Sea urchins were not reduced (control) or reduced to 50% or 0%. Within two locations (i.e. Lennards Is and Long Point) to the north and south of Eden, the treatments were replicated at two sites, each covering an area of reef of 2500 to 5000 m2. The density reductions were commenced in cooperation with commercial sea urchin divers in December 1999, and revisited haphazardly until March 2002 to maintain the appropriate density.
No significant differences in benthic environment.
The profit to the processor of removing urchins was estimated at $20. There were no significant differences in benthic environment.