Technological Innovations and Sustainable Practices in Fishing Vessels: A Systematic Literature Review

Abstract

The fisheries industry faces increasing sustainability challenges from environmental, economic, and social perspectives, which directly affect fishing vessels as its primary infrastructure. This study conducted a systematic literature review following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines to evaluate technological innovations that improve the sustainability of fishing vessels. Comprehensive searches were performed in Scopus, Web of Science, ScienceDirect, and IEEE Xplore, covering the period 2020–2024. The searches identified 756 articles, of which 105 met the predefined eligibility criteria after screening titles, abstracts, and full texts. Each innovation was categorised and analysed based on its functional vessel domain, contribution to environmental, economic, and social sustainability, maturity level using the Technology Readiness Levels (TRLs) framework, and relevance to Circular Economy (CE) principles. The results indicate that most innovations focus on environmental sustainability, particularly on emission reduction and energy efficiency. Social sustainability remains under-addressed, especially in terms of labour conditions and gender equality. CE principles are present in some initiatives but are not yet fully integrated into vessel design or operation. Most innovations are at medium TRL stages, with adoption limited by financial, infrastructural, and institutional barriers, especially in small-scale fisheries. Future research should address these gaps by enhancing CE integration and promoting a more balanced attention across all three sustainability dimensions.

1. Introduction

The fishing industry plays a crucial role in global food security, economic development, and the livelihoods of coastal communities. However, its future is increasingly threatened by overfishing, marine ecosystem degradation, and declining fish stocks, which undermine its long-term sustainability [1]. Fishing vessels, as the spearhead of the industry, stand at the centre of these issues. On the one hand, they are the primary means of harvesting marine resources; on the other hand, their operations contribute to environmental problems such as carbon emissions, bycatch waste, and the destruction of seabed habitats [2]. In response, the fishery industry is shifting toward more environmentally friendly practices. Technological innovations are continually being researched to mitigate adverse impacts, enhance operational efficiency, reduce environmental footprints, and ensure the industry remains resilient in the face of climate change and global pressure [3].

Sustainability in the fishing industry can be evaluated across three dimensions: environmental, economic, and social [4]. Environmental sustainability aims to minimise the industry’s impact on the environment by increasing energy efficiency and reducing emissions. Economic sustainability focuses more on growing profits, optimising resource use, and supporting the livelihoods of fishing communities. Social sustainability emphasises adequate working conditions, promotes equal rights, and enhances safety at sea. Various technological innovations have been suggested to meet these sustainability goals, ranging from hybrid propulsion systems and selective fishing gear to digital monitoring and AI-based navigation [5].

Despite significant progress, the uptake of sustainable technologies remains fragmented and context dependent. Small-scale and artisanal fisheries, which dominate many coastal and developing regions, face notable barriers, including financial limitations, lack of technical expertise, and institutional constraints [6]. Moreover, integrating novel technologies into traditional operational paradigms can generate tension between innovation and local practices [7]. Although some policy frameworks, including subsidies and certification schemes, have been introduced to support this transition, their impact remains inconsistent and often neglects regional differences.

An increasing amount of research has examined technological enhancements in fishing vessels; however, many studies have narrowly focused on isolated components or specific sustainability aspects without a comprehensive evaluation of innovation maturity or systemic integration. The use of TRLs provides an effective way to assess the development stages of these technologies, distinguishing between conceptual solutions and those ready for deployment. Nevertheless, few studies have systematically incorporated TRL assessments or connected them to functional vessel components.

Similarly, the implementation of CE principles, such as lifecycle thinking, life extension, waste reduction, and material reuse, has been limited in the context of vessel design and operation. Although efforts such as gear recycling and energy efficiency enhancements are gaining traction, a comprehensive CE framework still remains largely absent from the vessel-level sustainability discussion. This gap represents a missed opportunity to embed resilience and circularity into the core structure of fishing operations.

Several literature reviews have been conducted on innovations and technologies in fishing vessels. Granado et al. [8] reviewed studies focusing on optimisation and decision-making for fishing vessel routing. Welch et al. [9] analysed the application of Artificial Intelligence (AI) to monitor and evaluate fishing vessel activities. Similarly, Amuthakkannan et al. [10] discussed the automation of fishing vessels using AI to enhance sustainable fishing practices, particularly in relation to safety, security, navigation, and information sharing among fishers. However, these studies have not thoroughly addressed how sustainability aspects are assessed, the extent of technological readiness, or whether circular economy principles are incorporated into research.

To address these deficiencies, this systematic literature review focuses on sustainable innovations in fishing vessels. It adopts a vessel-centric perspective to classify technologies across key functional domains, including propulsion systems, hull design, digitalisation, and post-harvest systems, while also evaluating the integration of sustainability dimensions and CE principles. Innovation maturity is assessed through TRLs to gauge the proximity to practical applications, and gaps in the current research are identified to inform future directions. The research objectives of this study are summarised as follows.

(1)

To identify the types of technological innovations and functional components that have been developed and applied to fishing vessels to enhance sustainability.

(2)

To analyse the sustainability dimensions addressed in current research.

