Members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), release an Amazonian manatee on Trapinho lake at the Piagacu-Purus reserve in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Members the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), take measurements of an Amazonian manatee before its release in the Piagacu-Purus reserve, in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Biologist Diogo de Souza from the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), installs a transmitter in an Amazonian manatee before its release in the Piagacu-Purus reserve, in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), release an Amazonian manatee on Trapinho lake at the Piagacu-Purus reserve in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Students observe Amazonian manatees inside a boat, before members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), release manatees in the nature in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Biologist Diogo de Souza and researcher Vera Silva from the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), monitor Amazonian manatees on Trapinho lake at the Piagacu-Purus reserve in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Biologist Diogo de Souza from the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), weighs an Amazonian manatee before its release in the Piagacu-Purus reserve, in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

A child touches an Amazonian manatee in a boat, before members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), release manatees in the nature in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly - RC15FC23E2F0

An Amazonian manatee is seen inside a boat before members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), release manatees in the Piagacu-Purus reserve, in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Researchers and assistants from the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), put an Amazonian manatee in a boat before releasing it in the Piagacu-Purus reserve, in Manacapuru, Amazonas state, Brazil March 22, 2019. Picture taken March 22, 2019. REUTERS/Bruno Kelly

An Amazonian manatee is seen inside a boat, before members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), release manatees in the nature, in Anori, Amazonas state, Brazil March 24, 2019. Picture taken March 24, 2019. REUTERS/Bruno Kelly

Students observe Amazonian manatees inside a boat, before members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), release manatees in the nature in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Biologist Diogo de Souza and researcher Vera Silva from the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research), monitor Amazonian manatees on Trapinho lake at the Piagacu-Purus reserve in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly

Researchers and assistants from the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research) carry an Amazonian manatee to a boat, before it is reintroduced in the nature, in Manacapuru, Amazonas state, Brazil March 22, 2019. Picture taken March 22, 2019. REUTERS/Bruno Kelly

Researchers and assistants from the Amazonian Aquatic Mammals Project, partners of INPA (National Institute of Amazonian Research) remove Amazonian manatees from a lake on the bank of the Solimoes river, before they are reintroduced in the nature, in Manacapuru, Amazonas state, Brazil March 22, 2019. Picture taken March 22, 2019. REUTERS/Bruno Kelly

Researchers and assistants from the Amazonian Aquatic Mammals Project, partners of INPA (National Institute of Amazonian Research) remove Amazonian manatees from a lake on the bank of the Solimoes river, before they are reintroduced in the nature, in Manacapuru, Amazonas state, Brazil March 22, 2019. Picture taken March 22, 2019. REUTERS/Bruno Kelly

A member of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research) removes an Amazonian manatee from a lake on the bank of the Solimoes river, before they are reintroduced in the nature, in Manacapuru, Amazonas state, Brazil March 22, 2019. Picture taken March 22, 2019. REUTERS/Bruno Kelly

Residents form the Cuiana commmunity at the Piagacu-Purus reserve take part in an environmental education session with members of the Amazonian Aquatic Mammals project, partners of INPA (National Institute of Amazonian Research) and AMPA (Friends of the Manatee Association), before the release of Amazonian manatees, in Anori, Amazonas state, Brazil March 23, 2019. Picture taken March 23, 2019. REUTERS/Bruno Kelly