Should we allow human-induced migration of the Indo-West Pacific fish, barramundi Lates calcarifer (Bloch) within Australia?

Abstract

Some biologists have expressed concerns about the possible genetic impacts of translocation between stocks of barramundi Lates calcarifer (Bloch) in Australia. Recent genetic, biogeographical studies have provided an understanding of the evolution of the currently observed population structure in Australian barramundi by assessing the impacts of ice-age, sea-level changes on their distribution. These studies found that genetic differences between most barramundi populations are extremely small, have arisen in the past 17 000 years, and substantial migration and hybridization between eastern and western populations, isolated for at least 110 000 years, has occurred naturally. Some phenotypic support for these minor genetic differences can be inferred from the lack of adaptation to temperature in growth and survival responses of widely separated stocks (tropical and temperate). Based on a low level of genetic differentiation and high levels of gene flow between populations, with little evidence of local adaptation, translocation between populations should not pose a significant risk or problem.