Coastal sharks supply the global shark fin trade

Houtan, Kyle S. Van; Gagne, Tyler; Reygondeau, Gabriel; Tanaka, Kisei R.; Palumbi, Stephen R.

doi:10.1098/rsbl.2020.0609

Cited by 15 publications

(27 citation statements)

References 20 publications

(44 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While many shark populations are threatened and data poor 56 , dedicated fishery-independent monitoring programs face many logistical challenges 57 . Therefore, there is a critical need to incorporate innovative and open-access alternatives to supplement population monitoring, especially at spatial scales relevant for particular management concerns 58,59 . In this vein, community-based biodiversity monitoring may provide an efficient and nimble alternative to more conventional wildlife monitoring programs.…”

Section: Discussionmentioning

confidence: 99%

North Pacific warming shifts the juvenile range of a marine apex predator

Tanaka

Houtan

Mailander

et al. 2021

Sci Rep

Self Cite

View full text Add to dashboard Cite

During the 2014–2016 North Pacific marine heatwave, unprecedented sightings of juvenile white sharks (Carcharodon carcharias) emerged in central California. These records contradicted the species established life history, where juveniles remain in warmer waters in the southern California Current. This spatial shift is significant as it creates potential conflicts with commercial fisheries, protected species conservation, and public safety concerns. Here, we integrate community science, photogrammetry, biologging, and mesoscale climate data to describe and explain this phenomenon. We find a dramatic increase in white sharks from 2014 to 2019 in Monterey Bay that was overwhelmingly comprised of juvenile sharks < 2.5 m in total body length. Next, we derived thermal preferences from 22 million tag measurements of 14 juvenile sharks and use this to map the cold limit of their range. Consistent with historical records, the position of this cold edge averaged 34° N from 1982 to 2013 but jumped to 38.5° during the 2014–2016 marine heat wave. In addition to a poleward shift, thermally suitable habitat for juvenile sharks declined 223.2 km2 year−1 from 1982 to 2019 and was lowest in 2015 at the peak of the heatwave. In addition to advancing the adaptive management of this apex marine predator, we discuss this opportunity to engage public on climate change through marine megafauna.

show abstract

Section: Discussionmentioning

confidence: 99%

North Pacific warming shifts the juvenile range of a marine apex predator

Tanaka

Houtan

Mailander

et al. 2021

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…High market demand for high value shark products is the main reason for the overexploitation of shark resources [1,8], which ultimately leads to illegal trade [9]. Much of this trade involves poorly reported catches from Eastern and Western Pacific countries, which supply, for instance, global shark fin markets [10,11]. Understanding and regulating such trade is challenging because shark products are extremely diverse in both their usage and their value, and are processed in a myriad of different ways (Figure 1) [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Disentangling the shark and ray trade in Indonesia to reconcile conservation with food security

Prasetyo

McDevitt

Murray

et al. 2020

Preprint

View full text Add to dashboard Cite

Indonesian marine resources are among the richest on the planet, sustaining highly diverse fisheries and includes the largest elasmobranch landings in the world, making Indonesia one of the world’s largest exporters of shark and ray products. Socio-economic and food security considerations pertaining to Indonesian communities add further layers of complexity to the management and conservation of these vulnerable species. This study investigates how shark and ray trade flows in and out of Indonesia and attempts to examine patterns and drivers of the current scenario. We identify substantial discrepancies between reported landings and declared exports, and between Indonesian exports in shark fin and meat products and the corresponding figures reported by importing countries. These mismatches are estimated to amount to over $43.6M and $20.9M for fins and meat, respectively, for the period between 2012 and 2018. Although the declared exports are likely to be an underestimation because of significant unreported or illegal trading activities, we find that domestic consumption of shark and ray products plays a significant role in explaining these discrepancies due to the increasing local demand for meat. The study also unearths a general scenario of unsystematic data collection and lack of granularity of product terminology, which is inadequate to meet the challenges of over-exploitation, illegal trade and food security in Indonesia. We discuss how to improve data transparency to support trade regulations and governance actions, by improving inspection measures, and conserving elasmobranch populations without neglecting the socio-economic dimension of this complex system.

show abstract

“…The fact that the size of a nation's exclusive economic zone accounted for more of the variation in Van Houtan et al's [5] estimate of a nation's contribution to the fin trade (r 2 = 0.48) than its elasmobranch catch as reported to FAO (r 2 = 0.20) underlines this erroneous assumption. An example of the dissonance caused by excluding fishing activity is northwestern Australia, where Van Houtan et al [5] indicate a high probability of shark fin origin for many species, despite the area being closed to commercial shark fishing since 1993, and no operational fisheries to support suggested catch [7]. Such discrepancies have overinflated the estimated contribution of shark fins from nations as these factors have not been accounted for, leading to unrealistic conclusions about the source of fins in trade.…”

mentioning

confidence: 98%

mentioning

confidence: 99%

“…species distribution models from Van Houtan et al [5] known species distributions from the IUCN red list of threatened species The flaws in the methods used by Van Houtan et al [5] mean that the conclusions that they have drawn are erroneous. First, we argue that their results at best show the probability of where species in the fin trade occur, not probabilities that 'represent the top nations contributing the most shark fins to the global market' (caption for figure 2 in Van Houtan et al [5]). For example, the conclusion that Australia is the top contributor to the fin trade is impossible given that national shark and ray catch is less than 5000 t yr −1 [12], a level that cannot produce sufficient fins (they account for about 5% of landed weight, approx.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Assigning shark fin origin using species distribution models needs a reality check

et al. 2021

View full text Add to dashboard Cite

The conservation and management of shark populations have become urgent issues to ensure the future health of our oceans [1]. There are many drivers of the decline of shark populations, with the demand for shark fins being one of the more important [2]. Understanding fin origin can help identify regions for improved management, and hence has been the focus of recent research (e.g. Fields et al. [3], Cardeñosa et al. [4]). In a recent Biology Letters article, Van Houtan et al.[5] contributed to this work using data on species composition of shark fins at four markets and species distribution models (SDMs) to predict the probability of fin origin. Their purpose was to address knowledge gaps in source and trade routes of shark products, which currently limit the effective allocation of management resources. While the broad concept behind their paper is novel, we disagree with the results and conclusions owing to flaws in methodology and interpretation.We fundamentally disagree with the central assumption of the paper that there is a direct link between species distribution and shark fin origin. This assumption relies on fisheries catch being equal through the distribution of a species, which we know is not true. Fishing effort that catches sharks is spatially

show abstract

Coastal sharks supply the global shark fin trade

Cited by 15 publications

References 20 publications

North Pacific warming shifts the juvenile range of a marine apex predator

North Pacific warming shifts the juvenile range of a marine apex predator

Disentangling the shark and ray trade in Indonesia to reconcile conservation with food security

Assigning shark fin origin using species distribution models needs a reality check

Contact Info

Product

Resources

About