Fishing practices adapted in commercial fisheries: review

Appendix B Typology

Method: Reducing vessel fuel consumption

Intervention: Propulsion systems (Engines)

Location/ geographic relevance: UK (England)

Actions taken: Seven EMFF projects funding the replacement or modernisation of old engines in English fishing vessels.

Results: In one case, there was a reported reduction in fuel consumption of 30 to 70 litres per week (representing between 15 and 32 % of fuel used). Taking the average value, this represents an annual reduction of around 7 tonnes of CO2e from this one project, or an ongoing annual reduction of 4.81kg CO2e for every £1 of EMFF funding.

Strengths:

• Reengining is relatively straightforward;
• Recording results is relatively straightforward; and
• The initial cost is relatively low.

Weaknesses:

• Only one of the seven projects recorded and presented results; and
• Relatively low uptake - only seven vessels in the English fleet were funded for reengining.

Reference: Owen et al., 2019 (added after the systematic review)

Method: Reducing vessel fuel consumption

Intervention: Propulsion systems (Engines)

Location/ geographic relevance: EU (not specified)

Actions taken: Hybrid diesel electric propulsion system trial

Results: Reduce fuel consumption of up to 10 % achieved under laboratory conditions

Strengths:

• Reduced weight due to hybrid propulsion system;
• Noise, pollution and vibration reduced; and
• Weight on board can be better distributed for stability.

Weaknesses:

• Results only available for trials under laboratory conditions (i.e., no practical trails).

Reference: Notti and Sala, 2012

Method: Reducing vessel fuel consumption

Intervention: Propulsion systems (gearbox and propeller)

Location/ geographic relevance: UK (England)

Actions taken: Propeller modifications undertaken with EMFF funding, £29,262 received in funding across 6 projects.

Results: None reported

Strengths: N/A

Weaknesses: No results reported

Reference: Owen et al., 2019 (added after the systematic review)

Method: Reducing vessel fuel consumption

Intervention: Propulsion systems (gearbox and propeller)

Location/ geographic relevance: EU (Italy)

Actions taken:

• Two speed reduction gear boxes used to perform each fishing phase, in an effort not to overload the main engine and saving fuel.
• Engine and propeller were coordinated through the reduction gear to optimise conditions for steaming and trawling; and
• A ducted propeller was used to increase thrust, replacing fixed pitch propeller.

Results: A Bollard pull tests demonstrated that:

• With the ducted propeller, thrust was increased up to 25 %, compared with a standard propeller of equivalent and pitch and diameter.
• A 15/20 % reduction in fuel consumption was observed, due to less thrust require for same engine power.

Strengths:

• Observed fuel saving;
• Changes made are relatively easy to implement;
• The changes can be made in both older vessels and new ones;
• Possibility for reducing weight, and noise pollution.

Weaknesses: N/A

Reference: Notti and Sala, 2012

Method: Reducing vessel fuel consumption

Intervention: Hull design

Location/ geographic relevance: UK (England)

Actions taken: Two EMFF projects received funding (£42,300 across both projects) for bulbous bow hull modification to improve fuel efficiency.

Results: Resulted in a reduction in fuel consumption of around 5 %. This is an estimated reduction of 13,152 litres annually, equivalent to an annual saving of 35 tonnes of CO₂e or 1.67kg CO2e for every £1 of EMFF funding.

Strengths: N/A

Weaknesses:

• Beneficiaries confirmed that as a result of the modifications they are now able to fish in conditions where they couldn't previously. This may therefore have led to increased fishing effort, negating the fuel saving made.
• Under some conditions (e.g., certain speeds) bulbous bows can increase resistance and fuel use.

Reference: Owen et al., 2019 (added after the systematic review)

Method: Reducing vessel fuel consumption

Intervention: Antifouling

Location/ geographic relevance: UK (England)

Actions taken: Three EMFF projects received funding (£7,309 across all projects) for antifouling to improve fuel efficiency.

Results: None reported

Strengths: N/A

Weaknesses: N/A

Reference: Owen et al., 2019 (added after the systematic review)

Method: Selectivity

Intervention: Reduced fishing effort (time at sea)

Location/ geographic relevance: UK (Scotland)

Actions taken: Real time bycatch avoidance APP that uses mapping and fisher reporting. It is called BATmap

Results: Inconclusive

Strengths:

• Realtime reporting by fishers could help fishers avoid bycatch hotspot areas.

