Bigger or better: The relative benefits of protected area network expansion and enforcement for the conservation of an exploited species

Abstract

The global portfolio of protected areas is growing rapidly, despite widely recognized shortfalls in management effectiveness. Pressure to meet area-coverage and management effectiveness objectives makes it essential to determine how limited conservation funds should be allocated between expanding protected area networks and better enforcing existing reserves. We formally explore this question for the particular case of an exploited species in a partially protected system, using a general model linking protection, enforcement and legal/illegal resource extraction. We show that, on average, funds should be disproportionately invested in enforcement rather than expansion. Further, expansion alone, without additional enforcement, can actually reduce conservation outcomes. To help guide future decisions, we calculate the optimal allocation of resources between these two actions given any current level of enforcement and protected area coverage. In most cases, simultaneously investing in expansion and enforcement is the optimal decision. However, in places with low enforcement and high protection, protected area contraction, or strategically concentrating enforcement effort, produces the greatest benefits.

Evidence-Based Guidelines for Prioritizing Investments to Meet International Conservation Objectives

“…Further, Runting et al 45 found greater biodiversity outcomes from improved management compared to shifting to a landscape-sparing strategy. Similar results were found by Kuempel et al 44 in the marine context where optimal budget allocations were split across enforcement or expansion, but the long-term allocations favored enforcement, and by McGowan et al, 46 who found that small management budgets favor marine protected area establishment, whereas larger budgets favor fisheries management strategies. Even restoration, one of the most extreme forms of management, has been found to produce greater outcomes when carried out alongside or even in place of protected area expansion, 47 which is in contrast to tradition orthodoxies.…”

“…The system model can be parameterized to address these individually or collectively. 16,44 Alternatively, management that is required in perpetuity (such as enforcement) can be included in the model as a component of acquisition costs and assumed to be effective. 16 Given the lack of resourcing for effective management of protected areas, studies that aim to maximize species abundance and/or retention have found that management is the better first investment (over further expansion of protected areas) in many contexts.…”

“…Conversely, strategic PADDD events, or concentration of management efforts within smaller areas, have been proposed as a way to increase management effectiveness with limited resources. 44,50 Achieving Representation The current protected area system has been shown to perform poorly across most representation measures. For example, representation of habitats and species has been shown to be inadequate and unequally distributed.…”

To Conserve Nature in the Anthropocene, Half Earth Is Not Nearly Enough

“…Designating half of Earth's land as protected areas will not, in itself, ensure the conservation of most of Earth's biodiversity because protected areas conserve biodiversity only to the extent that their management and governance are supported by adequate and sustained investments and buy-in from stakeholders, including local people, together with other essential political, economic, and social supports. 11,12 Already, many protected areas remain ''paper parks,'' protected only in name without adequate support to conserve biodiversity in the face of competing demands from loggers, miners, poachers, fuel collectors, farmers, and other land users, together with other social and environmental pressures ranging from pollution to climate change to species introductions and invasions, which degrade the capacities of protected areas to conserve biodiversity.…”

“…Rather than saving biodiversity, overambitious protected area targets can actually accelerate losses of biodiversity. 11 Moreover, not all areas require biodiversity protections to conserve their biodiversity, and not all areas have biodiversity in need of protection. 8,12 All too often, protected area targets are met by ''protecting'' areas without current threats to biodiversity, including remote areas and lands less desirable for development, such as deserts, ice fields, and unsuitable terrain, because this is relatively straightforward and inexpensive, even though such areas might have little to no effect on biodiversity conservation overall.…”