Prawns, prawn fishers and water scarcity: challenges for fishery sustainability of Cryphiops caementarius in the Choapa river basin, Chile (2019-2021)

Abstract

Cryphiops caementarius is a native amphidromous prawn of ecological and fishing relevance in hydrographic basins of northern Chile. This species represents an important component of the cultural identity for prawn fishers’ communities that subsist from it, providing ecosystem services for social wellbeing. Currently, these populations are highly threatened, mainly due to water scarcity and habitat modification as a result of the worst drought seen in the last 10 years in the north-central zone of Chile and the consequent overexploitation of water resources for human uses. Although there are management measures in force for the extractive activity of prawn, such as minimum extraction size and biological closure, this activity is not formally recognized by the national fishing institutions, being a lack of knowledge of basic aspects of its operation, such as the number of associated prawns, the current status of their populations and their historical fishing sectors. In this context, the main objective of the present study was to characterize, together with the fishers’ organizations of the Choapa river basin, the socio-ecological system in which the C. caementarius fishery underlies, during the 2019–2021 period throughout: i) the compilation of the traditional knowledge of prawn fishers’ organizations, ii) the tracking of the fishery through the records compiled by the fishers during fishing activities, and iii) the construction of a conceptual model based on the perception of the stakeholders related to the local prawn activity. From the results obtained, recommendations are presented for the implementation of conservation and management plan(s) that support the sustainability of the C. caementarius fishery in the Choapa river basin. A probable local extinction of its populations in the high-altitude zone of the basin and in tributary rivers is discussed, as well as a possible facultative migratory behavior due to the severe fragmentation and degradation of the fluvial habitat. It is then remarked the need to design and develop, together with stakeholders, further conservation and management actions aiming at supporting local decision-making and granting greater resilience to the species and fishery in a context of great environmental vulnerability, given the current scenario of water scarcity that affects this and other basins in northern Chile.