Eneko Aspillaga

• PhD
• PostDoc Position at Mediterranean Institute for Advanced Studies

Background The lack of compatibility between acoustic telemetry equipment from different manufacturers has been a major obstacle to consolidating large collaborative tracking networks. Undisclosed encrypted signal coding protocols limit the use of acoustic telemetry to study animal movements over large spatial scales, reduce competition between man...

Home range size is a fundamental trait that can affect the probability of fish being harvested and, at the same time, may be affected by fishing. The relationship between home range size and fishing will impact the effectiveness of fully protected areas (FPAs), as it will influence the number of fish moving into fished areas, affecting both spillov...

Most organisms synchronize to an approximately 24-hour (circadian) rhythm. This study introduces a novel deep learning-powered video tracking method to assess the stability, fragmentation, robustness and synchronization of activity rhythms in Xyrichtys novacula. Experimental X. novacula were distributed into three groups and monitored for synchroni...

Climate change is impacting ecosystems worldwide, and the Mediterranean Sea is no exception. Extreme climatic events, such as marine heat waves (MHWs), are increasing in frequency, extent and intensity during the last decades, which has been associated with an increase in mass mortality events for multiple species. Coralligenous assemblages, where...

Protection from direct human impacts can safeguard marine life, yet ocean warming crosses marine protected area boundaries. Here, we test whether protection offers resilience to marine heatwaves from local to network scales. We examine 71,269 timeseries of population abundances for 2269 reef fish species surveyed in 357 protected versus 747 open si...

The brown meagre (Sciaena umbra) is an endangered species, which requires specific protection measures to ensure its conservation. These measures need to be informed by high-quality scientific knowledge on their space use patterns. Here, we used acoustic telemetry to assess its seasonal movement patterns and habitat use within a marine protected ar...

Despite great promise for understanding the impacts and extent of climate change and extreme weather events on aquatic animals, their species, and ecological communities, it is surprising that electronic tagging and tracking tools, like biotelemetry and biologging, have not been extensively used to understand climate change or develop and evaluate...

Chronotypes, the individual differences in daily activity timing, have profound associations with numerous physiological processes. Despite this, the covariance between chronotypes and other aspects of an individual's behaviour has been infrequently explored in non-human animals. This study delves into individual's variation across four axes of per...

Geolocating aquatic animals with acoustic tags has been ongoing for decades, relying on the detection of acoustic signals at multiple receivers with known positions to calculate a 2D or 3D position, and ultimately recreate the path of an aquatic animal from detections at fixed stations. This method of underwater geolocation is evolving with new sof...

Fish differ consistently in behavior within the same species and population, reflecting distinct behavioral types (BTs). Comparing the behavior of wild and reared individuals provides an excellent opportunity to delve into the ecological and evolutionary consequences of BTs. In this work, we evaluated the behavioral variation of wild and reared juv...

The rise of nature-based tourism has provided a new avenue for disturbing animal behaviour, especially in protected areas. One of the most important tourism sectors in aquatic environments is scuba diving, an activity considered sustainable given its non-extractive nature and capability of bringing relevant socioeconomic benefits to local communiti...

Recent technological advances in marine biotelemetry have demonstrated that marine fish species perform activity–rest rhythms that have relevant ecological and evolutionary consequences. The main objective of the present report is to study the circadian rhythm of activity–rest of the pearly razorfish, Xyrichtys novacula in its own habitat, before a...

Acoustic telemetry is a popular and cost-efficient method for tracking the movements of animals in the aquatic ecosystem. But data acquired via acoustic telemetry often contains spurious detections that must be identified and excluded by researchers to ensure valid results. Such data management is difficult as the amount of data collected often sur...

Novel insights were provided by contrasting the composition of wild and farmed fish gut microbiomes because the latter had essentially different environmental conditions from those in the wild. This was reflected in the gut microbiome of the wild Sparus aurata and Xyrichtys novacula studied here, which showed highly diverse microbial community stru...

Fish differ consistently in behavior within the same species and population, reflecting distinct behavioral types (BTs). Comparing the behavior of wild and reared individuals provides an excellent opportunity to delve into the ecological and evolutionary consequences of BTs. In this work, we evaluated the behavioral variation of wild and reared juv...

