Once again, there is a big stink in the media about cod. This time, it is prompted by a report that between 40 and 60% of the cod caught in the North Sea are caught inadvertently and must be discarded, dead, in order to comply with EU quotas. Apparently, 117 million of the 186 million fish caught in UK waters last year were thus discarded. Some people are calling for the quotas to be raised, so that fishers can keep the fish rather than discarding them. Of course, that would encourage more ‘accidental’ catches.
The real solution is to create and enforce a tax on by-catch. If killing a bunch of cod neither makes money for fishers nor costs them anything, they will essentially be indifferent to doing it. If they needed to pay for what they killed, they would be more careful about choosing where to fish and what sort of gear to use. Even fish that do not have commercial value in the way that cod do have ecological value as part of marine ecosystems. Killing them in unlimited numbers is not compatible with sustainability.
Producing sustainable fisheries requires limiting by-catch, which in turn requires effective measures. A by-catch tax could play such a role. Of course, the fishers would protest any such move, citing threats to their economic livelihood. In the end, however, natural resources, including fish, do not belong to whoever grabs them; they belong to everyone in trust. As a consequence, nobody has the right to loot or destroy a resource, even if the economics of their present way of life require it.