Weaknesses: Requires fishers to share catch data, which they are not always keen to do; Difficult in practise to define species hot-spots.

Reference: Marshall et al., 2021 (added after the systematic review)

Method: Selectivity

Intervention: Reduced fishing effort (time at sea)

Location/ geographic relevance: UK (England)

Actions taken: EMFF projects funded to improve selectivity in nets and pots via escape hatches.

Results: Unwanted catches with new more selective pots were reduced by 10-15 %.

Strengths:

• No reported decrease in landings with greater selectivity; and
• Allows smaller individuals of the target species to grow larger, leading to expected stock fecundity.

Weaknesses: No clear pathway to reduced fuel consumption as a result in increased selectivity.

Reference: Owen et al., 2019 (added after the systematic review)

Method: Selectivity

Intervention: Reduced fishing effort (time at sea)

Location/ geographic relevance: EU (not specified)

Actions taken: Modelling of real time reporting of areas with high abundance of non-target species, leading to shorter area closures compared to traditional area closures (enacted when bycatch is over a certain % of catch).

Results: Some potential utility in reducing bycatch

Strengths:

• Quick and adaptable to real time changes in species presence and abundance;
• Could supplement selective fishing gear and allows fishermen to spend less effort in areas with high abundance of unwanted species.

Weaknesses: Difficult in practise to define species hot-spots.

Reference: Eliasen and Bichel 2016

Method: Selectivity

Intervention: Reduced fuel consumption while fishing

Location/ geographic relevance: EU (Denmark)

Actions taken: New trawl system - using larger and lighter gear in the cod fishery. Optimizing the trawl and trawl doors. The 12 mm steel trawl warps were replaced with warps of 10 mm Dyneema® and the rest of the net, excluding the codend, was made of 1.4 mm Dyneema®. This was done to reduce drag.

Results: Trials showed:

• A reduction in fuel use by around 40 % of per kg of cod caught;
• Increased catch per unit effort; and
• Reduced bottom contact.

Strengths: Multiple benefits demonstrated during the trial (e.g., increased fuel efficiency, increased catch per unit effort, and reduced bottom contact).

Weaknesses: Multiple parameters were altered when trialling this new trawl rig, so exact causes of fuel savings are unknown.

Reference: Hansen and Tørring, 2012

Method: Selectivity

Intervention: Reduced fuel consumption while fishing

Location/ geographic relevance: UK (England)

Actions taken: Western Fish Producers Organisation (WFPO) recently conducted a trial with Sumwings, which replaced traditional otter doors on a beam trawler out of Brixham, in the south east of England.

Results: The WFPO trial found:

• a 42% reduction in fuel use (with ongoing use, the average reported fuel saving was approximately 30 %); and
• Reduced interaction with the seabed (by up to 84 %) leading to a 69 % drop in discards of benthic species.

Strengths: "Taking the average fuel saving of 90 litres per hour seen during the trial and an average towing time of 18 hrs per day, the potential saving totals 1,620 litres per day. Given a fuel price of £0.60 per litre the saving per day is £972.00. On average, if a SW beam trawler carries out 200 fishing days per year, the potential saving per year is £194,400. The cost of a set of two Sumwing beams is approximately £30,000 more than a set of traditional beams. The payback period to cover the additional cost of the Sumwing beams with the fuel saved equates to 31 days fishing" (Caslake 2022). The Decreased interaction with the seafloor doubled the expected lifespan of the fishing gear.

Weaknesses: N/A

Reference: Caslake 2022 (added after the systematic review)

Method: Selectivity

Intervention: Reduced fuel consumption while fishing

Location/ geographic relevance: EU (Netherlands)

Actions taken: Pulse trawling used in place of a tickler chain beam trawl.

Results: "pulse trawls had fewer fish discards (57 %, p < 0.0001), including 62 % undersized plaice (Pleuronectes platessa L.) (p < 0.0001), and 80 % discarded weight of benthic invertebrates (p = 0.0198) per hectare. The pulse fishing technique resulted in a lower fuel consumption (37–49 %), and consequently in spite of lower landings net revenues were higher"

Strengths:

• Fewer discards;
• Reduced seabed interaction; and
• Reduced fuel consumption.

