WATER QUALITY MONITORING DURING THE TRANSPORT OF AMAZONIAN ORNAMENTAL FISH

High mortality rates have been reported in the capture and transport of ornamental fishes from the Amazon basin, and much of it was probably stress induced. One of the primary factors that can be managed to reduce stress and mortality during transport is water quality. We assessed the physical and chemical conditions of the water used to transport the species Paracheirodon axelrodi, Symphysodon discus and Carnegiella strigata. Water samples were collected during capture, at the fishing camps, at the exporter’s Barcelos facilities, during the transport from Barcelos to Manaus, and at the exporters’ facilities in Manaus. During storage at the Barcelos facilities and transport to Manaus, samples were collected before and after partial water renewal to evaluate the effect of this practice on water quality. We measured temperature, electric conductivity, pH, dissolved oxygen, ammonia, chloride, sodium, and potassium. To assess fish stress response, the change in concentration of these ions in the water was measured over 20 hours during transport to Manaus. The changes observed in the ionic concentrations indicated that during transport the fishes were subjected to stress. Water quality during transport from fishing areas to the fishing camps, and at the fishing camps themselves, was good. Water quality at Barcelos facilities and during transport from Barcelos to Manaus differed significantly from those observed at the fishing grounds and fishing camps. Major differences were observed in the concentrations of dissolved oxygen, ammonia, sodium and chloride. The practice of partial water renewal and the use of table salt (NaCl) during these two phases of the transport process did not effective improving water quality. The poor water quality observed during transport and the lack of standard handling procedures resulted in a progressive decline in general fish health and perhaps a lowered resistance to diseases. At the Manaus facilities, water quality was considered adequate. The high mortality rates reported by the importers were probably caused by the inability of fishes to recover after the transport-induced stress. More detailed studies of water quality are necessary to establish protocol to reduced stress and improve survivorship. RESUMO Altas taxas de mortalidade tem sido registradas na captura e transporte de peixes ornamentais da bacia Amazônica, grande parte da qual é provavelmente induzida por estresse. Um dos fatores que podem ser manejados para reduzir o estresse e mortalidade é a qualidade da água. Foram avaliadas as condições físicas e químicas da água usada para transportar as espécies Paracheirodon axelrodi, Symphysodon discus e Carnegiella strigata. Amostras de água foram coletadas durante a captura, nos acampamentos de pesca, nas instalações dos exportadores em Barcelos, durante o transporte de Barcelos para Manaus e nas instalações dos exportadores em Manaus. Durante a estocagem em Barcelos e transporte para Manaus, amostras de água foram coletadas antes e após renovação parcial da água, para avaliar o efeito desta prática na qualidade da água. Na água foram medidas a temperatura, condutividade elétrica, pH, oxigênio dissolvido, amônia, cloro, sódio e potássio. Para avaliar a resposta dos peixes ao estresse, mudanças na concentração iônicas da água foram