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Mass whale stranding during Italian Navy exercises: sonar heard?

Effects of Noise on Wildlife, Ocean, Sonar Add comments

Over the past week, a mass stranding of Cuvier’s beaked whales has taken place along the shoreline of Corfu (a Greek island) and southern Italy. The first whales came ashore on November 30, halfway through an Italian Navy exercise taking place in waters on both sides of Italy, including the 130-mile wide Ionian Sea, which separates the two stranding sites. At least one of the Italian ships is known to be equipped with mid-frequency active sonar.

While it’s become common media sport to mention sonar in conjunction with any whale strandings, to the point that once I read the coverage, I rarely see any real evidence, this case is different.  Most strikingly, rescuers in two separate locations during the initial strandings report hearing a “whistling” noise at 10-15 second intervals; it’s quite likely that this sound was what drove the animals ashore. While rare, this is not the first time that humans above the water have heard underwater sound transmissions during stranding events.


On November 30, three or four Cuvier’s beaked whales stranded on Corfu, while two (a female and calf) came ashore across the Ionian Sea in italy. Some were helped back to sea by bystanders, and some died; two of the Corfu whales were collected and necropsies were done, with one being fresh enough for detailed observations.  On December 6 and 7, a total of four more Cuvier’s washed ashore in the same area of Corfu; these were all dead, and decomposed to the point that researchers believe they died at about the same time as the initial strandings took place. According to Alexandros Frantzis, a longtime beaked whale researcher, “It is reasonable to think that there are more animals in the pelagic waters of the Ionian Sea, which may never reach the coasts. The local and apparently small Ionian population unit has suffered three stranding events coinciding in time and space with use of military sonar in the past (plus one in east Sicily earlier this year). There should be little doubt (if any) that the cumulative damage at the population level is high.”

Marine mammal scientists in the region share Frantzis’ alarm about the vulnerability of this population of beaked whales. Both Guiseppe Notarbartolo di Sciara and Natacha Aguilar de Soto have sent urgent letters to officials at ACCOBAMS, a multinational binding agreement between most European and several North African and Middle Eastern countries aimed at coordinating cetacean conservation efforts in the Mediterranean and Black Seas. They ask ACCOBAMS to take the lead in investigating the circumstances of this stranding event, and stress the need to avoid further such incidents in this highly vulnerable population. di Sciara, a former chair of the ACCOBAMS Scientific Committee, notes agreements already made, and asks what steps have been taken to assure compliance and follow-through. In her letter, Aguilar de Soto notes that in the Canary Islands, after several such strandings, active sonar use was banned within 50 miles of the islands, and no further strandings have taken place; she note that similar policies may be necessary “in known important areas of distribution of beaked whales in the Mediterranean, to guarantee the sustainability of the populations.”

You can read the letters of Drs. di Sciara and Aguilar de Soto after the break.

Milano, 1 December 2011
To: Mrs. Marie-Christine Grillo Compulsione, Executive Secretary, ACCOBAMS
Cc: Mr. Oliviero Montanaro, ACCOBAMS Focal Point for ItalyMrs. Eleni Tryfon, ACCOBAMS Focal Point for GreeceMrs. Elvana Ramaj, ACCOBAMS Focal Point for AlbaniaMr. Alexei Birkun, Jr., Chair, ACCOBAMS Scientific CommitteeMr. Alexandros Frantzis, Scientific Director, Pelagos Cetacean Research Institute, Vouliagmeni, Greece

Dear Mrs. Grillo Compulsione,
You may already have seen the report by colleague Dr. Frantzis a few hours ago, posted on the ECS-Talk discussion list (below), describing the atypical mass stranding of a minimum of three Cuvier’s beaked whales, Ziphius cavirostris, which occurred yesterday, 30 November 2011, on the western shores of the Greek island of Corfu.  Based on this very preliminary information it is still impossible to tell whether the stranding event was caused by human activities.  However, on the basis of the report there appears to be strong evidence that human noise from an unknown source, similar to sound known to cause atypical beaked whale mass strandings, was generated in the location’s marine waters as the strandings were occurring.

Based on recommendations from the ACCOBAMS Scientific Committee, the waters of the eastern Ionian Sea (where the above mentioned strandings of Cuvier’s beaked whales have occurred) were listed in MOP Resolution 3.22 (“Marine Protected Areas for cetaceans”) as “areas of special importance for the common dolphin and other cetaceans”.  The deep marine waters off NW Greece and S Albania are widely known to contain important, possibly critical habitat of Cuvier’s beaked whales, as also suggested from the modeling exercise performed by Dr. Ana Cañadas, requested by the Scientific Committee of ACCOBAMS and presented to the Committee’s 7th Meeting in Monaco (March 2011)(see map of predicted relative density of animals, 1990-2010, in Dr. Cañadas’ report). In that occasion the Meeting agreed that beaked whales should not be exposed to a Sound Pressure Level greater than 140 dB re 1 ?Pa @ 1 m throughout most of Mediterranean waters deeper than 600 m.

