EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

Unravelling Complex Interaction among Coastal Management and Marine Biodiversity: A Case Study in Southern Spain

In this work, we use an integrated modelling approach to explore the complex relationships and interconnections in marine ecosystems among anthropogenic pressures, biodiversity loss, delivery of ecosystem services (ES), and implemented conservation and management strategies. We selected 60 indicators at regional (34), national (12) and international (14) scales that provided long-term information during the 1985–2019 time frame. The results show a decline in marine biodiversity and its associated provisioning services despite the increasing number of responses delivered by a society which are not enough and/or need more time to exert their effects and highlight the pressure on exploited species of unknown conservation status. The decline in Provisioning ES is explained by the decrease in the overall biomass of the captures, mostly large and carnivorous commercially-targeted species and the increase in the number of small-bodied fish species included in the IUCN Red List. The degradation of ecosystem integrity and the continuing loss of biodiversity affect the ability of the ecosystem to provide Regulating ES. The Cultural ES delivery, related to artisanal fisheries, is better preserved in the Gulf of Cádiz. We conclude how the implementation of new management regulations is needed and should be developed through participatory processes to protect and improve marine ecosystem status

Stable isotope analysis in two sympatric populations of bottlenose dolphins Tursiops truncatus: evidence of resource partitioning? Marine Biology 158

Abstract Skin and muscle from 43 bottlenose dolphins (38 juveniles/adults, 5 calves) stranded in NW Spain were analysed to determine whether stable isotope ratios (d 13 C and d 15 N) could be used to assess dietary variation, habitat segregation and population substructure. Results were compared with published stomach contents data. Stable isotope ratios from 17 known prey species were also determined. Isotope ratios of the main prey (blue whiting, hake) varied significantly in relation to fish body size. Dolphin calves showed significant heavy isotope enrichments compared to adult females. Excluding calves, d 15 N decreased with increasing dolphin body size, probably related to an ontogenetic shift in diet towards species at lower trophic levels, e.g. on blue whiting as suggested by stomach content results. Bottlenose dolphins were divided into two putative populations (North, South) based on previous genetic studies, and values of d 13 C and d 15 N differed significantly between these two groups, confirming the existence of population structuring

Fine scale population structure of bottlenose dolphins (Tursiops truncatus) off Galician waters, NW Spain

Bottlenose dolphins are known to have high dispersal capabilities that could lead to genetic connectivity. However, local resident populations are found worldwide as happens in southern Galicia (NW Spain). The aim of this research is to explore whether population substructure and habitat segregation do exist within the Galician bottlenose dolphin community. In the present study, samples from 43 bottlenose dolphins stranded or by-caught in Galicia between 1994 and 2008 were genotyped at 10 microsatellite loci and sequenced at the highly variable mitochondrial control region. In addition, variability of stable isotope ratios (δ13C and δ15N) was assessed for 43 dolphins (5 calves, 38 juveniles and adults) stranded or by-caught in Galicia between 1998 and 2007. Genetic results highlighted the existence of two populations in the area and dolphins from southern Galicia were assigned to a single genetic group. Seven dolphins were classified as possible migrants between putative populations as their genetic makeup did not correspond with their geographical stranding location. Values of δ13C and δ15N were significantly different between the two populations, suggesting resource specialization and partitioning. Dolphins from southern Galicia (inhabiting coastal inlets) showed more variation in their diet, higher trophic levels and greater δ13C compared to animals from northern Galicia (present in more open waters). The existence of fine scale population substructure should be considered in the future designation of Special Areas of Conservation (SACs) for the species as required by the European Habitats Directive

Intra-and interspecific niche partitioning in striped and common dolphins inhabiting the southwestern Mediterranean Sea

Community structure and functioning is shaped by resource partitioning between cooccurring species. Niche differentiation among sympatric species can be reached through trophic, spatial or temporal segregation to avoid competitive exclusion. Intraspecific segregation in the use of habitats and resources might determine, in turn, a population's niche width and interspecific segregation. The Alboran Sea is the only area in the Mediterranean where common and striped dolphins coexist abundantly. Therefore, these putative competing species provided the opportunity to investigate niche partitioning through spatial modelling and trophic analysis. Density surface modelling and nitrogen and carbon stable isotopes (δN and δC) were used to investigate spatial and trophic niche partitioning at inter-and intraspecific levels. The 2 species showed high isotopic overlap. However, we could not rule out the possibility of interspecific trophic segregation, as isotopic similarity does not necessarily mean true ecological or dietary similarity. Among conspecifics, variations in δN and δC values with dolphin length pointed to ontogenetic dietary changes in striped dolphins, while sex played only a minor role in δC values. Spatially, these species tended to segregate their core areas of distribution, with common dolphins being more coastal than striped dolphins, which occupied adjacent, deeper waters. Overall, the main enabler for the coexistence of common and striped dolphins in the Alboran Sea was spatial segregation.Peer Reviewe

Use of blubber levels of progesterone to determine pregnancy in free-ranging live cetaceans

