El valor económico no consumitivo de la vida salvaje: el caso de tres especies de cetáceos

The conservation of wildlife is one of the most pressing issues in the current times, but wildlife conservation economic values have often been largely ignored due to an absence of market prices, as setting an economic value on biodiversity or whole ecosystems can be challenging. Nevertheless, valuing wildlife can be of great significance to improve decision-making in the conservation field, as it can provide a complementary perspective based on economic principles. Whale-watching provides an opportunity for the economic valuation of wildlife. Specifically, it offers a framework in which the economic revenue allows the economic valuation of the targeted cetaceans to be estimated through the direct and indirect expenditure of the tourists who purchase whale-watching tours. Here, we performed an economic analysis based on population abundances of the three main species targeted by the whale-watching companies in the Strait of Gibraltar (Spain): long-finned pilot whales (Globicephala melas), common dolphins (Delphinus delphis) and killer whales (Orcinus orca). These species generated a total annual income of €4,089,056, €1,876,833, and €505,389, respectively, and each individual would generate an average of €14,048, €951, and €36,099 each year, respectively. Incorporating life expectancy, this corresponded to a total population value of €112,426,185, €16,685,147, and €19,171,107, respectively, over their lifetime. These values provide an idea of the potential contribution of cetaceans to the local economy but only represent their non-consumptive value based on tourism. Our results reinforce the idea that a sustainable, high-quality whale-watching culture, under ACCOBAMS High-Quality Whale-Watching requirements, should be promoted to ensure a sustainable industry, stable economic income and the viability of cetacean populations in the Strait of Gibraltar.La conservación de la vida salvaje es uno de los retos clave del mundo actual. Sin embargo, los valores económicos derivados de la conservación de la vida salvaje a menudo han sido pasados por alto debido a la ausencia de precios de mercado, ya que asignar un valor económico a la biodiversidad o a ecosistemas enteros puede ser complejo. No obstante, valorar la vida salvaje puede ser de gran importancia para mejorar la toma de decisiones en el campo de la conservación, ya que puede proporcionar una perspectiva complementaria basada en principios económicos. El avistamiento de cetáceos brinda una oportunidad para realizar este tipo de valoración económica. Específicamente, ofrece un marco en el cual los ingresos económicos generados permiten la evaluación y estimación del valor económico de los cetáceos objetivo basado en el gasto directo e indirecto de los turistas que realizan tours de avistamiento de cetáceos. En este estudio, realizamos un análisis económico basado en las abundancias poblacionales de las tres principales especies objetivo de las compañías de avistamiento de cetáceos en el Estrecho de Gibraltar (España): calderones comunes (Globicephala melas), delfines comunes (Delphinus delphis) y orcas (Orcinus orca). Estas especies generaron respectivamente un ingreso total anual de 4.089.056 €, 1.876.833 € y 505.389 €, donde cada individuo generaría un promedio de 14.048 €, 951 € y 36.099€ cada año. Al incorporar la esperanza de vida, esto se correspondió con un valor total de la población de 112.426.185 €, 16.685.147 € y 19.171.107 € a lo largo de su vida. Estos valores brindan una idea de la contribución potencial de los cetáceos a la economía local, pero solo representan su valor no consumitivo basado en el turismo. Nuestros resultados refuerzan la idea de que se debe promover una cultura de avistamiento de cetáceos sostenible y de alta calidad, bajo los requisitos de observación de cetáceos de alta calidad de ACCOBAMS, para garantizar una industria sostenible, ingresos económicos estables y la viabilidad de las poblaciones de cetáceos en el Estrecho de Gibraltar

The wetting behavior of NiAl and NiPtAl on polycrystalline alumina

In order to understand the beneficial effect of Pt on the adherence of thermally grown alumina scales, sessile drop experiments were performed to study the wetting of poly-crystalline alumina by nickel-aluminum alloys with or without platinum addition where the amount of Pt ranged from 2.4 to 10 at.%. Subsequent interfacial structure was evaluated using atomic force microscopy. Platinum addition enhances the wettability of NiAl alloys on alumina, reduces the oxide/alloy interface energy and increases the interfacial mass transport rates

Electrical spin injection into p-doped quantum dots through a tunnel barrier

We have demonstrated by electroluminescence the injection of spin polarized electrons through Co/Al2O3/GaAs tunnel barrier into p-doped InAs/GaAs quantum dots embedded in a PIN GaAs light emitting diode. The spin relaxation processes in the p-doped quantum dots are characterized independently by optical measurements (time and polarization resolved photoluminescence). The measured electroluminescence circular polarization is about 15 % at low temperature in a 2T magnetic field, leading to an estimation of the electrical spin injection yield of 35%. Moreover, this electroluminescence circular polarization is stable up to 70 K.Comment: 6 pages, 4 figure

Fine-scale population structure and connectivity of bottlenose dolphins, Tursiops truncatus, in European waters and implications for conservation

