4. Adapting fishing practices

4.1 Accompagnement des MARins pêcheurs pour la Réalisation d’Économies d’Énergie (Amarrée programme)

This programme¹¹, which ran from 2019 to 2022, was designed to lower fishing vessels’ fuel consumption. The programme consists of three major strategies: setting up a fuel economy observatory; installing econometers; and training in how to operate energy-efficient vessels. Some 181 professional ships were equipped (and seven maritime high schools) with analytical econometers, making it possible to monitor their consumption in real time and to adapt their ways of working. Savings are at least 5%, up to 15% in the best cases. A follow-up programme (Remove) will continue until 2025, focussing also on training in eco-consumption, as well as research on new silicone paints.

4.2 Stopping sediment resuspension in the water column: modern trawl doors in Mediterranean Spain

Since 2013, the fishers’ guild (“cofradia”) in Palamós, Spain¹², has been involved in discussions on the necessary shift towards gears with less impact on the surface sediments of the trawling grounds along La Fonera Canyon flanks.

The comparison between six different trawling doors (“otter board”) shows that the heavier otter boards that were in contact with the seafloor generated suspended sediment concentrations at 5m above seafloor up to 900 mg/l. On the contrary, the nets equipped with lighter material did not cause significant resuspension of sediments, thus favouring the long-term stocking of carbon.

4.3 Replacing traditional doors of a trawler with ‘flying’ doors

The Organization of Fisheries Producers (OPP) Owners of Puntal del Moral de Ayamonte (Huelva) did a project with ‘flying’ doors¹³, which do not touch the seabed. After testing the system in four vessels of different drafts and fishing areas, they found that it saves almost 20% of fuel and minimises the impact on the seabed. Savings were greater in vessels that fish several days in a row, reducing fuel consumption by 300 litres per day (from around 1 800 for these types of vessels) equating to a saving (in August 2022) of €225 per day per vessel.

Other benefits are that the use of the new system generates a lower demand for the machine, which translates into fuel savings and the consequent reduction of emissions, and significantly reduces the impact caused by the contact of conventional doors with the seabed. The ‘flying’ doors also do not diminish the ability to capture the fish and even allows greater control of the depth and position of the doors with respect to the rigging, thanks to sensors installed in the system.

4.4 Using trawl doors produced partly from recycled plastic

A Brixham (UK) trawler, Resolute 10 m, switched to using Pluto trawl doors, produced partly from recycled plastic and weighing 95 kg, instead of standard steel trawl doors weighing a quarter of a tonne each.

As well as spreading and handling well, a big factor is a reduction in fuel consumption, as the lightweight Pluto doors mean that Resolute is towing with less effort. In fuel terms, the difference is as much as 30%.

The General Fisheries Commission for the Mediterranean (GFCM) is also conducting a pilot study in the Mediterranean with such Pluto doors to assess fuel savings and efficiency¹⁴.

4.5 Reverting to wooden otter doors

In the Chioggia port trawl fleet (Adriatic Sea, IT)¹⁵, some experimenting is ongoing with otter trawl doors design and material. After years of use of iron or stainless steel doors, a part of the fleet has reverted back to otter doors with a metal frame and wood panels. This lighter equipment still ensures a similar spread of the otter trawl net wings, while reducing seabed friction and fuel consumption. Precise figures of these benefits are not yet available, but a pilot study for this is underway.

4.6 Using lighter nets

As well as developments for more environmentally-friendly nets, such as biodegradable nets¹⁶ and an EU standard for sustainable fisheries, aquaculture and fishing gear¹⁷, there are innovations in net design to reduce drag.

The commercially available Dyneema® nets are promoted to be a proven and certified solution to replace steel wire, heavy ropes or outperform low-cost synthetics. They are strong yet light, reducing drag and thereby helping to cut fuel costs by 40%, while also making boats easier to handle and safer.

The Mazara trawler fleet (Sicily, IT)¹⁸ during their fishing trips work non-stop 24 hours a day, always keeping the main engines of the boat in action. This typically meant that a Mazara trawler consumed about 1.0-1.2 tonnes of fuel per 24 hours of action. Since the 2000s, with the progressive importance of deep-water red shrimp as a target species for the Mazara fleet, there has been a change in the characteristics of the nets used, which have become lighter (polypropylene instead of nylon) and with thinner meshes, being no less than a 50 mm opening. These changes, together with the need to reduce fuel consumption, led to a decrease of 0.8-1.0 tonnes of fuel per day.

4.7 Developing ‘Twist Gear’

This approach is experimenting with using rubber strings instead of ticklers chains in combination with roundheads – or twisters – hence the term ‘Twist Gear.’ This new approach could be an alternative to pulse fishing for beam trawlers, although it is (August 2022) at an early stage and would need more development with more vessels, on more fishing grounds. Initial results indicate that fuel consumption is reduced and that the gear is gentler on the seabed.

4.8 Use of Apps to optimise arrival and delivery to market

Smartphone Apps like, for example, Rooser exist to connect seafood buyers and suppliers, including whilst at sea, giving them the right tools to trade efficiently, negotiate prices and process deliveries across Europe – all in realtime, at any time.

Another App developed in the Irish IFISH project aims to investigate how new technologies and mobile phone apps could be used to share real-time information to help skippers avoid unwanted catches and reduce discards.

Other applications, like, for example, Blue Visby have also been created, though so far for South-East Asia. It is a multilateral platform for reducing GHG emissions by avoiding the practice of “Sail Fast, then Wait.” By optimising arrival at destination, vessels can adjust their speed accordingly, thereby reducing its carbon footprint. Figures for the tanker fleet and bulker fleets estimate around 15% or overall 45 million tonnes of CO2 reductions. The GHG emissions reduction is not the only benefit of this Blue Visby Solution. It also reduces underwater noise pollution and whale strike risk; it improves the air quality outside ports; it reduces the risk of collisions and anchor loss at busy anchorages; and it reduces hull fouling, which in turn improves vessels’ operational efficiency.