SYDNEY — Ron Taylor, an Australian marine conservationist who helped film some of the underwater footage used in the shark thriller “Jaws,” has died after a long battle with cancer, a family friend said Monday. He was 78.

Taylor, who had suffered from leukemia, died Sunday at a hospital in Sydney, said Andrew Fox, who worked with Taylor.

Fox said Taylor had mixed feelings about his work on “Jaws,” which terrified beachgoers but ultimately helped draw attention to the intimidating yet often threatened animals.

Taylor and his wife, Valerie, spent years filming great white sharks and trying to persuade the public that the creatures were beautiful animals worthy of respect. Their images of sharks drew the attention of “Jaws” director Steven Spielberg, who asked the couple to film footage for his 1975 blockbuster.

The Taylors shot much of the now-classic sequence in which the shark tears apart a cage holding a main character. They filmed off South Australia, using a miniature shark-proof cage with a short diver inside in an attempt to make the real sharks look as large as the 25-foot mechanical shark used in the movie.