Capturing and Handling Beluga Whales in the Canadian Arctic

by Jack R. Orr

 

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'Don't go looking for Antarctica without this book.' - Susan Solomon

 

 

For many decades humans have captured white whales for their meat, oil and other products, and for research and public display. Today valuable scientific research into the movements, habitat use and diving behavior of these animals is conducted through the use of satellite-linked telemetry and pectoral flipper band tags. To attach this equipment the whales need to be captured and handled expertly and efficiently: they must be restrained in such a way so that they can breathe easily, have the tags attached and be released as quickly as possible.

Three principal techniques of capture have been developed and are described below. The choice of technique is made according to the turbidity of the water, tidal action, water depth, and bottom topography.

1. Hoop net

A hoop net is used when the water is clear enough to follow belugas swimming below the surface and they can be herded to relatively rock free beach areas.

A 3 m length of steel alloy tubing is formed into a cire and the ends welded together. Thick foam tubing of the type normally used to insulate water pipes is placed around the hoop to provide cushioning and buoyancy. A purse is made with small mesh netting attached to the hoop and cut to a length of approximately 1.5 m. A length of twine is then threaded through the loose end of the net, tied at one end and formed into a loop at the other as a handle to control the netting.

Once captured, a tail rope is used to restrain the animal. The tail rope consists of a 2 m length of polypropylene rope threaded through a 1m length of smooth rubber garden hose, such that the hose covers one end of the line. The hose-covered end is wrapped around the whale just forward of the tail. The rubber hose helps to reduce abrasion of the whale's skin. The free end is either held by hand or secured to another longer rope leading to the shore.

With this method a beluga must first be herded into water less than 1.5 m deep to reduce the chance of it escaping and to give the capture team adequate footing when they enter the water. One or several boats are used to herd the whale slowly toward shore, staying 30-80 m behind it and preventing it from going into deeper water.

The capture team consists of one person operating the motor, another handling the hoop net in the bow of the boat and a third in the middle with the tail rope. Once in shallow water with the whale swimming alongside with its head near the bow, the person with the hoop net places it around the animal's head and, still holding the net, jumps from the boat while the other person secures the whale with a tail rope. Together they move to a suitable tagging position. Normally the whale is brought toward the shore tail first until its back is sufficiently exposed to allow transmitter attachment and/or blood collection from the tail. The whale may have to be moved into deeper water as the tide recedes or into shallower water as it rises.

Risks to humans include being struck by the boat and motor, jumping from the boat onto a rock, getting stuck in a soft bottom and twisting ankles or knees, and being struck by the whale's tail, which may be thrashing vigorously.

Risks to whales include being struck by the boat or the motor, and abrasions from rubbing along the bottom, the tail rope and the netting.

To date there have been no fatal injuries to either human or whale while using this technique.

2. Seine net

Seine or encircling nets are used when the water is shallow but too turbid to see whales under the surface, and various configurations have long been used to capture several other marine mammal species around the world.

A 150 m length of large mesh net with float and lead line is let into the water from a fast-moving boat so that it surrounds the whale(s). Attached to the net at both ends are inflatable buoys. The net is piled accordion style (folded forward then backward over itself) in a wooden box secured firmly over the outboard motor.

Before setting the net, the belugas must be herded into water around 2 m deep. For this at least three boats are needed with at least two people in each.

When the whales are in the proper position, the first buoy is tossed into the water from the box above the outboard motor. The drag of the buoy in the water pulls out the net and, as it is discharged, the boat turns counter-clockwise, in front of the whales, keeping the lead line on the inside of the turn. Within a few seconds, the entire net is in the water and another buoy is thrown in to mark the end of the net. At the same time two or more small boats are driven in circles at high speed around the outside of the net to distract the whales and reduce the likelihood of escape.

Care is taken to encircle no more than three whales at a time because it increases the difficulty in handling them. Calves are particularly vulnerable. Young whales may have to be assisted to the surface if they are captured in a lower part of the net or entangled near another whale.

A hoop net and tail rope are then used to guide the whale to shallow water. At first the whale is held against an inflatable boat and that boat towed by another until the water is shallow enough for the capture team to get into the water and walk alongside. Young-of-the-year whales are kept and held close to the adult they were captured beside.

