Higher Abundance of Marine Predators and Changes in Fishers' Behavior Following Spatial Protection within the World's Biggest Shark Fishery

Abstract

Fisheries are complex social-ecological systems, where managers struggle to balance the socioeconomic interests of fishing communities with the biology and ecology of fisheries species. Spatial closures are a popular measure to address conservation and fisheries management goals, including the protection of shark populations. However, very little research has been published on the effectiveness of shark-specific closures to protect sharks, or their impacts on fisher behavior. Situated within the global center of tropical marine biodiversity, Indonesia's shark fishery contributes more to the international shark fin trade than any other nation. Here we evaluate the effect of shark-specific closures on sharks and other species of interest, as well as shark fishers' responses to losing access to their former fishing grounds. We assessed shark diversity and abundance in an open access zone (OAZ) and two No-Take Zones (NTZs) of a Marine Protected Area within the recently established shark sanctuary in Raja Ampat, Indonesia, where sharks have high monetary value as a tourism attraction. Shark abundance was significantly higher in the privately managed NTZs than in the OAZ. Across all management zones, neither zone size, depth nor reef complexity explained variations in shark abundance, suggesting that governance is the main driver of successful shark conservation areas. These trends were also reflected in species targeted by small-scale reef fisheries, including snappers, emperor, groupers, tunas, mackerels, and large-bodied wrasse and parrotfish. Interviews with shark fishers who lost access to their primary fishing grounds when the shark sanctuary was established showed that while most fishers (88%) knew that sharks were protected in Raja Ampat, many were unsure about the purpose of the sanctuary. Few fishers felt that the agencies implementing fishing bans understood their livelihood needs. We found that shark fishers adapted to the loss of former fishing grounds by shifting fishing effort to other locations or diversifying their livelihoods, including illegal petrol transport. While conserving sharks for tourism can be effective, it may inadvertently result in displacing fishing effort to unprotected regions. Jaiteh et al. Shark Protection in Eastern Indonesia We propose that effective shark conservation in Indonesia will need to combine strategic spatial protection with efforts to support livelihood security and diversification.

Ongoing decline of shark populations in the Eastern Red Sea

“…drifting vs. benthic BRUVs or bottom vs. surface set longlines), number of hooks, inter-hook distance or hook size. In the present study, sampling effort, number of hooks, amount of bait and survey time frames for both methods were in range of or exceeding those reported for most published BRUVs and longline surveys investigating elasmobranch abundance (Pikitch et al, 2005;Meekan et al, 2006;Bond et al, 2012;Goetze and Fullwood, 2013;Jaiteh et al, 2016). If anything, we would thus have expected higher yields of sharks than previous studies.…”

“…Most of the non-Red Sea regions used in our comparison have general fisheries management practices in place. In addition, the fished areas of these regions are often located adjacent to relatively well-managed marine protected areas (MPAs) (Meekan and Cappo, 2004;Meekan et al, 2006;Goetze and Fullwood, 2013;Ruppert et al, 2013;Espinoza et al, 2014;Santana-Garçon et al, 2014a, 2014bBeer, 2015;Jaiteh et al, 2016), while the SA Red Sea coast is lacking any managed marine reserves. The benefits of MPAs for shark abundance have been sufficiently proven in other locations.…”

“…The benefits of MPAs for shark abundance have been sufficiently proven in other locations. It has been demonstrated repeatedly that MPAs, especially no-entry zones, harbor significantly more sharks than nearby sites of similar habitat but open to fishing (Meekan and Cappo, 2004;Meekan et al, 2006;Robbins et al, 2006;Heupel et al, 2009;Bond et al, 2012;Goetze and Fullwood, 2013;Espinoza et al, 2014;Jaiteh et al, 2016). In addition to benefits observed within the reserve areas, MPAs are also expected to replenish shark stocks exploited in adjacent areas open to fishing (Palumbi, 2003).…”

The end of shark finning? Impacts of declining catches and fin demand on coastal community livelihoods

“…1). In 2013, the regency of Raja Ampat was declared a shark sanctuary and shark fishing became punishable by law, displacing Osi fishers to less productive fishing grounds around Halmahera and the Seram Sea [21].…”

“…Information on the fishing practices of the three study sites was collected from a total of 31 vessels during 46 fishing trips (Table S2). For a detailed summary of fishing trips and the data collection protocol at sea, see [21,24]. Fishers in Pepela and Dobo, whose vessels were equipped with handheld GPS, recorded the start and end points of longline and gillnet sets.…”