Sunday, January 13, 2008

When Death Brings Life

- by Dr Rob Davis (WSORC Director)
It is the first week of January 2008 and another beautiful day has begun on the Bay Island of Utila.

While working at the Whale Shark & Oceanic Research Center (WSORC), I get a call that a whale was found beached in East Harbor – this was the second whale found beached on the shores of Utila in three days, the first was discovered January 3, 2008. Both whales were examined by WSORC and were positively identified as “Cuvier’s Beaked Whales” (also known as “Goose Beaked Whales,” or Zifius cavirostris) by our colleague, Paula Mendez, of Vigo, Spain.

First Whale

On January 3, 2008, an adult female Cuvier’s Beaked Whale washed up on shore at Champas Beach. She was 17-feet long and approximately 3,000lb. Once the necropsy had been completed she was towed out to sea.

Second Whale

On January 5, 2008, a second beaked whale washed up on shore two days later and approximately one-half mile from where the first beaked whale was discovered.

The second whale was 11-feet long and approximately 1,000 pounds (460 kilos). Due to the close proximately and time frame from where both whales were discovered, it was determined this was the calf of the first whale.

Physical signs confirmed the calf was a male. His coloring was light gray on the ventral area with a darker gray on the dorsum; there were many large lacerations that developed post mortem. Like the female whale, the calf also had a small head and beak but no teeth were present. There was a depression located just behind the blowhole. There were small pectoral fins, a small dorsal fin approximately two-thirds down the body, and a large fluke with rounded tips that was similar to the female whale.

Analysis

A necropsy was performed on both whales by Dr. Loretta Potts, assisted by Dr. Rob Davis, Rodger Mehrer and Bryan Becker of WSORC. Samples of tissues and organs were taken and processed at WSORC laboratory for shipment to other laboratories for further examination.

What was found in the stomachs of each whale was rather concerning. The adult female’s stomach had squid beaks; however, it also had wood and plastic objects. The calf had more normal food in the process of being digested; however, it too had plastic material in its second stomach.

Burial at Sea

Rather than towing the male calf out to sea, WSORC decided to anchor the calf at depth for observation. It was decided to bury the calf at sea, not only for observation, but to provide the natural cycle of life and death at sea. By allowing the calf to decompose at sea, it would provide nutrients and life to other sea life.

The wreck of the Halliburton was selected because it sits in 100 feet of water and is located just outside the harbor. A dive team organized to develop a plan to remove, transport and submerge the calf.

The dive team consisted of Dr. Rob Davis and Bryan Becker from WSORC and Adam Clarke from the Bay Island College of Diving (BICD). Utila Lodge provided a boat with crew (Willie Waterhouse Jr. served as boat captain and Jose Romoan crew. The boat used to pull the calf off the beach and tow it to the mooring site was a 30-foot doray with a 200-horsepower engine.

The dive plan was to tether the calf to the bow’s anchor chain at a depth of 95 feet. There were many concerns about the safety of the operation. The dive team would be working at depth and did not know how long it would take to haul the calf to the mooring site. It would also be an effort to get the calf in position at depth and would cause greater air consumption than normal, thus, a reduced amount of bottom time; it was determined that bottom time would be 15-minutes with single aluminum 80s with 3,000 pounds of compressed air.

There was also a concern not to get tangled in the ropes and lines. A short, nylon line was attached to the calf’s fluke and used to secure the calf to the anchor chain. A 120-foot rope was tied to the nylon line and used to haul the carcass to depth.

Dive Operation

Rob Davis and Adam Clarke were the primary divers with Bryan Becker serving as the safety officer and photographer. Rob proceeded to depth and Adam brought him the end of the rope. Rob secured the rope around the anchor chain by propping his fins on the chain for leverage; Adam would pull down on the rope as Rob took up the slack and hold the rope in place. Bryan monitored the progress four feet away and insured neither Rob or Adam got tangled in the ropes; Bryan also monitored bottom time and air consumption.

The seas had two-foot swells and the visibility was approximately 15 feet . The divers back rolled out of the boat and began their descent. The calf floated on the surface as the divers took the haul line down to depth (100 feet). Once on the bottom, both divers began to pull the calf down which took effort at first. Once the calf was at 30-feet, it became easier and the divers were able to bring it to the mooring location with relative ease as the depth compressed the calf’s body.

Once the calf was at depth, the divers attached the nylon line around the calf’s fluke and onto the anchor chain – the haul rope was then released and the secured calf was floating nose up. With the operation complete, the divers began their slow ascent to the surface careful not to get tangled to the rope. After their safety stop they surfaced and handed the nylon rope to the crew, then passed our gear up to the crew and scampered back onto the boat.

Due to each diver’s experience and developing the dive plan, the task to submerge and secure the calf to the anchor chain was completed in 22 minutes and did not require a second dive.

Future Observations

This operation will provide interesting dives over the next few days. Recreational divers will be able to observe the interaction of sea critters that will visit the submerged calf. The scientific community will also be able to observe, photograph and evaluate what transpires as the calf decomposes.

WSORC thanks all those who assisted in the necropsy, sample processing and evaluation, and the dive operation. I am sure that even though this may be rare to happen often in any one location, it may be a common event throughout the world.

Future Certifications – What do you think!

Consideration should be given to consider the development of a certification program for the transporting/submerging of marine cadavers and also for observing, documenting and evaluating the decomposition of such submerged whales.

1 comment:

capepolly said...

Does anyone have any underwater photos of the beaked whale on the halliburton? I would love to see how it progresss - and if anyone sees anything interesting around them. maybe a curious silky shark will find it (this is the shark the locals call the blacktip).