Electric Pulse Technology: A Promising Solution to Shark Bycatch
Understanding the Problem of Shark Bycatch
Overfishing poses a significant threat to shark and ray populations worldwide, particularly oceanic species like blue sharks and pelagic stingrays. These species are often caught unintentionally as bycatch in fishing operations targeting other species, such as tuna. This bycatch not only harms marine ecosystems but also wastes time and resources for fishers. An estimated 100 million sharks and rays are caught as bycatch each year, contributing to the decline of over a quarter of these species.
The Role of Electromagnetic Fields and Shark Senses
Sharks possess a unique sensory organ called the ampullae of Lorenzini, which enables them to detect electromagnetic fields. This ability allows sharks to navigate, find prey, and avoid predators. Researchers have harnessed this knowledge to develop innovative solutions for reducing shark bycatch.
SharkGuard: An Electric Pulse Deterrent
SharkGuard is a device that emits electric pulses, mimicking the natural electromagnetic signals emitted by sharks. When attached to baited fishing hooks, SharkGuard creates an electromagnetic field that deters sharks and rays from approaching. This technology aims to reduce bycatch without affecting the target species, such as tuna.
Effectiveness of SharkGuard in Bycatch Reduction
A recent study conducted by researchers from the University of Exeter and Fishtek Marine demonstrated the effectiveness of SharkGuard in reducing shark and ray bycatch. The study involved deploying fishing vessels with hooks equipped with either SharkGuard or control devices.
The results were promising:
- Bycatch of blue sharks decreased by 91%, from 6.1 sharks per 1,000 hooks to 0.5 sharks.
- Pelagic stingray bycatch dropped by 71%, from 7 rays per 1,000 hooks to 2 rays.
These findings suggest that SharkGuard has the potential to significantly reduce the unintended capture of sharks and rays in longline fishing operations.
Potential Impact on Target Species**
While SharkGuard effectively deterred sharks and rays, researchers observed a slight decrease in bluefin tuna catch. However, this reduction was not statistically significant, indicating that the device may not significantly impact tuna populations. Further studies are needed to investigate this aspect more thoroughly.
Future Developments and Commercial Availability**
The research team is currently working on developing a lighter version of SharkGuard to address concerns about its potential impact on fishing depth. They aim to make SharkGuard commercially available by 2024, providing fishers with a practical solution for reducing bycatch.
Ocean Optimism and the Path Forward**
The development of SharkGuard and other innovative bycatch mitigation technologies represents a story of ocean optimism. It demonstrates the commitment of scientists and the fishing industry to finding solutions to the urgent problem of overfishing and bycatch. These advancements offer hope for the future of marine conservation and sustainability.