An Integrated Approach for Evaluating Water Quality between 2007–2015 in Santa Cruz Island in the Galapagos Archipelago

Abstract

Water quality in Galápagos has been deteriorating by increased human impacts over the past few decades. Water quality is a key environmental component and issue in need to be evaluated in the Pelican Bay Watershed, the biggest urban and economic development of Santa Cruz Island, for better management and regulation of water resources. This study assesses coastal and ground water bodies of Pelican Bay by employing a 9-year dataset obtained during a local water quality monitoring program conducted by the Galápagos National Park. Physical-chemical and microbial parameters were evaluated with respect to national and international water quality standards. A statistical integrated approach was performed to calculate environmental background levels of water quality parameters and to explore their seasonal and spatial variation. In addition, a sensitivity analysis was conducted to evaluate the impact of changes in tourism and residents in San Cruz Island in the degradation of water sources. Results highlighted are: (a) water is not suitable for drinking and domestic use at some inland sites; (b) saline water is used for irrigation in the highlands; (c) the presence of parameters of concern at coastal sites represent a risk for human and ecosystem health; (d) background levels may serve for defining site-specific limits to control water quality, and; (e) the influence of population change on water quality conditions varied at each site with a higher effect at coastal sites relatively to inland sites. This study provided valuable information of the water quality status in Santa Cruz Island and can serve as a baseline for effective water management and control of pollution.

"Agua para Galápagos": un programa de monitoreo de la calidad del agua en las islas Galápagos

“…La disponibilidad del recurso hídrico en esta isla es una preocupación constante, debido a la acumulación de agua salobre en grietas de piedras volcánicas. Además, la calidad del agua se ha visto afectada por la proximidad del asentamiento urbano con el acuífero, la falta de un sistema eficiente de tratamiento de aguas residuales, la intrusión de agua de mar y la posible sobreexplotación del acuífero [5]. Adicionalmente, en Puerto Ayora las familias de la isla colectan los efluentes domésticos en fosas sépticas, sin ninguna depuración extra; el 90% de estas fosas no funcionan correctamente, lo cual permite que las aguas residuales se infiltren en el acuífero y lo conviertan en una fuente inadecuada de agua de consumo humano, debido a la presencia de coliformes fecales [6].…”

“…Este análisis se llevó a cabo gracias a los datos recopilados durante nueve años (2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015) por el programa de monitoreo de la calidad del agua del PNG. Analizamos varios parámetros físico-químicos y microbiológicos, con el objetivo de entender el estado de la calidad del agua en la isla junto con las variaciones estacionales y espaciales [5]. Además, en enero de 2020 desarrollamos un proyecto de investigación sobre la disposición a pagar sobre servicios de agua mejorados.…”

Governance Mechanisms and Barriers for Achieving Water Quality Improvements in Galapagos

“…The increased presence of humans on the islands has resulted in severe water quality issues due to the lack of infrastructure to treat and manage drinking water, wastewater and stormwater [22,23]. For example, the groundwater in Santa Cruz Island, the most populated island in the Galapagos Archipelago, is contaminated with fecal coliforms due to the lack of an adequate sewer system and the location of the basal aquifer beneath urban settlements [24]. The release of high concentrations of pollutants into the oceans is a significant source of nutrient input [25,26] that could lead to environmental damage, including eutrophication and mortality of marine organisms [27].…”

“…Government plans last budgeted for the water monitoring program in 2013 and the program conducted by the GNP ended in 2015. An analysis of the data collected by the GNP between 2005 and 2015 provided valuable information of the water quality status in Santa Cruz and can serve as a baseline for effective water management and the future control of pollution [24]. Both technical specialists and local stakeholders emphasized the importance of implementing an effective water quality monitoring of municipal water supplies (Table 2).…”

“…Long-term water quality monitoring programs are recommended for all islands. While technical specialists have made significant contributions to establish baseline information on water quality in all three islands [23,24,47], the government needs to re-establish funding programs for monitoring and use the data more effectively, especially in Santa Cruz and Isabela. These monitoring programs should evaluate the efficiency and effectiveness of treatment plants to meet Ecuadorian environmental legislation for (i) water leaving the drinking water treatment plants according to the NTE INEN 1108 standard for drinking water [70], (ii) the water distribution systems by testing the water as it enters households, and (iii) water leaving the wastewater treatment plants for physical-chemical and microbial parameters according to wastewater discharge limits required to enter a water body [48]-in this case, the ocean.…”