Weaknesses: N/A

• Possible spinal damage to cod;
• issues of animal welfare (low social acceptance); and
• the injury and mortality of non-target species.

Reference: Van Marlen et al., 2014

Method: Selectivity

Intervention: Reduced fuel consumption while fishing

Location/ geographic relevance: Turkey

Actions taken: Experimenting with different sledge designs in sea snail beam trawl fisheries in the southern Black Sea, Turkey.

Results: Determined that the M-1 (sledge type shoe with a 5mm claw) modified design was the "most appropriate gear to reduce resistance and fuel consumption on both sea bottoms at constant rpm and towing speed".

Strengths: Relatively minimal modification needed- easy to implement and in doing so reduce resistance, seabed interaction and fuel consumption.

Weaknesses: N/A

Reference: Kaykaç et al., 2017

Method: Reducing waste

Intervention: Reduced loss of functional fishing gear

Location/ geographic relevance: UK (England)

Actions taken: the Sumwing trial by the WFPO.

Results: 84 % reduction in gear/seabed interaction, leading to doubling of the gear's operational life expectancy.

Strengths: Multiple benefits of the new Sumwing trawl gear, including reduced seafloor interaction.

Weaknesses: N/A

Reference: Caslake, 2022 (added after the systematic review)

Method: Reducing waste

Intervention: Reduced loss of functional fishing gear

Location/ geographic relevance: EU (Netherlands)

Actions taken: A mobile app to "reduce damaged and lost fishing gear". Gives location of set gill nets to help trawlers avoid them and causing damage. Gill net fishermen also supposed to set nets with space for trawlers to fish between them.

Results: Since the app was introduced damage to gill nets or loss of nets has "declined substantially".

Strengths: Decline in the damage and loss of static nets observed in practical trails

Weaknesses: Requires fishers to share the location of their actively fishing gear.

Reference: Mengo, 2017

Method: Reducing waste

Intervention: Reduced loss of functional fishing gear

Location/ geographic relevance: Norway

Actions taken:

• The Directorate of Fisheries carries out an annual retrieval operation to recover lost gill nets;
• There are facilities to report location of fishing gear when set to improve chances of recovery if lost; and
• Identification on gear discourages abandoning damaged gear or dumping fishing equipment at sea.

Results: There has been an increase in the reporting of lost gear which otherwise would not have been reported, improving the chance of successful recovery.

Strengths: Vessels can see and detect fishing gear in the water to avoid gear conflict and the possible relocation (leading to loss) or damage of the set gear.

Weaknesses: Requires fishers to share the location of their actively fishing gear.

Reference: Mengo, 2017; Langedal et al., 2020

Method: Reducing waste

Intervention: Reduce ALDFG

Location/ geographic relevance: UK (Scotland)

Actions taken: Fishing for Litter project, which facilitates the collection and removal of waste from fishing vessels. Coordinated in Scotland by KIMO UK. The project spans Europe, but in Scotland, 285 vessels and 20 ports are participating.

Results: 1800 tonnes of rubbish removed from the ocean.

Strengths: Incentivises best practice in gear disposal through improved awareness, facilities and logistics.

Weaknesses: Not strictly aimed at reducing fishing gear loss.

Reference: OSPAR, 2020

Method: Reducing waste

Intervention: Reduce ALDFG

Location/ geographic relevance: EU (Netherlands)

Actions taken: 'Green Deal Fishery for a Clean Sea' - "the fishing sector, fishing harbours, waste organisations, NGO's and the ministry, work together to decrease the amount of marine litter from the fishing sector and to increase the recycling of the fishing waste collected."

Results: Multi-sector collaboration to "decrease the amount of marine litter from the fishing sector and to increase the recycling of the fishing waste collected".

Strengths: N/A

Weaknesses: N/A

Reference: Mengo, 2017

Method: Reducing waste

Intervention: Reduce ALDFG

Location/ geographic relevance: EU (Spain)

Actions taken: Pilot projects to improve waste management on vessels and in harbours. Installing waste containers on vessels; installing recycling points in fishing and navigation docks; research on potential markets for fishing industry waste.

