Alexandre Alonso-Fernández

Instituto de Investigaciones Marinas (IIM-CSIC) · Ecology and Marine Resources

Octopuses are amongst the most fascinating animals in our oceans; however, while their intricate behaviours are often studied in laboratory settings, basic aspects of their movement ecology remain unstudied in the wild. Focusing on the socio-economically important common octopus (Octopus vulgaris), this study employs, for the first time, acoustic t...

Studies focusing on reproductive biology play a key role in deciphering fish population dynamics. We studied the main features of the reproductive biology of the greater weever Trachinus draco based on gonad histology and digital image analysis techniques and the main hypothesis of the study is that males of T. draco exhibit a nuptial colouration....

Diet studies on the endangered and genetically distinct Iberian population of the southern harbour porpoise Phocoena phocoena are scarce. The present study provides updated information on the feeding ecology of this cetacean along the Galician coast (NW Spain) over the last 3 decades (1990-2018). The stomach contents of 72 stranded harbour porpoise...

Fish fecundity is a key life history characteristic, and can be used in stock assessment and management. In this study, we estimated the batch fecundity of the Atlantic chub mackerel Scomber colias, along the coast of Morocco at two locations: Larache in eastern Atlantic and M’diq in western Mediterranean. The sampling program of the studied specim...

Fish movements are fundamental to their ecology and survival. Understanding the causes and consequences of the spatial behaviour of fish is of high relevance as it provides critical knowledge for conservation purposes. Skate (Rajidae) populations face an unprecedented global decline due to overfishing. In this study, we used acoustic telemetry to t...

Species Distribution Models are pivotal for fisheries management. There has been an increasing number of fishery data sources available, making data integration an attractive way to improve model predictions. A wide range of methods have been applied to integrate different datasets in different disciplines. We focus on the use of Integrated Species...

Shark populations have suffered dramatic declines across the world as a result of overfishing. Marine protected areas (MPAs) can help restore overfished populations; however, their effectiveness largely relies on understanding the ecology of the targeted species. This study investigated the spatial ecology of the intensely harvested but understudie...

Cetaceans play an important role in maintaining the health and stability of marine ecosystems. To understand the trophic relationships of these top predators in waters off the Northwest Iberian Peninsula, and to determine their possible competition with fisheries, the stomach contents of 751 common dolphins (Delphinus delphis), 60 striped dolphins...

Individual re-identification is critical to track population changes in order to assess status, being particularly relevant in species with conservation concerns and difficult access like marine organisms. For this, we propose photo-identification via deep learning as a non-invasive technique to discriminate between individuals of the undulate skat...

Functional connectivity patterns of threatened species provide critical information for effective management and conservation spatial planning. In this study, we used a non-lethal novel combination of acoustic telemetry and stable isotope analysis (SIA) on the Near Threatened elasmobranch Raja undulata to evaluate shifts in resource/space use in re...

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...

Discard reduction is a cornerstone of the European Common Fisheries Policy. The discard ban policy, which aims to reduce fisheries discards, is particularly challenging for small-scale fisheries. Demonstrating high survival rates of discarded individuals may provide flexibility to the application of the discard ban through the so-called survival ex...

Length-based methods have been widely applied to estimate biological parameters and to understand the dynamics of marine resource populations within the category of data-limited stocks. However, few studies have been performed to date to test the parameter sensitivity of length-based methods on stocks with different traits and fishery contexts. In...

Climate change is causing a northward shift of fish species and the tropicalisation of temperate zones. In this context, the toadfish Halobatrachus didactylus was found for the first time in 2018 in Galician waters (NW Spain), where a total of 39 specimens have been recorded so far in the southernmost part of those known as Rías Baixas. Preliminary...

Citation: Bañón, R.; Almón, B.; Fabeiro, M.; Rábade, S.; Alonso-Fernández, A.; Mosquera, S.; Mariño, J.C.; Ríos, M.B.; de Carlos, A. Abstract: Climate change is causing a northward shift of fish species and the tropicalisation of temperate zones. In this context, the toadfish Halobatrachus didactylus was found for the first time in 2018 in Galician...

Length-based methods have been widely applied to estimate biological parameters and understand the dynamics of marine resource populations within data-limited stocks. However, to date few studies have tested the sensitivity of parameters in length-based methods examining stocks with different traits and fishery contexts. In the Bay of Biscay and th...

In the Iberian Coast region, the common sole (Solea solea) is considered a very relevant species due to its high commercial value. Despite its importance, the current status of this stock is still poorly known due to the scarcity of available data to apply formal assessment methods. In data-poor situations length-based methods have been widely appl...

