Shark nets have been put in place at most popular coastlines around the globe. In some countries like Australia, they are strung up along the coastline and maintained by private contractors. The nets are made of nylon and only stop surface swimming species from entering the beach area by being about 6 meters deep but in some cases, the nets go all the way to the ocean floor.
The nets are supposed to stop sharks from swimming into the popular beaches and prevent humans from being attacked.
Most shark nets are accompanied with a bait line which is suspended by a buoy and has a piece of shark attached to it: supposedly to lure the shark into the trap.
Interestingly enough… The shark is de-finned and the valuable fin sold for a profit.
Although the nets may be an effective way of stopping sharks from swimming into the beach bathing area, the nets have some very nasty side effects.
Most of the creatures caught by the nets are not sharks. In fact a recent study in Australia revealed that only 4 or 5 “Dangerous” sharks are caught by the nets a year.
However, a study by the Sydney Aquarium Conservation Fund has found that for every “threatening shark” caught in the nets, up to 40 harmless marine creatures are trapped, including dolphins and turtles.
The majority of the marine creatures caught in the nets drown.
Recently a Humpback Whale became entangled in a shark net on Australia’s Gold Coast and had to be rescued.
A HUMPBACK calf struggled for three hours in shark nets yesterday as three adult whales hovered nearby, watching the rescue operation.
The 10m female was spotted about 7.30am by holidaymakers on the Gold Coast, who saw her become entangled on her way back out to deeper water.
Sea World sent a crew to a rescue effort that took three hours.
Sea World marine sciences director Trevor Long said the bigger whales made the operation more hazardous.
“The crew attached another buoy to keep the whale up and after a while we were able to release it,” he said.
“However there were three adult males that were very interested in her that were close by.
Source: Daily Telegraph
There are many alternatives to shark nets available. Some of the technologies available include:
- Shark Enclosures:
Shark enclosures provide an enclosed, unbroken full length net across the beach. The size of the mesh is much smaller than shark nets, protecting marine life from getting tangled.
- Shark Shield:
Shark shield emits an electrical wave that reaches up to 8 metres from the device. This wave is picked up by the ‘Ampullae of Lorenzini’ (gel-filled sacks on the sharks snout), and creates discomfort for the shark. The closer the shark comes to the device, the more unpleasant the experience is, therefore, deterring the shark. Once the shark is out of range, there are no lingering or harmful after affects.
- Sonar Systems:
There are many sonar systems that will detect a shark before it gets close to the shore. Once the shark is detected, boats and helicopters are sent out to herd the shark further away from the shore or lifeguards are notified to evacuate the beach.
Source: No Nets