Risks to humans include boat collisions, becoming entangled when working in the water or being pulled under. No serious injuries have occurred to date.

Risks to whales include becoming entangled in the net and being unable to surface for air.

All 29 whales, including five calves, captured during our trials were successfully released.


3. Stationary net

A stationary net attached to the shore is used when the water is deep, the shoreline steep, the bottom rocky or turbidity makes herding whales difficult.

Stationary nets are much like gill nets used to catch fish. The large mesh cotton nets are manufactured in 50 m lengths and two or three lengths are used at a time, with foam floats attached to the top line. The shore end of the net is solidly anchored to rocks along the shoreline, above the high tide line. The sea end of the net is attached by a nylon rope to a heavy anchor of rocks or metal. If the anchor is not heavy enough the tide and ice can cause it to shift position significantly.

The area is then scanned for approaching belugas, with boats positioned close to the net for quick and easy access but not so they can be easily detected by approaching whales.

When an entangled whale is brought to the surface, a hoop net secures the head and, to a certain extent, the pectoral flippers. The tail rope secures the tail and is sometimes tied to one of the boats. Straps can be placed around the whale at the front flippers and near the tailstock and held by one or more people.

Shorelines where stationary nets are used are often too rocky, slippery or affected by strong tidal currents to be suitable sites for attaching transmitters to whales. Therefore, the whales are normally handled and instrumented at the site of capture. The capture boats are tied to a section of the net where the work is performed. Paddles or stainless steel poles are used to keep the two boats apart, with the whale positioned between them. The whale must be lifted high enough out of the water for the area of transmitter attachment to be clear of the water.

There are other drawbacks to this technique. Belugas can detect the net and simply avoid it. There may also be long periods of waiting between chance encounters with whales, and nets must be continually monitored.

Risks to humans include becoming entangled in deep water, drowning, and muscle strain and back injury when leaning over the side of the boat to handle the whale.

Risks to whales include more than one becoming entangled at the same time, difficulty in getting them to the surface, and superficial cuts on the whale's flippers or tail caused by the net.

Of the 21 belugas caught using this method three expired, four were released because they were too small to attach a transmitter or there were too many in the net to handle effectively at the time, and 14 have been successfully instrumented.

Tag application

Restraint time usually lasts from 20-40 minutes. The satellite-linked radio transmitters or time-depth recorder/transmitters are attached with two or three nylon pins through the dorsal ridge area. The pins do not penetrate the muscle layers but rather pierce the thick skin, then travel perpendicularly through blubber to the other side. Metal cables, moulded into the epoxy package that houses the transmitter, are wrapped around the pins, cinched snug into a tight loop between two large nylon washers and crimped with a metal collar. The whales usually exhibit little or no reaction during the pin application process, indicating that there is little pain experienced. Over time the tag slowly migrates out of the whale much the same as a heavy ring of a pierced ear would.

Conclusions

Our experience has determined that:

  • a hoop net is the most efficient, safest and the least expensive method;
  • a seine net is particularly effective in silt-laden waters but speed of handling is essential; and
  • a stationary net is costly and time consuming, and potentially the most dangerous to both humans and whales.

Generally, belugas are not excessively aggressive toward humans during a capture. They attempt to escape when initially restrained but seldom continue struggling for more than a few minutes. Usually they do not try to hurt members of the capture team deliberately. A few large male belugas, however, have rammed boats, charged at and bitten people on the legs. No serious injuries have resulted. Injuries from being struck by a beluga's tail as it tries to escape are more the result of human carelessness than of beluga aggressiveness.

 

© Jack R. Orr 2003. Jack Orr is a marine mammal management technician at the Fisheries and Oceans Canada, Arctic Research Division based in Winnipeg.

This article is adapted from the paper entitled 'Capturing and handling of white whales (Delphinapterus leucas) for instrumentation and release in the Canadian Arctic' by Jack R. Orr, Ricky Joe and Davidee Evic, published in the September 2001 edition of Arctic, the journal of the Arctic Institute of North America.

 

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