Species diversification in aquaculture is a key strategy for achieving sustainable practices. In Chile, Small-Scale Aquaculture (APE) has been consolidated as a complement to artisanal fisheries, supported by specific regulations and mechanisms that promote diversification. This study implemented a participatory bottom-up approach to diversify aquaculture in estuarine zones of southern Chile, contrasting with the traditional top-down public policy model.
Two artisanal fisher organizations were engaged: S.T.I. Sotomó (Caleta Sotomó, Cochamó municipality) and S.T.I. Sirenita de Pichicolo (Caleta Pichicolo, Hualaihué municipality), to implement experimental cultures of Pacific oyster Magallana gigas (introduced species) and Northern scallop Argopecten purpuratus (native species) in aquaculture concessions traditionally dedicated to mussel farming. The process included site selection, installation of suspended lantern systems, and seed stocking: 30,000 oysters (~30 mm) and 10,000 scallops (~40 mm) in Sotomó, 10,000 oysters (~25 mm) in Pichicolo. Environmental monitoring and growth assessments were conducted, alongside a process of organizational strengthening and local governance.
In Sotomó, oysters reached ~70 mm in six months with marginal mortality, whereas scallops experienced total mortality due to local environmental conditions. In Pichicolo, oysters grew to ~50 mm in the same period; as this introduced species has no legal minimum harvest size, its market value begins at these sizes depending on target market preferences. The results demonstrate the technical feasibility of oyster culture and its potential to diversify production in mussel farming areas. Social and territorial factors essential for APE sustainability were identified, including collective learning, local institutional support, and adaptive capacity, providing evidence to replicate bottom-up initiatives that strengthen socioecological resilience in coastal aquaculture territories.
Funding: Small-Scale Aquaculture Transfer Program, Los Lagos Regional Government (IDI code: 40046065-0).