Pyrethroid bioaccumulation in Mediterranen dolphins

Pyrethroids are organic pollutants with high hydrophobicity used as insecticides. Concern exists about aquatic organisms¿ exposure to their toxicity. They were believed to be converted to non-toxic metabolites in mammals, but our group has detected them in human breast milk and has proved their bioaccumulation in marine mammals and river fish. The present study investigates the occurrence of pyrethroid compounds in liver samples from striped dolphins (Stenella coeruleoalba)and common dolphins (Delphinus delphis) from southern Spain, as the first attempt to determine the occurrence and bioaccumulation and distribution of pyrethroids in marine mammal tissues from the Mediterranean Sea. Samples of dolphin tissue were collected from the Abloran Sea (south of Spain) between 2003 and 2010, including 37 liver samples from striped dolphin and different tissues¿blubber, muscle, liver, brain and kidneys¿from 11 common dolphins. The analytical method monitored 10 pyrethroids, including cypermethrin and detamethrin. For the sample preparation?lyophilized sample was spiked with internal standards, extracted by sonication and underwent a clean-up with alumina and C18 SPE cartridges. Extracts were analysed by GC-NCI-MS/MS. Method recoveries for the pyrethroids ranged 53-116?% and method LODs and LOQs were 0.02-0.46?ng/g and 0.08-1.54?ng/g, respectively. Pyrethroids were detected in 87?% of the striped dolphins and 100?% of the common dolphins, with total concentrations of nd-5,210?ng/g?lw and 69-2,036?ng/g?lw, respectively. These levels were higher than those reported found in dolphins from Brazil (7.0-68?ng/g?lw). Permethrin and tetramethrin were the main contributors to the pyrethroid profiles for all tissues. The samples of striped dolphins where used to observe that bioaccumulation of pyrethroids was unlike that of persistent organic pollutants (POPs), as pyrethroid levels were not correlated to the age of the specimens. Levels slightly increase from calves to juveniles, whereas juveniles present similar levels to adults. Metabolization of pyrethroids after achieving sexual maturity might account for this pattern. Because of the pyrethroids lipophilic behaviour, blubber was the most contaminated tissue and brain showed the lowest levels. Normalizing the data to the lipid content, the highest value was for muscle by far, suggesting a preference for that tissue. SETA

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

Genomics reveals the role of admixture in the evolution of structure among sperm whale populations within the Mediterranean Sea

In oceanic ecosystems, the nature of barriers to gene flow and the processes by which populations may become isolated are different from the terrestrial environment, and less well understood. In this study we investigate a highly mobile species (the sperm whale, Physeter macrocephalus) that is genetically differentiated between an open North Atlantic population and the populations in the Mediterranean Sea. We apply high-resolution single nucleotide polymorphism (SNP) analysis to study the nature of barriers to gene flow in this system, assessing the putative boundary into the Mediterranean (Strait of Gibraltar and Alboran Sea region), and including novel analyses on structuring among sperm whale populations within the Mediterranean basin. Our data support a recent founding of the Mediterranean population, around the time of the last glacial maximum, and show concerted historical demographic profiles in both the Atlantic and the Mediterranean. In each region there is evidence for a population decline around the time of the founder event. The largest decline was seen within the Mediterranean Sea where effective population size is substantially lower (especially in the eastern basin). While differentiation is strongest at the Atlantic/Mediterranean boundary, there is also weaker but significant differentiation between the eastern and western basins of the Mediterranean Sea. We propose, however, that the mechanisms are different. While post-founding gene flow was reduced between the Mediterranean and Atlantic populations, within the Mediterranean an important factor differentiating the basins is probably a greater degree of admixture between the western basin and the North Atlantic and some level of isolation between the western and eastern Mediterranean basins. Subdivision within the Mediterranean Sea exacerbates conservation concerns and will require consideration of what distinct impacts may affect populations in the two basins

Diet of striped dolphins (Stenella coeruleoalba)in southern Spanish waters

Identifiable food remains were analyzed from 46 stomachs of striped dolphins (Stenella coeruleoalba) stranded in southern Spain between 2007 and 2014. Results suggest that the species feeds mainly on mesopelagic and neritic fish, but also on oceanic squids. Fish species of the family Myctophidae were the main prey in terms of numerical importance and reconstructed prey weight (62% N and 29% W), followed by squids of the family Ommastrephidae (20% W) and bogue (Boops boops) (15% W). The most important prey taxa according to the General Importance Index (GII) were C. maderensis, Ommastrephidae gen. spp., Notoscopelus spp., and M. punctatum. Higher number of mesopelagic myctophids were found in dolphins from the Mediterranean (73% vs. 29% N), while more demersal gobiids and European hake (Merluccius merluccius) were found in those from the Atlantic (44% vs. 1% and 8% vs. <1% N), where a more varied diet was also observed. Differences were also seen in the seasonal importance of some prey, as well as between years, sexes, and maturity states. The diet composition suggests that most of feeding occurred in oceanic regions, during twilight and night hours, while the observed dietary variation may reflect differences in topography, and changes in the prey availability.1,46