The northern pike (Esox lucius) has been intensively studied in terms of behaviour due to its relevance to fisheries and its importance for structuring fish communities in freshwater ecosystems. However, little is known about the behaviour of coastal pike living in brackish lagoons. Freshwater ecosystems, particularly lakes and small rivers, are us...

The Columbretes Archipelago and their submerged surroundings are part of an unusual, Pleistocene volcanic field located in the Western Mediterranean. This zone was designated as a Site of Community Importance (SCI) in the Natura 2000 Network in the early 2000s. However, poor information about its habitats has been available until now. In the presen...

The ocean is a key component of the Earth's dynamics, providing a great variety of ecosystem services to humans. Yet, human activities are globally changing its structure and major components, including marine biodiversity. In this context, the United Nations has proclaimed a Decade of Ocean Science for Sustainable Development to tackle the scienti...

Climate change is causing an increase in the frequency and intensity of marine heatwaves (MHWs) and mass mortality events (MMEs) of marine organisms are one of their main ecological impacts. Here, we show that during the 2015–2019 period, the Mediterranean Sea has experienced exceptional thermal conditions resulting in the onset of five consecutive...

Deep learning allows us to automatize the acquisition of large amounts of behavioural animal data with applications for fisheries and aquaculture. In this work, we have trained an image-based deep learning algorithm, the Faster R-CNN (Faster region-based convolutional neural network), to automatically detect and track the gilthead seabream, Sparus...

Acoustic telemetry (AT) is a rapidly evolving technique used to track the movements of aquatic animals. As the capacity of AT research expands it is important to optimize its relevance to management while still pursuing key ecological questions. A global review of AT literature revealed region-specific research priorities underscoring the breadth o...

The spatio-temporal variability of fish distribution is important to better manage and protect the populations of endangered species. In this sense, the vertical movements of a vulnerable and protected species, Sciaena umbra, were assessed in a marine protected area (the Réserve Naturelle Marine de Cerbère-Banyuls, south of France) to study the var...

Despite their potential to generate high-quality positioning data, the use of high-resolution acoustic telemetry systems (HRATS) has been neglected in coastal marine areas due to the limitations that these environments pose to the transmission of acoustic signals. In this work, we applied a HRATS and social network analysis (SNA) to study the socia...

Using acoustic telemetry to monitor swimming behaviour of seabream in sea-cages

Behavioural types (i.e., personalities or temperament) are defined as among individual differences in behavioural traits that are consistent over time and ecological contexts. Behavioural types are widespread in nature and play a relevant role in many ecological and evolutionary processes. In this work, we studied for the first time the consistency...

Recent advances in tracking systems have revolutionized our ability to study animal movement in the wild. In aquatic environments, high-resolution acoustic telemetry systems make it technically possible to simultaneously monitor large amounts of individuals at unprecedented spatial and temporal resolutions, providing a unique opportunity to study t...

Acoustic telemetry techniques are very useful tools to monitor in detail the swimming behavior and spatial use of fish in artificial rearing environments at individual and group levels. We evaluated the feasibility of using passive acoustic telemetry to monitor fish welfare in sea-cage aquaculture at an industrial scale, characterizing for the firs...

Marine Protected Areas (MPAs) have been recognized as effective management and conservation tools to protectmarine coastal ecosystems. However, due to an increasing interest in marine ecosystems, recreational activitiessuch as scuba diving are rapidly growing in these areas, highlighting the need to implement adaptive man-agement strategies based o...

Macroalgal communities have an essential role in the shallow benthic habitats of temperate seas, where changes in their composition can resonate through entire coastal ecosystems. As all major ecosystems on Earth, algal beds have already been affected by multiple disturbances. Passive conservation tools, such as marine protected areas or No-take zo...

Underwater visual census (UVC) is currently the primary tool used to survey shallow water fish assemblages in the Mediterranean Sea. However, the rapid development of digital technologies, such as underwater video cameras and photogrammetric techniques, are providing new sampling opportunities in marine ecosystems. In this study we compare two non-...

Passive acoustic telemetry provides the opportunity to monitor and contextualize the movements of diverse aquatic animals. Despite depth being an essential dimension along which many processes are organized, the Eulerian structure of the acoustic telemetry data (movements perceived from fixed locations) and the consequences of sound propagation in...

