Consistent Selection towards Low Activity Phenotypes When Catchability Depends on Encounters among Human Predators and Fish

Together with life-history and underlying physiology, the behavioural variability among fish is one of the three main trait axes that determines the vulnerability to fishing. However, there are only a few studies that have systematically investigated the strength and direction of selection acting on behavioural traits. Using in situ fish behaviour revealed by telemetry techniques as input, we developed an individual-based model (IBM) that simulated the Lagrangian trajectory of prey (fish) moving within a confined home range (HR). Fishers exhibiting various prototypical fishing styles targeted these fish in the model. We initially hypothesised that more active and more explorative individuals would be systematically removed under all fished conditions, in turn creating negative selection differentials on low activity phenotypes and maybe on small HR. Our results partly supported these general predictions. Standardised selection differentials were, on average, more negative on HR than on activity. However, in many simulation runs, positive selection pressures on HR were also identified, which resulted from the stochastic properties of the fishes' movement and its interaction with the human predator. In contrast, there was a consistent negative selection on activity under all types of fishing styles. Therefore, in situations where catchability depends on spatial encounters between human predators and fish, we would predict a consistent selection towards low activity phenotypes and have less faith in the direction of the selection on HR size. Our study is the first theoretical investigation on the direction of fishery-induced selection of behaviour using passive fishing gears. The few empirical studies where catchability of fish was measured in relation to passive fishing techniques, such as gill-nets, traps or recreational fishing, support our predictions that fish in highly exploited situations are, on average, characterised by low swimming activity, stemming, in part, from negative selection on swimming activity. © 2012 Alós et al.This work was supported by the research project CONFLICT (grant # CGL2008-00958) and REC2 (grant # CTM2011-23835), both of them funded by the Spanish Ministry of Economy and Competitiveness (MINECO). Additional funding was received from the research project ARTEVIGO (grant # 09MMA022402PR) financed by the Galician Government, Spain. RA also received additional funding from the German Federal Ministry for Education and Research (BMBF) through the Program for Social-Ecological Research for the project Besatzfisch (grant # 01UU0907)Peer Reviewe

High levels of organochlorine pollutants in the tunids Thunnus thynnus and Thunnus alalunga at the Balearic Islands

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Selection drivers of life-history traits in marine coastal fishes

Humans can induce contemporary evolution through harvesting wild animals. This thesis provides evidence of this process for recreational fishing at surprisingly small geographical scales. Marine fish populations are characterized by high variability in heritable individual life‐history traits which are exposed to biased fishing mortality. The life histories strategies of actual populations, which collectively reduce adult body size, mirror such biased mortality in populations exposed to limited gene flow. Because the relationship between life history and behaviour, it is very likely that fishing also induces adaptive responses in behavioural traits. Due the potential negative effects of fishing selection the productivity and quality of the fishery, this thesis recommend considering the evolutionary impacts of fishing in the management plans of species exploited by the recreational fishingEl humans poden produir evolució contemporània a través de la recol∙lecció de animals salvatges. Aquesta tesis proporciona evidencies d’aquest procés per la pesca recreativa a una sorprenent escala espacial petita. Les poblacions marines de peixos tenen una alta variabilitat individual en caràcters heretables de la història exposada a una mortalitat selectiva per pesca. Les estratègies vitals de les poblacions actuals de peixos costaners, les quals conjuntament produeixin una reducció en la mida del individu, són el reflexa d’aquesta pesca selectiva en poblacions amb baixa connectivitat. Degut a la correlació entre història vital i comportament, la pesca pot induir també respostes adaptatives en cert caràcters comportamentals. Considerant els efectes negatius de la selecció per pesca en la productivitat i la qualitat de les pesqueries, aquesta tesis recomana considerar els possibles efectes evolutius produïts per la pesca en les estratègies de gestió d’espècies explotades per la pesca recreativaEl hombre puede producir evolución contemporánea por la recolección de animales salvajes. La presente tesis proporciona evidencias de este proceso por la pesca recreativa en una sorprendente escala espacial pequeña. Las poblaciones de peces marinos presentan una alta variabilidad en caracteres heredables de la historia vital expuesta a mortalidad selectiva por pesca. Las estrategias vitales de las poblaciones actuales de los peces costeros, las cuales conjuntamente producen una reducción en el tamaño del individuo, son el reflejo de esta mortalidad selectiva en poblaciones con baja conectividad. Debido a la relación entre historia vital y comportamiento, la pesca puede también inducir cambios adaptativos en ciertos rasgos de comportamiento. Considerando los efectos negativos de la selección por pesca en al productividad y calidad de la pesquería, esta tesis recomienda considerara los posibles efectos evolutivos inducidos por la pesca en la estrategias de gestión de especies explotadas por la pesca recreativa