Funding: Fyssen post-doctoral fellowship, Fondation Total, a bridge funding from the School of Biology of the University of St Andrews and People’s Trust for Endangered Species (ML).1. Protecting species often involves the designation of protected areas, wherein suitable management strategies are applied either at the taxon or ecosystem level. Special Areas of Conservation (SACs) have been created in European waters under the Habitats Directive to protect bottlenose dolphins, Tursiops truncatus, which forms two ecotypes, pelagic and coastal. 2. The SACs have been designated in coastal waters based on photo‐identification studies that have indicated that bottlenose dolphins have relatively high site fidelity. However, individuals can carry out long‐distance movements, which suggests potential for demographic connectivity between the SACs as well as with other areas. 3. Connectivity can be studied using genetic markers. Previous studies on the species in this area used different sets of genetic markers and therefore inference on the fine‐scale population structure and demographic connectivity has not yet been made at a large scale. A common set of microsatellite markers was used in this study to provide the first comprehensive estimate of genetic structure of bottlenose dolphins in European Atlantic waters. 4. As in previous studies, a high level of genetic differentiation was found between coastal and pelagic populations. Genetic structure was defined at an unprecedented fine‐scale level for coastal dolphins, leading to identification of five distinct coastal populations inhabiting the following areas: Shannon estuary, west coast of Ireland, English Channel, coastal Galicia, east coast of Scotland and Wales/west Scotland. Demographic connectivity was very low among most populations with <10% migration rate, suggesting no demographic coupling among them. Each local population should therefore be monitored separately. 5. The results of this study have the potential to be used to identify management units for bottlenose dolphins in this region and thus offer a significant contribution to the conservation of the species in European Atlantic waters. Future studies should prioritize obtaining biopsies from free‐living dolphins from areas where only samples from stranded animals were available, i.e. Wales, west Scotland and Galicia, in order to reduce uncertainty caused by sample origin doubt, as well as from areas not included in this study (e.g. Iroise Sea, France). Furthermore, future management strategies should include monitoring local population dynamics and could also consider other options, such as population viability analysis or the incorporation of genetic data with ecological data (e.g. stable isotope analysis) in the designation of management units.PostprintPeer reviewe

Behavioural responses of humpback whales to food-related chemical stimuli

Publisher's version (útgefin grein)Baleen whales face the challenge of finding patchily distributed food in the open ocean. Their relatively well-developed olfactory structures suggest that they could identify the specific odours given off by planktonic prey such as krill aggregations. Like other marine predators, they may also detect dimethyl sulfide (DMS), a chemical released in areas of high marine productivity. However, dedicated behavioural studies still have to be conducted in baleen whales in order to confirm the involvement of chemoreception in their feeding ecology. We implemented 56 behavioural response experiments in humpback whales using two food-related chemical stimuli, krill extract and DMS, as well as their respective controls (orange clay and vegetable oil) in their breeding (Madagascar) and feeding grounds (Iceland and Antarctic Peninsula). The whales approached the stimulus area and stayed longer in the trial zone during krill extract trials compared to control trials, suggesting that they were attracted to the chemical source and spent time exploring its surroundings, probably in search of prey. This response was observed in Iceland, and to a lesser extend in Madagascar, but not in Antarctica. Surface behaviours indicative of sensory exploration, such as diving under the stimulus area and stopping navigation, were also observed more often during krill extract trials than during control trials. Exposure to DMS did not elicit such exploration behaviours in any of the study areas. However, acoustic analyses suggest that DMS and krill extract both modified the whales’ acoustic activity in Madagascar. Altogether, these results provide the first behavioural evidence that baleen whales actually perceive prey-derived chemical cues over distances of several hundred metres. Chemoreception, especially olfaction, could thus be used for locating prey aggregations and for navigation at sea, as it has been shown in other marine predators including seabirds.This research was funded by the Fondation Total (www.fondation.total.com), grant #144903 to A.C., and the Ministère de l'Enseignement Supérieur et de la Recherche (www.enseignementsup-recherche.gouv.fr) to B.B., Bourse doctorale. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe

Fin whale (Balaenoptera physalus) mitogenomics: A cautionary tale of defining sub-species from mitochondrial sequence monophyly

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 collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point was illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013), which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 380 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para- or polyphyly) can lead to erroneous conclusions due to relatively 'trivial' aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to the most recent common ancestor and hence the probability that individuals in a sample are monophyletic

New insights on the critically endangered population of bottlenose dolphins from Sado estuary (Portugal)

