Conservation benefits of a network of marine reserves and partially protected areas

Abstract

Marine biodiversity is becoming increasingly threatened worldwide. To help address this, networks of no take marine reserves are being promoted as a means of conserving biodiversity and managing coastal resources. Many studies have demonstrated the effectiveness of individual marine reserves and metaanalyses have shown that marine reserves provide positive outcomes for marine conservation. Few studies, however, have examined the effects of marine reserves with different levels of protection or examined shallow subtidal areas (1–3m depth). Here, we examine changes within a network of “no take” marine reserves relative to partially protected “take” areas after 5years of operation. We also examine similar open areas outside the boundaries of the marine reserve network. We show that some targeted species including red morwong (Cheilodactylus fuscus) and abalone (Haliotis rubra) were more abundant in marine reserves than elsewhere. Fish assemblages inside the marine reserve network differed from those outside the boundaries of the reserve network. This result was driven by habitat differences; abundant, schooling species of fish were more commonly encountered outside the marine reserve where urchin barrens dominated. The combination of large spatio-temporal variation in reef assemblages and variable effects of early reserve protection in shallow subtidal habitats made it challenging to detect other changes among zones. Careful consideration of variation in the design and analysis of shallow subtidal reef monitoring is necessary to ensure such programs can best inform adaptive management processes.