Global estimates of shark catches using trade records from commercial markets.
Despite growing concerns about overexploitation of sharks, lack of accurate, species-specific harvest data often hampers quantitative stock assessment. In such cases, trade studies can provide insights into exploitation unavailable from traditional monitoring. We applied Bayesian statistical methods to trade data in combination with genetic identification to estimate by species, the annual number of globally traded shark fins, the most commercially valuable product from a group of species often unrecorded in harvest statistics. Our results provide the first fishery-independent estimate of the scale of shark catches worldwide and indicate that shark biomass in the fin trade is three to four times higher than shark catch figures reported in the only global data base. Comparison of our estimates to approximated stock assessment reference points for one of the most commonly traded species, blue shark, suggests that current trade volumes in numbers of sharks are close to or possibly exceeding the maximum sustainable yield levels.
Clarke
Shelley C
SC
Joint Institute for Marine and Atmospheric Research, University of Hawaii and National Research Institute of Far Seas Fisheries, 5-7-1 Shimizu-Orido, Shizuoka 424-8633, Japan. scclarke@biznetvigator.com
McAllister
Murdoch K
MK
Milner-Gulland
E J
EJ
Kirkwood
G P
GP
Michielsens
Catherine G J
CG
Agnew
David J
DJ
Pikitch
Ellen K
EK
Nakano
Hideki
H
Shivji
Mahmood S
MS
D000818:Animals; D003132:Commerce / Q000706:statistics & numerical data*; D003247:Conservation of Natural Resources; D011157:Population Dynamics; D012754:Sharks / Q000235:genetics / Q000502:physiology*