Monday, August 25, 2008

Shark Chronicles 024 - The ups and downs of research

This week, the SAMPLA team’s objective was to tag a shark and track it for 48 hours. As is often the case with fieldwork, things did not go according to plan. On Tuesday morning, a group of interns went out with Steph to ‘tag & track’ a shark. After a couple hours of chumming, a shark arrived and stayed around the boat long enough to be tagged by Steph and the tracking began. The machine that goes ‘ping’ notified us which direction the shark swam, and how far away it was based on the strength of each ping. Originally named Scarface (its face was heavily scarred – by what we don’t know) great excitement surrounded the tracking of this shark because it was a male, of which few had been tracked recently. The shark spent much of the day swimming slowly around Seal Island, and our group followed it around the bay, recording the shark’s position approximately every ten minutes. As the afternoon wore on, what had been a beautiful sunny day dissolved into a rather ugly one, cloudy and windy, with an ever increasing chop. At the same time, the shark picked up speed, heading out of the bay. Despite the changing circumstances, we set of in full pursuit of Scarface.

As Scarface moved swiftly along the coast, Lamnidae, our second research vessel, approached carrying the next shift of trackers. We continued to follow the shark, and delaying the shift switch in order to get another data point. The transmitter signal continued to get weaker and even the heroics of Adam (an intern) could not prevent the inevitable. During the shift change, we lost the signal of Scarface’s transmitter, and best efforts by the new tracking team were confounded – Scarface’s ping was no longer audible.

While the loss was unfortunate, time had not been wasted. We had gathered several hours of data on Scarface’s movements. In addition, we completed more chumming trips than expected for the week (one of which involved a predation) as well as fitting in an extra 24-hour seal survey. Trouble’s with Scarface has been a valuable experience and we look forward to our next tracking episode.

Tricia Coyne (SAMPLA intern)


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