HURL submersibles have not just one but two encounters with Great White sharks!

By Terry Kerby

On October 28, 2002, the Pisces IV submersible was conducting a dive on Penguin Bank, a well known Hawaiian bottomfishing site near the island of Moloka'i, when it had a chance encounter with a Great White Shark, Carcharodon carcharias. Robert Moffitt of NOAA Fisheries was the Principal Investigator and the dive was one of 12 he was awarded to examine the recovery rates of areas closed to bottomfishing. Pilot Chuck Holloway was maneuvering the Pisces IV along the 350 m (i.e., 1150 ft) contour while observers Walter Ikehara and Jane Culp were looking through the ports identifying and counting all fish and invertebrates they could see. Suddenly a large shark moved quickly at the sub and bumped into the upper video camera knocking the laser ring loose. The camera recorded a quick glimpse of a nose and eye as it flashed by. This video image was distributed to a number of shark experts who verified that it was most likely a Great White. Fortunately for the many tourists who come to the islands to swim and dive, this species is rarely seen in this part of the Pacific. It's also rare to record a Great White from a submersible so the encounter wound up being shown in a Discovery Channel documentary called "Jaws of the Pacific".

Well, sometimes lightning really does strike twice. On October 4, earlier this year, the Pisces V was conducting precious coral research dives off of Oahu when there was another encounter! This time, I was piloting and had just landed on the bottom at 446m (i.e., 1,463 ft). Principal investigator Amy Baco-Taylor and BBC cameraman Tom Fitz were on board and were just settling into position to start observations while I was adjusting the trim. Just prior to lifting off, I caught a glimpse of something large approaching the sub, which then turned sideways presenting the unmistakable profile of a Great White. This encounter was not a quick hit and run; the animal swam up to the Pisces V, turned, and passed right in front of the sub before swimming slowly away. I was able to estimate its length at 13 ft and clearly determine it was a female. This one had a huge girth which Great Whites are known for but also she may have been pregnant.

These encounters raise some interesting questions according to HURL biologist, Chris Kelley. Was it just extraordinary luck to have this happen twice or are there more of these sharks in Hawaiian waters than we realize? What are they feeding on below 1,000 ft? Hawai'i has no sea lions and while there are a number of monk seal colonies in the Northwestern Hawaiian Islands, there are none in the main Hawaiian Islands. What are they doing down there? Was the female really pregnant and if so, could Great Whites be breeding or at least giving birth to their pups in deep water? Could Hawai'i be a breeding ground for this species and could that be why tracking data has shown these sharks to be migrating between the West Coast and the islands?

We don't yet have answers to these questions but you can bet we'll be keeping our eyes open on future dives, just in case lightning strikes for a third time.