The main objective of this pilot study is to establish the first successful precedent of the implementation of an acoustic array across Gibraltar Strait (one of the most important worldwide zone for the marine fauna transition) towards the big challenge to deploy a permanent acoustic curtain for the monitoring of this strategic gate. In this sense, several acoustic receivers has been deployed at the strategically locations in order to detect Bluefin Tunas (Thunnus thynnus) previously tagged at the North-Eastern Atlantic waters and that can potentially migrate across this important natural gate.