In a statement, the Institute for the Conservation of Nature and Forests (ICNF) defines that “the observation of cetaceans and the permanence of maritime-tourist and recreational vessels at the entrance to the Sado estuary is not allowed”, being “only allowed the circulation/passage of vessels, not being authorised the permanence, the anchorage and the observation of cetaceans, namely dolphins”.

This measure, explains the ICNF, “is a result of the conclusions and proposals of the Study for the Reassessment of the Carrying Capacity for Observation of Whales in the Sado Estuary and adjacent marine area, taking into account the fragility of the population, due to the small number of individuals and the probability that a population increase will not occur until the end of 2030, measures to be implemented in the short term were proposed”.

"Among these measures is the implementation, on an experimental basis, in the period between July 15 and August 30, of the prohibition of observation at the entrance to the estuary", underlines the institute. “The resident population of bottlenose dolphins (Tursiops truncatus) in the Sado estuary currently has around 25 individuals, many of which are over 40 years old”, says the ICNF.

That body explains that “after the downward trend observed in the 1990s, there was a slight increase with the survival of offspring born from 2010”, but recognises that there are still “risk factors that may hinder the ability to of population recovery and make it especially vulnerable to disturbances caused by human activities”.

The exclusion zone decided by the Institute for the Conservation of Nature and Forests (ICNF) will be disclosed in a public notice and is applicable to all maritime-tourist or recreational vessels, emphasises the ICNF.