Results: N/A

Strengths: The easy access for vessels to participate should makes them more likely to.

Weaknesses: N/A

Reference: Mengo, 2017

Method: Reducing waste

Intervention: Reduce ALDFG

Location/ geographic relevance: EU (Sweden)

Actions taken: 'No-Special-Fee' system. Commercial fishermen pay a port fee and can dispose of waste in port.

Results: N/A

Strengths: The easy access for vessels to participate should makes them more likely to.

Weaknesses: N/A

Reference: Mengo, 2017

Method: Reducing waste

Intervention: Reduce ALDFG

Location/ geographic relevance: EU (Sweden)

Actions taken: 'Keep the Sea Clean' project in Bohuslän facilitates the collection and recycling of fishing gear and marine litter.

Results: N/A

Strengths: The easy access for vessels to participate should makes them more likely to.

Weaknesses: N/A

Reference: Mengo, 2017

Method: Reducing waste

Intervention: Reduce ALDFG

Location/ geographic relevance: Norway

Actions taken: 2013 waste strategy - "marine litter caught in fishing gear can be handed in with no fee". Fee is incorporated into port charge so not dependent on amount of waste landed. Fishing gear can be recycled.

Results: N/A

Strengths: N/A

Weaknesses: N/A

Reference: Mengo, 2017

Method: Stock resilience

Intervention: Harvest strategy

Location/ geographic relevance: UK (Scotland)

Actions taken: Measures to improve stock status.

Results: The Scottish Marine Assessment 2020, compared 'key stocks' and found that the percentage of stocks fished at or below F_MSYhas increased from 46 % in 2016, to 54 % in 2018 (Marine Scotland 2020). This suggests that management measures have been effective within these fisheries.

Strengths:

• Improved stock status in terms of harvest rates and biomass indicators.
• Overall, Scotland compares favourably to the EU, where 74 % of species are fished above FMSY and 49 % of species are outside of safe biological limits (B < 0.5 B_MSY) (Froese et al., 2018).

Weaknesses: SSB is at, or below, B_trigger for 44 % of the eight most valuable fish species to Scotland (total landings value), and a further 22 % that are above B_trigger are fished above F_MSY

Reference: Marine Scotland, 2020 (added after the systematic review)

Method: Stock resilience

Intervention: Exploitation pattern

Location/ geographic relevance: UK (Scotland)

Actions taken: A prohibition on landing female lobsters with a carapace length over 145 mm (except the Orkney Islands and Shetland Islands).

Results: N/A

Strengths: As a regulatory instrument this should help increase the number of large fecund individuals, which produce a disproportionate quantity of high-quality eggs when compared to smaller sexually mature individuals.

Weaknesses: Orkney Islands and Shetland Islands excluded from these measures.

Reference: legislation.gov.uk (added after the systematic review)

Method: Stock resilience

Intervention: Exploitation pattern

Location/ geographic relevance: UK (England and Wales)

Actions taken: Prohibition on landing berried (egg bearing) female lobsters; and the adoption of a Maximum Landing size for lobsters.

Results: N/A

Strengths: As a regulatory instrument this should help increase the number of large fecund individuals, which produce a disproportionate quantity of high-quality eggs when compared to smaller sexually mature individuals.

Weaknesses: N/A

Reference: Woolmer et al., 2010

Method: Stock resilience

Intervention: Exploitation pattern

Location/ geographic relevance: UK (Northern Ireland)

Actions taken: Irish Sea Nephrops fishery - Escape panel in trawl nets to allow escape of juvenile haddock and whiting. Fitted a 120mm square mesh escape panel in the trawl gear.

Results: Reduce catch of juvenile haddock and whiting without loss of Nephrops catch: "16 comparative hauls this net configuration allowed 54 % of juvenile haddock and 65 % of juvenile whiting to escape from the net with no loss in Nephrops catch"

Strengths: No reduction in target species catch.

Weaknesses: N/A

Reference: Briggs, 2010

Method: Stock resilience

Intervention: Exploitation pattern

Location/ geographic relevance: EU (not specified) Intervention

Actions taken: Nephrops fishery: a square mesh panel - "300 mm window is placed at the top section at about 3–6 m from the cod line". This is done to reduce the bycatch of roundfish in Nephrops trawls.

