09 March 2017

WHY SPINNER DOLPHINS STRANDED IN SAUDI ARABIA

Lost Spinner Dolphins are casualties of Houthi militants

During an incoming tide, 10 non-navigating spinner dolphins swim blindly into a shallow swimming area close to the town of Rabigh, Saudi Arabia. Their echo-navigation system was rendered defective by a large explosive set off when Houthi militants attacked a Saudi warship with three small boats off the coast of Hodeida, Yemen 30 January 2017. (see more below)


The Saudi rescue teams tried to get the deafened dolphins to swim back to deep water. But with their biosonar system not working, they could not swim into the incoming current. The drag forces in the water simply turned them around and pointed them into the path of least drag.

All swimmers must have a sense of direction when they swim in a flowing current. If not, they will simply swim with the flow like a blind duck.  

After 4 days of effort, the rescuers loaded 10 non-navigating spinner dolphins into a vehicle and transported them to different location where the surface current was washing away from the beach.

Sadly, their claim to have rescued 10 Spinner dolphins was not true. Instead, they fed the 10 spinners to the sharks waiting just offshore.

The question is what caused the spinners to lose their acoustic sense of direction. In most cases, the loss is caused by rapid changes in water pressure caused by natural seafloor events. However, in this case, there is no records of any dolphin dangerous seafloor eruptions.

The only possible cause was a large explosive set off when Houthi militants attacked a Saudi warship with three boats off the coast of Hodeida, Yemen 30 January 2017. The explosion killed two crew members and injured three others.

The explosion was about 1,000 km south of the standing area, In my opinion, the dolphin were near enough to the Saudi warship to suffer auditory injury during the event. Lost, with no acoustic sense of direction, the non-navigating dolphins swim north with the prevailing current. It possible that they were able to avoid an earlier beaching by spy-hopping to see the nearby shore.

Eventually, they grew too weak to avoid being washed ashore during a tidal inflow that was also couple with a strong shoreward wind. The shoreward wind continued strong for 4 days, overcoming the strength of the tidal outflow. This is why it took so long to get them to swim away.

Spinners have foreward set eyes so it possible they might have caught a few fish along the way to maintain a fresh water balance and to keep their immune system from failing.

This is the first mass stranding we have ever tied directly to an explosion.