Ecología trófica del delfín listado en aguas del Mar de Alborán y el Golfo de Cádiz

Existe muy poca información sobre la dieta del delfín listado (Stenella coeruleoalba) en aguas del sur de España. En este estudio se analizaron los estómagos de 61 delfines varados en Andalucía en los últimos ocho años (2007-2014). Diez estómagos estaban vacios y de los 51 individuos restantes, 35 vararon en la costa del Mar de Alborán y 11 en el Golfo de Cádiz. Para las 5 muestras restantes no se dispone de localidad concreta. Los restos de las presas en los estómagos consistieron sobre todo en estructuras duras: otolitos, cristalinos y unos pocos huesos de peces, así como mandíbulas y cristalinos de cefalópodos. No aparecieron otro tipo de restos lo que parece indicar que los individuos no se habían alimentado recientemente. Para caracterizar la dieta se calcularon tres índices (calculados para cada categoría de presa): frecuencia de aparición en los estómagos, número de individuos y peso reconstruido y sus porcentajes respectivos. El delfín listado parece ser una especie predominantemente piscívora (se identificaron restos de 5682 peces frente a solamente 210 cefalópodos) que se alimenta de especies mesopelágicas principalmente. La familia más importante tanto en número como en frecuencia de aparición fue Myctophidae, principalmente Ceratoscopelus maderensis y Myctophum punctatum a las que pertenecieron casi la mitad de los peces identificados (36,4%N, 35,3%F y 12,3%N, 25,5%F, respectivamente). También se identificó Maurolicus muelleri (Sternoptychidae 13,4%N y 17,6%F). Otras familias identificadas presentan una distribución más costera: Sparidae (Boops boops) y Carangidae (Trachurus sp.) (4,5%N, 9,8%F y 1,2%N, 3,9%F, respectivamente). Los cefalópodos identificados pertenecieron a 11 familias siendo la más abundante Ommastrephidae (26,7%N y 39,2%F). Otras familias incluyen representantes oceánicos, Brachioteuthidae (16,7%N y 21,5%F); Chiroteuthidae (6,7%N y 9,8%F); Enoploteuthidae (4,8%N y 3,9%F), Ancistrocheridae (0.5%N y 2%F) y otros de distribución más costera, Sepiolidae (19%N y 19,6%F), Sepiidae (5,7%N y 3,9%F) y Loliginidae (3,8%N y 5,9%F)

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

The first cetacean sightings network in Spain: results of a co-operation within the Spanish Cetacean Society

3 pages, 2 tables.-- Fifteenth Annual Conference of the European Cetacean Society, Rome, Italy, 6-10 May 200ln 1999, the Spanish Cetacean Society (SEC) was created in order to co-ordinate the activities of different organisations and research groups in Spain, and to provide assistance to regional and national authorities in issues related to the conservation of the marine environment. In July 1999, the Spanish Ministry for the Environment appointed to the SEC the custody of a national database of shandings and sightings of cetaceans in order to standardise the methodology used by all groups involved in these activities, and to facilitate the exchange of information among researchers. The Sightings Working Group of the SEC has been, since then, developing and updating the cetacean sightings database with the participation of most research and conservation groups working in Spain. This is the fìrst time in Spain that most groups put together their information creating a National Sightings Network and giving a fairly complete vision of cetacean distribution throughout the whole country, showing the importance of co-ordinated co-operation in the context of conservationDGCN (National Environment Agency) of the Spanish Ministry for the EnvironmentN

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

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

Runs of homozygosity in killer whale genomes provide a global record of demographic histories

Runs of homozygosity (ROH) occur when offspring inherit haplotypes that are identical by descent from each parent. Length distributions of ROH are informative about population history; specifically, the probability of inbreeding mediated by mating system and/or population demography. Here, we investigated whether variation in killer whale (Orcinus orca) demographic history is reflected in genome-wide heterozygosity and ROH length distributions, using a global data set of 26 genomes representative of geographic and ecotypic variation in this species, and two F1 admixed individuals with Pacific-Atlantic parentage. We first reconstructed demographic history for each population as changes in effective population size through time using the pairwise sequential Markovian coalescent (PSMC) method. We found a subset of populations declined in effective population size during the Late Pleistocene, while others had more stable demography. Genomes inferred to have undergone ancestral declines in effective population size, were autozygous at hundreds of short ROH (1.5 Mb) were found in low latitude populations, and populations of known conservation concern. These include a Scottish killer whale, for which 37.8% of the autosomes were comprised of ROH >1.5 Mb in length. The fate of this population, in which only two adult males have been sighted in the past five years, and zero fecundity over the last two decades, may be inextricably linked to its demographic history and consequential inbreeding depression