06 December 2013

Why Did Pilot Whales Beach in the Florida Everglades?

They stranded due to barosinusitis in the cranial air spaces.

Mass stranding whales and dolphins dive deep practically everyday of their lives. Their single greatest threat during a dive is a surprize encounter with a series of rapid and excessive changes in the surrounding water pressures. Undersea earthquakes, volcanic explosions, impact of heavenly body with surface, military sonar, explosions, and geophysical air cannons are all capable to generating rapid changes in the surrounding water pressure and are thus the most dangerous encounters a diving whales can face.

The part of their anatomy most vulnerable to excessive pressure changes while diving is their massive cranial air spaces (sinuses and air sacs).

The air contained in these air chambers serve underwater as acoustic mirrors, bouncing sound around in a fashion to enable the function of biosonar. Busted, bleeding sinuses will not reflect or channel returning echoes, thereby disabling the ability of pod members to echo-navigate or to dive and feed themselves. In this fashion, a pressure-related diving injury (barosinusitis) that damages the air sinuses of an entire pod at the same time can explain mass strandings.

Pelagic toothed whales, like pilot whales, spend their entire lives above mid-oceanic ridges, the most earthquake-prone areas on Earth. Squid, the favorite food of pilot whales, breed and lay their eggs along these ridges because the bottom water is warmer, and the newborn squid have more feeding opportunities.

According to the US Navy's 1966 science report, seaquakes kill marine life and can sinks ships (link) These events are called sea shocks by the Japanese. If a ship is within 25 miles of the epicenter, the feeling aboard is like bouncing over a field of jagged rocks. Many ships have disappeared during a seaquake. The links below will give you an idea of what happens aboard a vessel. As you read these examples, imagine that there was a pod of pilot whales feeding on squid below the ship. Suppose the ship and the whales were within a few miles of the epicenter. You will not need to read too many seaquake encounters before you will be convinced that these events can and do injure whales and other marine mammals and fishes with swim bladders. 

Seaquakes are simply low frequency acoustic (compression) waves with both a positive and negative pressure phase. Dr. Clyde E. Nishimura, with the U.S. Navy’s Marine Geoscience Division estimated that a shallow 7 mag. undersea earthquake could produced a LF noise at about 260 dB (1450.5 psi). He added that this number was likely on the low side. Professor of Physics, M.A. Mironov, a member of the Russian Academy of Science, calculated that during an average earthquake in which the seafloor shifts up and down at 1 meter per second, the alternating pressures in the water would equal 15 atmospheres (243.62 dB or 220 psi) both above and below ambient pressure. This means the pressure would oscillate back and forth between 220 psi over ambient and 220 psi below ambient 5-7 times per second for as long as the earthquake lasted. The Danger of Seaquakes

Just like bats flying in the dark, toothed whales and dolphins use biosonar to echonavigate their way around the world's oceans. They do so by generating and sending biosonar clicks just like a nuclear submarine. The echoes return the the brain via the lower jaw bone. The acoustic vibrations are then funneled/guided to their cochleas through a maze of acoustic channels that are surrounded by air sinuses and air sacs. The air serves underwater as acoustic mirrors to route the returning echoes in a fashion to make their biosonar work. The two cochleas are also isolated from each other by special air sinuses. If the isolation between the two inner ears fails, both ears would receive signals at about the same time and there will be no acoustic navigation.

Let's assume for modeling purposes that our Everglades pod of short-fin pilot whales were feeding above the epicenter of a dangerous seabed earthquake. The rocky bottom pushed and pulled at the water column and caused the surrounding water pressure to change rapidly and excessively. The volume of air contained in their cranial air spaces instantly changes in tune with the surrounding water pressure. The change was excessive. The entire pod suffered internal barosinusitis in and around their cranial air spaces.

There is no outward evidence of the injury since the busted sinuses are contained inside their large heads. Besides intense pain and severe headache, the first thing the injured pod noticed is that their biosonar is no longer working. The next thing they noticed was that they can no longer dive and feed themselves due to intense head pain. Such injured whales might dive 4-5 feet, but they cannot feed on squid because they cannot dive to deep enough to reach the squid.


