According to available data (Table 3) the average rate of shark finning in 2000 was 80%. This high percentage was likely due to the high demand for the fins, their high value, as well as the lack of effective finning regulations in most fishing

areas. Thus it was estimated that 80%, or 908,000t  of discarded sharks, were finned, while the remainder (227,000 t) were released alive. A proportion of the sharks that are released alive suffer post-release mortality due to injury and stress. Published estimates of post-release mortality are in the order of 15% or higher [12] and [23]. Thus it Target Selective Inhibitor Library manufacturer was assumed here, that 15% of released (non-finned) sharks died from fishing-related injuries (34,000 t) and 85% survived (193,000 t). Combining reported and unreported catches, as well as dead or moribund discards, the total fishing mortality for sharks in 2000 was estimated here at 1,445,000 t (Fig. 2). Out of this, 1,409,000 t of landed catch plus finned discards were available to supply the fin trade. This is close to the independently derived median estimate for the 2000 shark fin trade of 1,700,000 t [9]. Using the average shark weights PLX-4720 clinical trial given in Table 2, these masses were converted into numbers of sharks. Using the median estimate of 20.8 kg for all sharks (Table 2), it was here calculated that the total mortality

of 1,445,000 t translates into 69,471,000 shark individuals. However, accounting for the fact that the species composition of the FAO catch is partly known (in 2000: 82,582 t small coastal species, 111,858 t large pelagic, 5004 t deepwater species, and 182,782 t unidentified) and that these groups have known average weights (see Table 2, and assuming 20.8 kg

for unidentified species), it was calculated that at least 49,011,000 sharks comprised the FAO reported landings in 2000. Assuming 20.8 kg per shark for the remaining catch (IUU and discarded dead sharks) Immune system a conservative mortality estimate of 99,618,000 sharks in 2000 was computed. This value is sensitive to our estimated average weights and species composition of the shark catch derived from published data. For example, one might assume that the species composition of the FAO species-identified catch also applies to the unidentified sharks reported to FAO; this would yield 74,321,000 sharks in the FAO catch, and 124,928,000 sharks in total including IUU and discards. Or one might assume the same species composition for the IUU catch; under this scenario the total mortality estimate increases to 140 million individuals. When assuming that both IUU and discards have a catch species composition similar to the reported FAO catch, this total estimate increases to 273 million sharks. It is unclear how these figures might have changed since 2000, given changes in finning legislation in several jurisdictions (e.g.