Reef Report for Saturday, July 22, 2000
Humpbacks Hail Hearty
The Humpback Whale has featured heavily in these articles of late. Guests on board day and live-aboard vessels have enjoyed some spectacular close encounters. One such encounter was had by guests onboard dive boat TUSA Dive III .
Skipper Jason from TUSA told me a tale of calm waters and gentle giants.
TUSA III was apparently cruising around Thetford Reef toward the southeasterly reefs when in the distance about 300 metres away, Jason spotted a fountain of water exploding into the air. Before he had the chance to shout "Whale!" a giant Humpback arched out of the water. Jason quickly maneuvered TUSA III closer to where the whale made its appearance, but the waters were still. The guests onboard resigned themselves to the great mammal having moved away when all of a sudden only eight metres from the stern, the whale jumped clear out of the water doing a tale dance. Jason immediately turned off the boatís engines and the crew and guests moved to the bow and watched in awe as the whale continued to dance. On one breach, it cleared the water and did a 180-degree spin, landing on its back. The whale played in the water for a full 15 minutes, giving those aboard TUSA a magical experience of a lifetime.
What do we know about the Humpback Whale? We know that it is a mammal. Common characteristics of mammals are their warm bloodedness, hair on their body, and that their young feed from the femalesí own breast milk.
Unique to the Humpback Whale is its spectacular behavior of launching itself out of the water. This is called breaching and is the stuff that awes us and captivates our attention. Scientists are not sure why humpbacks breach. They surmise that this may be a way for them to communicate, or to clean their bodies of pest. Iíd like to believe that they do it because itís fun!
Humpback Whales can also hold their breath for long periods of time. How they do this is they take deep breaths through their blowholes (equivalent to our nostrils) and they extract more oxygen from the air that they breathe. When they surface they exhale the air through the hole with great force, combined with moisture. This is why we can see the spray. Modern technology has also allowed us to understand a little about the way they mate. During the mating procedure, the male sings. Females can hear these underwater clicks, squeaks, and grunts up to 160 kilometres away
(Thanks to National Geographic Book of Mammals, 1998, and the Encyclopedia of Animals -Mammals, 1990.)
The weekly reef report is written by Sue-Anne Chapman of Pro Dive Cairns, who compiles them from the many conversations she has with divers, dive instructors, captains, and others in the Cairns dive community. The report is published weekly in the Cairn Post, the local daily paper and appears here thanks to the courtesy of Pro Dive Cairns.
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