His research and collaboration with the herpetologist Peter Pritchard produced the still-extant reference book on The Turtles of Venezuela,[2] the 2018 re-edition of which, alongside the biography done on him entitled Trebbau: Maestro por naturaleza by Albor Rodríguez, sparked the series Colección La Fauna, which aimed to collect Trebbau's work on the fauna of Venezuela.

[citation needed] In 1968 he led an expedition and rescue operation in the region of Guayana that protected an estimated 10.000 animals of 53 different species that would have drowned as a result of the construction of the Guri Dam.

[citation needed] He then worked as the zoo coordinator for the National Parks Institute (Inparques), and as Special Commissioner for the Ministry of Environment.

[6] In 1989 he took an active role on the advisory committee for a new Wildlife Law, and in 1991 he became president of the National Foundation of Zoological Parks and Aquariums.

[7] Trebbau produced and hosted several TV programs aimed at the dissemination of the knowledge of the local fauna, especially among the younger generations.