Community management yields positive impacts for coastal fisheries resources and biodiversity conservation

Abstract

Combining no-take marine reserves with exclusive access by communities to unreserved waters could provide the required incentives for community management to achieve positive impacts. However, few protected areas have been critically evaluated for their impact, which involves applying counterfactual thinking to predict conditions within protected areas if management had never occurred. Here, we use statistical matching to conduct a rigorous impact evaluation of dual management systems on coral reef fishes in Tonga, with communities having both full no-take areas and areas of exclusive fishing rights. No-take areas generally had positive impacts on the species richness, biomass, density, and size of target reef fish, while exclusive access areas were similar to predicted counterfactual conditions. The latter is likely because overall fishing pressure in exclusive access areas might not actually change, although more fish could be exploited by communities with access rights. Our findings suggest that dual management is effective at incentivizing effective community-based no-take areas for biodiversity conservation and resource management.

Linking small‐scale fisheries co‐management to U.N. Sustainable Development Goals

“…Most studies quantifying fisheries co‐management impacts in the South Pacific have correspondingly assessed changes associated with permanent closures. There is much evidence that these approaches do drive substantial improvements in resource status within boundaries (e.g., Bartlett et al., 2009 ; Bonaldo et al., 2017 ; Smallhorn‐West et al., 2020b ) and can result in spillover of larvae and adults into adjacent areas (e.g., Almany et al., 2013 ; Harrison et al., 2020 ; Januchowski‐Hartley et al., 2013 ). These changes can also have flow‐on benefits for ecosystem status (Bonaldo et al., 2017 ; Bonaldo & Hay, 2014 ; Dell et al., 2015 ), and there is some evidence for changes in long‐term patterns of catch (Clements et al., 2012 ; Pascal, 2011 ).…”

Hidden benefits and risks of partial protection for coral reef fisheries

“…1). Specifically, we build on previous studies that have explored standing stock biomass, density, and size, as well as overall species diversity (Smallhorn-West et al 2020b), by calculating the rate at which biomass of target fishes is produced (i.e., potential fisheries productivity) in openly fished, restricted access PPAs, and fully closed areas. Our impact evaluation covers only management areas established prior to 2014 and at least 3 years old at the time of ecological surveys.…”

Why does conservation minimize opportunity costs?

“…Greater fisheries biomass in local fishing areas as a result of implementing no-take MPAs, compared to counterfactual conditions (Smallhorn-West, Stone, et al, 2020) Counterfactual…”

“…The outcome that would have occurred in the absence of the intervention considered, or a different intervention (Smallhorn-West, Weeks, et al, 2020) A group of control samples quantitatively paired with treatment samples based on variables known to bias protected area establishment (Smallhorn-West, Stone, et al, 2020) Residual conservation…”

“…Yet the inverse is also true, that small protected areas are typically deemed less useful than larger ones, despite potentially far greater impact if implemented in areas of high resource value (Smallhorn‐West et al, 2019). Furthermore, if the process of protecting smaller areas with higher value (i.e., higher displacement potential) is integrated with bottom‐up participatory approaches, then those most affected by these actions are more likely to become engaged participants, resulting in more equitable protection and greater changes in actions than might be anticipated (Smallhorn‐West, Karen Stone, et al, 2020).…”