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

Koen Van Waerebeek corewam at gmail.com
Fri Dec 2 07:15:21 PST 2011


In support of below hypothesis, I have repeatedly observed in moribund 
captured small cetaceans (in artisanal fisheries settings)
that a peri-mortem posture is maintained after a death struggle as rigor 
mortis sets in fast. If dolphins die in a cramped posture,
eg S-shaped, it is very difficult to straighten the body immediately 
after death straigas to take accurate axial measurements. These are 
observations
in landed cetaceans; in a state of suspension in the water with no 
gravity interference, I would expect the likelihood of maintenance
of peri-mortem posture increased.

Now the reason why a wild small cetacean would sustain an unusual 
head-above-water posture in the general vicinity of a high-amplitude sound
source, e.g. seismic airguns, we suggested: severe acoustic distress, if 
not internal injury. We also suggested it may have a
lethal outcome. Dedicated research is needed.
See:    Gray, H. & Van Waerebeek, K. (2011)  Postural instability and 
akinesia in a pantropical spotted dolphin, /Stenella attenuata/, in 
proximity to
operating airguns of a geophysical seismic vessel. /Journal for Nature 
Conservation /19: 363-367.


Koen Van Waerebeek
corewam at gmail.com


On 12/01/2011 12:40 PM, David Bain wrote:
> 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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