Based on the above I cannot avoid considering the production of high level noise in the waters off western Corfu a deliberate take of Cuvier’s beaked whales, a protected species.
During the Third (Dubrovnik, 22-25 October 2007) and Fourth Meetings of the ACCOBAMS Contracting Parties (Monaco, 9-12 November 2010), Resolutions were adopted by all Parties (Resolution 3.10 and Resolution 4.17) that are relevant to prevent human-generated noise from jeopardizing the conservation status of protected cetacean species, such as Cuvier’s beaked whales, in the ACCOBAMS area.  Resolution elements include, amongst others:

  • urging Parties to give particular attention to the management of habitats that host sensitive species, such as beaked whales (Res. 3.10, 1, b)
  • urging Parties to include consideration of the effects of underwater noise in EIAs and in the consequent design of mitigation procedures for any activity that might introduce noise underwater (Res. 3.10, 1, d)(Res. 4.17, 4)
  • urging Parties and intergovernmental organisations to inform the Secretariat on current and reasonably foreseeable noise-producing activities occurring under their jurisdiction within the ACCOBAMS area (Res. 3.10, 10)
  • calling upon Parties to request information on the possible impact of anthropogenic noise on marine mammals in existing procedures relating to EIA and where necessary, to develop specific measures, by the competent national authorities, for activities which produce anthropogenic noise having an impact on marine mammals (Res. 3.10, 11)
  • inviting Parties to implement mitigation and monitoring measures for noise producing activities within the ACCOBAMS area, including, avoiding key marine mammal habitats, areas of high marine mammal density and marine protected areas, and defining appropriate buffer zones around them; establish safe, precautionary and scientifically-based exclusion zones around the noise source; effectively monitoring for marine mammals in the vicinity of that source; and managing activities in the light of cumulative, seasonal, and historical impacts from multiple sources (Res. 3.10, 12)
  • strongly requesting Parties to emphasize the need for a precautionary approach and to envisage the appropriate mitigation measures, including a provision for expert review by specialists and a provision for the action to be taken if unusual events, such as atypical mass strandings, occur (Res. 4.17, 5)
  • directing the Secretariat to distribute to the Parties the findings of the Scientific Committee on the habitat of species particularly vulnerable to noise … (Res. 4.17, 12)

Furthermore, Resolution 4.17 contains in its Annex Guidelines “to address the impact of anthropogenic noise on cetaceans in the ACCOBAMS area”, with explicit indication of measures to be adopted to avoid that events such as yesterday’s Corfu atypical mass stranding of Cuvier’s beaked whales will occur.  These include 19 specific guidelines of actions to be followed during the course of seismic surveys and airgun uses.

Since I am unaware whether most of the above Resolution commitments, recommendations and prescriptions were implemented, while I am aware that Cuvier’s beaked whales continue to be subject to episodes of atypical mass strandings in the ACCOBAMS area – with the Corfu event being only the last known – I am kindly asking you to inform me and the science and conservation community in the Mediterranean at large about what measures the Parties – with the support of the Secretariat – intend to implement, amongst those that the Parties have agreed upon in the above mentioned Resolutions, so that the illegal takes of a species protected by many international (e.g., ACCOBAMS, CMS, Bern Convention, EU Habitats Directive, SPA-BD Protocol to the Barcelona Convention) and national legal instruments be avoided in the future.  In particular, I think that it would be important to know whether the Secretariat or the Parties most concerned by the specific Corfu event (i.e., Albania, Greece and Italy) are informed about the occurrence of noise-producing human activities in the area, and if yes whether an EIA for such activity exists, whether you have seen such EIA, on what scientific bases the EIA was produced and approved by the competent authorities, whether there were Marine Mammal Observers on board, whether the EIA was brought to the attention of the Scientific Committee of ACCOBAMS, or whether the EIA was evaluated by cetacean bioacoustic experts.

Given our extreme concern for the continued existence of Cuvier’s beaked whales in the Mediterranean Sea, I look forward to your feedback on my questions above, and take this opportunity for sending you my best regards.