(3)

To assess the maturity level of identified innovations to determine their proximity to practical application on fishing vessels.

(4)

To examine the alignment of these innovations with circular economy principles.

(5)

To identify gaps in the literature concerning sustainable technological solutions for fishing vessels, thereby guiding future research and development.

2. Materials and Methods

This study employed a systematic literature review methodology, comprising three main stages: (1) article identification and searching, (2) screening and selection, and (3) data extraction and synthesis. The entire process was guided by the PRISMA 2020 framework to ensure the transparency and reproducibility of the research findings [11]. A schematic overview of these stages is presented in Figure 1. Furthermore, this approach aligns with established practices in previous maritime review studies [12,13].

2.1. Article Searching Process

The data for this study were obtained using the Scopus, ScienceDirect, Web of Science, and IEEE Xplore search engines [14]. These databases were selected because of their extensive coverage of peer-reviewed journals, conference proceedings, and high-quality publications in engineering, environmental science, and fishery management domains.

To enhance the comprehensiveness of the search process, the strategy was expanded to encompass abstracts, in addition to titles and keywords. The search terms used were (sustainable OR sustainability) AND (“fishing vessel” OR “fishing boat” OR trawler OR longliner OR seiner OR gillnetter OR drifter). This query was formulated to encompass articles about the sustainability aspects of fishing vessels across various types and technological domains. A five-year timeframe (2020–2024) was selected to ensure the inclusion of the most recent and pertinent studies. Furthermore, to maintain consistency and accessibility, only articles published in English were included.

Additionally, during the article retrieval process from academic databases, the search results were explicitly filtered to include only journal articles and conference papers; review papers were excluded. This decision focused exclusively on original research articles that presented empirical findings or practical implementations relevant to sustainable innovation and technology in fishing vessels.

The final database search conducted on 7 May 2025, yielded 756 articles, with the following distribution: Scopus (381 articles), ScienceDirect (147 articles), Web of Science (160 articles), and IEEE Xplore (68 articles). Subsequently, these records were consolidated into a single database. Duplicate articles identified during this consolidation were systematically removed using reference management software. The deduplication process resulted in the exclusion of 250 duplicate articles, leaving 506 unique records for the subsequent screening phases (title and abstract screening followed by full-text review).

2.2. Article Filtering and Screening

The article selection process was carried out in two steps, title and abstract screening, followed by full-text review. This sequential filtering approach ensured both efficiency and methodological rigour in identifying studies that aligned with the review objectives. Consistent inclusion and exclusion criteria were applied across both phases to maintain the thematic coherence.

Table 1. The inclusion and exclusion criteria.

Inclusion Criteria	Exclusion Criteria
(1) The article explicitly presents an innovation or technology applied to fishing vessels.	(1) The article does not explicitly address fishing vessels or fail to apply innovation or technology to them.
(2) The proposed innovation or technology aims to improve sustainability in the economic, environmental, or social dimensions.	(2) Sustainability is discussed in a context unrelated to fishing vessels, including marine biodiversity, fish species conservation, and general maritime ecological frameworks.
(3) The article optionally discusses CE principles relevant to fishing vessels.	(3) The article focuses on broader fisheries management, seafood supply chains, and policy-level discussions, without addressing vessel-level innovations.
(4) The study provides empirical evidence, practical application, or a concrete case study illustrating the implementation of innovation.	(4) The study lacks empirical or practical content (e.g., is purely conceptual or theoretical).

below shows the inclusion and exclusion criteria used.

A single reviewer performed an initial screening to ensure consistency. To minimise subjectivity, borderline cases were reassessed and discussed with second and third reviewers. Of the 506 unique articles obtained after deduplication, 389 were excluded during the title and abstract screening phase. These exclusions included 20 review articles and 369 articles that did not meet the predefined inclusion criteria. The remaining 117 articles were proceeded to the eligibility assessment stage through a full-text review. At this stage, 12 additional articles were excluded: one was a review article, and 11 did not meet the inclusion criteria due to factors such as a lack of empirical focus or content not specifically related to fishing vessels.

Ultimately, this rigorous selection process resulted in 105 articles that met all inclusion criteria and were retained for in-depth analysis. The entire screening process is summarised in the PRISMA flow diagram in Figure 1.

One limitation of the systematic literature review method was the potential for bias. The inclusion and exclusion criteria may have filtered out relevant work, particularly unpublished reports or industry-driven innovations that are less likely to be published in academic media. Although four major databases were searched, their coverage did not include grey literature or non-English publications, which could influence the balance of the findings. No formal bias assessment tools were applied because this review focused on mapping technological innovations, rather than synthesising intervention effects. However, study quality was indirectly evaluated through criteria such as empirical evidence, peer-review status, and methodological transparency. These measures mitigate bias to a limited extent, and the possibility of missing or uneven evidence remains.