Bayesian state-space modelling of conventional acoustic tracking provides accurate descriptors of home range behavior in a small-bodied coastal fish species

State-space models (SSM) are increasingly applied in studies involving biotelemetry-generated positional data because they are able to estimate movement parameters from positions that are unobserved or have been observed with non-negligible observational error. Popular telemetry systems in marine coastal fish consist of arrays of omnidirectional acoustic receivers, which generate a multivariate time-series of detection events across the tracking period. Here we report a novel Bayesian fitting of a SSM application that couples mechanistic movement properties within a home range (a specific case of random walk weighted by an Ornstein-Uhlenbeck process) with a model of observational error typical for data obtained from acoustic receiver arrays. We explored the performance and accuracy of the approach through simulation modelling and extensive sensitivity analyses of the effects of various configurations of movement properties and time-steps among positions. Model results show an accurate and unbiased estimation of the movement parameters, and in most cases the simulated movement parameters were properly retrieved. Only in extreme situations (when fast swimming speeds are combined with pooling the number of detections over long time-steps) the model produced some bias that needs to be accounted for in field applications. Our method was subsequently applied to real acoustic tracking data collected from a small marine coastal fish species, the pearly razorfish, Xyrichtys novacula. The Bayesian SSM we present here constitutes an alternative for those used to the Bayesian way of reasoning. Our Bayesian SSM can be easily adapted and generalized to any species, thereby allowing studies in freely roaming animals on the ecological and evolutionary consequences of home ranges and territory establishment, both in fishes and in other taxa.This study was funded through a Marie Curie Post-Doc grant (FP7-PEOPLE-2012-IEF, grant no. 327160). MP received additional funding from the research project REC2 (grant no. CTM2011-23835) and the research project CONFLICT (grant no. CGL2008-00958) and JA from a Juan de la Cierva Post-doc grant (grant no. FJCI-2014-21239), all of them funded by the Spanish Ministry of Economy and Competiveness. The project also received additional funding from the B-Types project funded through Leibniz Competition (grant no. SAW-2013-IGB-2) to RA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe

Consistent size-independent harvest selection on fish body shape in two recreationally exploited marine species

Harvesting wild animals may exert size-independent selection pressures on a range of morphological, life history, and behavioral traits. Most work so far has focused on selection pressures on life history traits and body size as morphological trait. We studied here how recreational fishing selects for morphological traits related to body shape, which may correlate with underlying swimming behavior. Using landmark-based geometric morphometrics, we found consistent recreational fishing-induced selection pressures on body shape in two recreationally exploited marine fish species. We show that individuals with larger-sized mouths and more streamlined and elongated bodies were more vulnerable to passively operated hook-and-line fishing independent of the individual's body size or condition. While the greater vulnerability of individuals with larger mouth gapes can be explained by the direct physical interaction with hooks, selection against streamlined and elongated individuals could either involve a specific foraging mode or relate to underlying elevated swimming behavior. Harvesting using passive gear is common around the globe, and thus, size-independent selection on body shape is expected to be widespread potentially leaving behind individuals with smaller oral gapes and more compact bodies. This might have repercussions for food webs by altering foraging and predation. © 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.This study was financed by the research project REC2 (grant#CTM2011-23835) funded by the Spanish Ministry of Economy and Competiveness (MINECO) and a Marie Curie Post-Doc grant to JA (FP7-PEOPLE-2012-IEF, Grant Number 327160). RA received funding from the German Federal Ministry for Education and Research (BMBF) through the Program for Social-Ecological Research for the project Besatzfisch (Grant Number 01UU0907, www.besatz-fisch.de) and the University of Florida, School of Forest Resources and Conservation, during a sabbatical stay during which this manuscript was drafted. The finalization of the project was financially supported by the BTypes project funded through the Leibniz Competition (SAW-2013-IGB-2) to R.A.Peer Reviewe

