Managing aquaculture in multi-use freshwater bodies: the case of Jatiluhur reservoir

D A Taskov,D C Little,M A Rice,F J Murray,T C Telfer,D A Bengtson

doi:10.1088/1748-9326/abe009

Abstract

The pressure on scarce freshwater resources from intensifying human activity is rising across the globe. This study presents the case of Jatiluhur—Indonesia’s largest reservoir, where unregulated aquaculture expansion has contributed to environmental degradation and associated conflicts with other water-users. Aiming to identify a strategy to improve the sustainability of cage aquaculture within Jatiluhur reservoir and other freshwater bodies facing similar challenges, this study consisted of an initial analysis of time bound satellite images of the reservoir and a systematic survey of 112 aquaculture farms. The results revealed that, with more than 45 000 production units in 2020, more than half of which are placed outside government-approved aquaculture zones, the carrying capacity of the reservoir is exceeded. An analysis of the farm-level production practices, pertinent to environmental regulation, indicated the existence of three main production strategies, with significant differences in eutrophication potential among them that would lead to better articulated policy actions. A feed manufacturer-focused policy to reduce total phosphorus levels in formulated diets by more than half, but still within the optimal level for fish performance, would have the most impact. Enforcement of registration and removal of illegal production units supported by satellite-based monitoring of compliance are key recommendations to support intensive cage culture remaining an important economic activity.

Highlights

Multipurpose freshwater reservoirs in populous fish-eating regions of Asia have become major centres of intensive, cage-based aquaculture development [1, 2]
This study presents the case of Jatiluhur—Indonesia’s largest reservoir, where unregulated maintain attribution to aquaculture expansion has contributed to environmental degradation and associated conflicts with the author(s) and the title of the work, journal other water-users
A failure of governance to control nutrient enrichment, caused by a host of human activities, such as agriculture, land conversion, urban and industrial discharge occurring in surrounding catchments [4], has led to responses ranging from outright bans of aquaculture, such as in most of China [2], to on-going chronic conflicts around poor water quality and costs associated with its remediation [4, 5]

Summary

Introduction

Multipurpose freshwater reservoirs in populous fish-eating regions of Asia have become major centres of intensive, cage-based aquaculture development [1, 2]. The coexistence of aquaculture in such structures together with reliable supply of clean water, and support for sustainable hydropower and agriculture has been questioned, even when it can significantly contribute to nutritional security whilst remaining within local and planetary environmental boundaries [3]. Rational management approaches that include aquaculture are urgently required [6] in locations such as the Citarum river basin, one the largest watersheds in West Java [7], that is of great strategic, economic and food security importance to Indonesia [8], supporting generation of some 20% of the country’s gross domestic product [9]. Whilst the inundation of the reservoirs has opened up new opportunities for income generation, more than 100 000 people were displaced from traditional agriculture-based livelihoods in the process [10]

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Conclusion