Survival response of Heliaster helianthus (Lamarck, 1816) to salinity increases associated with desalination brine discharges

Abstract

The increase in desalination as a source of freshwater supply has intensified brine discharge into coastal marine ecosystems, generating hypersaline conditions that may disrupt the ecological stability of benthic communities. In this context, experimental evidence is required to assess the sensitivity of key species to these physicochemical changes. The objective of the study was to determine the survival response of Heliaster helianthus (Lamarck, 1816) to salinity increases associated with desalination brine discharges. The research was experimental in nature, with a quantitative approach and a completely randomized design. A total of 24 individuals collected along the Ilo coastline (Peru) were exposed to a control treatment (35.35 g·L^-1) and seven salinity concentrations (38.98-72.98 g·L^-1) for 24 hours under laboratory conditions. The results showed a progressive decrease in survival as salinity increased. The estimated LC₅₀ (Median Lethal concentration) was 37.17 g·L^-1, while LT₅₀ (Median lethal time) ranged from 17.0 to 2.08 hours depending on the concentration. Treatments above 46.30 g·L^-1 caused total mortality in less than 4 hours. The Conesa matrix classified the impact as critical (I = -86), indicating high ecological sensitivity. It is concluded that H. helianthus exhibits high vulnerability to salinity increases, confirming its stenohaline nature and its potential as a bioindicator of disturbances induced by brine discharges. These findings suggest that even moderate salinity variations can compromise the survival of key species in coastal marine ecosystems.