2.3. Data Extraction and Synthesis

Following the identification and screening stages, data from 105 selected articles were extracted using a structured two-step process: bibliometric mapping and thematic coding. A single reviewer independently extracted the data using a piloted form. The first step involved compiling bibliographic and bibliometric data to analyse publication trends, citation patterns, and keyword co-occurrence. Tools such as VOSviewer and Biblioshiny were used to visualise research clusters and thematic evolution. In the second step, each article was categorised based on five core analytical dimensions: (1) functional areas of technological innovation, (2) sustainability dimensions addressed (environmental, economic, and/or social), (3) TRLs, (4) integration of CE principles, and (5) geographic distribution of innovation implementation, reflecting the context or country in which the innovation was tested or applied, rather than author affiliation.

Definitions and coding criteria were standardised to ensure consistency. TRL values were sourced from author statements or, when not reported, inferred from contextual evidence. CE relevance was determined through keyword tracing and qualitative content analysis. Where information was incomplete or ambiguous, assumptions were made transparently based on the context of each study.

The data were synthesised using descriptive statistics and thematic analysis to identify trends, regional patterns, research gaps, and innovation maturity. The results were tabulated and visualised using bibliometric maps, thematic networks, and summary tables to facilitate interpretation and to highlight clusters and gaps. Due to the heterogeneity of study designs and outcomes, a meta-analysis was not feasible; instead, descriptive and narrative synthesis were used. Heterogeneity was examined by comparing the findings across vessel functions, geographical contexts, TRL categories, and sustainability dimensions. Sensitivity analyses were not performed because the synthesis remained qualitative and descriptive.

The literature selected for this review provided a comprehensive foundation for this analysis. It covers a wide range of topics that illustrate the multidimensional aspects of sustainability within the fishing sector, including vessel design, propulsion systems, digitalisation, post-harvest handling, crew welfare, and safety. This dataset offers a holistic overview of current efforts and innovations focused on improving the environmental, economic, and social performance of fishing vessels. As the review synthesised qualitative and descriptive findings, no statistical effect measures (such as risk ratios or mean differences) were utilised. Certainty was not evaluated; instead, consistency across studies was considered narratively.

This review was not registered in a prospective database, and no prior protocol has been published. The methodology was defined a priori and strictly followed to ensure transparency and consistency during the review process. As no protocol was registered, no amendments or modifications to the predefined procedures were applicable.

3. Results

The findings of this systematic review are presented in two main sections. The first section details the results of the bibliometric and thematic mapping, revealing key research trends, structural patterns, and conceptual clusters within the literature. The second section provides a detailed synthesis of technological innovations, categorised by functional domain, sustainability focus, TRLs, and CE elements.

3.1. Summary of Selected Articles

The 105 articles analysed span the period 2020–2024, comprising 63 journal articles (60%) and 42 conference papers (40%), as shown in Figure 2. Publication output remains relatively stable from 2020 to 2022, before rising markedly in 2023 and 2024, with 30 and 32 contributions, respectively. Journal articles consistently represented a larger share, peaking at 19 in both 2023 and 2024, whereas conference papers showed parallel growth, reflecting expanding interest across academic and professional communities.

Appendix A.1 presents detailed publication statistics for the journals included in the review, listing the number of articles, references, and total citations per journal. Fisheries Research (Elsevier) had the highest number of included articles (six) and 57 citations, followed by Sustainability (MDPI) with five articles and 21 citations. Notably, while Ocean Engineering (Elsevier) included only two articles, it recorded the highest citation count (153), indicating a high impact. Other frequently cited journals include Marine Policy, Journal of Marine Science and Engineering, and Journal of Cleaner Production. The table also highlights the wide distribution of articles across journals from various publishers, although Elsevier and MDPI dominate in both volume and citation impact. This distribution underscores the multidisciplinary nature of research on sustainable fishing vessels and the importance of both environmental science and engineering-focused outlets.

Conference proceedings also constitute a vital channel for research dissemination. Appendix A.2 provides an overview of the publication statistics for the conference proceedings included in the study, detailing the number of articles, citations, and associated publishers. A total of 40 conference papers spanning major publishers such as IEEE, IOP Publishing, Springer, and EDP Sciences were identified. Notably, IEEE dominates this domain, contributing to the majority of conference papers, including those presented at ICPECTS, ICOIACT, ICMLA, and others. While most conferences report zero or low citation counts, a few show a relatively high scholarly impact. This pattern reflects the growing role of conferences in introducing emerging technologies and preliminary findings within the field of sustainable fishing vessel research. However, their long-term citation impact remains modest compared to journal publications.

Figure 3 illustrates the distribution of reviewed articles based on their publishers, considering only those with at least two publications. Elsevier leads with 26 articles, followed by IEEE with 22 articles, and MDPI with 13 articles, indicating their central role in disseminating research on sustainable vessel technologies. Other notable contributors include Springer (seven articles), IOP Publishing (five), and Frontiers Media S.A. (three). Several publishers, such as ASME, BIOFLUX SRL, EDP Sciences, and the International Institute of Refrigeration, each contributed two articles. The concentration of articles among a few key publishers suggests a degree of thematic clustering within specific journals or publishing platforms.

Several studies initially appeared to meet the inclusion criteria but were excluded during the full-text review because they did not directly focus on the sustainability of fishing vessels. Common reasons include a focus on fisheries management, seafood supply chains, species identification, fishing effort, and vessel tracking, rather than vessel-level sustainability. Other exclusions included boat designs without a sustainability analysis, robotics unrelated to fishing vessels, shipyard industry studies, and papers limited to safety features without a broader sustainability context. These exclusions ensured that only studies directly linked to fishing vessels and their sustainability performance were included.

