The cost of enforcing a marine protected area to achieve ecological targets for the recovery of fish biomass

Abstract

Protected areas are the primary management tool for conserving ecosystems, yet their intended outcomes may often be compromised by poaching. Consequently, many protected areas are ineffective ‘paper parks’ that contribute little towards conserving ecosystems. Poaching can be prevented through enforcement and engaging with community members so they support protected areas. It is not clear how much needs to be spent on enforcement and engagement to ensure they are frequent enough to be effective at conserving biodiversity. We develop models of enforcement against illegal fishing in marine protected areas. We apply the models to data on fishing rates and fish biomass from a marine protected area in Raja Ampat, Indonesia and explore how frequent enforcement patrols need to be to achieve targets for coral reef fish biomass. Achieving pristine levels of reef fish biomass required almost year-round enforcement of the protected area. Surveillance of the protected area may also be enhanced if local fishers who support the reserve report on poaching. The opportunity for local fishing boats to participate in surveillance was too small for it to have much benefit for total reef fish biomass, which increases slowly. However, specific functional groups of fish have much higher population growth rates and their biomass was predicted to increase markedly with community surveillance. We conclude that budgets for park management must balance the cost of conducting frequent patrols against supporting alternative activities, like education to build community support. Optimized budgets will be much more likely to achieve ecological targets for recovering fish biomasses and will contribute to fiscal sustainability of protected areas.

Analysis of fish population size distributions confirms cessation of fishing in marine protected areas

“…Our results will inform the pending assessment of California's MPA network in 2022 (California Department of Fish and Wildlife & California Ocean Protection Council, 2018) and offer a potential solution for estimating poaching rates inside MPAs and harvest rates outside of MPAs. This type of information is lacking for most MPA locations around the world, but is critical for assessing effectiveness and for adaptive management (Bergseth et al, 2015;Brown et al, 2018). Previous works have clearly shown a relationship between compliance and MPA success (Aburto-Oropeza et al, 2011;Giakoumi et al, 2017).…”

Predictive modelling of illegal fishing in no‐take marine protected areas

“…Therefore, while the identified predictor variables work now, for current enforcement, these variables may change, as illegal fishing behaviour shifts in response to changes in enforcement patterns. In addition, it should be noted that achieving high levels of compliance solely through enforcement is extremely costly (Brown et al, ). Behavioural interventions were identified as complementary management techniques, capable of increasing levels of voluntary compliance and, thereby, reducing the enforcement effort needed to achieve conservation outcomes (Brown et al, ).…”

“…In addition, it should be noted that achieving high levels of compliance solely through enforcement is extremely costly (Brown et al, ). Behavioural interventions were identified as complementary management techniques, capable of increasing levels of voluntary compliance and, thereby, reducing the enforcement effort needed to achieve conservation outcomes (Brown et al, ). Enforcement effort should, therefore, be accompanied by behavioural interventions to address social norms (Thomas et al, ) and to foster increased community support for NTAs (Arias et al, ).…”

Influence of protogynous sex change on recovery of fish populations within marine protected areas

“…), the possibility of poaching within MPAs (Brown et al. ), and perhaps most importantly, stochastic variation in larval recruitment (Kaplan et al. ).…”