Delta Natural Park Research Articles

Legacy and emerging contaminants in flamingos' chicks’ blood from the Ebro Delta Natural Park

The Ebro Delta is a wetland of international importance for waterbird conservation but severally affected by intensive agriculture, toxic waste discharges from a past chloro-alkali industry and affluence of tourism. The discharge of contaminants associated to these activities pose waterbirds breeding in the Ebro Delta at risk. The aim of this study is to evaluate the exposure of 91 emerging and legacy micropollutants in flamingo chicks (Phoenicopterus roseus), an emblematic species of the area. Fifty chicks of 45–60 days were captured, biometric parameters measured and whole blood collected. Compounds analyzed included perfluoroalkyl substances (PFASs), pharmaceuticals, organophosphate esters (OPEs), in-use pesticides, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCs), and polycyclic aromatic hydrocarbons (PAHs). The results indicate a multi-exposure of flamingo's chicks from a very young age. PFASs were the most ubiquitous compounds with ∑PFASs ranging from 9.34 to 576 ng/mL, being PFOA, PFOS and PFHxS detected in all samples. ∑PAHs ranged from 0.19 to 423 ng/mL, ∑PCBs from 0.5 to 15.6 ng/mL and ∑OCs from 1.35 to 37.8 ng/mL. Pharmaceuticals, OPEs and in-use pesticides were not detected. The flamingo's filtering behavior on mud and maternal ovo-transference are the more likely routes of exposure of organic micropollutants to flamingos' chicks. The reported levels of micropollutants were not associated with any alteration in the body condition of chicks. This is the first study to describe flamingos chicks' exposure to multiple contaminants, highlighting the importance of biomonitoring for wildlife conservation and biodiversity preservation.

A methodological proposal to co-design well-being experiences: the case of the Ebro Delta Natural Park and Els Ports Natural Park, Catalonia, Spain

ABSTRACT Protected areas (PAs) offer a wide range of well-being benefits closely linked to the objective of providing genuine experiences that intend to involve tourists across the physical, mental, social, emotional, spiritual, and environmental spheres. This article is part of a research project that aims to transfer knowledge about the well-being benefits provided by PAs through the design of well-being experiences, all within the framework of a methodological participatory process and co-design approach that integrates visual methods in data collection and analysis, together with the involvement of public and private agents. Methodology is apllied in two protected natural areas (PNAs): the Ebro Delta Natural Park (EDNP) and the Els Ports Natural Park (EPNP), both located in South Catalonia. The resulting experiences can be included in the tourist offer provided by parks and tourist sector; above all, they will drive efforts to include, reinforce, communicate, and share the health benefits of PNAs.

Stopping Winter Flooding of Rice Fields to Control Invasive Snails Has no Effect on Waterbird Abundance at the Landscape Scale

The invasive apple snail (Pomacea maculata) appeared in 2010 in the Ebro Delta Natural Park, an important area for rice production and waterbird conservation in the eastern Mediterranean. To control crop damage, farmers stopped flooding their rice fields in winter, an agri-environmental scheme (AES) applied for more than 20 years in some European and American regions to favor flora and fauna from wetlands, including wintering waterbirds. Thus, apple snail control is controversial because of its potential side effects on international waterbird conservation efforts. Despite the fact that 10 years have passed since the first flooding limitations, and the alarms raised by the managers of the Natural Park, the side effects of apple snail management on waterbird conservation have not been evaluated. Here we fill this gap by analyzing a 35-year time series to assess whether abundance trends of 27 waterbird species, from five functional groups, decreased in the Ebro Delta after stopping winter flooding. We considered the effects of confounding local factors by also assessing trend changes in l’Albufera, a similar nearby not invaded wetland where flooding has not been interrupted. In addition, as a control of the positive effect of winter flooding, we also assessed whether abundance trends increased in both wetlands after applying this AES winter flooding. Our results showed complex and decoupled trend changes across species and geographical areas, without statistical evidences, in general or for any particular functional group, on the positive effect of winter flooding in both wetlands neither on the negative effect of its cessation in Ebro Delta. These results suggest the safety of this apple snail control in terms of waterbird abundance at a landscape scale. In addition, these results question, at least in two important wintering areas in Europe, the attractor role associated with the flooding agri-environmental scheme applied for decades.