Fast-spreading green beds of recently introduced Halimeda incrassata invade Mallorca island (NW Mediterranean Sea)

6 páginas, 2 figuras, 1 tabla.Mediterranean marine biodiversity is undergoing a tropicalization process.We present the first record and spread dynamics of the tropical green seaweed Halimeda incrassata (Bryopsidales, Chlorophyta) fromthe Mediterranean Sea. Plants were observed at 2 sites offMallorca island (NW Mediterranean), and species identification was confirmed molecularly. Since the first observation of this alien seaweedin 2011, it has spreadrapidly inthe shallow subtidal habitat ofamarine protected area located in Palma Bay, which has a depth of up to ca. 20 m. By 2015, this species spread by a factor of 6.75 and extended to an area of 2.7 km2, covering a total of 41% of the monitored area. The dynamics of the invasion suggest rapid colonization and establishment and spreading of the species through shallow sedimentary and rocky habitats. H. incrassata has the potential to strongly alter the ecosystem services and functioning of shallow Mediterranean habitats. We encourage authorities to pay attention to the spread of this alien seaweed at larger scales and determine the positive and negative effects of the invasion in order to facilitate research- driven decision making.The data used for this study was ob - tained through the project REC2 (CTM2011-23835) and a Marie Curie grant (grant no. 327160). We thank Antoni Grau (Govern de les illes Balears) for supporting and authorizing the study in the MPAPB and Rosario Rosselló and Chiela Cremen for their help. J.A. was supported by a JdC postdoc (FJCI-2014-21239) and F.T. by a RyC grant (MINECO). The Verbruggen lab received funding from the ARC (FT110100585) and the ABRS (RFL213-08).Peer reviewe

Individual variability and sex-related differences in the growth of Diplodus annularis (Linnaeus, 1758)

10 páginas, 1 tabla, 10 figurasVariability and changes in the individual life-history parameters of fishes are frequently overlooked, and it is assumed that all individuals mature, spawn, grow, and die at the same rates over their lifespans. Here, the variability in the individualgrowth of the rudimentary hermaphrodite Diplodus annularis (Linnaeus, 1758) is described using a Bayesian approach. This approach enables the inference of individualgrowth curves, even in a species of a relatively short lifespan, and revealed a biphasic growth pattern for this species. Conventional von Bertalanffy growth failed to fit the individual back-calculated lengths-at-age data well. A generalization of this model is proposed for accommodating one change in the growth rate at some moment of the lifespan of this species. This novel five-parameter model (L∞, k0, k1, t0 and t1, i.e., size at infinite age, initial and final growth rate, age at size zero and age at the change of growth rate) represents the different allocation of energy to somatic growth or reproduction, prior to and post-sexual maturity. Moreover, between-sexgrowthdifferences are described; juvenile fish display similar growth rates in both sexes, but mature females have lower growth rates than males. The detailed description of the growth of the D. annularis shown here can provide adequate input for future implementation of population dynamics models that take into account individualvariability (e.g., IBMs, individual-based models). These models could facilitate the management of a species targeted by recreational fishery.This study was founded by the research project ROQUER (CTM2005-00283) funded by Ministerio de Educación y Ciencia of the Spanish Government. Finally, we would like to thank two anonymous reviewers for their useful comments. The first author was supported by a FPI fellowship (MICINN).Peer reviewe

MPA network design based on graph network theory and emergent properties of larval dispersal

Despite the recognised effectiveness of networks of Marine Protected Areas (MPAs) as a biodiversity conservation instrument, nowadays 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 early-life stages dispersal, but also from the spawning stock attributes that affect the reproductive output (e.g., passive eggs and larvae) and its survivorship. Early-life stages are virtually impossible to track in the ocean. Therefore, numerical ocean current simulations coupled to egg and larval Lagrangian transport models remain the most common approach for the assessment of marine larval connectivity. Inferred larval connectivity may be different depending on the type of connectivity considered; consequently, the prioritisation of sites for marine populations' conservation might also differ. Here, we introduce a framework for evaluating and designing MPA networks based on the identification of connectivity hotspots using graph theoretic analysis. We use as a case of study a network of open-access areas and MPAs, off Mallorca Island (Spain), and test its effectiveness for the protection of the painted comber Serranus scriba. Outputs from network analysis are used to: (1) identify critical areas for improving overall larval connectivity; (2) assess the impact of species' biological parameters in network connectivity; and (3) explore alternative MPA configurations to improve average network connectivity. Results demonstrate the potential of graph theory to identify non-trivial egg/larval dispersal patterns and emerging collective properties of the MPA network which are relevant for increasing protection efficiency.Comment: 8 figures, 3 tables, 1 Supplementary material (including 4 table; 3 figures and supplementary methods