Several specimens of Alepisaurus ferox Lowe, 1833 were caught in the coastal Galician waters (Northwest Spain). From two preserved specimens, morphometric and meristic parameters, along with DNA barcoding, confirmed the identification of the specimens. Examination of the stomach contents revealed a diverse diet with up to 13 different preys with on...

Un total de 58 spécimens de Trachinus draco Linnaeus, 1758 ont été capturés dans les eaux de Galice (nord-ouest de l’Espagne) et dans le golfe de Cadix (sud de l’Espagne) entre juin et novembre 2020. Vingt-huit d’entre eux, tous des mâles, présentaient une tâche sombre distincte située au-dessus de la nageoire pectorale et sous la ligne latérale de...

The effectiveness of Marine Protected Areas (MPAs) depends on the mobility of the populations that are the target of protection, with sedentary species likely to spend more time under protection even within small MPAs. However, little is understood about how individual variation in mobility may influence the risk of crossing an MPA border, as well...

• Knowledge of the spatial behaviour of aquatic living resources is essential to assess their vulnerability to environmental and anthropogenic stressors and inform efficient management strategies. • Elasmobranchs are particularly vulnerable to exploitation. Within this group of fish, the implementation of species-specific conservation actions has b...

Queen scallop Aequipecten opercularis, is exploited by small-scale trawlers in separated aggregations along the east Atlantic coast and the Mediterranean Sea. However, population performance is poorly known. Here, we combine official information and on-board observers’ data over two decades to study the fishery ecology of an aggregation occurring i...

The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundr...

Individual acoustic tracking is a valuable tool to understand the behavioral ecology of aquatic species and to inform conservation actions. In this study, we examined the spatial behavior of single individuals of four common coastal fish species (striped red mullet, Mullus surmuletus;corkwing wrasse, Symphodus melops;pollack Pollachius pollachius;a...

The protection of fish nurseries has been recognized as a useful tool to efficiently manage fisheries given that protected areas enhance the recruitment of target species. To identify and locate potential nursery areas, a solid understanding of species-environment relationships and their spatio-temporal dynamics is needed. Within this context, in t...

Body size plays a key role for the productivity and resilience of marine populations. This work analyses the variation in body size indicators taken from ~ 400 000 individuals during the period 2000–2018 for a set of 20 key commercial species of the small-scale fishery of Galicia (SW Europe). Mean body size showed relatively stable inter-annual tre...

Despite the recognised effectiveness of networks of marine protected areas (MPAs) as a biodiversity conservation instrument, MPA network design frequently disregards the importance of connectivity patterns. In the case of sedentary marine populations, connectivity stems not only from the stochastic nature of the physical environment that affects di...

Evidences of changes in the fish fauna of Galician waters is documented based on the occurrence of 24 specimens belonging to eight warm affinity fishes. Information about the morphology and new findings of Desmodema polystictum (Trachipteridae), Halobatrachus didactylus (Batrachoididae), Dacty-lopterus volitans (Dactylopteridae) Anthias anthias (Se...

La presente guía es el fruto del trabajo realizado durante el proyecto de investigación Monitoreo con Telemetría Acústica del Comportamiento de especies costeras y evaluación de la protección ejercida por un área marina protegida (TAC). El grupo de Ecología Pesquera del Departamento de Ecología y Recursos Marinos del Instituto de Investigaciones Ma...

Marine ecosystems have been traditionally exploited by coastal communities in several ways, especially by fishing. More recently, aquaculture has emerged as an activity through which coastal communities have diversified their economies. Thus, many regions of the world face the challenge of allowing both activities to maximise their yields while com...

One specimen of the boreal Clupea harengus (Clupeidae) was caught southerly, in the Gulf of Cádiz (southern Spain), whereas a specimen of the subtropical Epinephelus aeneus (Serranidae) was caught northerly, in Galician waters (north‐west of Spain). These catches represent a new southernmost record in the eastern Atlantic for C. harengus and the se...

Boletín de la Red de Seguimiento del Cambio Global en Parques Nacionales

Todos los aspectos de la biología y ecología de las especies animales se desarrollan en el espacio. Por lo tanto, el estudio del papel que juegan los patrones espaciales en los procesos ecológicos (como la dinámica poblacional, interacciones entre especies o procesos de dispersión que finalmente afectan a su distribución) es vital para lograr una g...