4 páginas, 1 tabla.We tested the possibility of measuring progesterone levels in bubbler samples collected from free-ranging live bottlenose dolphins (n = 11) and long-finned pilot whales (n = 2) as a tool to evaluate the pregnancy status of individuals. Samples were collected during January 2004 and September–October 2005 in the Strait of Gibraltar and Gulf of Cadiz and used for sex-determination by genetic methods (skin samples) and for quantification of progesterone levels by enzyme immunoassay. Photo-identification tracking of females after taking the biopsy was used to observe the presence of newborns and, in this way, to determine if the female was pregnant at the time of sampling. Mean progesterone levels from pregnant bottlenose dolphins (n = 2) were around 9 times higher than those from non-pregnant females (n = 9), with no overlap between concentration ranges demonstrating that this method could constitute an effective tool for determining pregnancy in wild populations of bottlenose dolphins and other cetacean species.Our study was made possible due to the financial support received during several cetacean campaigns in the Iberian Peninsula. We thank the Foundation Loro Parque, the Foundation Biodiversidad and CEPSA.Peer reviewe

Living apart together: Niche partitioning among Alboran Sea cetaceans

Co-occurring species are expected to distribute themselves unevenly throughout ecological niche dimensions to avoid competitive exclusion. However, few studies have previously investigated spatial and trophic factors structuring an entire cetacean community. Here, we combined density surface models (DSMs) with two dimension (δN and δC) isotopic niche spaces in order to identify the mechanistic processes underlying niche partitioning for the most abundant cetacean species inhabiting the Alboran Sea: the long-finned pilot whale (Globicephala melas), the Cuvier's beaked whale (Ziphius cavirostris), the Risso's dolphin (Grampus griseus), the bottlenose dolphin (Tursiops truncatus), the striped dolphin (Stenella coeruleoalba), and the short-beaked common dolphin (Delphinus delphis). DSMs provide a spatially-explicit assessment of species distribution through key spatial and environmental gradients, whereas isotopic niches characterize habitat and resource use. Our isotopic niche approach pointed to habitat and/or trophic segregation between the small (striped and short-beaked common dolphins) and large-sized cetacean species (Risso's and bottlenose dolphins, and long-finned pilot whales). Conversely, DSMs suggested a larger degree of spatial segregation among species by depth, with some overlap for offshore species (long-finned pilot, Cuvier's beaked whales and Risso's dolphins) and also between bottlenose and common dolphins. Thus, both components of the ecological niche apparently played an important role in explaining niche partitioning among species, which, in turn, might explain the high abundance and diversity of cetaceans in the Alboran Sea. Further, when both methodologies were applied in isolation, the structure and functioning of this cetacean community was poorly resolved. The combination of both approaches is therefore desirable when investigating niche partitioning among ecologically similar species within communities.This work was funded by Fundación Loro Parque, Fundación Biodiversidad, CEPSA (Compañía Española de Petroleos S.A.), EcoCet Project [CGL2011-25543], LIFE + Indemares [LIFE07NAT/E/000732], LIFE “Conservación de Cetáceos y Tortugas de Murcia y Andalucía” [LIFE02NAT/E/8610]. Thanks to the Consejería de Agricultura, Pesca y Medio Ambiente and the Agencia de Medio Ambiente y Agua (Junta de Andalucía) and to CREMA (Centro de Recuperación de Especies Marinas Amenazadas). J.G., F.R, and R.dS. were supported by the Spanish Ministry of Economy, Industry and Competitiveness through the Severo Ochoa Program for Centers of Excellence in R + D + I [SEV-2012-0262]. F.R was also supported by the “Juan de la Cierva-Incorporación Program” [IJCI-2015-24531]

Fine scale population structure of bottlenose dolphins (Tursiops truncatus) off Galician waters, NW Spain

Bottlenose dolphins are known to have high dispersal capabilities that could lead to genetic connectivity. However, local resident populations are found worldwide as happens in southern Galicia (NW Spain). The aim of this research is to explore whether population substructure and habitat segregation do exist within the Galician bottlenose dolphin community. In the present study, samples from 43 bottlenose dolphins stranded or by-caught in Galicia between 1994 and 2008 were genotyped at 10 microsatellite loci and sequenced at the highly variable mitochondrial control region. In addition, variability of stable isotope ratios (δ13C and δ15N) was assessed for 43 dolphins (5 calves, 38 juveniles and adults) stranded or by-caught in Galicia between 1998 and 2007. Genetic results highlighted the existence of two populations in the area and dolphins from southern Galicia were assigned to a single genetic group. Seven dolphins were classified as possible migrants between putative populations as their genetic makeup did not correspond with their geographical stranding location. Values of δ13C and δ15N were significantly different between the two populations, suggesting resource specialization and partitioning. Dolphins from southern Galicia (inhabiting coastal inlets) showed more variation in their diet, higher trophic levels and greater δ13C compared to animals from northern Galicia (present in more open waters). The existence of fine scale population substructure should be considered in the future designation of Special Areas of Conservation (SACs) for the species as required by the European Habitats Directive