Understanding how no-take zones (NTZs) shape the population dynamics of key herbivores is crucial for the conservation and management of temperate benthic communities. Here, we examine the recovery patterns of sea urchin populations following a high-intensity storm under contrasting protection regimes in the NW Mediterranean Sea. We found significa...

La cigarra de mar (Scyllarides latus) es una especie de crustáceo decápodo altamente conocida en el mar Mediterráneo debido a su valor comercial. No obstante, sus rasgos biológicos y ecológicos han permanecido ocultos a la ciencia hasta finales del siglo XX. Debido a estos dos factores, las poblaciones de la especie se han visto diezmadas en gran m...

The ability of the subtropical North Atlantic to sustain export production despite the lack of available nutrients is fascinating. Subtropical gyres are expected to expand under a global warming scenario, so it is important to understand the mechanisms supplying the required nutrients. Current issues for the region concern the nutrient and metaboli...

Dispersal and recruitment are fundamental processes for population recovery following disturbances in sessile species. While both processes are well understood for many terrestrial species, they still remain poorly resolved for some macroalgal species. Here we experimentally investigated the effective dispersal and recruit survival of a mesophotic...

Complementary analyses. Model diagnostics (Figures A and B), individual (for each direction and site) dispersal models (Table A), AIC results for individual models (Table B) and best-fitted models summary (Table C). (PDF)

Animal movement is a key biological process for the maintenance of ecosystem services, and a major concern for the conservation of biodiversity. The aim of movement ecology is to understand the causes and consequences of these movements, including the effect of internal and external factors and its ecological implications. This research field has r...

Passive acoustic telemetry is being widely used to study the movement of aquatic animals, and provides essential ecological information for species management and conservation. However, data from acoustic telemetry presents particular challenges for data analysis, especially if we aim to estimate the space use of individuals. As an example, many tr...

Marine protected areas (MPAs) are used as the main tool to confront the ecological impacts of overfishing, but in order to be effectively designed and managed, require accurate information on the biology and behaviour of targeted fish species. Here we used acoustic telemetry and novel analysis and visualization techniques to study the long-term mov...

A characterization of the thermal ecology of fishes is needed to better understand changes in ecosystems and species distributions arising from global warming. The movement of wild animals during changing environmental conditions provides essential information to help predict the future thermal response of large marine predators. We used acoustic t...

Remote sensing and animal movement datasets are increasingly used to answer key questions in ecology and conservation. Collecting and accessing this data is becoming ever cheaper and easier, but limited analytical expertise limits its wider use. Working at the interface between these two disciplines is challenging as there are no standard technique...

It is important to account for the movement behaviour of fishes when designing effective marine protected areas (MPAs). Fish movements occur across different spatial and temporal scales and understanding the variety of movements is essential to make correct management decisions. This study describes in detail the movement patterns of an economicall...

Results of the signal range-tests performed in the study site. The dots represent the mean (±SE) probability of tag detection at increasing distances from acoustic receivers. (PDF)

Spatial chronogram plots for each tagged Diplodus sargus individual. (PDF)

Distribution of phase-transition values (PT) calculated for the hourly reception number between consecutive day-night (A) and day-day (B) phases, for each Diplodus sargus individual. Lower and upper boundaries of the boxes represent the first and third quantiles of value distributions. Significant results of the Wilcoxon signed-rank tests against t...

Ocean acidification is receiving increasing attention because of its potential to affect marine ecosystems. Rare CO2 vents offer a unique opportunity to investigate the response of benthic ecosystems to acidification. However, the benthic habitats investigated so far are mainly found at very shallowwater (less than or equal to 5 m depth) and theref...

Although recruitment is considered an essential process regulating populations of many marine species, there is still a lack of knowledge about the ultimate factors that influence it. This is especially true for seaweeds, where population dynamics studies are also lacking. The main objective of this study was to investigate the main mechanisms driv...

Although recruitment is considered an essential process regulating populations of many marine species, there is still a lack of knowledge about the ultimate factors that influence it. This is especially true for seaweeds, where population dynamics studies are also lacking. The main objective of this study was to investigate the main mechanisms driv...

Knowledge about key demographic processes is required to understand and to predict the response of populations to environmental change. Recruitment is an essential process regulating population abundance and dynamics of many marine species. From the initial settlement of propagules to the first appearance in the population, algae are likely to expe...