Recreational Fish-Finders--An Inexpensive Alternative to Scientific Echo-Sounders for Unravelling the Links between Marine Top Predators and Their Prey. oleh Alistair M McInnes, Arjun Khoosal, Ben Murrell, Dagmar Merkle, Miguel Lacerda, Reason Nyengera, Janet C Coetzee, Loyd C Edwards, Peter G Ryan, Johan Rademan, Jan J van der Westhuizen, Lorien Pichegru