Global view


The whales return to the surface after the injury. The acoustic mirrors inside their heads are busted. Their biosonar is dysfunctional. They are now as lost as a blind man adrift in a row boat without a compass.

Where will they go? The flow of the current from the epicenter is toward the west and into the Caribbean Sea. Assuming an average downstream current of 1.5 knots and a swim speed on 2.5 knots means that our pod will swim downstream from where they were injured about 100 miles a day. Since the earthquake occurred 28 days before the first beaching, the whales will travel downstream for about 2,800 miles.

If we trace the current downstream for 2,800 miles from the epicenter, we find ourselves at the beach in the Everglades..

Scientists know that surface currents build beaches. They also know that surface currents deposit plastic jugs, seaweeds, logs, and other flotsam on the beaches built by the currents. In fact, everything floating along with the current gets deposited on beaches. No shoreward current; no beach, no flotsam, and no stranded whales.

On top of losing their ability to sense direction, the Everglades pod had also lost the ability to feed itself evidenced by the empty stomachs found during the necropsy. Furthermore, 6 of the first 11 to strand had to be put to sleep because they were too weak to survive. This fits in with the 4 weeks they have been at sea without food and water.  The 11 whales in the second stranding in the lower Florida Keys were dehydrated, malnourished, and emaciated. Obviously, these poor animals suffered some type of accident weeks before they reach the Everglades.

After they were freed, some of the whales just turned around and swam back to the same beach. This happens often and is a sure sign that the surface currents picked the stranding site, not the whales.

You can also tell by the smooth sea in this video that the shoreward surface currents died down to no appreciable movement causing the whales to mill around in shallow water. Some slowly swim one way and others slowly swim in the opposite direction. Obviously, "no surface current" results in "no sense of direction" in the whales.

Let's also dispel a myth so often quoted by scientists.  Whales do not have a social bond so strong that they will beach themselves and die rather than be separated from their pod mates. The truth is that the whales are as scared as humans of being eaten alive by vicious sharks.

Sharks trail these injured pods like wolves trail a herd of caribou. In 1971, in the oft cited article "Geometry For The Selfish Herd," evolutionary biologist W. D. Hamilton asserted that each individual group member reduces the danger to itself by moving as close as possible to the center of the group. Thus a herd or pod appears as a close-net loving family unit when moving together, but its function emerges from the uncoordinated behavior of self-serving individuals. No whale wants to be ripped apart; they will stay with the pod to save their own lives. This is especially true if whatever affliction or accident that caused the pod to be lost at sea also happened to the individual. If the individual is as lost as the rest of the pod, where is he/she going to go on its own. The lost individual is compelled to stay with the non-navigating pod because it has also lost the ability to navigate. Nor can it defend itself against a pack of starving sharks.

Let's also dispel the myth about whales following a leader ashore. On occasion, a brave, restless pod member or two will swim away (downstream) from the others. The rest of the pod, thinking the brave whales know the way to open water, will follow them. This creates the illusion of the entire group following a pod leader to the beach. What is really observed is a lost non-navigating whale taking a bold step and the rest of the pod following along because they are completely and totally lost.

The often-quoted idea that pilot whales live in tightly cohesive groups and typically will not leave ailing or dead members behind is also false. If any adult whale could navigate and find its own food, it would quickly leave its pod behind and save its own butt. The whales near the beach know they are injured and that many hungry sharks are waiting just offshore. They know the odds favor that they will be the next whale ripped apart by sharks if they leave the beach alone. This is why whales near the beach are not too interested in leaving unless they leave with many other pod mates. The surface currents also need to flow away from the beach before the whales will swim away. This is why rescue teams release stranded whales just after high tide when the current starts to flow away from the beach.


Most seaquake-injured pods likely did recover several hundred years ago because the oceans were teaming with massive schools of surface fish. All they needed to do to grab healing nutrition and fresh water was to swim into a school of fish with their mouths wide open. They were also likely smart enough to realize that diving birds meant life-saving food and water.

