Blue sharks (prionace glauca) international tagging program
If you should happen to catch a live blue shark with a dart tag on it please record the following information:
- Species
- Tag number
- Position (latitude and longitude)
- Date caught
- Fork length (measured from the tip of the snout to the fork in the tail) or Interdorsal length (measured from the inside of the trailing edge of the first dorsal fin to the start of the second dorsal fin) in cm.
- Sex of the shark (male or female)
- Depth, temperature and any other relevant information.
If the shark is dead
Please remove a piece of the backbone from above the gills so that it can be aged. Wrap the backbone in a sealed bag and freeze. Send the tag and information (and backbone) to:
Canadian Shark Research Lab
Population Ecology Division
1006
Dartmouth, Nova Scotia
B2Y 4A2
Canada
902-426-6382
In July 2007 G.A. (Sandy) McFarlane and Dr. Jackie King from the Pacific Biological Station, along with Dave Holts of the National Marine Fisheries Service (NMFS) at the Southwest Fisheries Science Center in La Jolla, California, conducted the first blue shark tagging survey to occur off the west coast of Canada. NMFS is working with TOPP (Tagging of Pacific Predators) to study the migratory behaviour of blue sharks.
Between July 20 and July 27, 2007, ten blue sharks over 6 feet (~2 m) long were tagged on the west coast of Vancouver Island with satellite and archival tags. Sharks are reporting back regularly. (You can view their track lines and latest positions online on the TOPP website. To identify "our" sharks look for deployment dates between July 20 and July 27 2007)
One hundred and thirty-four blue sharks were injected with OTC (oxytetracycline) and tagged with conventional fish tags in the hope that they will be recaptured in subsequent years, providing valuable data on the age and growth of blue sharks. In addition, DNA samples were collected from as many sharks as possible.
What if you catch a tagged shark?
Satellite and Archival Tags
If your shark has a satellite or archival tag, please note where and when you caught it, and return it immediately ALIVE to the water. Contact us at the addresses below to let us know you caught it.
- SPOTs (Satellite Position Only Tags) -- report location and time to satellite receivers every time the shark comes to the surface and its dorsal fin breaks the surface of the water
- PATs (Popup Archival Tags) -- have a series of sensors that collect data on swimming depth, water temperature and location on a RAM memory chip. The tags are programmed to release (and "pop up" to the surface) after 275 days and send the data to a satellite.
Conventional Tags
If your shark has a conventional tag, please note where and when you caught it, and if possible return it frozen whole to the address below, and we will send you a reward! If it is not possible to retain the whole shark, please measure the total length of the shark and cut out and freeze the vertebrae (back bone) between the gill slits and dorsal fin. Please include the tags with the frozen vertebrae.
Each shark received TWO tags:
Fisheries and Oceans Canada "Spaghetti" tags
NMFS (National Marine Fisheries Society) tags
Two styles of shark tags used shown above
Sark diagram
Since the beginning of the tagging program in 2006, more than 1400 blue sharks have been tagged across all the derbies in Nova Scotia. More than 40 of these sharks have been recaptured to date, including several from Spanish longliners fishing the North Atlantic. This map shows the tagging location (circle) and recapture location (end of arrow) for each of these tags.
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