Using spatially explicit data to evaluate Marine Protected Areas for abalone in Southern California

Designate a Marine Protected Area and prohibit all types of fishing

A site comparison study in 1983–2001 of three sites of kelp forest in the Channel Islands National Park, southern California, North Pacific Ocean, USA (Rogers-Bennett et al. 2002) found that the effects of designating protected areas prohibiting all fishing (no-take) on abundance, size, and egg production of pink abalone Haliotis corrugata depended on the level of enforcement. Five to 23 years after their designation, cumulative abundance across years was higher in an enforced (333 abalone/13,040 m) compared to a not enforced (116) no-take area, but these were not significantly different from a fished site (431). Abundance declined over time at all sites. Size of abalones was higher in the enforced no-take area (147 mm) and in the unenforced no-take area (134 mm) compared to the fished site (122 mm). More large abalone (above minimum landing size of 158 mm) were found in the enforced no-take area (30%) and in the unenforced no-take area (6%) compared to the fished site (2%). Egg production was higher in the enforced no-take area (2,555; units unclear) compared to the other sites (unenforced no-take: 550; fished site: 1,420). Annually between 1983 and 2001, pink abalone were counted and measured by divers along 10–12 transects (40–60 m²) at three sites. Two were no-take areas established in 1978 (one enforced, one not enforced) and one a site where non-commercial fishing occurred (commercial fishing was prohibited). Egg production was estimated from abundance and size data.

(Summarised by: Anaëlle Lemasson)