Legacy and Emerging Contaminants in Flamingos’ Chicks’ Blood from the Ebro Delta Natural Park

Legacy and Emerging Contaminants in Flamingos’ Chicks’ Blood from the Ebro Delta Natural Park

Online Public Participation Geographic Information System (PPGIS) as a landscape and public use management tool: a case study from the Ebro Delta Natural Park (Spain)

This paper presents a Public Participation Geographic Information System (PPGIS) application conducted in the Ebro Delta Natural Park, Spain. It aims to support decision-making and management activities. The application is based on an online PPGIS questionnaire using Google Maps API. Participants were asked about the spatial and temporal usage while visiting the Natural Park, about their landscape preferences, and appreciations. A set of eight pairs of bipolar adjectives related to landscape characteristics and experience, four items related to public use, and nine to leisure activities were used. In total, 204 valid answers and 3,969 georeferenced opinions were mapped by this case study. The results of this mapping give insights in the use, perception and appreciation of landscape naturalness and aesthetic beauty, accessibility, facilities, services, and signposting. Furthermore, this study discuss the outcomes of mapping the results and how they support the park management with regard to the identification of conflicts, and the need for action. Finally, this study discuss potentials and limitations of PPGIS as a tool for public participation to capture visitors' experiential knowledge in order to optimize and enhance the management of protected areas.

Landscape characterization using photographs from crowdsourced platforms: content analysis of social media photographs

Abstract Landscape characterisation using social media photographs from popular platforms has been proposed as a landscape and ecosystem services approach. However, popular crowdsourced websites provide uncharacterized data and are only representative of the general public. Photographs from crowdsourced sports platforms, whose users are more homogeneous, could help to characterise landscape more uniformly. In this study we use automated content analysis from photographs on Wikiloc, a crowd-sourced sports platform, to characterize landscape in the Ebro Delta Natural Park, a protected area in Spain. Our approach applies big data procedures and spatial analysis to provide in-depth information regarding what draws visitors’ attention to a landscape and to ascertain their intrasite flow. Our results show that sports users are keen on natural landscapes and pay less attention to rural and degraded landscapes, and that areas closer to paths are more photographed than more distant areas.

PPGIS and Public Use in Protected Areas: A Case Study in the Ebro Delta Natural Park, Spain

This paper analyses public use in the Ebro Delta Natural Park using PPGIS (public participation geographic information system) methodology. An online survey was designed using Google Maps API, HTML, and JAVASCRIPT. Respondents were asked to place and rate thirteen items on an interactive map to characterize and georeference public use with regard to accessibility, facilities and services, signposting, safety and security, and leisure activities. In total we collected 209 valid surveys and mapped 2617 georeferenced opinions. Facilities and services were rated highly by users (72.46% were “very satisfied”). These were followed by accessibility (61%, “very satisfied”) and signposting (60.2%, “satisfied” or “quite satisfied”). Safety and security items were hardly rated perhaps because users do not feel insecure in the area. Respondents’ mapping of opinions and experiences, which are heterogeneous and were well rated, enabled us to visualize areas that might be understood as social hotspots. Our results show that PPGIS is an effective procedure for measuring public use in protected areas and may be a valuable tool for park managers and planners.

Autumn migration of the Common Sandpiper Actitis hypoleucos in the Ebro Delta Natural Park

Autumn migration of the Common Sandpiper Actitis hypoleucos in the Ebro Delta Natural Park

Presence of Vibrio mediterranei associated to major mortality in stabled individuals of Pinna nobilis L.

Presence of Vibrio mediterranei associated to major mortality in stabled individuals of Pinna nobilis L.

Bat boxes and climate change: testing the risk of over-heating in the Mediterranean region

Habitat loss and forest fragmentation are currently substantially reducing the availability of natural bat roosts worldwide. However, since bat populations have been recognized as important ecosystem service providers, bat boxes have become one of the most popular measures employed to protect them. Evidence exists that in arid regions bat boxes act as ecological traps due to abrupt rises in summer temperatures. Several reported mortality events highlight the lack of appropriate guidelines in temperate areas, which might be putting bat conservation in jeopardy. We aimed to explore which bat box features might cause mortality so we compare temperatures in bat boxes, modelling the influence of the orientation and model, and quantifying the risk of extreme heat episodes. A total of 797 overheating events were recorded during a bat-box monitoring program in Catalunya (2014–2015). In 2016, we compared temperatures in up to 15 models side-by-side in the Ebro Delta Natural Park. Bat-box model and orientation clearly affected the number of overheating events. Black-coloured and south-facing boxes recorded the highest temperatures, including the most popular models, with temperatures over 40 °C. The number of overheating events was clearly dependent on the bat-box model. For example, a new model manufactured from rice chaff did not experience any overheating event in contrast with the 2F model that recorded over 50. We do not recommend the use of black boxes in south-facing sites in warm areas. In fact, observed internal temperature gradients suggest that complex boxes may help counteract the effects of overheating. We highlight the importance of taking microclimate characteristics into consideration when setting up a bat-box scheme.

