I noticed that on our story “5 Things You Should Know about Sharks,” the first reader comment was left by scuba diver and ocean enthusiast Mike Bear.
I know his name from couple of blogs he runs: Rapture of the Deep, a site featuring stories and photos of ocean life, and Sevengill Shark Sightings, which collects information about encounters with sevengill sharks. The second site is part of the Shark Observation Network, where shark-sightings from around the world are reported.
Bear writes on his sevengill site,
I have been diving regularly in the San Diego area since 2000, averaging about 100 dives per year, mainly in the area of La Jolla Shores, La Jolla Cove, Wreck Alley and Pt. Loma, as well as being actively involved in the San Diego diving community and I do not recall hearing of any diver reports of encounters with sevengill sharks before 2008, when we began hearing the first reports.
I emailed Bear and asked him to tell us more about his experiences. He told me,
I started the website to document sevengill sightings off San Diego when we began hearing of increased numbers of encounters between them and divers, because, to my knowledge, no researchers at either Birch Aquarium or Scripps Institution of Oceanography have ever done any baseline studies of this species.
Although not a shark researcher myself, I am working with a PhD candidate in biology from SDSU to try and identify individual animals from their unique freckling patterns by running them through a pattern recognition algorithm, similar to previous work done by Brad Norman with whale sharks. …
I have personally had two encounters with sevengills in the past two years here locally. … We have not had any instances of sevengills being aggressive, except one, reported by a spearfisherman, who was trailing a line of bloody, speared fish behind him, but the bite did not break the skin.
According to an article in Wired UK, Norman’s work uses “algorithms designed to guide the Hubble telescope’s starscape surveys,” and “a database of 32,000 photographs of some 2,800 different whale sharks, contributed by more than 2,600 people” to track the individual creatures.
There’s more about Mike Bear’s interest in sevengill sharks on the California Diver website. The book “Sharks of North America” has a good explanation of sevengill sharks.
He also sent a link to this beautiful hi-res video of sevengill sharks, taken in La Jolla Cove on July 24.
I’m Grant Barrett, engagement editor for voiceofsandiego.org, in part a new-fangled opinion editor. Share the your pastimes and hobbies with me. Drop me a line at grant@voiceofsandiego.org or call me at (619) 550-5666.
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