+1 for the classic Sherlock Holmes-style title. Unfortunately, unlike the original, the mystery is not solved by the end of the story - nor is it likely that th

+1 for the classic Sherlock Holmes-style title. Unfortunately, unlike the original, the mystery is not solved by the end of the story - nor is it likely that they will find a single culprit... However, the top illustration for the article is not really well chosen, because it shows "spawning-phase" salmon, which always look (and are) unhealthy, because they are genetically programmed to die off after spawning. To quote Wikipedia: > Highly elevated cortisol levels mediate the post-spawning death of semelparous Oncorhynchus Pacific salmon by causing tissue degeneration, suppressing the immune system, and impairing various homeostatic mechanisms. After swimming for such a long distance, salmon expend all of their energy on reproduction. One of the key factors in salmon rapid senescence is that these fish do not feed during reproduction so body weight is extremely reduced.