Table 1. Ledge states and relevant characteristics: summary.

Ledge state Urchin abundance Quality and price Dominant harvesting strategies Nature and value of fishermen’s knowledge about state.
a. Barrens High.
Initial absence of harvesting.
Low. Unselective. Broad-scale, long-term, widely known, but of little competitive value.
 
Harvesting causes a transition to conveyor belt state
Kelp starts to grow back, urchin roe content increases, few predators
b. Conveyor belt Medium.
Sufficient numbers of urchins left to balance kelp growth.
 
High. Moderately selective (harvesting from feedline). Ledge specific, short-term, tightly guarded, competitively valuable.
Heavy, continuous harvesting creates transition to kelp-dominated state
Predators abundant, little or no urchin survival post-settlement
c. Kelp-dominated
 
Absent or very low. No fishing. No fishing. Broad-scale, long-term, widely known, but of little competitive value.