Michael Bear is the co-founder of Ocean Sanctuaries and director of its Citizen Science Projects programme.

Ocean Sanctuaries is a nonprofit organisation based in California, dedicated to creating and supporting marine citizen science projects.

In 2010, Ocean Sanctuaries began a baseline population study of the sevengill shark after receiving reports of encounters between local divers and this species in the San Diego area. According to the IUCN Red List of Threatened Species, the sevengill shark (Notorynchus cepedianus) is a data-deficient species and is common in temperate seas worldwide from the western coasts of both Americas to Japan, including South Africa.

A False Bay sevengill shark underwater. Photo courtesy Morne Hardenberg

After some investigation, it was determined that no previous baseline population studies had been done of the sevengill shark in Southern California, so we decided to start one of our own for the benefit of future researchers.

This will be a long-term, five-to-10-year population dynamics study of this species, which has now been expanded to include False Bay and Mossel Bay in South Africa.

The scientific question we are attempting to answer is: Are the same sharks returning to the same locations from year-to-year?

How it works

Around the gill, eye and mouth area, sevengill sharks have a black freckling pattern, which researchers believe is unique to each animal, much like a fingerprint, and it can be used to identify individual sharks.

A sevengill shark photo marked for algorithm processing

Local divers take a camera with them while diving, and if they encounter a sevengill shark, they take a photograph of the lateral side of the head, without endangering either the animal or the diver’s safety, as the shark passes by.

Once the photograph is taken, the diver uploads it to an online database designed by information architect Jason Holmberg, called Wildbook, which contains a pattern-recognition algorithm, specially designed for recognising patterns in wildlife markings—it has been successfully tested and used to identify whale sharks

From there, a specially trained principal investigator (PI) runs the photograph through the pattern-recognition algorithm and compares it to photographs taken previously of other sevengill sharks in the area, to determine whether or not there is a match. If there is, then the shark is identified as a unique individual and marked as such. So far the programme has proven effective, with the algorithm identifying over 40 individual sevengill sharks in the San Diego area since 2010.

Want to participate?

South African divers need only go to Sevengill Shark Sightings and follow the instructions marked “How to Log an Encounter”. At least one photograph of a sevengill shark is required, but encounters going back several years are welcome.

Once the encounter has been successfully logged in our database, the user will receive an email to confirm the submission.

Didn’t see any sevengill sharks on your dive? No problem – we still need your data! "Zero data" is an important concept in long-term population studies in a fixed location with a single species: it’s also called "presence/absence" data, meaning, we still want to know when you did not see a certain species in a given location, because it tells us a lot about why that particular species may or may not be present at certain times of the year.

The portal can accessed through our main website at http://sevengillsharksightings.org/ or go directly to the Zero Data portal here: http://tinyurl.com/zr6qndz. And, it goes without saying, of course, if you did see some sevengill sharks, we certainly accept your photographs! 

Get the Android app

Ocean Sanctuaries has released the Sevengill Shark Tracker App available for free download on Amazon for Android devices:

Contribute to an ongoing citizen science study of Sevengill sharks
On-the-go convenience for shark citizen scientists
Upload shark photos directly from your phone to the Sevengill Shark ID Project database from your Android

Download the Android app by clicking here: http://smile.amazon.com/Ocean-Sanctuaries-Sevengill-Shark-Tracker/dp/B01EJ18X7W?ie=UTF8&redirect=true&ref=mas_ty

A sevengill encounter recorded on Isla Vista Reef in Goleta, California and submitted to Ocean Sanctuaries' ID project. Photo courtesy Ocean Sanctuaries

In the near future, Ocean Sanctuaries is planning an "Adopt a (Sevengill) Shark" programme, where users will be able to track individual sharks of their choosing.

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