Characteristics of effective marine protected areas in Hawaiʻi

Abstract

Ancient Hawaiians developed sophisticated natural resource management systems that included various forms of spatial management. The state of Hawaiʻi established its first legislated marine protected area (MPA) in 1953, and today there exists a patchwork of spatial marine management strategies along a range of sizes, with varying levels of governance, enforcement, and effectiveness. Approximately 12% of waters within the 50 m depth contour and 5% of waters within state jurisdiction (≤3 nmi) have some form of marine management. No‐take areas make up <0.5% of nearshore waters, and combined with highly protected areas account for 3.4% of this habitat. Most of the existing MPAs are small, with a median area of 1.2 km2 (confidence interval 0.2–8.1). Twenty‐five datasets, representing 1,031 individual surveys conducted throughout Hawaiʻi since 2000, were used to compare fish assemblage characteristics amongst a subset of MPAs using a regulation‐based protection classification scheme. Fully and highly protected areas had significantly greater resource fish biomass than areas with intermediate or low protection did. High human population density adjacent to MPAs had a negative influence on fish trophic structure within MPAs, whereas remote MPAs harboured higher fish biomass. Complex and heterogeneous habitats were important contributors to MPA effectiveness. Long‐term monitoring of select MPAs showed mixed and complex trajectories. Resource fish biomass increased after the establishment of the Hanauma Bay Marine Life Conservation District in 1967 but plateaued after ~15 years, followed by changes in assemblage structure from fish feeding and invasive species. The Pūpūkea Marine Life Conservation District, established in 1983, was expanded sevenfold in 2003 and showed dramatic increases in resource fish biomass following increased protection. This information is critical to improving effectiveness of existing MPAs, helping inform ongoing efforts to implement a network of MPAs statewide, and aiding in the development of comprehensive statewide marine spatial planning.

Impacts of pollution, fishing pressure, and reef rugosity on resource fish biomass in West Hawaii

“…Our results suggest that banning gear types could be effective for protecting fish biomass in this region. This is similar to a recent analysis of MPAs in Hawaii that showed both full and highly protected (typically limited to pole and line fishing) MPAs had greater fish than in areas of low or intermediate protection (Friedlander et al 2019). A global synthesis of the effectiveness of MPAs showed that the positive response to protection was primarily driven by targeted fish species (Sciberras et al 2013).…”

“…There is considerable evidence that supports that coral reef fishes will recover with reductions in fishing pressure (Campbell et al 2017). It is important to note, though, that for our study, there were very few sites representing no‐take areas, with some fully protected no‐take areas only recently established in West Hawaiʻi as late as 2016, where prior to 2016, there were only two full MPAs protecting only a small combined area of ~0.6 km ‐2 (Friedlander et al 2019). Long‐term observations of no‐take MPAs have shown that effects of MPA establishment can occur within 5 yr but can still take a decade or more to fully develop (Babcock et al 2010, Friedlander et al 2019).…”

“…In Hawaii, marine protected areas (MPAs) are a subset of marine managed areas that focus on protection and conservation of marine ecosystems. Some MPAs restrict some types of gear while very few are full no‐take areas or highly protected, representing less than 3.4% of nearshore habitat across the Main Hawaiian Islands (Department of Land and Natural Resources Division of Aquatic Resources State of Hawaii 2019, Friedlander et al 2019; Fig. 1).…”

“…1). Highly protected areas have been effective in increasing fish biomass in Hawaii; however, these gains have been offset in part by their proximity to increased human population, whereas more remote geographies contain some of the greatest fish biomass (Friedlander et al 2019). Human population density is a common proxy for fishing pressure and is often negatively correlated with reef fish biomass (Stallings 2009, Williams et al 2015 a , b , Friedlander et al 2017) although studies have shown that global drivers such as ocean warming, can mask local effects (Bruno and Valdivia 2016).…”

Combining point counts and autonomous recording units improves survey efficacy across elevational gradients on two continents

“…cornerstone of ecological studies used to identify biodiversity hotspots, infer the impact of natural or anthropogenic disturbance on communities, assess the effectiveness of management practices, and identify important habitats for species of conservation concern (e.g. Dorji et al, 2019;Friedlander et al, 2019;Ibarra & Martin, 2015;Rosenberg et al, 2017). For effective conservation decision-making to occur, biases associated with any given survey technique should be quantified and, where possible, corrected for.…”