Mediterranean Sea. The short-beaked common dolphin is a highly vocal species with a wide sound production repertoire including whistles. Whistles are continuous, narrowband, frequency...

To improve our understanding of the complex genetic and ecological structure of bottlenose dolphin ( Tursiops truncatus ) populations, we examined the acoustic features of communication signals from two geographically contiguous areas: the Central–Eastern North Atlantic and the Mediterranean Sea. Variations in the whistles were evaluated for four l...

Malcolm Roy Clarke (1930–2013) was a British teuthologist who made an important contribution to marine science in the Azores archipelago (Portugal). Malcolm started doing research in the Azores from 1980s onward, settling for residency in 2000 after retirement (in 1987). He kept publishing on Azorean cephalopods collaborating in 20% of the peer rev...

Argos recently implemented a new algorithm to calculate locations of satellite-tracked animals that uses a Kalman filter (KF). The KF algorithm is reported to increase the number and accuracy of estimated positions over the traditional Least Squares (LS) algorithm, with potential advantages to the application of state-space methods to model animal...

Cetaceans living in offshore waters are under increasing pressure from anthropogenic activities. Yet, due to the lack of survey effort, relatively little is known about the demography or ecology of these populations. Spatial and temporal distribution of cetaceans in mid-Atlantic waters were investigated using a long term dataset collected from boat...

The need to balance energy reserves during migration is a critical factor for most long-distance migrants and an important determinant of migratory strategies in birds, insects and land mammals. Large baleen whales migrate annually between foraging and breeding sites, crossing vast ocean areas where food is seldom abundant. How whales respond to th...

We compared the spatial structure across the North Atlantic Ocean of the genetic variation in the mitochondrial and nuclear genome in minke, fin, blue and humpback whales. Across all four species we found a qualitatively similar spatial distribution of genetic diversity where the major break in genetic homogeneity follows the edge of the sea ice co...

Pham, C. K., Canha, A., Diogo, H., Pereira, J. G., Prieto, R., and Morato, T. 2013. Total marine fishery catch for the Azores (1950–2010). – ICES Journal of Marine Science, 70: 564–577. Official fishery statistics often fail to report what has been truly extracted from the marine environment. Therefore, in this study, we estimated illegal, unreport...

Geographic variation in the acoustic features of whistles emitted by the striped dolphin (Stenella coeruleoalba) from the Atlantic Ocean (Azores and Canary Islands) and the Mediterranean was investigated. Ten parameters (signal duration, beginning, end, minimum and maximum frequency, the number of inflection points, of steps, of minima and maxima i...

How to improve estimation of tracking locations from animal telemetry

1 A bibliometric analysis of the literature on the sei whale Balaenoptera borealis is presented. Research output on the species is quantified and compared with research on four other whale species. The results show a significant increase in research for all species except the sei whale. Research output is characterized chronologically and by oceani...

Several seamounts have been identified as hotspots of marine life in the Azores, possibly acting as feeding stations for top predators, including cetaceans. The pelagic predator-prey interaction is a crucial ecological factor affecting animal distribution and abundance. To understand this relationship, this study explores cetacean movements in rela...

Micro- and macro-geographic variations of the whistles of striped dolphins (Stenella coeruleoalba)

North Atlantic fin whales are thought to undertake annual migrations between low-latitude, oligotrophic breeding grounds and high-latitude, productive feeding areas. Although there is some information on the whale’s distribution and behaviour in these high-latitude areas, very little is known about their migratory paths and behaviour. In 2009-2011,...

A right whale (Eubalaena glacialis) from the western North Atlantic population, sighted in the Azores, was subsequently found to have moved back to the northwest Atlantic. The whale was sighted in the Azores on 5 January 2009 travelling in a west-south westerly direction at a constant speed. A photographic match was found to an adult female in the...

The steady growth of the whale‐watching activities in the Azores and its concentration in a small area that partly overlaps the home range of a resident group of bottlenose dolphins ( Tursiops truncatus ) was one of the driving forces to proposing part of the range of this group as a marine protected area (MPA). Six years of data collected during b...

In this chapter an overview of cetacean research undertaken in the Azores is given. Starting with the accounts by Gaspar Frutuoso dating back to the XVI Century, a brief historical account is made. Focus is then given to the current research and the several techniques involved: photo-identification, surveys, acoustics, biologging, satellite telemet...