UOG Study Finds the Number of Sharks Around Guam has Declined


Guam –  UOG Associate Professor of Fisheries Dr. Jenny McIlwain released findings of a recent study on the shark population on Guam.

The study was done in collaboration with PhD student Steve Lindfield.

It was released during a hearing on Vice Speaker B.J. Cruz’s Bill 44 Tuesday night. The bill seeks to ban the sale and trade of shark fins.

According to a release, Dr. McIlwain testified, “75 hours of video footage has been analyzed for Guam.  This footage was taken at 75 sites extending from Hagåtña, north around Pati Point to Harmon on the east coast at depths between 30-100 feet.  In total, we counted only 10 sharks.  Most were black tips, reef sharks, and two gray reef sharks.”

” This equates to 0.13 sharks per hour of footage, nearly four times fewer sharks than that from Fiji and northwest Australia.” McIlwain adds, “The extirpation of sharks from tropical waters by fishing is not unique to Guam and is an increasingly common event that has been occurring over enormous areas of the tropical Pacific and Western Atlantic.  On that note, I urge you to consider the data I have provided and support this bill.”

Dr. McIlwain described the study methodology stating, “The method we used was deploying baited remote underwater video stations (BRUVS). This technique has been widely used to assess fish and shark populations around the world, including the Pacific and Indian Oceans. Two video cameras are mounted on a steel frame and set to film for one hour. In front of the cameras is a length of PVC pipe with a small mesh bait bag. The use of bait is an effective means of attracting sharks and provides robust estimates of their numbers.”

For more information please contact the University of Guam Marine Lab at 735-2176