3.2. Keyword Co-Occurrence and Thematic Mapping

To explore the thematic structure and intellectual development of innovations in sustainable fishing vessels, a keyword co-occurrence analysis was conducted using VOSviewer (version 1.6.20) and Biblioshiny (R version 4.5.0). This dual-software approach enables both structural and temporal insights by combining keyword frequency data with network visualisation techniques to identify conceptual relationships and thematic shifts.

Author keywords from the 105 selected articles were analysed using a minimum occurrence threshold of four. Visual outputs were generated, including a density map, network diagram, and temporal overlay. Collectively, these results illustrate dominant research themes, keyword interconnections, and emerging areas of interest.

Table 2. Keywords, occurrences, and link strength in the cited articles.

No	Keywords	Occurrences	Total Link Strength
1	Fishing vessel	47	145
2	Fisheries	36	134
3	Sustainability	21	70
4	Fisheries management	19	55
5	Sustainable development	19	88
6	Fish	13	48
7	Fishing	11	31
8	Energy efficiency	10	58
9	Ships	8	42
10	Climate change	7	34
11	Fishing industry	7	24
12	Accident analysis	6	21
13	Environmental regulations	6	40
14	Fishing effort	6	20
15	Bayesian network analysis	5	17
16	Bycatch	5	11
17	Fossil fuels	5	27
18	Decision making	4	26
19	Deep learning	4	7
20	Environmental impact	4	24
21	Fishing gear	4	7
22	Fleet operations	4	25
23	Life cycle assessment	4	7
24	Maritime sector	4	22
25	Profitability	4	17
26	Renewable energy	4	5
27	Safety	4	13

presents the 27 most frequently occurring keywords and their total link strengths, which capture both their prominence and relational intensity. “Fishing vessel” (47 occurrences; 145 total link strength), “fisheries” (36; 134), and “sustainability” (21; 70) form the conceptual core of the reviewed literature. These are followed by “sustainable development”, “fisheries management”, and “energy efficiency”, which signal cross-cutting concerns with governance, performance, and environmental impact. Meanwhile, terms such as “deep learning”, “renewable energy”, and “life cycle assessment”, though less frequent, highlight recent shifts toward systems innovation and environmental assessment tools.

The keyword network visualisation (Figure 4) revealed five major clusters, reflecting the interdisciplinary nature of sustainable fishing vessel research. The first and largest cluster centres on “fishing vessel” and “sustainability” and includes terms such as “fishing industry”, “safety”, “accident analysis”, and “Bayesian network analysis”. This cluster underscores the operational, safety, and risk analysis dimensions of fishing vessel research. The second cluster connects “sustainable development”, “energy efficiency”, and “life cycle assessment”, indicating a focus on emissions reduction, energy optimisation, and lifecycle-based performance metrics. A third cluster, which includes “fishing”, “fish”, “bycatch”, and “deep learning”, reflects the intersection of ecological selectivity, fisheries science, and the application of advanced AI-driven monitoring tools. The fourth cluster, built around “fisheries”, “fisheries management”, “fishing gear”, and “fishing effort”, emphasises the governance, institutional frameworks, and the management of fishery resources. Finally, the fifth cluster comprises “renewable energy”, “fossil fuels”, and “climate change”, reflecting growing academic engagement with decarbonisation pathways and clean energy transitions in vessel operation.

The overlay visualisation (Figure 5) illustrates the temporal progression of research themes by mapping the average publication year of keywords, with colour gradients ranging from blue (older themes) to yellow (recent themes). Foundational topics such as “fishing vessels”, “fisheries”, “sustainability”, and “fisheries management” are depicted in blue to turquoise, indicating their consistent relevance throughout the early review period (2020–2022) and their continued importance as core pillars of the literature. In contrast, more recent themes, including “energy efficiency”, “climate change”, “life cycle assessment”, and “renewable energy”, are displayed in yellow, signalling their increasing prominence in studies published between 2023 and 2024. This shift reflects a growing research emphasis on performance optimisation, emission reduction, and holistic environmental assessment. Situated between these extremes, keywords such as “fleet operations”, “environmental regulations”, “fossil fuels”, “accident analysis”, “deep learning”, and “Bayesian network analysis” appear green, suggesting an increase in scholarly attention between mid-2022 and early 2023. These intermediate themes mark a transition toward data-driven and regulatory-informed approaches. Collectively, overlay visualisation reveals an evolving research landscape that is grounded in established sustainability concerns, yet increasingly oriented toward decarbonisation, digitalisation, and life-cycle-based innovation in fishing vessel technologies.

The density map (Figure 6) reinforces these findings. High-density zones (depicted in red) highlight central and frequently co-occurring terms such as “fishing vessel”, “fisheries”, and “sustainable development”. Medium-density areas surrounding these include terms like “climate change”, “fisheries management”, and “energy efficiency”, which are conceptually important though less dominant. Peripheral but strategically notable terms, such as “Bayesian network analysis”, “bycatch”, and “deep learning”, may represent early-stage innovation areas that warrant further exploration.

