[MARMAM] New atypical mass stranding of Ziphius in the Ionian Sea, Greece

David Bain dbain at u.washington.edu
Thu Dec 1 09:40:07 PST 2011


In the Haro Strait case, the sonar was audible in air while the ship 
producing it was over 22 km away.  It was over the horizon and hence not 
seen at that distance.  Mid-frequency sonar is used by both military and 
non-military vessels, so could have been what was heard even if no 
military exercises were underway.  The regular interval reported is more 
typical of mechanically generated sound than natural whistles.

After rescue, I have observed stranded cetaceans rest with their flukes 
on the bottom and heads above water.  Air in the lungs provides enough 
flotation for individuals that otherwise would be negatively buoyant (it 
may be that resting like this improves survival probabilities enough 
that sick or injured cetaceans have been selected to come into the 
nearshore to attempt to recover, and some strandings occur when they are 
too debilitated to remain offshore).  I'm not sure how likely it is that 
that posture could be maintained after death, but if it died while 
holding its breath, it would have been in the described posture until 
water movement pushed it away.

--Dave

On 12/1/2011 5:56 AM, Jasny, Michael wrote:
>
> In response to one of Alexandros' questions: in at least one incident 
> involving Navy sonar training (the Haro Strait, Washington, event of 
> May 2003) witnesses reported hearing sonar whistles above the waterline.
>
> These latest strandings are extremely concerning.  It has sometimes 
> taken governments months or  years to publicly divulge information on 
> intrusive acoustic activities -- including sonar training and seismic 
> surveys -- after a mass stranding event has occurred.  Along with 
> Giuseppe, I would urge ACCOBAMS and CMS -- and other intergovernmental 
> organizations that have adopted resolutions on ocean noise -- to 
> request relevant information from their member states; and I would 
> urge states to respond as soon as possible.
>
> Finally, this incident underscores the need for meaningful, 
> habitat-based mitigation for sonar training, seismic exploration, and 
> other intense sources of ocean noise.  It seems clear -- simply on the 
> basis of prior mass stranding events -- that the eastern Ionian Sea 
> should be put off-limits to such activities, as were the Canary 
> Islands to mid-frequency sonar training through the responsible 
> actions of the Spanish government several years ago.  The MPA that 
> ACCOBAMS has proposed there is long overdue.
>
> Best to all,
>
> Michael
>
> *From:*marmam-bounces at lists.uvic.ca 
> [mailto:marmam-bounces at lists.uvic.ca] *On Behalf Of *Alexandros Frantzis
> *Sent:* Wednesday, November 30, 2011 4:05 PM
> *To:* ecs-talk at jiscmail.ac.uk; marmam at lists.uvic.ca
> *Subject:* [MARMAM] New atypical mass stranding of Ziphius in the 
> Ionian Sea,Greece
>
> Dear all,
>
> Once more we have bad news regarding Cuvier's beaked whales in the 
> Ionian Sea. The local population unit, which has repeatedly been 
> affected by NATO naval activity (last time in February 2011 east of 
> Sicily) may be steadily heading towards its extinction...
>
> Today 30 November 2011 at least three Cuvier's beaked whales stranded 
> alive and atypically in west Corfu, along 23 km of coast. All whales 
> were led offshore by people who tried to rescue them. One whale died 
> some 200 m offshore. Another whale, after having swam some 600 m 
> offshore, returned and stranded once more (if this wasn't a different 
> animal). It was led once more offshore after the sunset, so no further 
> information is available so far. The third animal was not seen after 
> it was "rescued".
>
> *I would like to draw your attention on two "peculiarities":*
>
> *1)* Independent rescuers in two different stranding areas, reported 
> that they were hearing "whistles" while approaching the single 
> animals. The "whistles" were heard even out of the water at a distance 
> of 100 m from the animal (!), and became much louder when the rescuers 
> entered the water to approach the animal. The rescuers kept hearing 
> the "whistles" until they left the place, two hours after the death of 
> the unique whale present! They thought that there might be other 
> whales calling the stranded animal from further offshore, although 
> they could observe nothing for hours.
>
> Two independent rescuers (separated by 23 km) described these 
> "whistles" as "emission"-pause of 10-15 seconds-"emission"-pause and 
> so on. *I wonder if what the rescuers were hearing was the probable 
> sonic cause of the stranding*. If you have a similar experience or 
> knowledge, please share it with us.
>
> The rescuers didn't see any military or seismic survey vessels from 
> the shore. A fisherman from the area said that today he saw an 
> "unusual" research vessel offshore that he believes (it is known in 
> the area that seismic surveys have started or are about to start) was 
> performing research for oil.
>
> *2)* The whale that died 200 m offshore was found at about 3-4 m depth 
> at an unusual position (to me at least). Its flukes were on the sea 
> bed while the beak and part of the head of the animal was out of the 
> water! For some reason the head could float at surface and the animal 
> never sunk. *Does anyone has an explanation?
> *
> Unfortunately no necropsy was performed to the animal that died.
>
> The port-police authorities and local volunteers have been alerted and 
> we just hope that tomorrow we won't find more animals along the coasts.
>
> Repeated use of military sonar and now growing seismic survey activity 
> go on in an area that is critical for the two deep diving 
> Mediterranean species, the Cuvier's and the sperm whales. In 2007 
> ACCOBAMS officially proposed the creation of a MPA for deep diving 
> cetaceans in the eastern Ionian Sea (Hellenic Trench), but nothing has 
> happened so far.
>
> Best wishes,
> Alexandros
>
> -- 
> ___________________________________________
>   
> Dr. Alexandros Frantzis
> Scientific director
> Pelagos Cetacean Research Institute
> Terpsichoris 21
> 16671 Vouliagmeni,
> GREECE
> Tel.: +30-210-8960108
> e-mail:afrantzis at otenet.gr  <mailto:afrantzis at otenet.gr>  
> website:http://www.pelagosinstitute.gr  
> ___________________________________________
>
>
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