Energy-efficient fishing already exists. How do we unlock it?

Parts of the EU fishing fleet are under real pressure from marine diesel costs (EUMOFA), and the sector must decarbonise regardless. Facing both without pitting them against each other would keep progress moving.

Encouraging news from our data analysis and modelling work at DTU Aqua: we have already identified some effective levers. They don’t wait on a technological breakthrough, and they don’t require choosing between viable fisheries and energy transition goals.

What the data shows

In the same waters (for example, the ones visited by the Danish fleet), the difference gear choice makes is measurable:

  • Otter bottom trawlers, fishing a mix of Nephrops, cod, plaice and flounder, may burn 0.83 litres of fuel per kilogram of fish landed, generating €4.19 of revenue per litre.
  • Vessels using passive gear (gillnets, hooks, etc.) burn only 0.17 to 0.24 l/kg, and may yield up to €9.57 per litre.

That is a 70–80% fuel saving and more than double the revenue per litre. Two vessels leave the same harbour; one operates at roughly half the energy cost per fish on the dish plate (and those fisheries also use different vessel sizes, see details in Bastardie et al. 2022)

And the gap is arguably even larger EU-wide: in the Mediterranean, bottom-trawling fuel use intensity runs considerably higher than the Danish figures above, so if anything this comparison understates the European potential.

The real policy difficulty: the shocks

To be fair to everyone involved: fuel-price shocks do call for emergency relief. Fishing communities are real, food supply is real, and it is expected that no responsible government would let a sector collapse mid-crisis.

The difficulty is that emergency relief also removes the incentive to make the structural change that would end the vulnerability, and the sector ends up needing relief again at the next price spike. Getting both right simultaneously (solidarity in the short term, energy transition in the medium term) is hard policy design. It is also, we would argue, the central design task of the EU Energy Transition Partnership.

Our modelling consistently points to the same ranking of levers: stock recovery combined with a gear change would reduce fuel-use intensity more than any engine upgrade would in the short term. Supporting fuel-intensive effort while stocks rebuild means paying twice for the same fish (1: for the fuel, 2: for the rebuild). The transition should be seen less as a cost imposed on the sector and more as the exit from the crisis loop.

Extracted from here

Likely three concrete choices, available now

  1. Transition-linked aid? Emergency support stays (for example as in here), but would come with a committed pathway: continue working on, and financing, drag-reduction technology and “precision fishing“, with gear-switching plans agreed with producer organisations, phased realistically.
  2. Reward efficiency with access? Low-fuel, passive-gear fishers earning more euros per litre of fuel could receive preferential access, more fishing days, quota flexibility, etc., making efficiency profitable before the fuel bill punishes inefficiency.
  3. Capital support for retrofits, not just operating costs? Direct EMFAF-type funding and investment toward hybrid retrofits, gear changes, and vessel adaptation, so today’s aid builds the fleet of tomorrow instead of renting the fleet of yesterday (Bastardie et al. 2026).

Stakeholders would agree that each of these would be implementable within existing instruments, and would make sure that each has precedent elsewhere in the EU’s decarbonisation toolbox. Consultation works point to industry readiness, not only a lack of flexibility in the policy framework, as the primary missing feature. The primary obstacles are likely a widespread resistance to change, driven by the high costs and low uptake of commercial feasibility studies. Ultimately, operators’ pervasive fear of losing market access during the transition likely stalls progress. This includes the challenge of gaining flexibility to align each operator’s quota portfolio and capacity with available marine living resources.

When energy prices spike, fuel-dependent industries adjust in stages: absorbing the shock through margins, then coping in the short term, and finally adapting structurally. Cost-effective efficiency investments are routinely delayed because of uncertainty, irreversibility, and the “option value of waiting” (Gerarden et al., 2017).

In fisheries, fuel price shocks manifest primarily as behavioural coping: shifted effort and fishing closer to port, fewer trips and fewer exploratory trips, and accepting lower catches (for example, see Abernethy et al., 2010). In contrast, Structural changes would mean new gear, vessels, and techniques. Today, the EU fleet remains stuck in Phase 2: coping, but not transforming.

An open question

What would make transition-linked support workable in practice, not just on paper? Which conditions feel fair? This is a design problem best solved by consulting the people who will live under the rules. But even when considering alternative viewpoints, one should not ignore the numbers science studies bring to the table.

