From this month 400 hundred vessels, including 20 from the UK fleet, have been having their speed and movements monitored by satellites.
Throughout the world too many boats are chasing too few fish. European Union fisheries policy attempts to ration stocks in European waters and prevent overfishing.
As the hostilities over tuna fishing in the Bay of Biscay during August showed, these regulations are unpopular and difficult to enforce. Outside the 200-mile coastal zone in international waters, vessels cannot be policed at all.
The British trial, which is to last nine months, is being run by Smith System Engineering of Guildford. Twenty volunteer vessels, selected to represent the range of boats sailing from British ports, are being fitted with receivers that determine position by triangulating signals from satellites in the Global Positioning System.
This is an American-owned network of 24 satellites, three of which are always in contact with any point on the earth's surface. The system is accurate to plus or minus 100 metres. The data on a vessel's position is transmitted by a communications satellite to BT's earth station at Goonhilly Downs, Cornwall.
From there, it goes over the public network to the Ministry of Agriculture's private network, and then on to central tracking and monitoring computers in London and Edinburgh. Readings can be taken from boats as frequently as every 15 minutes.
The monitoring computers each contain geographical information systems. This means that every vessel's position is displayed on a map, allowing its route and speed to be followed in real time.
The system will alert the operator if, for example, a boat goes outside territorial limits.
The accuracy of readings will be assessed by cross-referencing to the vessel's log as well as to records from the existing fisheries enforcement patrol vessels and aeroplanes.
A crucial part of the assessment will be to see if the monitoring is sensitive enough to tell the UK Fisheries Departments whether or not a vessel is fishing. Speed is the key indicator here: a vessel could not go at full speed pulling its nets.
There are other problems, too: for example, vessels not only have quotas, they may be told for how many days they can go fishing. The trial also needs to look at what happens if the captain turns off the receiver, or puts a metal bucket over the aerial.
The Council of European Ministers has to decide before January 1996 if, to what extent and when a continuous position monitoring system should be installed on the fishing fleets of countries belonging to the European Union.
There is a precedent for this type of monitoring in the use of satellite imaging to check the validity of farmers' claims for set-aside and other crop subsidies.
At present, each member state is doing its own fisheries surveillance trials. This means the question of how to build an integrated system will have to be tackled if satellite monitoring goes ahead.
Without a Europe-wide system it is difficult to see how national fleets can have confidence that the rules covering commercial fishing are being fairly applied.