Back in the 80's, a few of us decided to see if we could rebuild part of the old fish traps just below the Larrakeyah base golf course [ the one with the sump oil greens ] . We didn't get permission from anyone, kept it to ourselves, that's the way it was back then. And we caught fish, not many, but enough for a feed. Couldn't do that now, I suggest. This is a story of another indigenous people on the other side of the world , and their use of fish traps to sustain their population. From Hakai;

The Ingenious Ancient Technology Concealed in the Shallows | Hakai Magazine