BACKGROUND: Spawning stock biomass (SSB) has been generally used as an indicator of spawning stock production but it is not exact because there are other factors like size, experience or condition that affect capacity of females to produce viable offspring that may eventually recruit to adult population or fishery. This ability is the Stock Reprodu...

Spawning stock biomass (SSB) has been generally used as an indicator of spawning stock production but it is not exact because there are other factors like size, experience or condition that affect capacity of females to produce viable offspring that may eventually recruit to adult population or fishery. This ability is the Stock Reproductive Potent...

Estimation of fish stock reproductive potential has been of increasing importance in recent years. It involves the estimation of several key parameters in a routine basis, such as potential and/or batch fecundity, spawning fraction, atresia… To achieve this routinely it is highly recommended the use of methodologies that reduce time for estimation,...

Understanding the connectivity patterns of marine populations is essential for their management and conservation. In the case of sedentary marine populations, connectivity stems not only from the stochastic nature of the physical environment that affects early-life stages dispersal, but also by the spawning stock attributes that affect reproductive...

The occurrences of 13 specimens belonging to 9 species of little known marine fishes in the Northeast Atlantic in 2017 and 2018 are reported. Information about the morphology and new findings of Decapterus tabl and Decapterus macarellus (Carangidae), Kyphosus vaigiensis (Kyphosidae), Remora osteochir (Echeneidae), Antigonia capros (Caproidae), Hype...

Small-scale fisheries (SSFs) are large contributors to worldwide catches and local economies; however, SSFs have been historically under-attended in national and international policies. This work presents a standardization of catch-per-unit-of-effort data obtained from onboard observers for twenty commercial coastal species caught by the SSFs off t...

2018. First record of Epinephelus costae (Actinopterygii: Perciformes: Epinephelidae) from Galician waters (north-western Spain): Exploring the northward range expansion. Acta Ichthyol. Piscat. 48 (4): 399-402. Abstract. The first record of the goldblotch grouper, Epinephelus costae (Steindachner, 1878), from Galician waters is reported. Two specim...

signalement le plus septentrional et nouvelles données biologiques du dragonnet phaéton Synchiropus phaeton (calliony-miformes: callionymidae) dans l'atlantique est. Une femelle reproductrice active du dragonnet phaéton Syn-chiropus phaeton (Günther, 1861) de 22 cm de long, a été capturée avec un chalut de fond dans la zone portugaise de l'océan at...

The first record of the prickly puffer Ephippion guttifer (Tetraodontidae) from Galician waters (north‐west Spain) is reported based on a male specimen of 570 mm total length (LT) caught in the Ría de Vigo. Morphometric, meristic and DNA barcode data confirmed the identification. Histological examination of reproductive tissue was carried out in th...

Many marine species, including anemones, snails, jellyfish, coral and fish, are venomous to humans, causing serious injuries or even death. Most of these animals live in warm, shallow waters, which increase the chances of an encounter with them. The majority of these interactions with humans are accidental; however, it is not well known under which...

Blue shark Prionace glauca (L. 1758) (Carcharhinidae) is an oceanic–epipelagic and fringe littoral species worldwide distributed in temperate and tropical oceans. It is one of the most abundant, widespread, fecund and fastest growing sharks. Blue shark also is one of the most exploited shark species globally and in European waters. The anomalous pr...

Common octopus is a worldwide important cephalopod resource fished by both industrial and small-scale fleets which has gained market value in recent decades. In Galicia (NW Iberian Peninsula), common octopus (Octopus vulgaris sensu stricto) has been exploited since ancient times in intertidal and subtidal areas using multiple methods and fishing ge...

The first records of the spearfish remora, Remora brachyptera (Lowe, 1839) (Actinopterygii: Echeneidae), and the white grouper, Epinephelus aeneus (Geoffroy Saint-Hilaire, 1817) (Actinopterygii: Serranidae), from northern Spanish waters are reported. Both findings are, respectively, the second and the first northernmost reports, for both fish speci...

Sex ratio is a fundamental demographic parameter with major implications for the dynamics, management, and conservation of animal populations. The objective was to study the main factors affecting the post-settlement population sex ratio (SR) of Octopus vulgaris off the NE Atlantic. We investigated the spatio-temporal dynamics in SR using more than...

Catchability, a key parameter in stock assessment, is often considered constant in time and space. However, when fishing with passive gears like traps or gillnets, fish behavior determines the odds of encounter with the fishers and thus catchability. Few studies have presented comprehensive empirical evidence of the link between behavior measured i...

ABSTRACT: Fish body size is a key life history trait that influences population dynamics. Individual growth and size distribution are generally affected by both intrinsic and extrinsic factors. However, the drivers of body size changes are still poorly understood. The NW Iberian Peninsula is one of the most important fishing regions in Europe, wher...

