Episode 401: Tracking Tigers

Sharks are beleaguered species. The oceans’ most formidable apex predators are overfished worldwide for their fins, which are considered a delicacy in many Asian countries. Shark populations have declined by up to 90 percent in some cases. But much is still unknown about the animals. Tiger sharks in particular display behaviors that are not well understood. Known to travel long distances, these fish have a broad diet and spend time in shallow, near-shore habitats as well as the depths of the open ocean. Scientists use satellite tags and DNA forensic tools to better understand their migration patterns. Such information is crucial for resource managers to make more informed fisheries management decisions in the future.

Experts

Meet the experts featured in this episode.

Episode Photos

Changing Seas

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Charter fisherman Jeff Izanec (left) and shark researcher Mahmood Shivji, Ph.D. from Nova Southeastern University chat as the boat leaves Ft. Lauderdale and heads to the Bahamas.

Changing Seas

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The beautiful waters of the Bahamas are famous for their sharks.

Changing Seas

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The R/V Sandbob, shark research hub for a week.

Changing Seas

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The crew setting fishing lines to catch tiger sharks. From left to right: Alex Godknecht, Ph.D., Norman Welter, Brad Wetherbee, Ph.D., Mahmood Shivji, Ph.D., and Jeff Izanec.

Changing Seas

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Alex Godknecht, Ph.D. (left) from the Shark Foundation, and Brad Wetherbee, Ph.D. with the Guy Harvey Research Institute setting the shark lines.

Changing Seas

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The Changing Seas crew captures the action as the fishermen and scientists set the shark lines.

Changing Seas

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This tagging research is part of a larger study on tiger shark migrations conducted at the Guy Harvey Research Institute at Nova Southeastern University’s Oceanographic Center.

Changing Seas

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Videographer Sean Hickey capturing the action from the chase boat.

Alex Godknecht, Shark Foundation

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The first large tiger shark is on the line! Notice the bait is still attached as well.

Alex Godknecht, Shark Foundation

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Once the sharks are on the line, researchers move quickly to bring them up to the boat and attach the satellite tags.

Changing Seas

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Shark experts Mahmood Shivji, Ph.D. and Brad Wetherbee, Ph.D. attach a satellite tag by drilling holes into the shark’s dorsal fin.

Alex Godknecht, Shark Foundation

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Mahmood Shivji, Ph.D. attaches the satellite tag to a tiger shark’s dorsal fin.

Changing Seas

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The tiger sharks are brought to the side of the boat and secured with several ropes while the researchers take measurements and attach the satellite tag.

Changing Seas

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A satellite tag is tightly secured to the dorsal fin which will last up to two years. This provides crucial migration data that was previously unknown.

Changing Seas

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Those are some teeth!

Changing Seas

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The Changing Seas crew captures footage from multiple angles.

Changing Seas

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A rare face-to-face encounter with one of the ocean’s foremost predators.

Changing Seas

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Videographer Sean Hickey getting the money shot!

Changing Seas

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Videographer Sean Hickey ready to get a shot of the shark as it’s being released.

Changing Seas

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Once the satellite tag is securely attached to the dorsal fin, it’s time to let the shark go.

Changing Seas

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Seeing a free-swimming tiger shark is an incredible sight.

Changing Seas

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Off it goes, back into the abyss.

Changing Seas

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Videographer Sean Hickey and Producer Alexa Elliott are thrilled after their up-close encounter with a ten foot tiger shark.

Changing Seas

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A tired, but satisfied crew after almost a week of shark tagging in the Bahamas.

Changing Seas

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Videographer Sean Hickey films Mahmood Shivji, Ph.D. as he is demonstrating DNA forensic techniques in his lab.

Changing Seas

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Changing Seas Videographer Jeremy Nicholson filming Marine Life Artist Guy Harvey, Ph.D. as he perfects one of his paintings.

Changing Seas

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Videographer Allan Farrell sets up a scene with Supervisory Special Agent Paul Raymond from NOAA’s Office of Law Enforcement.

Changing Seas

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Shark fins that have been confiscated by NOAA Law Enforcement. The shark fin trade is a multi-million dollar business, contributing to the rapid decline of shark populations.

Special Thanks:

Squalo North Miami Beach Divers
16604 NE 2nd Ave
North Miami Beach, FL 33162
(305) 940-0927

Central Broward Construction, Inc.
931 N.W. 53rd Court
Ft. Lauderdale, FL 33309
(954) 491-2772

Moss & Associates
(855) 360-MOSS
Miller Construction Company
(954) 764-6550

Image Credits

Changing Seas would like to thank the following individuals and institutions who kindly allowed their footage, images and other media to be used in this production:

George Schellenger

Jim Abernethy

Guy Harvey

Shawn Heinrichs

Guy Harvey Ocean Foundation

WildAid

Shark Foundation
Alexander Godknecht, Ph.D.

Mark the Shark

NOAA Office of Law Enforcement

Shelley Clarke, Ph.D.

Special Thanks:

Bob Moss

George L. Hanbury II, Ph.D

Jeff Izanec

John Santulli

Justin Lord

Norman Welter

Richard Dodge, Ph.D.

Wendy Wood-Derrer

Episode 401: Tracking Tigers

Experts

Mahmood Shivji, Ph.D.

Brad Wetherbee, Ph.D.

Guy Harvey, Ph.D.

Paul Raymond

Special Thanks:

Image Credits

Special Thanks:

Web Extras

Tiger Shark Tagging in the Bahamas

Funding for this episode of Changing Seas was provided by: