Action Summary:
In a marine protected area, sea urchins were culled (via hammering) in spring 2015, over an area of 1.2 hectares at about 5m depth. The effects of sea urchin removal were monitored at regular intervals for a time span of 3 years and were compared with two control sites adjacent to the culling area.
Lessons Learned:
Recovery occurred even though sites were 60% urchin barren, however this was mainly driven by turf algae rather than by kelps.
Project Outcomes:
Culling reduced sea urchin populations compared to control sites (75% less), and this was consistently maintained throughout the experiment. Assemblages were different between control and culled sites, and the size of barrens was reduced in culling sites. This was driven by increased abundance of macroalgae, turf algae and filamentous algae and a reduction in invertebrates typical of barrens.
