The nursery role of the Guadalquivir estuary for marine fish. A long-term ecological research

Trabajo presentado en el 23rd Biennial CERF Conference (Grand challenges in coastal and Estuarine Science: securin our future), celebrado en Portland (Oregón, US) del 8 al 12 de noviembre de 2015.N

Multidecadal (1997-2020) telecoupling of water management for terrestrial agriculture and a marine fishery at southern Spain

Climate change is decreasing water supplies globally while water demand is rising, making water access and distribution essential for sustainability, equity, and efficiency. In response, water management has shifted towards practices that improve water efficiency. However, links between geographically separated socioecological systems, known as telecouplings, can obscure the potential consequences of water use. This study focuses on a telecoupling between terrestrial water use and marine fisheries for the period 1997 to 2020. We develop a case study in southern Spain using multidecadal time series of the Guadalquivir river’s hydrology, its estuarine community, and the European anchovy (Engraulis encrasicolus) fishery in the Gulf of Cadiz. We found that water extracted to irrigate crops decreased the river’s flow and seasonality. However, anchovies used the estuary as a nursery before recruiting to the ocean, where they were harvested. Anchovy recruitment improved when estuary hydrology matched the Guadalquivir River’s historical hydrology (i.e., high discharge and seasonality). Then using hydro-economic modeling, we explored the outcomes of different water policies on the telecoupled socioecological systems. Our models predicted that improved water efficiency incentivized agricultural expansion. In contrast, continued marine fishery yields required management values that supported the value of the marine fishery. We highlight estuaries’ critical role in driving marine systems; yet, upriver processes drive estuaries dynamics. Overall, marine-terrestrial telecouplings provide evidence that marine fisheries that rely on estuarine reliant species would benefit of water policy and management being extended beyond the water basin

Population dynamic and trophic position of mysid community demonstrates its key role for nursery function in a temperate estuary

Guadalquivir Estuary is a main nursery ground of marine goal species for Gulf of Cadiz fisheries. It is a well-mixed temperate estuary with horizontal salinity gradient and clear seasonal water temperature trend. Mysid community with Mesopodopsis slabberi, Neomysis integer and Rhopalophthalmus tartessicus make up to over 80% of total macrofauna biomass in the estuary. Life history, population structure, secondary production, trophic level and community spatio-temporal dynamic were unravelled combining analysis of long term 16y monitoring data with 2y of in depth population analysis and trophic biomarker studies. Results show a key trophic role in food web, a seasonal trend showing density peaks ( 23, 3 and 6 mg/m3, respectively) in spring-summer and winter marine coastward migration. Despite being euryhaline, the three species of showed unevenly spatial distribution, being salinity the variable best explaining structure changes of mysid assemblage. Inter- and intra-specific euryhalinity differences both for prey and predators seem to determine the entire spatial estuarine community distribution. High secondary production (P/B rates 38.2, 10.3 and 10.7) and food web studies confirm key role of mysids transferring energy up to juveniles (fish and crustaceans) arriving yearly in spring to their nursery area

Distribution and salinity tolerance of the invasive isopod Synidotea laticauda in the Guadalquivir estuary (SW Spain): Field and laboratory observations

Trabajo presentado en ECSA 56 (Coastal systems in transition: From a 'natural' to an 'anthropogenically-modified' state), celebrado en Bremen del 4 al 7 de septiembre de 2016.The effects of the exotic species in native communities are unpredictable and ecological studies should be required for environmental management. In Europe, the exotic species Synidotea laticauda has been introduced in several estuaries but there was not any previous biological study about these non-native populations. The spatio-temporal field distribution of S. laticauda in the last 30 km of the Guadalquivir estuary (salinities 0 to 30) was assessed during 7 years (August 1997-June 2004) by sampling at each new moon with a mesh size net of 1 mm. Survival and osmoregulatory patterns of the species under different experimental salinity conditions were also estimated. This exotic species is a permanent resident of the estuary, with presence of juveniles and adults during most of the year, but showing maximum densities in the warmest period (summer to early autumn). Spatial patterns were closely related to the salinity gradient: the highest densities were observed between 10 and 30 of salinity, with a maximum at 20 (≈ isosmotic point). In fact, the isopod is a weak osmoregulator, which maintains the osmolality of the hemolymph partially independent of the medium osmolality (in a salinity range of 5 to 25). Moreover, survival experiments showed a high tolerance (mortality < 30%) to sudden salinity changes between 2 and 35 and virtually no mortality in salinities (15-25) close to the isosmotic point (20). Osmoregulatory and survival patterns were not dependent on sex but they seemed to be specific-dependent on salinity acclimation. Although it is a euryhaline species, its weak osmoregulatory capacity explains its salinity-dependent distribution pattern. Our results provide a framework to predict the distribution of this invasive species under sceneries of climate change and consequent freshwater scarcity.N

Long-term ecological research of aquatic ecosystem at Guadalquivir estuary (1997-2014): community structure and food web

A long term ecological research program (LTER) is developed monthly at the Guadalquivir estuary since 1997. Inter- and intra-specific euryhalinity differences both in prey and predators seem to determine spatial species distribution at this important nursery area: the less euryhaline species (marine recruits) tends to occur at physiologically more favourable salinities (lower osmotic stress and mortality risk); whereas most euryhaline species (estuarine species) occurred at ecologically more favourable salinities (lower inter-specific competition and predation). Likewise, inter-specific differences in spawning periods cause certain temporal segregation of those marine recruits using the estuary. High spatiotemporal coincidence of prey (mainly mysids and copepods) density peaks with that of their predators suggests food availability as a key factor in the estuarine nursery function. According to their distribution, the estuarine stretch situated seaward from the 5 isohaline position is mainly used as a nursery ground, principally during warm period (T > 15 °C). Thus, human management of the freshwater input to the estuary (from a 110 km upstream dam) modifies the nursery ground extent due to seaward/upstream displacements of the estuarine salinity gradient. During droughts, this freshwater control may also lead to a partial loss of the estuarine nursery function due to a decrease of prey availability linked to extremely high-turbidity events

Climate Driven Egg and Hatchling Mortality Threatens Survival of Eastern Pacific Leatherback Turtles

Egg-burying reptiles need relatively stable temperature and humidity in the substrate surrounding their eggs for successful development and hatchling emergence. Here we show that egg and hatchling mortality of leatherback turtles (Dermochelys coriacea) in northwest Costa Rica were affected by climatic variability (precipitation and air temperature) driven by the El Niño Southern Oscillation (ENSO). Drier and warmer conditions associated with El Niño increased egg and hatchling mortality. The fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC) projects a warming and drying in Central America and other regions of the World, under the SRES A2 development scenario. Using projections from an ensemble of global climate models contributed to the IPCC report, we project that egg and hatchling survival will rapidly decline in the region over the next 100 years by ∼50–60%, due to warming and drying in northwestern Costa Rica, threatening the survival of leatherback turtles. Warming and drying trends may also threaten the survival of sea turtles in other areas affected by similar climate changes

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially