Not enough fish in the sea?

Salmon are amazing creatures. Born in fresh water streams, they migrate out to sea to grow to adulthood, then return to their birthplaces to spawn and die. But with dams, fishing, habitat destruction and more, salmon populations have taken a big hit--and may be in danger of extinction. Armed with modern genetics, researchers have been able to figure out exactly which stream an individual fish comes from. Now, this information is being applied to when, and if, salmon can be harvested from the sea. Read the whole article here.