This video says about itself:
23 August 2014
Chris Cilfone dives in the waters off Maui, Hawaii and encounters a school of Giant Oceanic Manta Rays.
From Wildlife Extra:
Protection sought for Hawaii’s manta rays
Manta rays in Hawaii are at risk of entanglement in fishing lines
Despite laws in Hawaii protecting manta rays from being killed or captured, one in 10 manta rays observed in the area of Olowalu suffers from an amputated or severely damaged cephalic fin, reports the Hawaii Association for Marine Education and Research (HAMER).
The cephalic fin is an important appendage used to guide water and plankton into their mouths when feeding and these injuries are caused by entanglement in fishing line.
When they encounter a line, most likely at night, they lock their cephalic fins together and begin to roll to try to get free, only wrapping themselves tighter into the line.
They eventually break free but over weeks and months the wrapped fishing line cuts into the flesh eventually removing the entire fin or rendering it useless.
HAMER is campaigning to stop entanglement by tagging mantas with acoustic pinger and satellite tags that can be tracked and identified to each individual manta.
By doing this it hopes to identify important habitats and understand how and where they overlap with fishing areas where there is a high risk of entanglement.
In addition to the acoustic tags, satellite tags can provide much greater fine-scale resolution of habitat use with instantaneous results on the animal’s location and dive profile.
Once these important habitats have been identified, HAMER can begin work to engage with local fishermen and gain their support to protect the mantas.