Satellite Technology and IUU Fishing

We end the year with this timely blog post from Beatriz Ortega-Gallego. Our contributor has a lifelong curiosity about all things nautical, and a passion for the ocean that led her to complete a degree in Environmental Sciences. She is currently pursuing a career as a fisheries inspector, and we wish her the best in her endeavour.

This topical blog, which surveys the main satellite technology applications for IUU fishing control, will be of special interest to those concerned with fisheries compliance. With increasing emphasis on the eradication of IUU fishing across domestic domains and internationally, and with global efforts to establish high seas marine protected areas underway, satellite technology is taking centre stage across the sector.

In this informative contribution to the IUU Fishing Blog, Ms Ortega-Gallego unveils the mechanisms and functions of Vessel Monitoring Systems (VMS), Electronic Recording and Reporting Systems (ERS), Automatic Identification System (AIS), Vessel Detection Systems (VDS), and voluntary Electronic Monitoring Systems.

Happy New Year!


Control and management tools are essential in order to fight overfishing, protect fish stocks, and ensure fish supplies for future generations. The main fishing management tools are based on access requirements (fishing licenses or authorisations), technical measures (when, how and where it is possible to fish), limitations on fishing effort (that is, the time spent at sea by a fishing vessel of a given engine power). Also they are based on the management of total allowable catches and on quotas.

These management tools are effective in theory, but they must be combined with control tools which monitor the fulfilment of legal obligations, while identifying and sanctioning breaches. The traditional way of doing this is through fisheries inspections. However, in practice there are insufficient traditional control resources (a lack of trained inspectors, aircraft or vessels) to adequately monitor the correct implementation of domestic legal requirements on each fishing vessel in any part of the ocean.

How technology solves these surveillance difficulties 

In the 80s, Inmarsat and IMO (International Maritime Organisation) established the Global Maritime Distress and Safety System (GMDSS). This is a combination of a global positioning and a satellite communication system. Throughout the decade of the 90s this system was revealed as a very efficient tool in the control of the fishing vessels activities at sea.

The development of new monitoring, surveillance and control technology has gone a long way in counteracting the aforementioned difficulties, and is now able to detect suspicious illegal, unreported and unregulated fishing activity effectively, in any part of the ocean, and without any additional monitoring support.

Credit: European Commission DG Mare

Which systems are useful as a fishing control tool?

There are several different types of control technologies. The most widespread of them is the Vessel Monitoring System (VMS). It is a satellite-based monitoring system placed on board of certain fishing vessels. It receives position data signals from satellites and retransmits them at regular intervals to the flag State´s monitoring and information centre, which in turn forwards them to other control centres and inspection authorities. In addition to knowing the vessel´s position, this system is also able to determine the vessels course and speed.

All this data is stored in a closed and sealed box to avoid manipulation. This allows that, if an action suspected of constituting an infraction was not detected immediately, it could be discovered later by contrasting data.

Why is this data useful?

Knowing the position of vessels allows, for instance, monitoring of the closed areas or fishery protection zones, contrasting effort data and capture area with the data entered by the captain in the logbook, and/or ascertaining the exact coordinates of the vessel, allowing an on board inspection to be carried out.

From course and speed data we can calculate the estimated time of arrival at port, whether a vessel is fishing (3-5 knots) or sailing (10-12 knots) and even determine the type of fishing activity that is being carried out. For example, a trawler shows many consecutive positions in a small space and traces that intersect each other. A longline vessel can show numerous positions in a certain direction to set the fishing gear and others in the opposite direction to pick it up.

Therefore, VMS is considered a powerful instrument in the fight against illegal, unreported and unregulated fishing and is present in more and more RFOs like NAFO, NEAFC, ICCAT, CCAMLAR or IOTC. The contracting parties must send the VMS data to the control centres of the RFMOs with the frequency established by these organisms. For the purposes of EU legislation, for instance, VMS is mandatory for vessels of 12m in length and over, and they must transmit their data with a minimum frequency of 2 hours, as a general rule.

Another control technology is the Electronic Recording and Reporting System (ERS) or electronic logbook. It is a system that allows the recording, processing, storing and transmitting of data relating to fishing activities such as catch, transhipment, landing declarations, prior notifications, etc.

Through this system, illegal practices can be detected, alarms can be set up in case of non-compliance with legislation, and it is also a way of recording catch data facilitating quota control.

By cross-referencing electronic logbook data with VMS data, control authorities can detect untimely notifications, captures in fishery restricted areas, lack of mandatory prior notifications, or any other IUU activity. It replaces paper logbooks and also sales notes.

In 2002, the IMO approved the Automatic Identification System (AIS). It is used for maritime safety and security, but it may be used for control purposes. It allows identification, position, course and speed data to be communicated from vessels to other proximate vessels, to control authorities or to anyone interested in reviewing the data globally. The AIS is an autonomous and continuous system which implies an advantage over VMS, which transmits data approximately (varying according to legislations) every two hours. It does, however, have the disadvantage of not being able to be used in the high seas.

It is a system with a great potential as a tool again IUU fishing but will need implementation at a global level.

It may be the case that vessels turn off their AIS or VMS. The Vessel Detection System (VDS) allows position data derived from images captured by remote sensing (satellite imaging of sea areas) to be contrasted with vessel data transmitted by the VMS or AIS. Thus, if a satellite image shows, for example, the presence of 6 vessels in an area, but only a signal of 5 ships is received, it could be assumed that the vessel not transmitting is a vessel suspected of being IUU. It also determines the number of fishing vessels and their position in a given area and cross-checks the positions of the fishing vessels detected by VDS with position reports from VMS.

This system is still implemented experimentally in some RFMOs.

New technologies for the control of fishing continue to be developed and tested, like the Electronic Monitoring System. This is being used experimentally and voluntarily in some fishing fleets. It consists of multiple on board cameras recording all fishing activities.

None of these technologies substitute traditional control methods, but nevertheless they do focus efforts and as a consequence it increases the effectiveness and reduces costs of inspections. At the same time, control technologies improve the access to good quality fisheries data and make it possible to cross-check information from different sources.

Author: Beatriz Ortega-Gallego