Arapaima, or Pirarucu, may be closer to extinction than previously thought and current procedures for ensuring the sustainability of their populations are insufficient to protect them from decline, according to a study by conservation biologist Leandro Castello and ichthyologist Donald Stewart.
The study, published in the most recent issue of the Journal of Applied Ichthyology, critically assessed Brazil's regulations for non-detriment finding (NDF) procedures for pirarucu using IUCN's checklist for making NDFs.
The NDF procedures, which assure that export of the fish will not adversely affect the population and regulates its international trade, were found to be insufficient to ensure the sustainability of Pirarucu populations.
Pirarucu are threatened mainly by overfishing, with the fishery being mostly unregulated because government regulations on size, season, and even moratoriums on capture have been very poorly enforce.
The failure to insist on sound scientific evidence (which is lacking anyway given how little we understand of the population and biology of Pirarucu) and the loopholes in the current NDF procedures for Brazil makes it very difficult to impose harvest control measures.
The authors also highlight deficiencies in our understanding of the taxonomy, biology, and conservation status of the Pirarucu in the paper, and cite evidence from their ongoing studies that at least four species of Pirarucu exist.
This news was broken in Practical Fishkeeping's September 2009 issue (see Five Arapaima species, not one).
Although there are no data on catch levels or status of wild populations, available information suggests that Pirarucu are in decline.
For more information, see the paper: Castello, L and DJ Stewart (2010) Assessing CITES non-detriment findings procedures for Arapaima in Brazil. Journal of Applied Ichthyology 26, pp. 49–56.