Fish spawning frequency varies from daily to once in a lifetime. Some species spawn and feed in separate areas, during different seasons, by storing energy and drawing on it later for reproduction (i.e. capital breeding). Other species spawn using energy acquired locally, throughout a prolonged spawning season, allocating energy directly to reprodu...

When gene flow is limited and harvesting is intensive, fishing may alter life-histories and favour trait combinations that collectively reduce adult body size. However, empirical evidence of downsizing of adults in small-bodied coastal fish is still scarce, in part due to the lack of knowledge about the selective nature of certain fishing gears, su...

Energy allocation is an important component of life-history variation since it determines the tradeoff between growth and reproduction. In this study we investigated the state-dependent and sex-specific energy allocation pattern and the reproductive investment of a protogynous hermaphrodite fish with parental care. Individuals of Labrus bergylta, a...

The quantity and quality of propagules, i.e., reproductive output, play a key role in the dynamics of exploited populations, with particular implications for sex-changing fish. Here, we studied for the first time the effects of maternal traits on the reproductive output of the Mediterranean rainbow wrasse Coris julis, a sequential hermaphroditic fi...

The pollack, Pollachius pollachius, is an important commercial species for the Spanish artisanal fleet in Atlantic Iberian waters. This study provides information on the reproductive biology of the species, including length at maturity, reproductive cycle and gamete development pattern based on histological methods. A collection of 622 individuals...

Fish populations are often treated as homogeneous units in typical fishery management, thereby tacitly ignoring potential intraspecific variation which can lead to imprecise management rules. However, intraspecific variation in life-history traits is widespread and related to a variety of factors. We investigated the comparative age-based demograph...

Reparametrized von Bertalanffy growth function (rVBGF) parameters estimates with upper and lower 95% confidence intervals. (DOCX)

(DOCX)

Parameters of the unconstrained Von Bertalanffy growth functions with upper and lower 95% confidence intervals and Akaike Information Criteria (AIC) for each model. (DOCX)

We studied multiple individual parameters that affect the reproductive output in the painted comber Serranus scriba, a simultaneous hermaphroditic fish that is widely exploited by recreational fishing in temperate marine coastal regions. Batch fecundity was significantly affected by maternal size, but was not related to maternal age or condition. H...

Oogenesis in fishes follows a universal plan; yet, due to differences in the synchrony and rate of egg development, spawning frequency varies from daily to once in a lifetime. Some species spawn and feed in separate areas, during different seasons, by storing energy and drawing on it later for reproduction (i.e. capital breeding). Other species spa...

We studied multiple individual parameters that affect the reproductive output in the painted comber Serranus scriba, a simultaneous hermaphroditic fish that is widely exploited by recreational fishing in temperate marine coastal regions. Batch fecundity was significantly affected by maternal size, but was not related to maternal age or condition. H...

For many fish populations reproductive patterns remain unknown, which often results in inadequate management strategies. Timing and intraspecific variability in the main reproductive traits of ballan wrasse (Labrus bergylta) were investigated based on microscopic analysis of gonads sampled from NW Spain in 2009-2012. This species displays two main...

Proximate composition and energy content in Trisopterus luscus have been studied to address energy allocation strategy. Energy reserves in pouting females are mainly associated with lipids stored in the liver. Water content appeared to be a useful index in order to obtain very accurate predictions of energy density, particularly for ovaries and liv...

It is well documented and accepted that the reproductive potential of a population is not only influenced by the abundance of spawners but also by their age, size, and condition. Most studies of maternal effects on the reproductive potential have focused on factors such as egg production and quality, and less attention has been paid to the maternal...

It is well documented and accepted that the reproductive potential of a population is not only influenced by the abundance of spawners but also by their age, size, and condition. Most studies of maternal effects on the reproductive potential have focused on factors such as egg production and quality, and less attention has been paid to the maternal...

It is well documented and accepted that the reproductive potential of a population is not only influenced by the abundance of spawners but also by their age, size, and condition. Most studies of maternal effects on the reproductive potential have focused on factors such as egg production and quality, and less attention has been paid to the maternal...

Fish regulate egg production by atresia. Sometimes, oocytes are encapsulated in cystic structures that might remain in the ovary for months, altering female reproductive potential in future spawning seasons. Ovaries of Atlantic cod (Gadus morhua, L.) from the Flemish Cap and European hake (Merluccius merluccius, L.) from the Galician Shelf (NW Spai...