The circle has come round

The distinctive smell that hung over the area, the low buzzing of flies, and the oblong mounds of sand told us well before we reached the gate that we were entering the world of rotting cadavers and drying bones. And indeed, passing through the gate, the first thing that greeted us was a row of bleaching skulls. Whale skulls.

This was no gruesome graveyard but an important part of scientific research. Osteology is the scientific study of bones, and osteologists have an important place in research organisations as they extract valuable information such as species, age, gender, health and disease from skeletons. As such, SECAC’s Marisa Tejedor Fuentes is indispensible for both the organisation’s research into cetaceans and for preparing bones and skeletons for its cetacean museum in Lanzarote. We were very pleased that Marisa showed us the research site, and spent time explaining the process to us and answering our questions.

Preparing the bones

As cetaceans are so difficult to study, given the inhospitable environment for humans, the cadavers of dead animals provide scientists with much valuable information. When a stranding occurs, the first thing that happens is a necropsy of the animal to determine the general health status and the possible cause of death. This is carried out by specialist veterinarians, and when they are finished the osteologists move in. They remove as much of the flesh as possible and then bury the bones in marked graves. These were the mounds that we saw at the research site. Worms, maggots and beetles do their job and within several months, depending on the size of the carcass, the bones are mostly cleaned of flesh. The remaining flesh is removed by boiling the bones, which are then cleaned using warm water and gentle soap.

Once the flesh is removed the bones are put in the sun to dry. Interestingly, the length of time that the bones remain in the sun differs with species and age. It seems that, in general, the deeper diving species have more porous and brittle bones than the shallow diving species. Marisa prepares and mounts some of the skeletons for the museum to be used for educational purposes. The rest are used for research.

The victims of naval sonar

Animals strand for various reasons, and mass strandings are particularly tragic. Between 1985 and 2004 the Canary Islands has seen seven mass strandings, costing the lives of at least 59 beaked whales. At least, these were the ones whose bodies washed ashore. Who knows how many others died further out at sea, their bodies being carried away from shore? What was the cause of the mass strandings? While the cause is clouded in controversy and debate, most scientists concur that it was due to the use of naval sonar during military exercises.

The odontocetes, or toothed whales and dolphins, use echolocation to locate their prey and other objects. (See http://en.wikipedia.org/wiki/Animal_echolocation for an explanation of echolocation). This sensitive system is vulnerable to external influences and frequencies in certain ranges. The result is that the animals become disoriented, probably suffer pain, panic and shoot to the surface of the water much too quickly. Like divers, they get decompression sickness, commonly known as ‘the bends’, from a rapid ascent to the surface. (See http://en.wikipedia.org/wiki/Decompression_sickness for an explanation of decompression sickness) In a sickened state, or already dead, they are swept by the currents onto beaches and strand.

From the mass stranding of about 14 whales on the islands of Lanzarote and Fuerteventura in September 2002, the skulls of seven of them (Blainville’s beaked whale and Cuvier’s beaked whale) have landed in the hands of Marisa. These were the skulls that we saw when entering the premises. With so many whales stranding at the same time, and in the chaos of people trying to help the live whales back into the water, and the emotion of doing so with navy ships still on the horizon, the skulls were the only parts of the skeleton that they could get.

The circle had come round

When Marisa told us the history of the beaked whale skulls, I felt a deep sadness. When Ernie and I first decided to embark on the voyage of Morganonline and started work in the Canary Islands in 2005, one of the first things we did was attend a public conference on the dolphins and whales of the Canary Islands. Among the presentations was one given by Dr Antonio Fernandez of the University of Las Palmas’ School of Veterinary Sciences. Unbeknownst to us at the time, he is one of the world’s leading experts on the effects of military sonar on cetaceans, and it was the first time that we became aware of this tragic occurrence. I never forgot the presentation of his findings of the 2002 mass stranding, and the horrifying photographs of damaged organs. Since then we have talked with a number of people about this issue, have seen film footage, and have done background reading. While the horror may be blunted by this exposure, the emotion does not go away. So when I realised that the skulls that Marisa was explaining were the very same individuals that Dr Fernandez had talked about that had moved me so much, it was with a feeling of homage that I looked at the skulls. The circle had come round.

Links about strandings associated with military sonar:

- Protecting Whales from Dangerous Sonar
- Military SONAR may give whales the bends
- Protect Whales from Harmful Ocean Noise
- Animals and Sound in the Sea
- Background on Military Active Sonar