Giuseppe Notarbartolo di Sciara
President of the Tethys Research Institute – Partner of ACCOBAMS
Former Chair, ACCOBAMS Scientific Committee



Auckland, 5 December 2011
To: Mrs. Marie-Christine Grillo Compulsione, Executive Secretary, ACCOBAMS
Cc: Mr. Oliviero Montanaro, ACCOBAMS Focal Point for ItalyMrs. Eleni Tryfon, ACCOBAMS Focal Point for GreeceMrs. Elvana Ramaj, ACCOBAMS Focal Point for AlbaniaMr. Alexei Birkun, Jr., Chair, ACCOBAMS Scientific CommitteeMr. Alexandros Frantzis, Scientific Director, Pelagos Cetacean Research Institute, Vouliagmeni, GreeceMr. Giuseppe Nortarbartolo di SciaraEuropean Cetacean Society

Dear Mrs. Grillo Compulsione,
Following the recent letter from Dr. Notarbartolo di Sciara and the information provided by Dr. Frantzis and Prof. Bruno Cozzi about the recent mass stranding of three Cuvier’s beaked whales in Corfu and other two whales in the Ionian Coast of Calabria. I would like to express my concern about these events and to kindly suggest some important measures to establish potential causes of death and prevent new mortalities.

As you know there have been several mass strandings in Spain that have been related to the use of military sonar. The latest event occurred in the coast of Almeria (SE Spain) and the veterinary team of the University of Las Palmas de Gran Canaria identified findings in the necropsy similar to those in beaked whales stranded in Canary Islands in temporal and spatial coincidence with naval exercises. Only strong dedication from different parties finally got information on the co-occurrence of naval exercises using tactic sonar with the mass stranding event in Almeria. This indicates that it is of maximum importance to obtain information on the acoustic activities occurring in the Ionian Sea that have the potential to be related with the recent Corfu-Calabria strandings. ACCOBAMS seems to be ideally positioned to take the lead on the process of requesting this information from the parties.

Spatial mitigation has been identified a one of the most effective ways of reducing impact, i.e. avoiding  known important habitats for sensitive species when planning an activity with serious potential impact. As you know beaked whales seem to be highly vulnerable to naval sonar and the effectiveness of spatial mitigation has been proven in different places. An example is the Canary Islands: after a historical record of coincidences between naval exercises and atypical beaked whale mass strandings in the Archipelago, there have been no more of these events since the moratoria to the use of sonar within 50 nm of the Canary Islands was declared in 2004. It may be an important  effort, but worthy to pursue, to initiate a process to request spatial mitigation measures in areas of known important areas of distribution of beaked whales in the Mediterranean, to guarantee the sustainability of the populations. Again, ACCOBAMS seems to be very well positioned to initiate this process and this initiative would count with serious scientific support.

Thank you in advance for your interest on this subject, in which you have previously shown concern. I’m looking forward being able of supporting your efforts to aid beaked whale conservation in the ACCOBAMS area

Yours faithfully

Dra. Natacha Aguilar de Soto
Directora Línea de Investigación de Cetáceos
Grupo Investigación BIOECOMAC
Dpto. Biología AnimalUniversidad de La Laguna
Tenerife, Islas Canarias

European Marie Curie Research Fellow
Leigh Marine LaboratoryUniversity of AucklandNew Zealand

3 Responses to “Mass whale stranding during Italian Navy exercises: sonar heard?”

  1. Edward W. Johnson Says:

    I am in rather desperate need of information to oppose a naval request for sonar surveillance work to be conducted in the Indian Ocean. This will involve the use of 2 105 in3 air guns on the Scripps Institutes RV Melville to be conducted Jan-Feb. The comment period ends dec. 21 so time is of essence.
    I submitted my objections to a similar project which was conducted between the Hawaian Islands and Midway, this was in Sept.
    I noticed that Jack Caldwell is another authority in this field but has not published anything since 2002.
    A special thanks for any help or references you may give

  2. aeinews Says:

    Hi Ed,
    Sounds like you may be talking about a geophysical research project (airguns imaging geology below the sea floor), rather than a sonar mission (Scripps doesn’t do surveillance for sure, and probably no mid-frequency active sonar at all unless perhaps occasionally as part of controlled exposure experiments, which, while controversial for many, use quite moderate levels and are very carefully monitored).

  3. Edward W. Johnson Says:

    I hate to be ignorant but looking at what happened in the Med. Sea a place in which supposed testing is not conducted in shallow waters but rather in deeper pelagic surrondings and we have deaths. Are you saying that SURTASS LFA that I am working on has no correlation with the sonar presumably involved in your reference above. Help please Ed