Presence and impact of Stockholm Convention POPs in gull eggs from Spanish and Portuguese natural and national parks

The aim of the present work was to comparatively assess the occurrence and impact of persistent organic pollutants (POPs) in nine natural and national parks from Spain and Portugal using gull eggs (Larus michahellis and L. audouinii) as bioindicators of environmental contamination. Sampling was performed during the breeding season of 2016. Compounds studied include polychlorinated biphenyls (PCBs), organochlorinated pesticides (OC pesticides), perfluorooctane sulfonic acid (PFOS) and polybrominated diphenyl ethers (PBDEs), and were analyzed using mass spectrometric based techniques. The results showed a high contamination by PCBs in all colonies, with total levels ranging from 59 to 1278ng/g wet weight (ww), despite their use is not currently authorized. OC pesticides were also present in all colonies, with a high incidence of 4,4′-DDE in gull eggs at levels up to 218±50ng/g ww in L. michahellis and 760±412ng/g ww in L. audouinii from the Ebro Delta natural park. PBDEs and PFOS were also detected at levels up to 91.7±21.3ng/g ww, which can be attributed to a more recent use. Except for PBDEs, the POP levels in eggs from L. audouinii were higher than in L. michahellis, presumably associated to the fish-based diet of the former. Finally, the effect of POP levels on eggshell parameters (volume, eggshell thickness and desiccation index) were investigated for each colony and gull species in order to evaluate the egg viability and, therefore, the reproduction success.

Seagrass epiphytic assemblages are strong indicators of agricultural discharge but weak indicators of host features

Wastewater pulses from rice agriculture are persistently discharged into the northern shore of the Alfacs Bay (Ebro Delta, NW Mediterranean) from April to November. The bay also receives water from coastal lagoons which are subjected to freshwater inputs from the Ebro River mixed to an unknown extent with agricultural wastewater during the same period. This paper compares epiphyte assemblages growing on leaves of Cymodocea nodosa in sites exposed to agricultural drainage channels, lagoon connection channels, and control sites in the Ebro Delta Natural Park (southern shore of the bay). Leaf epiphytic assemblages of Zostera noltii patches in the northern shore of the bay were also compared with those of adjacent beds of C. nodosa. Drainage channel sites had consistently distinctive assemblages (higher species richness, biomass load, and taxa composition) than control sites. Assemblages from lagoon channel sites were more variable, with three sites showing particularly high covers of epiphytic algae and two sites more similar to controls. Epiphyte patterns clearly matched in situ measures of nutrient availability, and were consistent with decreased shoot densities in discharge sites. In contrast, differences in epiphyte assemblages between seagrass species were minor, and mostly a result of higher epiphytic loads on C. nodosa than on Z. noltii, which features thinner leaves. Further research is needed to investigate the consequences of these plant and epiphyte alterations in important ecosystem processes such as decomposition and export rates, as well as overall effects of nutrients and salinity in secondary producers such as associated macroinvertebrate assemblages supporting locally important marine fisheries.

Structural damage caused by the invasive crayfish Procambarus clarkii (Girard, 1852) in rice fields of the Iberian Peninsula: a study case

The red swamp crayfish (Procambarus clarkii) is considered one of the most invasive species for aquatic ecosystems. Since its introduction in Spain in 1973, it has spread over different wetlands throughout Western Eu- rope, having rapidly adapted to lakes, ponds and coastal marshes. Among the invaded ecosystems, rice-growing areas have been largely affected by crayfish habits, mainly due to their digging behaviour. In pursuit of this, we at- tempted to draw some patterns about the dynamics of the red swamp crayfish population inhabiting the Ebro Delta Natural Park (NE Spain) - one of the main rice-producing areas within the Mediterranean region - in relation to the structural damage caused to draining structures. More specifically, we aimed at establishing links between the local densities of crayfish, the abundance of burrows they use to shelter, and the intensity of damage involved by crayfish digging activity. For this purpose, two approaches relating crayfish density data with abundances of burrows, com- plemented with in-situ observations of structural damage, were designed. Preliminary results indicated that crayfish density and the number of active burrows were positively related, with higher values implying severe damage to draining structures. However, intense digging activity periods did not directly relate to crayfish density, since other factors were also involved. The information obtained could be useful in planning future surveys in which sound details on digging behaviour and, consequently, the structural damage entailed, could be profitably assessed.

