Vessel-based surveys are important in assessing and managing fishery stocks. However, vessel surveys are usually a very time-consuming, expensive affair. Moreover, working conditions at sea can be very rough, and for safety reasons even a small vessel needs a crew of at least two. But what if the vessel was unmanned? The crew could be limited to one person, with no need to be at sea but rather working remotely from an office or from home.
With this in mind, the Estonian Marine Institute at the University of Tartu has set up a project to create an autonomous vessel and survey platform that would significantly reduce the need for manpower and use of large vessels in the future. EU funding has been essential for this project, which could have not been implemented otherwise. By supporting innovative solutions, the EU encourages the development of new technologies while furthering the objectives of decarbonisation and sustainability which are at the core of the European Green Deal.
What is the innovation about?
Currently, fishery-independent surveys are conducted regularly using large survey vessels. This survey methodology has two components: acoustic sounding with sonars, and trawl sampling.
The project promoters at the Estonian Marine Institute at the University of Tartu have assessed that the sonar sampling could be conducted entirely on smaller vessels, since the sonar itself is quite small (less than 100 kg) and the system is very reliable. The goal is thus to use an unmanned vessel for the sonar work and reserve the large survey vessels for trawl sampling.
Less fuel, less CO2 emissions and increased safety at sea
Using two vessel types would significantly reduce the working time of the large vessel, which has a large crew and uses a lot of fuel. The researchers behind the project have calculated that currently with 10–12 hours of daily sonar recording, only 3–5 hours are spent on the trawl samples. With the autonomous vessel conducting the sonar recording, the time saving on the large vessel would be around 25%. This would translate into fuel savings and hence CO2 savings. As an example, the project beneficiaries have calculated the direct reduction in survey vessel use: the annual Gulf of Riga herring survey would need 25% less survey vessel time if just parts of the sonar work could be carried out by autonomous vessels, and this would not even need any changes in survey planning. With more thorough testing and analysis, the reductions would be even larger.
An autonomous vessel is very economical and does not need any crew on board as it can be operated from anywhere with good internet connectivity, so it is also safer for the single “captain”. Apart from increased safety, the significantly reduced fuel costs mean that the savings could be re-allocated to collect more data and hence improve assessments of fish stocks.
The prototype autonomous vessel developed for this project is 6.2 m long and 2.5 m wide. It currently has a hybrid propulsion system, running on both diesel and electricity, and its range can be easily extended by adding a larger fuel tank. The current estimated duration of the vessel is 36 hours, giving a range of 180 nautical miles at a working speed of 5 nautical miles per hour, while carrying up to 400 kg of instruments.
A very promising project, some technological limitations to overcome
Of course there are currently some technological limitations, mainly in terms of energy storage, which do not allow the vessel to cover the entire Baltic Sea on a single battery charge. At the moment a generator is installed to extend the range, but future technical advances, such as progress in batteries and hydrogen technology, may eliminate this need. Another current limitation is the quality of data connection available at sea: hopefully this situation will improve in time as other marine users identify similar needs. In any case, the design of the vessel allows the beneficiaries to move forward with the development and to test innovations as they become feasible. The use of this kind of vessel is planned at first for the entire coast of Estonia, and in the future for the whole of the Baltic Sea (or even further!).
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- Publication date
- 29 September 2022
- Directorate-General for Maritime Affairs and Fisheries