Large Whale Disentanglement

Since the threat of entanglement to large whales is not typically immediate, there is time to cut the animal free.  However, disentangling a 45-foot, 40-ton, and typically free-swimming animal is not an easy task and can be quite dangerous for any rescue team as well as the entangled animal.

	HIHWNMS, MMHSRP Permit #932-1489

Technique

Large, mobile whales are disentangled by using a modification of an old whaling technique called “kegging”.  Historically, kegging involved attaching barrels or kegs to whales by harpooning them. The extra drag and buoyancy of the kegs would tire the whale out and keep it at the surface where it could eventually be lanced to death.  For disentanglement purposes, rescuers throw grapples or use hooks on the end of poles to attach to the gear entangling the animal.  Instead of barrels, the network uses large polyballs (buoy floats) for buoyancy and drag to keep the whale at the surface, slow it down and generally tire it out.  The desired result is a whale that is more approachable, allowing rescuers to safely assess the animal and entanglement, and attempt to free the animal of all entangling gear. Specially designed hooked knives on the end of poles are then used to cut the animal free.


Disentanglement Equipment 

The network has four complete caches of disentanglement equipment.  Caches include: an inflatable response vessel, outboard, grabbing tools (e.g. grapples and skiff hooks), buoys for kegging, various knives, safety gear, documentation gear, and telemetry (transmitters for tracking entangled whales).

The caches of equipment are located on Kauai, Oahu, Maui, and the Big Island. In addition, two responders kits, representing a subset of the gear, reside on Maui and the Big Island.

	HIHWNMS, MMHSRP Permit #932-1489

Technology

In addition to specially designed tools that help us get hold of and cut free large entangled whales, there are transmitters and receivers that allow us to automatically and remotely track an entangled animal over time.  The science is called telemetry and it is an important tool in helping us rescue whales. The Hawaiian Islands Humpback Whale National Marine Sanctuary uses telemetry to track and re-locate entangled whales that cannot be disentangled during the initial response due to limited resources (experience of on-site personnel, proper equipment), and / or condition restraints (weather, sea state, time of day, remoteness of location). 

In addition, telemetry is useful in those cases where an effort has been initiated, but terminated early due to those same condition considerations or the behavior of the animal has made in dangerous for the rescue team or for the welfare of the animal to proceed.  Thus, in all regards, telemetry increases the safety of disentanglement operations, and may assist in its overall success.  The Network uses a pair of transmitters – an Argos/ GPS-based transmitter along with a VHF radio transmitter.  Both transmitters complement each other and are placed together on a telemetry buoy that is specially designed to hold the tags and be attached to the entangling gear trailing behind the animal. Transmitters, receivers, antennas, and telemetry buoys, like the disentanglement tools, are strategically placed throughout the state with trained personnel. 

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