Capt. David Williams, founder of the DEAFWHALE SOCIETY, solves the centuries-old mystery of why pods of whales and dolphins mass strand on beaches around the world!
The answer turns out to be barotrauma in the pterygoid air sacs (sinus cavities) surrounding the ear bones (cochlea). The injury is induced by rapid and excessive changes in water pressure above the epicenter of certain thrusting earthquakes in the seabed.
Feeding on squid along earthquake prone mid ocean ridges exposes pods of whales to underwater earthquakes. In 70% of these events, the motion in the seafloor is side-to-side and relatively slow. Such sideways motion “slides” through the water like a boat paddle turned on edge and is usually harmless to nearby whales.
On the other hand, when the hard bottom dances up and down violently, the vertical thrusting turns a portion of the seafloor into the faceplate of a gigantic sonar transducer, pushing and pulling at the water column, generating changes in the surrounding water pressure that, in extreme cases, may approach 280 decibels re 1 micro PA (14,500 psi) one meter off the bottom.
These waves of alternating pressure (called T-waves by seismologists) quickly dissipate as the energy fans out above the epicenter but still may easily exceed 200 pounds per square inch 500 meters off the bottom.
Earthquake magnitude plays a part in determining the danger faced by the pod but is not the major factor. For example, a magnitude 4 earthquake 2 km deep in the seabed is likely to be far more dangerous to diving whales than a magnitude 6 event 20 km deep. Another dangerous facet is the speed (acceleration) of the vertical thrusting. Water tends to flow to areas on less pressure. During earthquakes in which the seafloor dances relatively slow, the water has time to flow to the sides reducing the danger above the epicenter. Conversely, rapid up and down jerking builds extreme pressure changes much faster than the flow of water can counter. Thus, extremely shallow explosive earthquakes are the most hazardous to diving whales.
Just as it would be if a large group of scuba divers were suddenly exposed to rapid pressure changes from a nearby explosion, a pod of diving whales caught off-guard by rapid and excessive changes in the surrounding water pressure during thrusting earthquakes are subject to barotraumatic injury in their head and middle ear sinuses when the rapid changes in pressure exceed their ability to adjust.
Of particular concern are the small air sacs (pterygoid sinuses) that surround each cochlea and help the whales sense sound direction underwater.
The oscillating pressure changes cause the volume of air in the head sinuses to expand and contract to the point of an injury that interrupts diving and causes biosonar failure. An earthquake-injured whale could hear sounds perfectly well, but would not be able to determine from which direction the sounds came. Ruptured sinuses would also disrupt feeding since the injury would prevent the whales from diving to the depth of their prey due to extreme pain.
Diving-related injuries of this nature are far more common than one would imagine. The injured pods are forced to remain on the surface until their sinuses heal and they can resume diving and feeding. Recovery may occur in days, in weeks, or not at all depending on the extent of the injury and the availability of food on or near the surface.
Offshore whales normally fix their location along the Mid Ocean Ridges by “listening” to the constant seismic rumble going on below them. Once the sinuses are ruptured and this tool is lost, so is the pod.
The flow of the water offers six times the resistance when swimming upstream as it does when swimming downstream. Without a sense of direction on the part of the whale, the resistance factor would quickly turn the whale’s streamlined body head first and keep the animal pointed in a downstream direction in a similar fashion as how a weather vane points the direction of the wind. In other words, the lost pod can not help but swim downstream in the path of least resistance. In fact, they are eventually stirred by reduced resistance into the fastest downstream flow where they remain until some other factor causes a change. Thus, the swim path of the wounded pod is controlled by the surface currents and the wind and nothing else–especially not a geomagnetic compass. Beached whales are carried to the beach by the same force that carried each grain of sand to build the beach in the first place.
Geographic land masses that extend out to see opposing the flow of current, like Cape Cod in the US and Golden Bay in New Zealand, serve as giant catching arm, guiding the non-navigating whales into a sand trap.
The wounded pod naturally attracts the attention of large oceanic sharks that move in to take stragglers. Deep water sharks get big by feeding on wounded whales, not squid. The hungry predators dog these pods like wolves dog a herd of caribou, forcing them to huddle together for protection as they continue to swim in a general downstream direction.
Many pods recovery within a few days. Others within a few weeks. Those that do not recover stand an excellent chance that the surface currents will eventually carry them to a sandy beach, especially a sand trap inside a large catching-arm system that happens to be located downstream from a seismically-active feeding ground for the species in question.
In summary, the SEAQUAKE SOLUTION developed by CAPT David Williams, founder of the Deafwhale Society, indicates that barotrauma in the head sinuses, as a result of exposure to potent earthquake-induced changes in ambient pressure, solves the centuries-old mystery of why whales and dolphins mass strand on beaches around the world.
http://www.deafwhale.com/