34th European Cetacean Society Conference, O Grove, 16-20 April 2023Identifying threatened populations and quantifying their vulnerability is crucial for establishing priorities for conservation and providing robust information for decision-making. Small population size is a fundamental factor increasing the risk of extinction, owing to demographic and genetic stochasticity. When populations become too small, additional threats to stability and persistence arise, which can exacerbate the difficulty of stopping or reversing the decline. The bottlenose dolphin (Tursiops truncatus) population inhabiting the Sado estuary region (Portugal) is one of the smallest resident populations of this species in Europe. Dedicated research over the last four decades has revealed year-round long-term site fidelity to the estuary, very low levels of immigration, high calf/juvenile mortality, and an ageing, declining population. In this collaborative study, we update previous information on population dynamics and add important information about the genetic diversity (microsatellites, mtDNA, SNPs markers), inbreeding levels, population structure, and persistent organic pollutants (PCBs, DDTs, PBDEs, and HBCDs) loads. Presently, the Sado population has 25 individuals (10M; 8F; 7 Unknown sex), of which six individuals are more than 40 years old. We found lower genetic diversity, presence of unique maternal lineages, and high levels of relatedness (r˃0.412). These animals are genetically differentiated from the other bottlenose dolphins sampled in the area (Iberian Peninsula, Azores and Madeira) suggesting an isolated population. For PCBs, five (62%) animals had concentrations higher than the highest threshold for PCB toxicology (˃41mg/kg lipid weight, can cause immunosuppression and/or reproductive impairment) including one calf less than 6 months old. This, together with the fact that this population inhabits one of the most polluted estuaries in Portugal, characterized by multiple sources of contamination and increasing anthropogenic pressures (e.g. dredging, boat traffic, and dolphin-watching activities) highlights the critical situation of this resident bottlenose dolphin population and the urgency to implement stringent and effective conservation measuresN

Fine scale population genomics of the bottlenose dolphin off Western Iberia (northeast Atlantic)

34th European Cetacean Society Conference, O Grove, 16-20 April 2023Bottlenose dolphin (Tursiops truncatus) populations sampled across various geographic regions show fine-scale patterns of genetic structure, likely associated with local habitat preferences. Several population genetic studies have focused on populations from the northeast Atlantic Ocean (NEA), very few including the Portuguese coast. This study investigated the population structure and demographic history of the bottlenose dolphin in this region using double digest restriction site associated DNA sequencing (ddRAD-seq). Samples were collected from the Iberian Peninsula including SW Spain, the Portuguese coast (including Sado estuary), NW Spain and from two Portuguese Macaronesian archipelagos, Madeira and Azores (N=110 samples). We genotyped thousands of single nucleotide polymorphisms markers to study the fine-scale population structure, inbreeding levels and demographic history. Bayesian clustering and Principal Component Analyses showed three major genetic clusters: Pelagic (incl. Madeira and Azores; North Galicia, Portugal coast), Southern/Mediterranean (incl. Gibraltar/Cadiz, previously identified as of Mediterranean origin, and Portugal coast), and Resident (Sado and south Galicia). These clusters differ from each other in terms of genetic diversity and inbreeding levels. While the Pelagic and Southern/Med clusters shows high genetic diversity and a wide geographic distribution, the Resident populations show the opposite. The Resident cluster can be subdivided in Galicia and Sado populations, the latter revealing concerning levels of inbreeding. Preliminary demographic analyses suggest that the Resident populations diverged from the others prior to the Southern/Med-Pelagic divergence, although further analyses are needed. Our results suggest that i) the Resident populations of the Iberian Peninsula should be considered as different management units; ii) bottlenose dolphins sampled along the Portuguese coast are highly genetically diverse, including individuals from the three different clusters; and iii) the Sado population faces a critical situation. Within the framework of the recently proposed SACs for bottlenose dolphins in Portugal, these results highlight the importance of discussions on conservation and management policiesN

Isotopic evidence of limited exchange between Mediterranean and eastern North Atlantic fin whales

RATIONALE The relationship between stocks of fin whales inhabiting the temperate eastern North Atlantic and the Mediterranean Sea is subject to controversy. The use of chemical markers facilitates an alternative insight into population structure and potential borders between stocks because the two areas present dissimilar isotopic baselines. METHODS Baleen plates, composed of inert tissue that keeps a permanent chronological record of the isotopic value of body circulating fluids, were used to investigate connectivity and boundaries between the stocks. Values were determined by continuous flow isotope ratio mass spectrometry. RESULTS Stable isotopes confirm that, while the two subpopulations generally forage in well-differentiated grounds, some individuals with characteristic Atlantic values do penetrate into the Mediterranean Sea up to the northernmost latitudes of the region. As a consequence, the border between the two putative subpopulations may be not as definite as previous acoustic investigations suggested. The discriminant function obtained in this study may assist researchers to use baleen plate isotopic data to assign the origin of fin whales of uncertain provenance. CONCLUSIONS This study strengthens the stock subdivision currently accepted for management and conservation while recognizes a low level of exchange between the Mediterranean and temperate eastern North Atlantic subdivisions. Copyright © 2013 John Wiley & Sons, Ltd.Peer Reviewe