DFFE Addresses Fish Mortality in Hartenbos Estuary

Mossel bay: The Department of Forestry, Fisheries and the Environment (DFFE) has clarified the cause behind the mass fish mortality observed in the Hartenbos Estuary in Mossel Bay. The department emphasized that the incident is neither linked to the red tide nor to a sewerage spillage. According to South African Government News Agency, investigations in collaboration with the Mossel Bay Municipality revealed that the fish deaths were caused by multiple interacting factors. These include elevated nutrient inputs leading to eutrophication, reduced freshwater inflow due to water abstraction and dam development, and harmful algal blooms accompanied by high phytoplankton biomass. These conditions contribute to eutrophication and ammonia toxicity, as highlighted in the National Biodiversity Assessment and earlier studies, particularly affecting smaller and temporarily closed estuaries like Hartenbos. The DFFE has warned the public against handling or consuming any marine organisms that have washed up, as they may pose health risks. Despite the situation, water quality monitors and relevant authorities have confirmed that oxygen levels in the estuary have returned to normal, and the situation is under control. Previously, the department noted a similar event involving the washing up of dead marine life at St Helena Bay and Elandsbaai on the West Coast, though it was confined to those areas.