Science: Satellites that go fishing: Surveillance from on high will be used to enforce EC quotas, writes Steve Homer

WITH French trawlermen complaining about cheap fish being dumped on the market, you might think one of the world's major environmental crises was over. But you would be wrong.

All over the world fish stocks are dwindling and almost every maritime government is alarmed. Nearly all have introduced measures to protect stocks, including limiting catch sizes, setting minimum sizes for individual species, prohibiting certain types of fishing techniques and requiring fishing vessels to remain in port for a certain number of days a month.

All well and good, but enforcing these agreements is a potential nightmare. There is a lot of sea out there and keeping it well policed is an expensive proposition. To help, the European Commission has proposed that fishing boats be fitted with devices that will beam back, via satellite, details of a vessel's position, speed and heading. While this may make life easier for the regulating authorities, fishermen worry that the new system will cost them money and strain already hard- pressed European Community fishing budgets.

'We are not over-enamoured with the idea (of satellite surveillance). We see it as a substitute for proper enforcement in the ports,' says Barrie Deas, secretary of the National Federation

of Fishermen's Organisations. 'There are many other problems that this will not cover, such as what tonnage you've caught, what gear you are using and if you are obeying minimum size rules.'

At present, the Commission's proposals are simply a basis for discussion, but they recommend the system be installed by the end of 1995 on all vessels of more than 10 metres (33 feet) that stay out of port for more than 24 hours at a time. A study by the consultants Logica for the Commission said this would affect about 10,000 vessels and cost up to 120m ecus ( pounds 100m). European Commission officials are at pains to point out that most of the funding would come from the EC, and national governments and fishermen would not be left to pick up the tab.

However, the Commission is suggesting that 50 per cent of the costs should be paid from EC funds, with national governments deciding how the rest should be paid. So there is still plenty for fishermen to worry about.

Tests have been carried out on three satellite systems, but the Commission is refusing to recommend any specific one. It is possible that more than one will be used.

The Global Positioning System (GPS) operated by the US military is one of the most widely used satellite navigation systems in the world. GPS determines vessels' positions to within 100 metres by accurately measuring the distance to three or, ideally, four satellites. By calculating the distance from each of these satellites, the vessel can tell where it is. As this information is collected, it is possible to assess quickly both the vessel's speed and heading. However, GPS is passive and does not send this information back to the satellite.

The second system, operated by Eutelsat, a satellite consortium owned by a group of European nations, was developed for monitoring lorries. The system uses two satellites to receive signals from a transmitter on the lorry. This information is sent back to Earth and, by calculating the time difference between the two signals, the system is able to calculate the lorry's position to within 300 metres. The system is also used for transmitting messages.

The third system, the French Argos, uses satellites in polar orbits. The ship or lorry has a detector that waits until the satellite flies over and then calculates its position. The information can be sent back to the satellite via the Argos system.

While GPS looks like a non- runner, as it cannot send information back to ground controllers, it is already being widely used for ships' safety systems alongside a system developed by the international satellite organisation Inmarsat. All ships on international routes will have to have the Global Maritime Distress and Safety System (GMDSS) installed. This system includes a GPS receiver to locate the vessel and a transmitter to send the information back to the Inmarsat C satellite. It is Inmarsat C that could well end up as the backbone of the future EC fishing system.

Inmarsat C can be used to send messages to and from ships, and the system carries frequent weather updates, emergency transmissions and other services designed for seafarers. For example, a message can be sent to vessels in a certain area that can be as small as one nautical mile. The system has the added advantage that adding GPS to an Inmarsat C terminal costs, at most, a few hundred dollars, as the systems use similar radio signals, share much of the electronics and can use the same antenna.

There have already been many tests of this type of satellite surveillance system around the world. New Zealand will be the first to introduce an operational system. All large capacity vessels fishing in its waters will have to have this system installed by April.

'This is an idea whose time has come,' said Robert T Gallagher, marketing manager for fisheries at Inmarsat. He believes the system should not be just about surveillance, but should offer some real benefit to the seaman who has to invest time and money installing it. For example, information could be provided on fish prices at all ports so that a captain could decide where to land a catch. It is not inconceivable that a fish brokerage system could be developed in which a catch could be sold by satellite before a vessel reached port. Both services could boost fishermen's earnings.

'With all this talk of protecting the fish stocks, it would be a pity to miss the opportunity to offer some protection to the fisherman,' Mr Gallagher said.