Marine Protected Areas for Deepwater Fish Populations: An Evaluation of Their Effects in Hawaii

The success of marine protected areas (MPAs) as a tool for conservation and fisheries management has been well documented.  However, these results have typically been seen in shallow water systems and questions remain whether this management strategy could be successfully applied to deepwater ecosystems.  Our objectives were to determine the efficacy of several deepwater MPAs, with various time spans of protection, monitored at depths between 90 and 310m from 2007-2011 for several deepwater snappers and one grouper in the Main Hawaiian Islands.  Results suggested that duration of protection influenced reserve effects.  Mean fish length, and in some cases abundance, increased for one or more of the most economically important target species inside nearly all protected areas.  In addition, more fish of a sexually mature size were seen inside the protected area with the longest duration of protection (~14 yrs); species richness increased outside this area while inside it remained the same.  More recent results (2012-2014) also suggested that spillover of adults may be occurring from at least two protected areas. Here we provide the first evidence that deepwater MPAs can have positive effects on deepwater species and that many protection effects were consistent with results found in shallow water ecosystems.