Ongoing acoustic research in the Mediterranean has confirmed earlier indications that fin whales are far more affected by oil and gas exploration noise than has long been assumed. Manuel Castellote’s most recent paper details a set of disturbing findings, here summarized by the website Science Codex:
Maritime traffic and geophysical exploration –including the search for hydrocarbons– “drastically” reduces the song effectiveness –linked to reproduction and which propagates hundreds of kilometres beneath the Sea– of the whales, which are also the group of marine mammals with the greatest acoustic sensitivity at low frequencies. “The noise generated through human activity in the oceans leads to possible chronic effects on the health of this species”, Castellote states.
After analysing 20,547 hours of recordings of the sounds emitted by the whales, the study published in Biological Conservation indicated that the whales modified the characteristics of their songs in order to try to reduce the impact of noise on their propagation. In addition the researchers recorded a massive displacement of fin whales, triggered by the noise from geophysical prospecting at a distance of 285 km from the study area. “These recurrent displacements, together with the changes in acoustic behaviour, could increase the energy expenditure and reduce the reproductive success of whales affected by the noise”, the expert indicated.
In the long-term the consequences for these mammals are clear: chronic effects which impact on their survival emerge. “Noise in the marine medium, despite being recognised as a significant pollutant, is far from being controlled and regulated within the waters of the Exclusive Economic Zone of Spain”, warns Castellote