Management of Urban Wastewater on One of the Galapagos Islands

Detection and quantification of microplastic pollution in the endangered Galapagos sea lion

Marine debris pollution poses a significant global threat to biodiversity, with plastics being the primary debris type found in oceans due to their low-cost production and high demand worldwide. Microplastics (MPs, <5 mm in size) are highly bioavailable to a wide range of marine taxa, including marine mammals, through direct and indirect ingestion routes (i.e., trophic transfer). Recently, MP pollution has been detected on the Galapagos Marine Reserve, so in this study we developed a baseline framework for MP pollution in the Galapagos sea lion (GSL, Zalophus wollebaeki) through scat-based analysis. We collected 180 GSL scat samples from the southeast region following strict quality assurance/quality control protocols to detect, quantify and characterize physical-chemical properties of MPs through visual observations and μFT-IR spectroscopy. We recovered 81 MPs of varying sizes and colors in 37 % of samples (n = 66/180), consisting mostly of fibers (69 %, x¯ = 0.31 ± 0.57 particles scat-1). The number of particles per gram of sample wet weight ranged from 0.02 to 0.22 (x¯ = 0.04 ± 0.05 particles scat wet g-1). El Malecón and Punta Pitt rookeries at San Cristobal Island had the highest number of MPs (x¯ = 0.67 ± 0.51 and 0.43 ± 0.41 particles scat-1, respectively), and blue-colored particles were the most common in all samples. We identified eleven polymers in 46 particles, consisting mostly of polypropylene-polyethylene copolymer, polypropylene, cellulose, polyethylene, and polyvinyl chloride. The textile, fishing, and packaging industries are likely significant sources of microfibers into this insular ecosystem. Our results suggest that the GSL is exposed to MPs due to anthropogenic contamination that is subsequently transferred through trophic processes. These findings provide an important baseline framework and insights for future research on MP pollution in the region, as well as for management actions that will contribute to the long-term conservation of the GSL.

The performance evaluation of wastewater service: a protocol based on performance indicators applied to sewer systems and wastewater treatment plants

This research aimed to identify a tool to objectively analyse the performance and the environmental contextualisation of sewer systems (SwSs) and wastewater treatment plants (WWTPs). This procedure performs assessment by calculating performance indices which could be subsequently applied to SwSs and WWTPs with different characteristics. The proposed tool can be applied conveniently over the years by managers of integrated urban water management systems for the analysis of different realities also allowing the evaluation of the effects of upgrades carried out during the management phases. The proposed analysis allows the optimisation of SwSs and can profitably guide the choice and the priority among possible interventions for the sewerage infrastructure and WWTPs providing a verification and evaluation protocol as well as a financial planning tool.

Water Security in the Galápagos: Socioecological Determinants and Health Implications

Water security is strongly associated with important health outcomes and has many socioecological determinants. Several studies have documented the social determinants of water security and impacts of water security on health, independently. Yet few have examined both components in one setting. Using data from Ecuador's nationally representative health survey (ENSANUT-ECU), we proposed a new methodological framework for assessing water security in the Galápagos and assessed the relationship between socioecological indicators and water security among 2701 individuals in 693 households. We then tested the link between water security and childhood stunting using multilevel mixed effects logistic regressions controlling for household clustering. We found that being higher income in rural settings is significantly protective of water quality (OR 7.35) and increasing household size is associated with reduced water access (OR 0.44). We found no impact of water insecurity on childhood stunting. We observed a marked divergence in water security between islands and discussed potential underlying structural determinants. Understanding the structural predictors of water security and health is a necessary step in improving local health outcomes in the Galápagos. The social and physical factors leading to this water security environment may also be shared by similar locations, broadening the application of these findings.