According to
a global analysis of large predatory fish published in
Nature the last 50 years have seen a
90% decline in the abundance of fish such as
tuna, marlin + sharks (as well as
substantial reductions in adult sizes) due to over-intensive "industrial" fishing.
In order to save them from extinction the authors recommend
50% reductions in fishing effort for the worst hit species and the creation of
largescale networks of protected areas made entirely off-limits to fishing.