Drivers of fishery status for the cultural keystone pāua (Haliotis iris) in Customary fishery Protection Areas in Aotearoa New Zealand

Abstract

Drivers of coastal fishery status are complex due to the broad range of stressors to which coastal species are subjected. For successful fisheries management it is essential to understand drivers of population variability. In Aotearoa New Zealand, the cultural keystone, pāua (Haliotis iris, blackfoot abalone) has undergone considerable stock declines, and stock enhancement efforts have had limited success. Multiple regression modelling, and generalised linear modelling were used to assess drivers of H. iris size and density at 50 sites around southern New Zealand. These data were gathered across six Customary fishery Protection Areas (CPAs, Mātaitai Reserves and Taiāpure Local Fisheries) across the takiwā (tribal area) of the Te Waipounamu (South Island) iwi (tribe) Ngāi Tahu. Our results suggest that H. iris density and size are driven by different factors: H. iris density was negatively correlated to time under fishing restrictions and macroalgal density, and shell length was larger in deep habitats and negatively related to the density of the gastropod, Cookia sulcata. This study highlights that fishing restrictions may not lead to an increase in population size, and that declines of cultural keystone species may have intergenerational impacts. Therefore, it is essential to empower local communities supporting management of reefs at small scales and very conservative catch levels to maintain the broad values of this species in customary protection areas while fisheries rebuilding occurs.