If they are thrown back into the sea (“discarded") they do not survive (with rare exceptions) so although they may conceivably provide food for some other species they do not help the conservation of their own species, nor do they contribute to satisfying market demand for fish, so more fish than are needed for this are caught. Rather than throw them into the sea a vessel may hope to land them illegally or transfer them to an intermediary who will land them in a port outside the national or EU jurisdiction. One is that they are not wasted and the other is that they are recorded. The disadvantage is that there is some economic incentive to over-fish, which seems counter-productive. The Norwegian view is that allowing discards while penalising landings provides an economic incentive to systematically fish for large and higher priced fish and systematically discard “unwanted" fish - so-called "high grading". However, the EU did introduce a ban on high grading in the North Sea in 2009, Furthermore, a vessel’s record of overfishing can be monitored and the economic incentive removed in the case of persistent offenders.