Accumulation and maternal transfer of perfluorooctane sulphonic acid in yellow-legged (Larus michahellis) and Audouin's gull (Larus audouinii) from the Ebro Delta Natural Park

This study aimed to determine the accumulation and maternal transfer of perfluorooctane sulphonic acid (PFOS) in yellow-legged gulls (YLG, Larus michahellis) and the protected species Audouin's gull (AG, Larus audouinii), which cohabit in the Ebro Delta Natural Park (Catalonia, Spain). The Estimated Daily Intake (EDI) through diet (fish and crayfish), depuration rates and transfer capacity from blood to first eggs was studied for a set of 44 pairs. For AG, mean (±SD) EDI was of 128±36ng/d in males and 119±32ng/d in females, and for YLG, 170±48ng/d in males and 159±42ng/d in females. PFOS levels in blood were higher in males than females (60.6±21 and 61.1±27ng/g ww in AG and YLG males versus 25.2±12 and 27.3±14ng/g ww in AG and YLG females), with little differences among species. The lower levels in females were attributed to the annual release of PFOS to eggs during the laying period, which was estimated of 5544±1571ng/egg for AG females and 6716±2689ng/egg for YLG. The overall mass balance of PFOS calculated for both species clearly demonstrates that uptake is higher than elimination rates, considering depuration rates and transfer of PFOS to eggs, and this explains that PFOS is accumulated in gulls in a yearly basis.

Freshwater inflows and seasonal forcing strongly influence macrofaunal assemblages in Mediterranean coastal lagoons

Coastal lagoons of the Ebro Delta (Catalonia, Spain) are part of the Ebro Delta Natural Park managed by regional government authorities. Coastal lagoons have persistently received freshwater inputs from the Ebro River from May to November that have altered their natural ecology and hydrological cycle. In this study, we evaluate the seasonal effect of contrasting salinity regimes (polyhaline in the Tancada lagoon, mesohaline in the Encanyissada and oligohaline in the Clot lagoon) on the composition, abundance, species richness, alpha diversity and biomass of benthic macrofauna communities, and we assess the relative contribution of local environmental variables to the observed patterns. Additional sampling was conducted in the largest lagoon (Encanyissada) in order to assess variability at lower spatial scale. At both spatial scales (i.e., among-lagoon and within-lagoon), species richness and diversity tended to increase at higher salinities, particularly in summer. At the assemblage level, significantly different groupings were also found among lagoons and among zones of the Encanyissada lagoon, with more distinctive differences also in summer. Environmental factors accounted for up to 56–60% of the variation in macrofaunal assemblages at both spatial scales, with salinity and temperature accounting for the largest contributions (approx. 14% and 10%, respectively), whereas biomass was mostly controlled by temperature and nutrients. Distinctive oxygen and organic matter levels across the lagoons were also associated with the freshwater influx and displayed significant contributions to observed patterns. Our study shows that the low salinity regime and/or other factors related to long-term inputs of freshwater shape the community of macrofauna within the lagoons, a central trophic resource for most of the local species of fish and aquatic birds. Restoration of these systems to their natural hydrological functioning without further inputs of freshwater and higher marine connectivity is suggested as the more appropriate management.

Persistent Organic Pollutants in gull eggs of two species (Larus michahellis and Larus audouinii) from the Ebro delta Natural Park

The aim of this study was to determine the impact of priority and emerging Persistent Organic Pollutants (POPs) in gull eggs from two species, the scavenger Larus michahellis and the protected species, Larus audouinii. These two species share habitat in the Natural Park of the Ebro delta (Catalonia, Spain). Compounds studied are included or under consideration in the Stockholm Convention and comprise polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), organochlorinated compounds (OCs), perfluorinated compounds (PFCs) and short chain chlorinated paraffins (SCCPs). Four methods based in selective extraction and gas or liquid chromatography coupled to mass spectrometry were used and quality parameters are provided. OC pesticides and marker PCBs were the most abundant chemical families detected in eggs from the two species, followed by PFCs, PBDEs (especially BDE 209) and SCCPs. Dioxin-like PCBs and PCDD/Fs were also detected in all samples. The overall widespread presence of POPs is discussed in terms of feeding habits, bird ecology and anthropogenic pressures in the protected Ebro delta breeding area.

