Home / Environment / Trieste Trial Uses Magnets to Deter Protected Bull Rays
Trieste Trial Uses Magnets to Deter Protected Bull Rays
17 Jul
Summary
- Bull rays are increasing in the Gulf of Trieste, impacting mussel farms.
- A trial is underway using magnetic deterrents to ward off the rays.
- Stricter fishing rules and warming seas contribute to bull ray population growth.
The Gulf of Trieste is experiencing an unprecedented surge in bull ray sightings, a protected Mediterranean species. These large rays, previously uncommon in such numbers, are now frequently congregating in groups of up to 50 individuals, a scale not seen before in the region. This increase is attributed to a combination of factors, including more selective European fishing policies that reduce bycatch and warmer winter sea temperatures, making the gulf a suitable year-round habitat.
These bull rays, which typically forage on the seabed, are now posing a direct threat to local mussel farms. Their opportunistic feeding habits have led them to consume mussels directly from farm lines, causing substantial economic losses. To address this conflict, a joint initiative by the Miramare Marine Protected Area and European projects Life Eu Sharks and Life Prometheus has launched trials using electromagnetic deterrents.
These non-harmful magnetic devices are being installed on mussel lines in an effort to guide the bull rays away without causing them distress. While the effectiveness and cost-efficiency of this solution are still under evaluation, researchers are optimistic about finding a coexistence model. Efforts are also underway to identify designated areas for eco-tourism activities like snorkeling with these rare creatures, aiming to create value from their presence.
