SAvE Whales: A life board for the sperm whales of the Eastern Mediterranean


Sperm whales that live in the Eastern Mediterranean were not more than 200-300 individuals during the past decade. Alarming results from Pelagos Cetacean Research Institute, conducting systematic observations since 1998, indicate that the population might have been halved to only 100-150 whales. The main threat to this population are the more than 30.000 cargo vessels that annually cross their habitat at high speed and the risk of collision with them.

International and regional agreements oblige Greece to take action to protect the sperm whales, including their habitat, the Hellenic Trench. The pilot system SAvE Whales which was developed through the collaboration of OceanCare, the Pelagos Cetacean Research Institute (Greece) and the Foundation for Research and Technology – Hellas (FORTH) contributes to this direction, offering an innovative technology that transmits the exact location of sperm whales to passing ships in real time, in order to avoid collision. It is the first system of its kind for sperm whales globally and a milestone in cetacean conservation, complementing further action to protect the last sperm whale population of the eastern Mediterranean. Results of the pilot application of the SAvE Whales technologies were recently presented in a paper published in the scientific journal “Frontiers in Marine Science”.

In short, the SAvE Whales system uses solar-powered high-tech buoys equipped with hydrophones that record the clicking sounds of the sperm whales, process them and send filtered data to a land-based analysis centre where computer models are used to detect, precisely localize the animals, and finally forward the localization fixes to nearby ships, all in real time. Specifically developed software combines localization results with shipping information from Marine Traffic, a leading ship tracking service provider, to assess collision risk. If a vessel is on a collision course with a whale, its captain can be warned well in advance, such that the ship slows down and/or changes course in time to prevent the collision.

The pilot project has resulted in a system which can become the missing link for the effective protection of sperm whales from ship strikes, in particular where re-routing is not possible. Shipping should slow down anyhow, but by being alerted to the presence of sperm whales, vessel captains can and shall act to reduce the collision risk to the absolute minimum. The SAvE Whales system constitutes an important tool and know how available to relevant authorities in Greece as well as any maritime country, where sperm whales face similar risks”, explains Nicolas Entrup, Director International Relations at OceanCare.

Now we know that saving the sperm whales is feasible thanks to the pioneering technology that we have developed collectively. It is time for both the Greek and the European authorities to use this technology locally, regionally and beyond, in order to allow sperm whales to live safely and survive”, says Alexandros Frantzis, Scientific Director at Pelagos Cetacean Research Institute,:

The design, development, deployment and operation of a real-time acoustic detection and localization system was an extremely challenging endeavour that we addressed with enthusiasm and care. I hope that the success of the SAvE Whales project paves the way for the use of underwater acoustics for the protection of sperm whales and for the good of the environment in general”, notes Emmanuel Skarsoulis, Research Director, Underwater Acoustics Group, Institute of Applied and Computational Mathematics FORTH.

The system is particularly recommended for use in those areas where other measures, such as the re-routing of ships is not possible. Such a case is the sea area between Kythira and Cape Tainaro in Greece, but the know-how can also be applied to other regions in the Mediterranean.

Having overcome most of the technical challenges, it is now time for the SAvE Whales system to go to the next level: to be presented to the relevant authorities and other stakeholders, so that it can be applied full scale in those situations, where no other options to prevent ship strikes are available”, comments Ioli Christopoulou, Policy Director of the Green Tank.

The joint Press Release is co-signed by: OceanCare, Pelagos Cetacean Research Institute, the Foundation for Research and Technology-Hellas, The Green Tank.




  1. The paper in the scientific journal «Frontiers in Marine Science» titled A real-time acoustic observatory for sperm-whale localization in the Eastern Mediterranean Sea can be found here.
  2. The abbreviation “SAvE Whales” stands for “System for the Avoidance of ship-strikes with Endangered Whales”. The project was supported and funded by OceanCare. It was carried out by experts from the Institute of Applied and Computational Mathematics FORTH (Greece), the Pelagos Cetacean Research Institute (Greece), Marine Traffic, Green2Sustain and CINTAL at the University of the Algarve (Portugal).
  3. In the framework of the SAvE Whales project, the acoustic stations were deployed in sea for 3 months in 2020 and another 3 months in 2021, detecting sperm whales for a total of 46 days. The system succeeded in 3D localization of sperm whales, with high precision, at distances up to 7 km. Some of these results are presented in the cited scientific paper, which also discusses the challenges faced due to the weather conditions, as well as recommendations on the system’s improvement. It also discusses the need for further study on issues regarding energy consumption and storage capacity to enable year-round operation or at higher latitudes when solar energy is limited.