Características del rendimiento reproductivo del hermafrodita simultáneo Serranus scriba en el Mediterráneo Occidental (Islas Baleares)

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. However, egg quality as estimated by egg dry weight was significantly influenced by the interaction effect of maternal size and age. An empirical assessment demonstrated the existence of a diel spawning pattern based on a daily release of a partial fraction of eggs related to sunset time. Buoyancy varied during the incubation period, but it consistently resulted in positive buoyancy that situated the eggs near the top of the water column. This study represents the first estimation of reproductive output of the simultaneous hermaphrodites S. scriba and also provides a comprehensive study about the potential maternal factors that affect egg production. These results are a crucial step towards ongoing efforts to improve the stock assessment of this species.Se estudiaron varios parámetros individuales que afectan el éxito reproductivo de la especie Serranus scriba, un pez hermafrodita simultáneo que es intensamente explotado por la pesca recreativa en regiones costeras de aguas templadas. La fecundidad parcial está significativamente relacionada con el tamaño de los individuos; pero no se encontró relación con la edad o condición. Sin embargo, la calidad de los huevos (estimada a partir del peso seco) resultó significativamente influenciada por la interacción del tamaño y edad de los individuos. Se demostró empíricamente la existencia de un patrón de desove diario, basado en la puesta diaria de una fracción de los huevos del total con anterioridad a la puesta del sol. La flotabilidad de los huevos varió durante el período de incubación; pero presentando de forma consistente una flotabilidad positiva que sitúa a los huevos liberados cerca de la parte más superficial de la columna de agua. Este estudio representa la primera estimación de los parámetros reproductivos relacionados con la producción de huevos en el hermafrodita simultáneo Serranus scriba. Proporciona además un detallado estudio sobre los posibles factores parentales que afectan a la producción de huevos en esta especie. Estos resultados son un paso fundamental para los esfuerzos en curso para mejorar la evaluación y gestión de las poblaciones de Serranus scriba

Fitness consequences of fish circadian behavioural variation in exploited marine environments

The selective properties of fishing that influence behavioural traits have recently gained interest. Recent acoustic tracking experiments have revealed between-individual differences in the circadian behavioural traits of marine free-living fish; these differences are consistent across time and ecological contexts and generate different chronotypes. Here, we hypothesised that the directional selection resulting from fishing influences the wild circadian behavioural variation and affects differently to individuals in the same population differing in certain traits such as awakening time or rest onset time. We developed a spatially explicit social-ecological individual-based model (IBM) to test this hypothesis. The parametrisation of our IBM was fully based on empirical data; which represent a fishery formed by patchily distributed diurnal resident fish that are exploited by a fleet of mobile boats (mostly bottom fisheries). We ran our IBM with and without the observed circadian behavioural variation and estimated selection gradients as a quantitative measure of trait change. Our simulations revealed significant and strong selection gradients against early-riser chronotypes when compared with other behavioural and life-history traits. Significant selection gradients were consistent across a wide range of fishing effort scenarios. Our theoretical findings enhance our understanding of the selective properties of fishing by bridging the gaps among three traditionally separated fields: fisheries science, behavioural ecology and chronobiology. We derive some general predictions from our theoretical findings and outline a list of empirical research needs that are required to further understand the causes and consequences of circadian behavioural variation in marine fish.This study was funded by the research project Phenofish (grant no. CTM2015-69126-C2-1-R) funded by the Spanish Ministry of Economy and Competiveness. Josep Alós was supported by a JdC post-doc grant funded by the Spanish Ministry of Economy, Industry and Competitiveness (ref. IJCI-2016-27681). Andrea Campos-Candela was supported by a FPU predoctoral fellowship (ref. FPU13/01440) from the Spanish Ministry of Education, Culture and Sports (MECD)