鲨鱼鳞片揭示的压力

The fossil record attributes shark decline in the Caribbean to human activity Peter D. Roopnarine P opulations of species in the wild have experienced a global average decline of 73% since 1970 (1), generally caused by hu- man activities, such as species overexploitation. Populations are also affected, however, by natural processes, including intrinsic population dynamics and environmental variabil- ity. Proper attribution of declines to processes is therefore as important as the association of extreme weather events to global warming and is key to determining whether interventions and policy actions would be effective. Among marine species, sharks are of particular concern. Although they make up only ~2% of annual global catch weight (2), 71% of shark species are declining (3). …