Antibioticsin a multifunctional reservoir: exploring its occurrence, sources, and impact on reservoir services

Introduction

Cirata is a multifunctional reservoir. The reservoir is simultaneously used for hydropower generation, extensive aquaculture, and the disposal of untreated domestic sewage and livestock discharges. As a result, Cirata receives antibiotics from several sub-catchments. The continuous supply of antibiotics from activities in and around the reservoir will potentially threaten the services it provides. This study aims to provide insights into the effect of possible mitigation options to promote the sustainability of the reservoir’s services. To achieve this objective, four steps will be performed. First, the antibiotics will be prioritized through laboratory analysis along with a comprehensive risk assessment to identify the current situation of antibiotics including their type, level, and risk. Second, the contribution of each source of the prioritized antibiotics resulting from RQ1 to the reservoir will be evaluated using a modelling approach. Third, the potential link between ecosystem services and the prioritized antibiotics will be explored by linking the loads of nutrients and antibiotics to the eutrophication levels and how this may affect the ecosystem services. Fourth, considering the antibiotic sources of major contribution and ecosystem services which are potentially affected by prioritized antibiotics, mitigation options to reduce the impact of antibiotics on the reservoir will be proposed.

Objective

To contribute to safeguarding the future ecosystem services of the multifunctional reservoirs, this study aims to increase the understanding of antibiotics in relation to their environmental state, potential sources, impacts and mitigation options. The multifunctional reservoir, Cirata, will be a case study in this research. To this end, several tasks to achieve the research objectives will be performed including analyzing antibiotics presence and concentrations in the Cirata reservoir and evaluating the risk; evaluating relative sources of antibiotics in the Cirata reservoir; evaluating how antibiotics and nutrients limit the ecosystem services; and assessing potential mitigation options to reduce the impacts of antibiotics on the services provided by Cirata reservoir.

Method

The type, level and risk of antibiotics would be assessed using direct sampling and measurement meanwhile the relative source of antibiotics will be defines using MARINA models and new developed model. Using the results from the first and second step how antibiotics will limit ecosystem services will be evaluate. To this end, The adequate mitigation options to reduce the impact of antibiotics and nutrients will be selected based on their contributions to reducing the antibiotics risk in the reservoir. Taking into account the potential mitigation options and the current situation (level and risk) of antibiotics their impact after the application of mitigation on each of the ecosystem services will be revealed.

The methodology of this research project is summarized in Figure 2