Reuters

Cut back on tuna and salmon and load your plate instead with herring and sardines if you want to help save the world's fish. So says the scientist who led the most comprehensive analysis ever carried out of fish stocks in the world's oceans and how they have changed over the past century.

The study by Villy Christensen of the University of British Columbia's Fisheries Centre confirmed some previous indications that populations of predator fish at the top of the food chain, such as cod, tuna and groupers, have suffered...