To complement the co-occurrence analysis, a thematic map (Figure 7) was generated using Biblioshiny (R version 4.5.0) to classify the research themes by centrality (relevance) and density (development). This map provides a strategic perspective on the maturity and influence of the topics in the literature. The upper-right quadrant (motor themes) features well-developed and highly relevant issues such as “fishing vessel”, “fisheries”, “sustainability”, “fisheries management”, “climate change”, and “bycatch”, which form the core of current research and are closely interconnected. In contrast, niche themes such as “fish quality”, “fishing methods”, and “marine communication” appear in the upper-left quadrant, indicating that they are well-developed but less central to the field. The lower-right quadrant highlights basic yet underdeveloped topics, including “renewable energy” and “electric propulsion”, which, while foundational, remain at an early stage of research but are likely to gain prominence as the sector pursues decarbonisation. The lower-left quadrant encompasses emerging or declining themes, including “life cycle assessment”, “automatic identification system”, “circular economy”, and “recycling”. Although currently limited in both development and centrality, these topics, particularly “life cycle assessment” and “circular economy”, are beginning to attract greater scholarly attention and are expected to become more central as sustainability and resource efficiency rise in priority.

This analysis revealed a research landscape defined by well-established foundations and emerging opportunities. Core themes such as vessel operations, fisheries governance, and environmental regulation remain dominant. There is clear evidence of a strategic shift toward data-driven systems, clean energy solutions, and lifecycle-based approaches. The growing use of AI and digital technologies highlights a future trajectory toward smart vessel innovations, offering a roadmap for aligning academic research with the needs of policymakers and industry stakeholders to advance sustainability transitions and regulatory compliance.

The included studies varied widely in design, from simulation-based analyses and case studies to experimental trials, with most being peer-reviewed and empirically grounded. Although no formal risk-of-bias tool was applied, common limitations such as small sample sizes, reliance on modelling without field validation, and selective reporting were noted. No statistical syntheses or meta-analyses were undertaken, as the review focused on qualitative and descriptive mapping. Heterogeneity was examined narratively, and no sensitivity analyses were conducted due to the descriptive scope of the review.

3.3. Characterisation of Innovations in Sustainable Fishing Vessels

3.3.1. Functional Areas of Innovation

To systematically assess technological developments in sustainable fishing vessels, this study classifies the innovations reported in the literature into ten functional areas. This classification was developed through inductive coding and thematic grouping of the relevant studies. As illustrated in Figure 8, the frequency of studies within each area varied from 2020 to 2024, reflecting evolving research priorities and emerging technological trends. The most frequently addressed domains were “smart vessel systems and digitalisation” (31 articles), followed by “propulsion and energy systems” (16 articles), and “LCA and circular economy integration” (15 articles). These three categories represent key areas in which digital technologies, energy transitions, and lifecycle thinking converge to redefine modern fishing operations.

Table 3. Distribution of reviewed articles by functional innovation area.

Functional Area Addressed	Subtopics/Focus	Key Innovations/Technologies Identified	No. of Articles
Design Optimisation and Retrofitting	- Green retrofitting - Energy-saving design modifications	Evaluate and enhance the operational efficiency; Retrofitting fishing carriers to meet International Maritime Organization (IMO) energy efficiency regulations; Retrofitting older fishing vessels through refrigeration system upgrades using R290 (propane)/R744 (carbon dioxide) and R717 (ammonia)	3
Fishing Technology and Selectivity	- Fishing gear/equipment - Bycatch reduction - Catch/fish identification	Flashing LED NetLights to reduce bycatch; Bycatch reduction and target species efficiency; Gear design for selective fishing	10
Hull Design and Material	- Hull construction - Hull coating - Anti-fouling systems	Eco-friendly antifouling agents; Laminated bamboo as a sustainable alternative for hull materials; Alternative structural materials	4
LCA and Circular Economy Integration	- Life cycle assessment - Recyclability of materials - Circular design approach	Life Cycle Assessment (LCA) of fishing vessels and operations; Carbon footprint and GHG (Greenhouse Gas) emissions analysis; Fuel consumption and energy performance evaluation; Alternative fuels and decarbonisation pathways (e.g., liquefied petroleum gas (LPG), Bio-LPG); Plastic waste mitigation and gear recycling (including MFA); Environmental and socio-economic impact indicators for fleet evaluation	15
Labour and Social Welfare	- Labour protection - Seafarer rights - Working conditions onboard	Integrated tool system for detecting labour exploitation	1
Policy, Economic, and Cultural Aspects	- Regulatory frameworks - Economic incentives - Local wisdom / Indigenous knowledge	Socio-economic and cultural dynamics in fishing communities; Policy frameworks and regulatory interventions (e.g., gear bans, total allowable catches, Vessel Monitoring System (VMS)); Co-management, local governance, and fisher-scientist collaboration; Economic efficiency and technology adoption impacts; Gender perspectives and livelihood transitions	13
Post-Harvest Handling Systems	- Fish preservation systems - Fish processing onboard	Deep learning for detecting and estimating the weight of discarded fish; Natural refrigerants and integrated energy systems	2
Propulsion and Energy Systems	- Engine type - Fuel efficiency - Alternative fuels - Renewable energy - Emission reduction	Electric and hybrid propulsion systems (including AI-based control and HENSUS tool); Solar PV systems for main and auxiliary power; Wind, hydrogen, and micro-hydro energy integration; Alternative fuels (e.g., methanol, marine gas oil, heavy fuel oil, LNG); Renewable-powered energy grids and transition strategies; Cryogenic cooling from LNG for fish preservation	16
Safety and Risk Management	- Safety analysis - Vessel stability - Fire prevention - Emergency procedures	Safety enhancement and accident prevention strategies; Risk assessment and prediction frameworks; Risk-based inspection (RBI) for alternative-fuel vessels; Standardisation of accident reporting and classification methods	10
Smart Vessel Systems and Digitalisation	- Vessel monitoring - Communication - Global positioning system (GPS)/tracking - Navigation - Internet of Things (IoT)	AI and machine learning for fishing behaviour analysis, route optimisation, and anomaly detection; Deep learning and computer vision for species classification and catch monitoring; IoT systems integrating GPS, global system for mobile communications (GSM), and sensors for vessel tracking and real-time alerts; Digital monitoring tools, electronic logbooks (eLog), and remote sensing; AIS trajectory analysis and spatial analytics for effort estimation and illegal fishing detection; Mobile and onboard systems for real-time data reporting and image-based identification	31

