Sockeye salmon decline from the recent (1993) historical cycle peak of 23,631,000 and the return abundance was the lowest in over 50 years. The reasons for this (former) decline remain speculative. According to a consortium of scientists assembled to review the problem, the decline highlights the uncertainty in forecasting salmon returns. After the low returns, the Government of Canada launched a formal inquiry into the decline, the Commission of Inquiry into the Decline of Sockeye Salmon in the Fraser River. The Commission has been tasked with investigating all the factors which may affect Fraser River sockeye salmon throughout their life cycle. According
Pain in fish that the absence of C-type fibres in cartilagenous sharks and rays indicates that signalling leading to pain perception is likely to be impossible, and the low numbers for bony fish (e.g. 5% for carp and trout) indicate this is also highly unlikely for these fish. Rose concludes there is little evidence that sharks and rays possess the nociceptors required to initiate pain detection in the brain, and that, while bony fish are able to unconsciously learn to avoid injurious stimuli, they are little more likely to experience conscious pain than sharks. A-delta-type fibres, believed to trigger avoidance reactions, are common