1) The results of this comprehensive analysis have been published in Science.
2) They have spent the past three years crunching all the numbers they could lay on their hands on.
3) These ranged from the current UN Food and Agriculture Organization's database to information hundreds of years old, gleaned from kitchen records and archeology.
4) In order to establish whether diversity matters in the sea as well as on land, 11 marine biologists, along with three economists, have joined forces.