provides a detailed breakdown of each functional area, including the representative subtopics and the key innovations or technologies identified. For instance, studies on smart vessel systems and digitalisation have explored the integration of AI, computer vision, IoT-based tracking, and real-time monitoring systems to enhance vessel performance, regulatory compliance, and fishing efficiency. Similarly, the Propulsion and Energy Systems category includes electric and hybrid propulsion, solar and wind energy integration, and advanced fuel options such as methanol and liquefied natural gas (LNG), highlighting the industry’s gradual shift toward decarbonisation.

In the domain of “LCA and circular economy integration”, research has primarily focused on LCA, carbon footprint evaluation, and plastic waste mitigation, offering comprehensive insights into the environmental impacts of fishing vessels. Meanwhile, “policy, economic, and cultural aspects” (13 articles) addressed issues such as regulatory frameworks, socio-economic impacts, and traditional knowledge, underlining the importance of inclusive governance and the local context in technology adoption.

Other areas, although less frequently discussed, remain significant. For example, “fishing technology and selectivity” (10 articles) concentrated on bycatch reduction tools and gear innovations, whereas “safety and risk management” (10 articles) examined risk assessment frameworks and safety enhancement strategies. “Hull design and material, post-harvest handling systems”, “design optimisation and retrofitting”, and “labour and social welfare” were also addressed, albeit with fewer studies, reflecting more specialised or emerging research niches.

3.3.2. Technology Readiness Level Distribution

A wide range of maturity levels is observed across technological innovations in sustainable fishing vessels, as measured by the TRLs. Among the 105 articles analysed, the majority (68 studies) fell within the TRL 4–6 range, which corresponds to the stages of component validation, prototype testing, and system demonstration. A further 31 articles reported innovations at TRL 7–9, indicating technologies that have reached the level of operational validation or are close to commercial deployment. By contrast, only six articles fell into the early-stage TRL 1–3 category, reflecting conceptual research and laboratory-scale testing.

As shown in Figure 9, the innovation types exhibit distinct TRL distributions. “Smart vessel systems and digitalisation” dominate the TRL 6 level, with 16 studies, and remain significant at TRL 5, 7 and 8, highlighting their relatively fast transition from pilot studies to field applications, particularly for monitoring systems, machine learning models, and real-time data analytics. Similarly, “LCA and circular economy integration” appeared across mid to high TRLs, with a notable presence at TRL 9, reflecting their methodological maturity and integration into broader sustainability assessments.

In contrast, technologies related to “propulsion and energy systems” are concentrated mainly in TRL 4–6, indicating that while alternative fuels and hybrid propulsion systems are under development, they have yet to be widely implemented in practice. Emerging concepts in “safety and risk management” and “fishing technology and selectivity” appear at both early and mid-TRLs, suggesting ongoing experimentation and refinement of novel systems for reducing operational risks and improving gear selectivity.

Overall, the distribution of TRLs indicates that while digital and analytical technologies are rapidly advancing toward deployment, physical vessel modifications, particularly in propulsion and structural systems, continue to face challenges related to scalability, cost, and infrastructure. The dominance of TRL 4–6 studies further underscores the transitional state of the field, where many innovations are beyond theoretical exploration but are not yet ready for full-scale adoption.

3.3.3. Sustainability Dimension Coverage

Assessing the distribution of sustainability dimensions in the reviewed literature is critical for understanding how technological innovations in fishing vessels align with broader developmental goals. The synthesis of these dimensions helps identify where research efforts are concentrated, where gaps persist, and how well current innovations address the interrelated challenges of ecological impact, economic viability, and social equity. The findings reveal that, while there is a gradual shift toward multidimensional sustainability frameworks, the emphasis remains imbalanced across the environmental, economic, and social pillars.

