Analysis of lipid peroxidation in animal and plant tissues as field-based biomarker in Mediterranean irrigated agroecosystems (Extremadura,Spain)

ABSTRACT

The development of field-based biomarkers can allow for a more reliable assessment of the exposure of organisms to pollutants. Different sampling sites, along two streams running through an irrigable agricultural area, were selected to evaluate the effect of agrochemical load on the measured endpoints. The levels of lipid peroxidation were evaluated in several organs of Procambarus clarkii. The same method was applied to leaves of two woody species. Determining levels of MDA (malonaldehyde) by thiobarbituric acid reactive substances assay allows measuring the levels of lipid peroxidation. Differences in lipid peroxidation levels were observed in P. clarkii individuals collected at different sites; however, the patterns varied depending on the organ (when accounting for variations due to sex). The use of a MDA-gills/MDA-hepatopancreas index allowed for discrimination between reference and polluted sites. Significant differences in oxidative damage between sites were found in the leaves of Quercus rotundifolia but not in Salix sp. The lipid peroxidation of crayfish organs and holm oak leaves as a suitable biomarker of environmental pollution deserves further investigation.     

An evaluation of fishery co-management experience in an Amazonian black-water river (Unini River,Amazon, Brazil)

We evaluated the implementation of a fishing agreement, which was created by negotiation among all users of the resources as a co-management strategy because its definition was a result of meetings between all users of the resources. The fishing agreement was implemented in Unini River, a tributary of the right bank of Negro River. Our approach was based on the perception of the people who live in that area, called ribeirinhos. The management strategy was based on spatial distribution of the different types of fishing. We used two logistic regression models to identify the variables which are important to determine the previous concordance and satisfaction with the agreement. First, we analyzed the initial effort to implement the agreement. The variable that influenced the decision of support for the agreement and satisfaction with the results of agreement in both models was the distance from the interviewee’s residence to the sport fishing area. The results showed that the perception of improvement in well-being of the communities and structured social organization are crucial for the success of the co-management strategy.     

Effects of brackish water incursions and diel phasing of tides on vertical excursions of the keystone predator Pisaster ochraceus

The physical factors that constrain the vertical foraging excursions of the keystone predator, the sea star Pisaster ochraceus, hold considerable interest because they indirectly shape the vivid patterns of zonation of rocky shore communities by impeding or enhancing the ability of P. ochraceus to traverse the intertidal zone. In this paper, we describe a study conducted in the Pacific Northwest of North America in which we examined, in the field and laboratory, the abiotic factors that can affect vertical excursions by P. ochraceus. Our field observations revealed that the extreme upward reach and average shore level height reached by P. ochraceus were significantly lower for daylight high tides than nocturnal high tides. Based on diver observations following a severe storm, it would also appear that these diurnal movements can be impeded by freshwater incursions into the intertidal zone; a regularly occurring event in the Pacific Northwest. As part of an experimental investigation into this phenomenon, we observed that sea stars maintained in tall cylindrical aquaria, without tidal flux, remained near the bottom during daylight and moved to the top of the column at night, suggesting that photoperiod alone can influence the cycle of vertical movement. Adding a freshwater layer to the aquaria restricted these vertical excursions. Our results suggest that on rocky coastlines susceptible to fresh water incursions, the suppression of foraging may be an important factor in the spatial and temporal variation in the intensity of predation. Furthermore, given the relative increase in frequency and intensity of freshwater incursions in the Pacific Northwest and the intolerance of P. ochraceus to lowered salinity, there is the long-term potential to significantly alter patterns of species zonation in this essential marine habitat.     

Interactions Between Spatially Explicit Conservation and Management Measures: Implications for the Governance of Marine Protected Areas

Marine protected areas are not established in an institutional and governance vacuum and managers should pay attention to the wider social–ecological system in which they are immersed. This article examines Islas Choros-Damas Marine Reserve, a small marine protected area located in a highly productive and biologically diverse coastal marine ecosystem in northern Chile, and the interactions between human, institutional, and ecological dimensions beyond those existing within its boundaries. Through documents analysis, surveys, and interviews, we described marine reserve implementation (governing system) and the social and natural ecosystem-to-be-governed. We analyzed the interactions and the connections between the marine reserve and other spatially explicit conservation and/or management measures existing in the area and influencing management outcomes and governance. A top-down approach with poor stakeholder involvement characterized the implementation process. The marine reserve is highly connected with other spatially explicit measures and with a wider social–ecological system through various ecological processes and socio-economic interactions. Current institutional interactions with positive effects on the management and governance are scarce, although several potential interactions may be developed. For the study area, any management action must recognize interferences from outside conditions and consider some of them (e.g., ecotourism management) as cross-cutting actions for the entire social–ecological system. We consider that institutional interactions and the development of social networks are opportunities to any collective effort aiming to improve governance of Islas Choros-Damas marine reserve. Communication of connections and interactions between marine protected areas and the wider social–ecological system (as described in this study) is proposed as a strategy to improve stakeholder participation in Chilean marine protected areas.     

Occurrence of Human Enteric Viruses in Commercial Mussels at Retail Level in Three European Countries

In this study, the prevalence of different enteric viruses in commercial mussels was evaluated at the retail level in three European countries (Finland, Greece and Spain). A total of 153 mussel samples from different origins were analysed for human norovirus (NoV) genogroups I and II, hepatitis A virus (HAV) and hepatitis E virus (HEV). Human adenovirus (HAdV) was also tested as an indicator of human faecal contamination. A full set of controls (such as sample process control, internal amplification controls, and positive and negative controls) were implemented during the process. The use of a sample process control allowed us to calculate the efficiencies of extraction, which ranged from 79 to 0.5?%, with an average value of 10?%. Samples were positive in 41?% of cases, with HAdV being the most prevalent virus detected (36?%), but no significant correlation was found between the presence of HAdV and human NoV, HAV and HEV. The prevalences of human norovirus genogroup II, HEV and human NoV genogroup I were 16, 3 and 0.7?%, respectively, and HAV was not detected. The estimated number of PCR detectable units varied between 24 and 1.4?×?10³?g^?1 of digestive tract. Interestingly, there appeared to be a significant association between the type of mussel species (M. galloprovincialis) and the positive result of samples, although a complete overlap between country and species examined required this finding to be confirmed including samples of both species from all possible countries of origin.