White Shark Tagging: controversial technique flounders in the Farallons

Controversy is now dogging the white shark tagging efforts of Dr. Michael Domeier of the Marine Conservation Science Institute. The SPOT (smart positioning or temperature) tagging began in Isla Guadalupe under the eyes of a film crew for a National Geographic Channel program to air on the 19th. It involves a technique whereby the shark is hooked and reeled on board, aerated with a water hose, while the crew literally drills and bolts a satellite transmitting tag to the shark's dorsal fin.

This is a rather elaborate tagging technique that has generated much concern within the shark conservation community (click here for prior posting about the Isla Guadalupe taggings, and here are two from other sites: click here and here).

Now, Dr. Domeier has moved northward to the Farallon Islands and, with the approval of Maria Brown, superintendent for the Gulf of the Farallones National Marine Sanctuary, has been tagging sharks there but with less than optimal success. Apparently, one shark swallowed the hook deep into its throat causing the bait's float to become lodged in the shark's jaws, thereby blocking access for the aerating water hose and requiring the cutting of the hook by working straight through the shark's gills. All in all a disaster in humane animal treatment as far as I'm concerned.

While there are concerns about the stresses this type of tagging places on the shark, there is also the question as to the need for more data acquired in the Northern California area. Dr. Barbara Block of Stanford, Dr. Pete Klimley of UC Davis, and others have amassed a considerable body of data that tracks the migratory patterns of these animals. They and their colleagues just recently issued a detailed report that can be viewed in the Proceedings of the Royal Society, published online on 11/04/09 in the Biological Sciences section ("Philopatry and migration of Pacific white sharks").

I always felt that this particular tagging technique was a more elaborate mousetrap than necessary. Now its efficacy has become controversial, the California data may ultimately be redundant, and the National Marine Sanctuary must defend a decision to allow catching a protected species in a manner that would most likely not be allowed for, say, a protected marine mammal.

Too many questions, too much controversy. . .

Read article in Bay area bohemian.com.