In those days, seaquakes were likely evolutionary advantages. There were so many healthy pods along the mid-ocean ridges that the most dangerous threat they faced was overgrazing on the squid. If a pod was hit be a seaquake, it would be forced to swim along downstream for 2,000 to 3,000 miles until it was completely recovered. The recovered pod then had to find a new habitat; it could not return to its previous feeding grounds because pod members had no acoustic connection with the seafloor and no idea how to get back to where they came from. In this fashion, species were spread all around the world and this was good for the whales. Since earthquakes were beneficial as long as there was plenty of food on the surface, there was little evolutionary pressure to adapt a better means of dealing with seaquake pressure changes.

But condition have changed since then. The ocean purse seining industry has removed 90% of the surface schools needed by the injured whales to recover. More pods are standing today and the number of whales in each beached pod is rapidly dwindling. At this current rate, we will lose our pelagic toothed whales in less than 50 years to the pressures of seaquake injury alone.


Site Map for http://deafwhale.com  

Dec 09: Whale Dangerous Earthquake South of Perth 
Dec 09: Seaquake causes dolphins to strand Baja California   
Nov 23: Seaquakes kill 322 baleen whales in Chile    (shocking)  
Aug 24: NOAA whale scientists dumbfounded   
Aug 14: stranded dolphin is determined to be deaf   
Aug 08: seaquake causes pilot whales to strand Nova Scotia   
Jul   27: is our stranding solution flawed as scientists claim   
Jun  01: pilots stranded Isles of Skye from Reykjanes Ridge   
May 22: dead whales washing ashore on the California Coast   
May 10: earthquake kills 20 Sei Whales near Chile Coast   
Apr  10: seaquake strands 150 melon-headed whales in Japan   

Dec 25: navigation failure in mass stranded whales  (most popular)   
Dec 08: seaquake causes 7 sperm whales to beach Australia   
Nov 24: seaquake beaches 3 sperm whales at Golden Bay   
Nov 04: seaquake beaches 60 pilot whales in Bay of Plenty   
Oct 29: nine pilot whales strand on Prince Edward Island   
Apr  11: 60 pilot whales beach in Bay of Plenty   
Mar 20: Cape Ray Newfoundland 37 dolphins beach   
Mar 14: undersea quakes louder than nuclear explosions   
Mar 13: seaquakes cause whale strandings 32 million years   
Mar 02: blue whale killed by seaquake in Kuwait   
Feb 27: seaquake kills young killer whale   
Feb 23: predicting mass beachings based on seaquakes   
Feb 21: lessons in understanding why whales beach   
Feb 18: seaquake Greenland Sea kills 3 sperm whales   
Feb 12: nine orcas killed by seaquake   
Jan 30: Cape Cod mass stranding predicted   
Jan 20: seaquake causes 39 pilot whales to strand Florida   
Jan 16: seaquakes beach 65 pilot whales in Golden Bay   
Jan 05: seaquake beaches 30 pilot whales in Golden Bay   

Dec 06: why did pilot whales beached in the everglades?   
Apr 30: seaquake beaches 6 killer whales in Iceland   
Apr 25: beached whales stop war games   

Dec 08: seaquake beach pilot whales South Carolina   
Nov 15: pilot whales beach at Golden Bay, New Zealand   
Nov 04: seaquake causes two pods to beach at King Island   
Oct 28:  pilot whales strand on North Andaman Island   
Oct 17: earthquakes cause New Zealand whale stranding   
Sep 09: earthquake kills pregnant sperm whale   
Sep 03: seaquake strands pilot whales in Scotland   
Aug 24: two quakes cause near beaching in Cape Verde   
Jul  28:  200 Pilot Whales Northwest of Iceland   
Mar 19: Four Sperm Whales Wash Ashore in China   

Dec  31: world's rarest whales killed by earthquake   
Mar 06: 52 melon-headed dolphins strand in Japan   

Nov 20: 52 Pilot Whales Stranded in Tasmania


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