A NEW principle of fisheries policy was backed overwhelmingly by the European Parliament yesterday: "As of 2015, the principle of maximum sustainable yield shall apply, which means that each year we do not harvest more fish than a stock can reproduce."

It might seem remarkable that this has not been in place for years. Surely it is common sense? Yet common sense has too often been sacrificed in European fisheries negotiations for the interests of individual countries pushing for excessive quotas.

It is to be hoped that this will no longer be the case. The overhaul of the Common Fisheries Policy (CFP) as laid out yesterday is sensible and long overdue, particularly in dealing with the disgrace of discards, unwanted edible fish thrown back into the sea. The practice has justifiably outraged public opinion. Discards, which are thought to account for one-quarter of all catches, represent a scandalous waste and pointless loss of marine life.

The reform plan's other significant measure – giving more control to regional fishing organisations – should result in more appropriate conservation measures.

These reforms are a just reward for Scottish fishermen, who have made the greatest decrease in cod discards in Europe. They offer a beguiling vision of healthy seas capable of sustaining the fishers as well as the fished. Under the measures, the European Commission expects fish stocks to increase by 15 million tonnes by 2020 and one-third more jobs to be created in the benighted industry as fleets land half a million more tonnes of fish.

Can those twin aims really be compatible, though? Yes they can, but first the CFP reform bill must go through the wringer of further negotiations, between the Council of Ministers, the European Commission and the European Parliament.

As part of that process, provision must be made to ensure the new system is properly policed Europe-wide. No one who has observed overfishing by certain fleets – a Spanish firm and its subsidiary UK-registered company were fined £1.62 million for quota-breaking only last July – would place much faith in leaving the fate of this new plan to self-restraint. Technology to ensure compliance with quotas is required, as is better scientific data about a wide range of fish species.

Unfortunately, the hoped-for measures will not solve the problem of Iceland and the Faroes, both non-EU countries, taking an excessive share of mackerel quotas, a pressing issue which requires an urgent resolution. After three years of deadlocked negotiations between the EU, Norway, Iceland and the Faroes, the Scottish fisheries minister Richard Lochhead has sensibly proposed that a neutral meditor be appointed.

It is also to be hoped that progress can be promptly made on that parallel issue; the CFP reform plan can only help by setting a new standard for the management of fisheries.

This new plan provides the best hope in years for the future health of Scotland's fish stocks. The opportunity has been created and it must not be wasted.