The Department of Environment and Conservation (DEC) is asking boaters to take extra caution around a newly discovered aggregation of whale sharks off the Ningaloo coast.
The whale sharks are feeding at the surface, making them vulnerable to boat strike.
The group of at least 25 whale sharks was spotted earlier this month by recreational boater Luke Ryan feeding on krill west of the Muiron Islands, and later confirmed by DEC marine rangers.
DEC Exmouth whale shark conservation officer Emily Wilson said it was the first time feeding aggregations of more than 20 whale sharks had been recorded in the Ningaloo area, although aggregations of this size have been observed in other parts of the world.
"At this stage, it was clear from observations and plankton samples collected the sharks were in the area due to the abundance of food on the surface of the water, however we are unsure if this feeding aggregation is a unique event or a common occurrence at night when no-one is there to witness it," she said.
"This discovery is very exciting as it may help us unravel many mysteries about the whale shark population at Ningaloo and how it links with other populations around the world.
"Whale sharks are a threatened species and they need to be in prime health in order to reproduce, so disturbance needs to be minimised so that normal feeding behaviour can be maintained.
"DEC asks that recreational and commercial boat operators watch their speed around the Muiron Islands Marine Management Area and maintain a good lookout at all times."
Ms Wilson said people were encouraged to report any sightings of whale sharks to DEC.
"We ask that people report any unusual sightings to the department so we can continue to piece together the movements of whale sharks off the Ningaloo coast, and further focus our research and monitoring efforts in these areas, she said."
[attach]1706196[/attach]
Swimming with Whale Sharks
[attach]1706197[/attach]
One of the most exciting and rewarding experiences is to swim with whale sharks.
These huge yet gentle creatures visit Ningaloo Reef, off the north-west coast of Western Australia, between March and July each year.
Their appearance has resulted in the development of an increasingly popular, seasonal ecotourism industry. Starting in the late 1980s, the whale shark ecotourism industry has attracted an increasing number of visitors wanting to swim with whale sharks in Ningaloo Marine Park, from just 1000 in 1993 to over 17,000 in 2011.
Interaction and Management
The Department of Environment and Conservation is responsible for the conservation and management of Western Australia’s wildlife, lands, waters and resources for the benefit of present and future generations. Consequently we are responsible for the protection and management of whale sharks within Western Australian waters.
Whale sharks are fully protected under the Wildlife Conservation Act 1950 and the Conservation and Land Management Act 1984 . The department is also responsible for the day-to-day management of whale sharks within Commonwealth Waters, under a memorandum of understanding between the department and Department of Sustainability, Environment, Water, Population and Communities .
[attach]1706198[/attach]
With increasing numbers of tourists visiting Ningaloo annually to see the whale shark aggregation, the department has introduced a licensing system to manage commercial operations within Ningaloo Marine Park and to reduce disturbance to whale sharks. Only operators licensed by the Department are permitted to conduct commercial tours with whale sharks. Two codes of conduct have also been developed in conjunction with tour operators, applying to people swimming with whale sharks, and vessels (private and commercial) operating in the vicinity of a whale shark.
Codes of Conduct
Although they appear to be ‘gentle giants’, whale sharks are wild animals that can potentially inflict serious injury if they strike a swimmer with their body, tail or fins.
To ensure that you have a safe, enjoyable experience, and to prevent the animals from being harmed or disturbed, please follow the Code of Conduct when interacting with whale sharks.
[attach]1706199[/attach]
Exclusive Contact Zone
- An exclusive contact zone of a 250 metres radius applies around any whale shark.
- Only one vessel at a time may operate within the zone for a maximum of 90 minutes and at a speed of 8 knots or less.
- The first vessel within that zone is considered to be ‘in contact’.
- A second vessel to arrive must keep a distance of 250 metres from the shark.
- Any other vessels must be 400 metres from the shark.
Vessel Operators in the Contact Zone:
- must not approach closer than 30 metres to a shark
- should approach from ahead of the shark’s direction of travel when dropping swimmers into the water
- must display both whale shark (commercial vessels only) and dive flags when swimmers are in the water.
Commercial tour operators operate under similar requirements to other vessels but have specific licence conditions that apply to their operation.
Swimmers in the Contact Zone must not:
- attempt to touch or ride on a whale shark
- restrict the normal movement or behaviour of the shark
- approach closer than 3 metres from the head or body and 4 metres from the tail
- take flash photography
- use motorised propulsion aids
- exceed more than 10 people in the water at any one time
[attach]1706200[/attach]
The Closed Season Notice published under the Wildlife Conservation Act, sets out rules that have been developed for the protection of whale sharks.
Both commercial and private vessels are bound by these rules which must be followed when they are within the "exclusive contact zone".
Reducing Disturbance
Whale sharks can be disturbed by uncontrolled snorkelling and vessel activities, and may display avoidance behaviours such as banking, diving, eye rolling and change of speed or direction in response to swimmers and boats.
[attach]1706201[/attach]
[attach]1706202[/attach]
Generally, the best way to enjoy a whale shark experience is to participate in a tour with experienced and trained whale shark tour operators, who are able to locate the sharks and correctly apply the code of conduct.
This will give you a greater chance of:
- viewing the whale shark clearly and for longer
- minimising disturbance to the whale shark
- seeing whale sharks behaving normally in their natural environment - the essence of the ecotour experience作者: vandas 時間: 2012-6-18 02:42 PM
SCREEN GRAB: Nearly 40 feet long and weighing up to 20 tons, the mysterious whale shark is the largest fish in the sea. Ironically, its survival depends on some of the tiniest creatures. Whale sharks feed on plankton and also congregate during snapper spawning in order to feed on the fish eggs.
鯨鮫是海洋中最大的魚，有些長度可達12公尺或更長。牠們可選擇的食物很多，最喜歡的是浮游生物。不過牠們也喜歡魚卵，就像我們在大遷徙「分秒必爭」(Race To Survive)一集節目中看到的一樣。牠們在海平面附近游泳時，會張開自己的巨大嘴巴，將微小的植物和動物，以及剛好在周圍的小魚，一起吃進嘴裡。
