Site Selection Criteria and Recommendations for the Restocking of Juveniles of River Prawn Cryphiops caementarius in the Semiarid Region of Chile: A Basin and Participatory Approach

Abstract

The fishery of the river prawn Cryphiops caementarius in semiarid basins of northern Chile constitutes a small-scale artisanal activity, developed in fragmented habitats with extended periods of drought, which represents a severe threat for the conservation of its populations. Fishers filed an environmental complaint for massive prawn mortalities caused by river channellings in the Choapa River basin. The government promoted a participatory program with fishers to carry out a restocking initiative in this basin, releasing ~4000 hatchery reared juveniles. The aim of this study was to evaluate site selection criteria for the releases, which included ecological variables relevant to the life habits of juveniles. These criteria incorporated background of the natural history of the species, seasonal monitoring of habitat indicators (fluvial habitat index and hydraulic stress index) and recommendations of fishers (traditional ecological knowledge). This study demonstrated that the integration of these criteria and restocking sciences based on aquaculture is beneficial when selecting the release site, with a high coincidence of ecological characteristics for C. caementarius to thrive. The results of this experience are discussed, emphasizing the pioneering character of this type of measure in freshwater crustaceans in Chilean basins, the ecological framework used to responsibly assist these measures in basins with intense anthropogenic impacts and recommendations that allow the improvement of the releases and monitoring efforts of this species, considering the drought scenario that affects this region of Chile.