DataSheet_1_Biomass accrual benefits of community-based marine protected areas outweigh their operational costs.pdf

The costs and benefits of customary top-down Marine Protected Areas (MPAs) have been studied at length. But the costs and benefits of community-based MPAs –an increasingly common tool in conservation and fisheries management– remain understudied. Here, we quantify the operational costs of maintaining community-based MPA monitoring programs in nine small-scale fishing communities in Mexico. We then compare these costs to the potential extractive use value of invertebrate and fish biomass contained in the reserves. We find that the annual monitoring costs (median: 1,130 MXN/ha; range: 23-3,561 MXN/ha) represent between 0.3% and 55% of the extractive use value of the biomass contained in the reserves (median: 21.31 thousand MXN/ha; 5.22 - 49/12 thousand MXN/ha). These results suggest that the direct monetary benefits of community-based marine conservation can outweigh the costs of monitoring programs, providing further support for these types of management schemes. While further research should explore other mechanisms that would allow fishers to leverage the non-extractive use value of reserves (e.g., tourism) or the non-use value (i.e. existence value of biodiversity) to sustainably finance their conservation efforts, a stop-gap measure to ensuring long-term monitoring costs are covered might include limited extractive use of resources contained in the reserves.</p

Scorecard produced by MAREA for the “La Plana / Las Cuevas” marine reserve in Isla Natividad, Mexico.

<p>Scorecard produced by MAREA for the “La Plana / Las Cuevas” marine reserve in Isla Natividad, Mexico.</p

A user-friendly tool to evaluate the effectiveness of no-take marine reserves

<div><p>Marine reserves are implemented to achieve a variety of objectives, but are seldom rigorously evaluated to determine whether those objectives are met. In the rare cases when evaluations do take place, they typically focus on ecological indicators and ignore other relevant objectives such as socioeconomics and governance. And regardless of the objectives, the diversity of locations, monitoring protocols, and analysis approaches hinder the ability to compare results across case studies. Moreover, analysis and evaluation of reserves is generally conducted by outside researchers, not the reserve managers or users, plausibly thereby hindering effective local management and rapid response to change. We present a framework and tool, called “MAREA”, to overcome these challenges. Its purpose is to evaluate the extent to which any given reserve has achieved its stated objectives. MAREA provides specific guidance on data collection and formatting, and then conducts rigorous causal inference analysis based on data input by the user, providing real-time outputs about the effectiveness of the reserve. MAREA’s ease of use, standardization of state-of-the-art inference methods, and ability to analyze marine reserve effectiveness across ecological, socioeconomic, and governance objectives could dramatically further our understanding and support of effective marine reserve management.</p></div

List of indicators to evaluate the effectiveness of no-take marine reserves.

<p>List of indicators to evaluate the effectiveness of no-take marine reserves.</p

Summary of differences in socioeconomic indicators before and after the implementation of the reserve.

<p>Summary of differences in socioeconomic indicators before and after the implementation of the reserve.</p

Plots for values of each biological indicator (y-axis) through time (x-axis).

<p>Red and blue correspond to the reserve and control sites, respectively. Black lines indicate yearly mean values, and ribbons indicate ± 1 standard error. Dots are horizontally jittered to aid visualization. This figure contains information for fish Shannon’s diversity index (a), fish species richness (b), fish density (c), fish trophic level (d), fish biomass (e), invertebrate Shannon’s diversity index (f), invertebrate species richness (g), invertebrate density (h), lobster density (i), urchin density (j), snail density (k), and sea cucumber density (l).</p

Summary of average treatment effect of the reserve on biological indicators.

<p>Summary of average treatment effect of the reserve on biological indicators.</p

Scorecard produced by MAREA for the “La Plana / Las Cuevas” marine reserve in Isla Natividad, Mexico.

<p>Scorecard produced by MAREA for the “La Plana / Las Cuevas” marine reserve in Isla Natividad, Mexico.</p

General location of Isla Natividad (left) and map of the island (right).

<p>The marine reserve polygon is indicated in red, and the approximate location of control sites is indicated by blue squares (B = Babencho, D = La Dulce). Shapefiles for Mexican coastline and the United States were obtained from INEGI [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191821#pone.0191821.ref058" target="_blank">58</a>] and the tmap R package [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191821#pone.0191821.ref059" target="_blank">59</a>], respectively.</p

Summary of governance indicators.

<p>Summary of governance indicators.</p