<P> During the process of catching the commercialized fish, the Amazon river dolphins get caught in the nets and exhaust themselves until they die, or the local fishermen deliberately kill the entangled dolphins . The carcasses are discarded, consumed, or used as bait to attract a scavenger catfish, the piracatinga (Calophysus macropterus). The use of the Amazon river dolphin carcass as bait for the piracatinga dates back to 2000 . Increasing demand for the piracatinga has created a market for distribution of the Amazon river dolphin carcasses to be used as bait throughout these regions . </P> <P> Of the 15 dolphin carcasses found in the Japurá River in 2010--2011 surveys, 73% of the dolphins were killed for bait, disposed of, or abandoned in entangled gillnets . The data do not fully represent the actual overall number of deaths of the Amazon river dolphins, whether accidental or intentional, because a variety of factors make it extremely complicated to record and medically examine all the carcasses . Scavenger species feed upon the carcasses, and the complexity of the river currents make it nearly impossible to locate all of the dead animals . More importantly, the local fishermen do not report these deaths out of fear that a legal course of action will be taken against them, as the Amazon river dolphin and other cetaceans are protected under a Brazilian federal law prohibiting any takes, harassments, and kills of the species . </P> <P> In 2008, the International Whaling Commission (IWC) expressed concern for captured botos for use as bait in the Central Amazon, which is an emerging problem that has spread on a large scale . The species is listed in Appendix II of the Convention on International Trade in Endangered Species Fauna and Flora (CITES), and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals, because it has an unfavorable conservation status or would benefit significantly from international co-operation organized by tailored agreements . </P> <P> According to a previous assessment by the Scientific Committee of the International Whaling Commission in 2000, the population of botos appears great and there is little or no evidence of population decline in numbers and range . However, increased human intervention on their habitat is expected to, in the future, be the most likely cause of the decline of its range and population . A series of recommendations were issued to ensure proper follow - up to the species, among which is the implementation and publication of studies on the structure of populations, making a record of the distribution of the species, information about potential threats as the magnitude of fishing operations and location of pipelines . </P>

When did the amazon river dolphin become endangered