Batrachochytrium dendrobatidis in amphibians from the Po River Delta, Northern Italy

Batrachochytrium dendrobatidis is a pathogen infecting amphibians at the global scale and causing their decline, but knowledge of the distribution of this patho- gen is far from complete. We sampled amphibians from three species (Hyla interme- dia, Rana dalmatina and Pelophylax synklepton esculentus) to evaluate whether B. dendrobatidis infects amphibians in the Po River Delta Natural Park, Northern Italy. We detected the pathogen in one population of P. sk. esculentus (prevalence: 0.33). These findings expand the known distribution of B. dendrobatidis in Italy and add fur - ther concern to the conservation of amphibians in this area.

Partial‐Likelihood Analysis of Spatio‐Temporal Point‐Process Data

We investigate the use of a partial likelihood for estimation of the parameters of interest in spatio-temporal point-process models. We identify an important distinction between spatially discrete and spatially continuous models. We focus our attention on the spatially continuous case, which has not previously been considered. We use an inhomogeneous Poisson process and an infectious disease process, for which maximum-likelihood estimation is tractable, to assess the relative efficiency of partial versus full likelihood, and to illustrate the relative ease of implementation of the former. We apply the partial-likelihood method to a study of the nesting pattern of common terns in the Ebro Delta Natural Park, Spain.

Lipid dynamics in the viperine snake, Natrix maura, from the Ebro Delta (NE Spain)

Body reserves play a major role in several aspects of vertebrate biology. Accurate identification and quantification of body reserves constitute a useful contribution to the better understanding of the energetic costs of reproduction and the implication of food availability in life history traits of organisms. In this study, lipid content in fat bodies, liver and muscle of the viperine snake (Natrix maura) were measured along an active season. Samples were collected monthly from a natural population of the Ebro Delta Natural Park (NE Spain). This methodology pointed out that lipids stored in fat bodies were the main energetic source during reproduction. In addition, lipids stored in liver appeared to be critical for vitellogenesis, while lipids stored in muscle turned out to be a supplementary energetic resource to fuel reproductive effort. Relationships between changes in body reserves and prey availability in canals of the Ebro Delta were also considered. In males, lipid reserves presented a positive correlation with food availability. On the contrary, lipid reserves in female viperine snakes decreased during vitellogenesis even though food availability increased in this period, which suggests a quick transfer of body lipids to clutch. In April, when rice fields of the Ebro Delta were dry and aquatic prey was scarce for viperine snakes, males and females presented a lower lipid content in fat bodies, liver and muscle than they did in other months, showing a clear link between prey availability and body reserves during food shortage. Thus, patterns of variation in fat levels indicated that Natrix maura is a capital breeder since it acquires resources in advance and stores them until they are invested during the reproductive period. Nevertheless, the shortage in April forces Natrix maura to turn into a facultative income breeder to fuel vitellogenesis. Finally, fat reserves in body components were compared with an estimate of body condition calculated by the residuals from the regression of body mass on body length. In male viperine snakes, the estimate of body condition was correlated with fat levels, revealing that this index is useful to measure condition in living individuals. On the contrary, body condition in females was not correlated with fat levels, which suggests that it is not appropriate to infer condition in female viperine snakes since it depends on the reproductive status of the individuals.

Relationships between the Red Fox and Waterbirds in the Ebro Delta Natural Park, N.E. Spain

Abstract We studied the basic biology of the Red Fox (Vulpes vulpes) and its interactions with the waterbird colonies in the Ebro Delta natural park, Spain. Dens (earths) were found in areas characterized by sandy dune vegetation, a few buildings, areas where human entry was prohibited, and areas where hunting of waterfowl was banned. Regression associated the presence of dens to the abundance of dunes, halophytic vegetation and prohibited entry. Birds constituted 96% of the prey found at dens, mainly waterfowl (68%), gulls (16%) and rails (10%), but this differed markedly between areas. During the breeding season, foxes obtained their food from a reduced number of sources in the area surrounding their dens, and impacted the nearest breeding birds. We propose changes in the management of foxes in the natural park to safeguard internationally threatened bird species and to prevent them from decreasing, or even disappearing, as a result of fox predation.