Results: "both reduction of cod catches and the estimated proportion of cod that contact the window were >85 %"

Strengths: The use of the window instead of a grid avoids the loss of marketable lobster.

Weaknesses: Loss of other commercial species, such as plaice. Window is placed far back so further escape may be possible during haul back.

Reference: Madsen et al., 2010

Method: Stock resilience

Intervention: Refrigerants

Location/ geographic relevance: UK (not specified)

Actions taken: Since 2020, fluorinated GHGs with a GWP greater than 2500 have been prohibited in Scotland for use in servicing or refilling refrigeration systems

Results: N/A

Strengths: As a statutory instrument this should act to reduce the use of refrigerants with a very high GWP. However, progress results are not available.

Weaknesses: Progress results are not available

Reference: sepa.org.uk (added after the systematic review)

Method: Stock resilience

Intervention: Alternative energy

Location/ geographic relevance: UK (Wales)

Actions taken: Milford Haven industrial site: modelling a smart energy cluster that can manage energy production more effectively, using energy from local photovoltaics and a solar farm.

Results: Model showing that the it could be possible to:

• Provide "cost advantages for industries and stakeholders and can provide a more competitive integration of small and medium energy businesses within the wholesale energy market";
• Provide green energy to the fish industries and local community; and
• Sell excess energy back to the national grid.

Strengths: N/A

Weaknesses: Relies on solar energy, so less reliable in winter, when output is expected to dip below demand.

Reference: Alzahrani et al., 2020; Petri et al., 2020.

Method: Stock resilience

Intervention: Alternative energy

Location/ geographic relevance: EU (Finland)

Actions taken: Production of biodiesel from fish waste from fish processing. The biodiesel is used in fish farm operations and local buses.

Results: "plant produces approximately 400 litres of fish biodiesel a day. In a year, the plant can turn 15–20 m3 of fish oil into biodiesel."

Strengths: Cuts operational costs and produces a close to carbon neutral fuel.

Weaknesses: It has not been implemented for commercial sale yet as biodiesel is taxed in the same way as fossil fuels.

Reference: Mikkola and Randall, 2016

Method: Stock resilience

Intervention: Alternative energy

Location/ geographic relevance: EU (Denmark)

Actions taken: Aquapri - aquaculture and fish processing plant design and implementation of a bespoke ventilation system to reuse waste energy.

Results: N/A

Strengths: The return on investment was expected to take 2.5 years

Weaknesses:

• Took 9 months to complete from start to finish (longer than expected); and
• Large initial outlay.

Reference: Solberg et al., 2016

Method: Stock resilience

Local markets

Location/ geographic relevance: N/A

Actions taken: N/A

Results: N/A

Strengths: N/A

Weaknesses: N/A

Reference: N/A

Method: Stock resilience

Consumer behaviour

Location/ geographic relevance: UK (Scotland)

Actions taken: Promotion of the MSC by Marine Scotland

Results: N/A

Strengths: This endorsement could be seen to build consumer trust in the eco-label.

Weaknesses: N/A

Reference: gov.scot (added after the systematic review)

Method: Stock resilience

Consumer behaviour

Location/ geographic relevance: UK (Scotland)

Actions taken: Work to educate the public about seafood sustainability by Open Seas

Results: N/A

Strengths: N/A

Weaknesses: N/A

Reference: openseas.org.uk/ (added after the systematic review)

Method: Stock resilience

Consumer behaviour

Location/ geographic relevance: UK (Scotland)

Actions taken: Seafood Scotland's strategy for Scotland's seafood industry, which aims (amongst other things) to "use standards and accreditation to support marketing and improve business performance"

Results: N/A

Strengths: N/A

Weaknesses: N/A

Reference: seafoodscotland.org (added after the systematic review)

Method: Stock resilience

Consumer behaviour

Location/ geographic relevance: UK (not specified)

Actions taken: The Marine Conservation Society's Good Fish Guide provides information to help consumers understand which species and stocks are sustainable and which are not. Species are rated based on stock status, where it was caught or farmed and how.

Results: N/A

Strengths: There is accessible information granulated to a stock level.

Weaknesses: N/A

Reference: mcsuk.org (added after the systematic review)