A good day yesterday. Some female white sharks showed up. Since the white shark tag team finished putting all the pop-up tags on the sharks, says white shark researcher Sal Jorgensen, they attached two acoustic tags to two females. Here's how it works: The researchers drop a video camera off the side of the small boat they use as their tagging platform. They use a seal decoy to attract the sharks to the boat. When the sharks swim by, they attach a tag just beneath their thick, sandpapery skin beside the dorsal fin. Some sharks sense the "stick", some don't. The video camera records the image of the sharks so that the researchers can identify the individuals later. After this female was tagged, she returned to check out the camera. Now THAT'S a closeup worth retrieving for a later blog posting!

The acoustic tags the tag team put on the sharks yesterday are part of the beginning stages of a world-wide effort to put "listening curtains" in 14 ocean regions around the globe. TOPP researchers have joined this world-wide collaboration, which is called the Ocean Tracking Network. Here's what the OTN site says about this ambitious plan:

It's being hailed as "the ocean's internet."

The Ocean Tracking Network at Dalhousie University will provide vast details about changing marine conditions and their impact on sea animals and fish. It will open a new window on marine life, using unprecedented technical innovation developed in Canada, much of it in Atlantic Canada. It will improve the world's ability to study, manage and protect three-quarters of the planet, amid the increasing threats from climate change and overfishing.

With investment from the Canada Foundation for Innovation, the OTN is developing a global infrastructure to collect comprehensive data on sea animals, in relation to the ocean's changing physical properties. Scientists will tag a wide range of aquatic species — salmon, tuna, whales, sharks, penguins, crab and seals, to name a few — with small electronic transmitters that are surgically implanted or attached externally, and can operate for up to 20 years.

Receivers will be arranged 800 metres apart in "listening curtains" in strategic locations along the sea floor, in 14 ocean regions off all seven continents. Roughly the size of kitchen food processors, these receivers will pick up coded acoustic signals identifying each tagged sea creature that passes within half a kilometre. Tags and receivers can also be outfitted with sophisticated sensors that measure the ocean's temperature, depth, salinity, chemistry and other properties.

Sal and the white shark team sailed in late last night and, since today looks like another good tagging day, they jumped back on the boat at 6 a.m. this morning. He had time only to send one photo of the female, above. So, here are a couple of photos from another successful tagging day earlier this month.