23.03.2013 Views

TROUBLED WATERS - Whale and Dolphin Conservation Society

TROUBLED WATERS - Whale and Dolphin Conservation Society

TROUBLED WATERS - Whale and Dolphin Conservation Society

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

8 Weather, sea condition <strong>and</strong> ship<br />

motions affecting accuracy in whaling<br />

Dr D.W. van Liere, CABWIM consultancy, Gansmesschen 33, 9403 XR Assen, Netherl<strong>and</strong>s,<br />

dvanliere@cabwim.com<br />

Introduction<br />

The dimensions of exploding penthrite harpoons are such (Kestin 1995), that a harpoon shot into or<br />

through the body of a whale results in a wound at least 20 centimetres wide. This size triples when the<br />

harpoon barbs become extended <strong>and</strong> anchor the harpoon inside the body. Massive injury is caused<br />

when the penthrite grenade, fitted to the harpoon, detonates 60-70 centemetres inside the body<br />

(Knudsen <strong>and</strong> Øen 2003). A whale that is shot with such equipment will, therefore, be significantly<br />

injured <strong>and</strong> will suffer, if it remains conscious. The whale is then hauled towards the vessel, using the<br />

forerunner rope, which is attached to the harpoon. Thus, in addition to the injury, the restrained whale<br />

will be disabled <strong>and</strong> unable to control, predict or flee from the life threatening circumstances it faces.<br />

Loss of ability to predict <strong>and</strong> control are key psychological factors in evoking severe <strong>and</strong> pathological<br />

levels of stress in vertebrates (Weiss 1972; Wiepkema <strong>and</strong> Koolhaas, 1993).<br />

The efficiency of whale killing methods is evaluated by the IWC, primarily by measuring the time to<br />

death (TTD) according to the current IWC criteria (chapter 11). Gunners are advised to aim for the<br />

upper thorax of the minke whale. This is because it is assumed that a hit here renders the animal<br />

rapidly unconscious or immediately dead (Anon 1999, Knudsen <strong>and</strong> Øen 2003). According to<br />

Norwegian whalers, the latter is defined as dead within ten seconds after being hit by a harpoon (Øen<br />

2003). Nevertheless, a significant proportion of harpoons are shot at other parts of the body (Knudsen<br />

<strong>and</strong> Øen 2003). The question of whether or not the animal is indeed brain dead or irreversibly <strong>and</strong><br />

deeply unconscious is outside the scope of this chapter. While this uncertainty remains unresolved<br />

(chapter 11), Norway reports that 20 per cent of the minke whales that it takes are not killed<br />

instantaneously (Øen 2003). During the 2002 hunt this equated to 127 whales (of 634 whales caught).<br />

The figures are systematically higher in the Japanese hunt for Antarctic minke whales. During the<br />

2002/2003 season, 60 per cent of the 440 minke whales killed, were not killed instantaneously<br />

(Ishikawa 2003). This equated to 264 whales. These poor instantaneous death rates occur despite<br />

technical adjustments to the harpoon <strong>and</strong> penthrite grenade (chapter 6) <strong>and</strong> the development of a<br />

training programme for the gunners over the past 20 years. The current high proportion of animals<br />

which are not killed instantaneously, <strong>and</strong> the systematic differences between Norwegian <strong>and</strong> Japanese<br />

whaling, even following 20 years of weapon research <strong>and</strong> training, indicate that the accuracy of the<br />

gunner may be significantly influenced by other major factors.<br />

Commercial <strong>and</strong> special permit whaling activities typically use a harpoon canon, mounted relatively<br />

high above the bow. The height from the cannon above sea level is at the least 6.5 metres in Japanese<br />

vessels (estimated on the basis of photos <strong>and</strong> unchallenged in Anon 2003) <strong>and</strong> four to six metres in<br />

Norwegian whaling (Øen 1992). The more vigorous <strong>and</strong> frequent the movement of a ship, the more<br />

WEATHER, SEA CONDITION AND SHIP MOTIONS AFFECTING ACCURACY IN WHALING<br />

63

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!