Shark finning in eastern Indonesia: assessing the sustainability of a data-poor fishery

Abstract

For over two decades, Indonesia has reported higher average shark landings than any other nation, but very little local information exists on the fishery and life histories of targeted species. This poses severe challenges to shark sustainability and conservation in this vast archipelago. We draw on diverse sources of data to evaluate the sustainability of the shark fishery in eastern Indonesia, a particularly data-poor region where sharks are primarily targeted for their fins. Shark fishers from three coastal communities were interviewed on their perceptions of catch trends over the past twenty years and asked to collect fishing data during fishing trips in the Seram, Arafura and Timor Seas. For the most frequently harvested species, we estimated maximum intrinsic rates of increase (rmax) to predict their resilience to fishing pressure. Our results indicate that shark fishing practices in the region are likely to be unsustainable. The catches of several species largely comprised of immature individuals and most fishers attributed observed declines in shark numbers, size and species diversity to overfishing. Hammerhead sharks have relatively high intrinsic resilience but are nevertheless at risk of local extinction due to their availability to the fishery and the value of their fins. Sandbar, dusky and grey reef sharks have lower resilience and are frequently caught but not managed. We recommend a composite management approach, including consistent implementation of existing trade restrictions, fisheries research and opportunities for fishers’ livelihood diversification, to stem shark harvests in eastern Indonesia.

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

“…These include campaigns aimed at reducing demand by raising awareness of the effects of finning on diminishing shark populations [16]; social dissent prompting a ban on shark fin soup at official banquets [7]; concerns about food safety and fake shark fins leading to reduced demand [17]; changes in custom commodity codes (where shark fins are labelled as shark meat) that disguise continued trade [4]; and diminishing supplies following global declines in shark stocks [4]. The last of these is in line with estimates of reduced fisheries production [4,7] and fishers' observations of declining catches over the last decade [18].…”

Integrating science and citizen science: the dusky grouper (Epinephelus marginatus) sustainable fishery of Copacabana, Rio de Janeiro, Brazil

“…Both methods and concepts, i.e., local knowledge and citizen science, can be helpful not just for data-poor countries: management in the North Sea shows several weaknesses, indicating that there is a need to integrate citizens because fishers can communicate as both citizens and knowledgeable experts with defined interests at stake. Indonesia has high average shark landings, but with very little local information [60]; this is another study conducted in a particularly data-poor region where sharks are primarily targeted for their fins with the help of shark fishers.…”

Introducing Relational Values as a Tool for Shark Conservation, Science, and Management

“…Recreational fishing businesses may market several different species-focused expeditions, one of which may be sharks (Shiffman and Hammerschlag, 2014). Indonesia represents one of the few directed/targeted shark fisheries; where sharks play a significant role in Indonesian fishing communities, there is greater economic significance from the fluctuations of local shark populations (Jaiteh et al, 2016a(Jaiteh et al, ,b, 2017. From a values assessment perspective, to these communities, sharks' economic value may be of great importance, whereas in other communities where sharks are of less relative financial importance versus other fishery species, other values from the shark fishing activity, such as RVs, might be more apparent than the economic value.…”

“…However, the value of this partnership may go unacknowledged by fishery managers, presenting an untapped resource for gathering ecological data, while fostering stewardship through acknowledging the expertise of fishers. In developing nations, researchers associated with academic institutions are gathering experiential knowledge such as shark abundance, size trends, and market values through questionnaires, interviews, or by employing community members as data collectors (Jabado et al, 2015, Jabado, 2018Jaiteh et al, 2016a;Humber et al, 2017). These findings are shared with the academic community and others with access to scientific journals, however, pathways on how to use this in management are not explicit.…”