How Do Traditional Shark Drum Lines Work?
A traditional drum line is a rather simplistic mechanism which basically involves catching sharks on the end of a baited hook attached to a line dangling from a drum floating in the ocean. Typical baits include red mullet and false jacopover. Traditional drum lines have caused much controversy over the years as they are chillingly effective in killing sharks (and other sea creatures). The Queensland Government in Australia has been using them for almost 60 years, but not without vehement opposition from environmental activists. It is estimated that 84,000 marine animals have been ensnared by drum lines in QLD since the program's inception in 1962.
How Do SMART Shark Drum Lines Work?
Now that we know sharks are a vital part of the marine ecosystem, scientists have developed a more ethical shark attack prevention system known as a SMART drum line (SDL). SMART stands for “Shark Management Alert in Real Time”.
SDL’s are deployed along the coastline around 500m from shore and alert local authorities when a shark has been caught so that experts can arrive at the scene and release the shark back into the wild. The sequence of events is as follows:
- The shark bites a baited hook which pulls on a trigger line setting off the communications unit.
- The communications unit sends a real-time GPS alert (text message, email and phone call) to the local authorities.
- Local marine rangers arrive at the scene within 15 minutes (weather permitting) to retrieve the shark.
- The shark is tagged with GPS satellite and acoustic tracking devices and is re-released 1km offshore.
- Tagged sharks are then monitored by VR4G listening devices and satellites.
Are Shark SMART Drum Lines effective in preventing shark attacks?
SDL’s have proven to reduce the number of shark attacks in designated protected areas based on trials conducted in NSW in Australia, Recife in Brazil and KwaZulu-Natal in South Africa. Sharks that have been tagged and released back into the ocean have not returned to the protected zone and, in fact, some sharks have been recorded to travel up to 13,000kms (8,078 miles) away after their release.