References and details:

Abernethy, K. E., Trebilcock, P., Kebede, B., Allison, E. H., & Dulvy, N. K. (2010). Fuelling the decline in UK fishing communities? ICES Journal of Marine Science, 67(5), 1076-1085. https://doi.org/10.1093/icesjms/fsp289

Bastardie, F., Hornborg, S., Ziegler, F., Gislason, H., & Eigaard, O. R. (2022). Reducing the Fuel Use Intensity of Fisheries: Through Efficient Fishing Techniques and Recovered Fish Stocks. Frontiers in Marine Science, 9, 817335. (Open access.)

Bastardie, F., Wakeford, R. C., Torreele, E., Aranda, M., Doering, R., Ligas, A., Mele, I., Castresana, J., Gabiña, G., Maes, S. M., Sabatella, R., & Malvarosa, L. (2026). How to ensure sustainable fisheries while renewing the EU fishing fleet for modernization and energy transition? Frontiers in Marine Science, 13, 1812898. https://doi.org/10.3389/fmars.2026.1812898 (Open access.)

Gerarden, Todd D., Richard G. Newell, and Robert N. Stavins. 2017. “Assessing the Energy-Efficiency Gap.” Journal of Economic Literature 55 (4): 1486–1525.

Innovation in fisheries: Good ideas risk remaining unused

New fishing technologies designed to protect marine environments show promise, but their success relies on more than just invention. A 2024 study by the European Parliament (https://www.europarl.europa.eu/stoa/en/document/EPRS_STU(2024)762843) examined alternatives to bottom trawling in EU Marine Protected Areas and found a significant barrier: voluntary uptake is extremely low.

The core issue is short-term economic. Most current innovations do not match the catch efficiency of traditional gear. For fishers, switching means potentially lower yields and higher costs without immediate compensation. As a result, many continue using established methods to maintain their income. In some cases, this leads to increased effort to make up for lost catch, which can negate environmental benefits.

If it costs money now, it won’t happen, even if it saves more fish for later.

The report suggests that, because industry adoption has stalled in the absence of financial incentives, the most effective solutions may need to be mandatory rather than optional. It also highlights that policy frameworks must address the socioeconomic reality of fisheries. True sustainability likely requires a balanced approach in which environmental rules are paired with support mechanisms to ensure fishers are not left bearing the full cost of the transition.

However, the debate often misses a crucial long-term perspective: protecting marine habitats is not just an ecological goal, but a safeguard for the fisheries that depend on them. When habitats are degraded, they can no longer sustain the levels of exploitation needed to meet current catches. This fundamentally narrows the supposed trade-off between conservation and fishing; in the long run, one cannot exist without the other. Therefore, sustainable investment and the adoption of innovative technologies cannot succeed unless exploitation is balanced with the fish resources. Without this equilibrium, short-term gains risk leading to long-term collapse.

In the European context, this points to a clear conclusion: technological innovation is necessary, but it must be supported by smart policy that aligns conservation goals with the economic stability of the fishing sector. Without this alignment, good ideas risk remaining unused.

See some slides here.

References:

STOA (2024). Exploring the viability of innovative fishing technologies as an alternative to bottom trawling in European marine protected areas: An environmental and socioeconomic analysis 2024. Author: Bastardie F. for STOA Panel for the Future of Science and Technology (Brussels: The European Parliament).

Bastardie, F., Salvany, L., Cooper, A. M., & Carvalho, N. (2024). A roadmap to reduce the risk of overexploiting EU marine living resources in a changing ocean. Frontiers in Marine Science, 11, 1352500. https://doi.org/10.3389/fmars.2024.1352500

Working with DISPLACE toward identifying Carbon Free Transition Pathways from fuel‑intensive fleets to low-carbon Danish Fleets

See the slideshow presenting the project here. We will soon incorporate scenario results into fisheries management plans for policymakers.

Preliminary outcomes now allow us to simulate the (2025) fishing activities of Danish vessels over 12 meters in length as they seek a good catch around Denmark on different resources. The following short animation presents the kind of first results we will get out of this simulation:

Disclaimer: This animation is a rough simulation provided for illustrative purposes and does not represent the vessels’ past activities.