According to the Cape Times the fishermen, who had permits, cast their treknets at Surfer's Corner this week to catch a school of yellowtail that had entered False Bay.
All beaches in the bay were on high shark alert on Thursday as the fish could attract predators.
"Surfers and other beachgoers are extremely angry. It was so close to a surfer who almost got hit by the ropes," Surf Shack surfing school owner David Chudleigh told the newspaper.
"Ten years ago, Muizenberg was a dump, but surfing has helped improve the area dramatically. Fishermen are now having a greater impact on the beach."
Fisherman Jeff Patty said their permit allowed them to fish for yellowtail in that area.
"This is a tradition for us. We can trek, but we are also considerate. If the beach is crowded like it was on Human Rights Day we stay away."
Fishermen said they always gave advance notice of their activities to authorities.
Zigzag surfing magazine reported on Thursday that this is the third time in less than a month that fisherman had driven onto the beach and cast their nets from the shoreline. The previous two incidents resulted in the beach being closed when the shark alarm was sounded shortly after the nets were pulled in.