Environmental sustainability is the most frequently addressed dimension, appearing either independently or in combination in the majority of the reviewed articles. Specifically, 36 articles focused exclusively on environmental aspects, such as emission reduction, fuel efficiency, and marine ecosystem preservation. In addition, 25 articles integrated environmental and economic considerations, while 13 addressed both the environmental and social aspects. A significant subset of the 22 articles adopted a comprehensive, three-dimensional sustainability approach that simultaneously considered environmental, economic, and social issues. By contrast, social sustainability remained underrepresented when considered in isolation, appearing as the sole focus of only nine articles.

This distribution is illustrated in Figure 10, which presents a Venn diagram of sustainability dimension coverage. The visual highlights that approximately two-thirds of the reviewed literature includes environmental sustainability as a core focus, either as a standalone dimension or in conjunction with others. The growing number of integrative studies that address all three pillars suggests a gradual evolution toward more holistic sustainability frameworks in recent years.

The temporal trends, shown in Figure 11, further reinforce this shift. From 2020 to 2022, most studies concentrated on a single sustainability dimension, primarily environmental. However, from 2023 onwards, there has been an apparent increase in the number of studies addressing multiple dimensions. Notably, in 2024, eight publications applied a full three-pillar sustainability lens, compared to one in 2021, while studies integrating two dimensions became more common. This progression reflects a maturing research agenda that is increasingly oriented toward capturing the interdependencies among ecological sustainability, economic viability, and social equity in fishing vessel innovation.

3.3.4. Geographic Distribution of Innovations

The geographical coverage of sustainable fishing vessel innovations spans multiple regions, reflecting diverse efforts to enhance the environmental, economic, and operational performance across the fisheries sector. This classification is based on the operational context of the fishing fleets studied rather than on the authors’ national affiliations. While several studies include multi-national settings, others lack explicit geographical references. Such differentiation provides a more accurate picture of where innovations are actively trialled or applied.

Figure 12 compares the geographical distribution of case studies with the types of technological innovations addressed, presenting data from the ten most frequently represented countries in the reviewed literature on sustainable fishing vessels. Norway and Indonesia led 16 and 15 studies, respectively. Norway demonstrates a balanced focus across LCA and CE, policy, propulsion systems, and digitalisation, reflecting a comprehensive national approach to vessel sustainability. Indonesia’s contributions are concentrated in smart vessel systems and fishing technology, highlighting efforts to improve operational efficiency within its predominantly small-scale fleets. China and Spain each appear in nine studies, with China primarily focusing on digitalisation and Spain exhibiting balanced attention to digital systems and LCA. India also featured nine articles largely centred on smart technologies. Croatia, in eight studies, was active in propulsion and energy systems. Denmark, Taiwan, Turkey, and the United States contribute fewer but focused studies, each addressing specific priorities such as fishing technology, safety, and smart vessel digitalisation, aligned with their respective maritime development contexts.

Figure 13 presents the same ten countries, focusing on the distribution of TRLs. Most countries exhibit a concentration of innovations within the TRL 4 to TRL 6 range, representing systems at the prototype testing or demonstration stages. Indonesia shows a particularly high concentration at TRL 5, corresponding to field testing of selective gear and small-scale hybrid systems. Norway stands out for its presence in both TRL 6 and TRL 7, suggesting more mature operational technologies, particularly in digital monitoring and energy optimisation. Countries such as China, Spain, and India also contribute to these mid-TRLs, reflecting the ongoing efforts to translate conceptual innovations into field applications. Notably, TRL 9, indicating full deployment and operational use, was observed in only a few countries, including Indonesia, Norway and Turkey, highlighting the limited number of technologies that have reached commercial maturity across the reviewed studies.

3.3.5. Circular Economy Integration

To assess the extent of CE integration within fishing vessel research, each reviewed article was classified into three levels of relevance: high, moderate, or low/not specified. This categorisation was based on content analysis of the articles’ main texts and abstracts. Articles were deemed highly relevant if they explicitly addressed CE principles, such as material recycling, upcycling, circular product design, or end-of-life (EOL) strategies. Moderate relevance was assigned to studies that indirectly contributed to CE through energy efficiency, renewable energy adoption, or operational optimisation. The Low/Not Specified category includes articles with no discernible reference to CE principles.

Table 4. Classification of Reviewed Articles Based on Circular Economy Relevance.

Levels of Relevance to CE	CE Principles Discussed	No. of Articles
High	Recycling and upcycling (e.g., gear, nets) Use of biodegradable materials and bio-based antifouling End-of-life circularity (reuse, repair, recycling of vessel components) Operational efficiency indirectly supports circularity	16 Articles
Moderate	Renewable energy integration (solar, wind, hydrogen, LNG) Fuel and energy efficiency; refrigeration and propulsion system upgrades Retrofitting for life extension Smart tools for monitoring and discarding minimisation Material substitution (e.g., biocompatible gear) Knowledge retention (e.g., intergenerational craft skills, offboard battery reuse) Indirect CE policy mechanisms (e.g., buyback schemes, carbon tax incentives)	50 Articles
Low/Not Specified	No explicit or meaningful discussion of CE concepts	39 Articles

summarises this classification, outlining the specific CE principles discussed in the reviewed articles and the number of studies in each category.

