Protecting the small: preliminary investigation of bryozoan community change in New Zealand's oldest marine reserve

Cape Rodney–Ōkakari Point Marine Reserve (North Island, New Zealand/ Te Ika‐a‐Māui, Aotearoa), is New Zealand's oldest marine reserve and includes one of the most visited beaches in the country. The reserve's effect on both target species and biogenic habitats is well‐documented. It is less well‐known, however, how protection affects other taxa. Here, we present two surveys, made nearly 50 years apart, of encrusting, intertidal bryozoans from Echinoderm Reef, quantify their relative abundance and species richness, and discuss possible reasons for the changes between 1971 and 2019. Prior to protection, encrusting bryozoans were common under boulders on Echinoderm Reef, a rocky intertidal mudstone terrace within the reserve. Since the reserve designation, however, there has been a decline in both abundance and species richness within this intertidal bryozoan community. Inconsistent sampling of the reserve's bryozoans makes it difficult to correlate changes in the bryozoan community with changes in the reserve's biotic and abiotic characteristics. Despite monitoring shortcomings, there is still value in the ad hoc biological surveys that have been performed, as they provide a snapshot of what communities were like at the time of collection. In the future, however, more research is needed to understand change within this bryozoan community.