The dominance of articles in the moderate relevance category (50 of 105) suggests that CE-related considerations are gaining traction, albeit not yet fully integrated into vessel design or end-of-life frameworks. Many of these articles focus on decarbonisation, energy transition, and system optimisation, which, while environmentally beneficial, do not necessarily reflect closed-loop material flows.

By contrast, only 16 articles (15%) demonstrated a high level of integration with CE principles. Examples include studies that proposed biodegradable fishing gear, examined the recyclability of vessel components, and evaluated end-of-life strategies, such as material recovery and reuse. For instance, one study analysed the circular use of refrigerants and another focused on gear upcycling in artisanal fleets.

Conversely, 39 articles (37%) did not mention CE concepts, reflecting a persistent gap in aligning technological innovation in the fishing sector with systemic circulation. This highlights the need for future research to move beyond efficiency and more explicitly incorporate whole lifecycle thinking, reuse strategies, and circular design principles.

4. Discussion

4.1. Functional Areas of Technological Innovation for Sustainable Fishing Vessels

The reviewed literature demonstrates extensive technological innovations across multiple domains, including hull structure, propulsion, energy management, fishing gear, post-harvest systems, and digital infrastructure, all geared toward enhancing vessel sustainability. These innovations reflect a systemic approach that aligns technological upgrades with broader environmental and socio-economic objectives. Retrofitting existing vessels, particularly ageing fleets, has proven effective, achieving fuel efficiency improvements of 20–26% through hull optimisation and advanced refrigeration systems using natural refrigerants such as CO₂ and ammonia [15,16]. These retrofits provide practical sustainability pathways for fleets that cannot afford to invest in complete vessel replacements.

Innovations in fishing technology have notably improved selectivity and reduced ecological disruption. Examples include midwater trawl doors and bycatch excluder devices, designed to minimise seabed contact and fuel usage [17]. The Restriction, Modernisation, and Innovation framework further encourages transitions toward less invasive fishing methods, reflecting context-dependent adaptation based on target species, vessel specifications, and regulatory constraints [17,18]. Hull design innovations focus on sustainable materials, replacing traditional wood with steel or laminated bamboo composites because of their superior strength-to-weight ratios and lower environmental impacts [19]. Concurrent advancements in antifouling technologies, including eco-friendly biocides such as phlorotannins, have addressed biofouling challenges linked to fuel inefficiency and invasive species transmission [20,21].

LCA has become integral to evaluating environmental performance and integrating CE principles into vessel design. Studies have consistently highlighted operational fuel consumption as a primary environmental factor. However, broader CE applications beyond gear recycling remain underexplored [22,23]. Policy frameworks and economic incentives significantly influence the adoption of sustainable technology. International climate agreements and regulatory measures such as the IMO’s EEDI, SEEMP, and EEXI increasingly shape low-carbon practices, although challenges remain for smaller vessels [24,25,26]. Addressing the absence of cultural and indigenous knowledge in these transitions could enhance local relevance and acceptance of sustainable innovations.

Labour, social welfare, policy, economic, and cultural dimensions are closely interlinked in shaping the sustainability of fishing vessels. Fishing remains one of the most hazardous occupations, with high fatality rates arising from factors such as confined workspaces, fluctuating gear tension, fatigue, and unsafe practices. Strengthening awareness and implementing safety regulations tailored to fishing vessels are essential steps [27,28]. Labour costs, often the largest operational expense, directly affect profitability, fishing effort, and technology adoption, while indicators such as employment levels, wages, and the roles of women in small-scale fisheries value chains contribute to social sustainability and poverty reduction [24,29]. At the same time, international agreements, IMO measures, and the Common Fisheries Policy shape low-carbon practices, though smaller vessels are frequently excluded [24,30]. Cultural heritage, including traditional boatbuilding and fishing knowledge, further informs management measures, underscoring the need for integrated approaches that balance ecological, economic, and social objectives.

Post-harvest innovations focus on maintaining product quality and extending shelf life through improved refrigeration systems utilising natural refrigerants, which aligns with evolving environmental regulations [15,31]. Integrating heating and cooling processes, such as waste heat recovery, further enhances overall energy efficiency [31]. Propulsion and energy systems are pivotal for reducing emissions. Innovations include transitioning to cleaner fuels (such as hydrogen, LNG, biodiesel, and ammonia), hybrid propulsion systems, and the integration of renewable energy. Infrastructure developments, such as renewable-powered charging stations and sail-assisted technologies, have complemented these efforts [15,25,26,32].

Digitalisation and smart vessel systems have become the most prominent areas of innovation in the reviewed literature, with publication trends steadily increasing from 2020 to 2024. This trajectory underscores the central role of artificial intelligence (AI), particularly through machine learning and deep learning approaches, in the context of fishing vessels. AI enables data-driven optimisation in vessel design, particularly hull optimisation through surrogate modelling and generative techniques such as diffusion models, achieving drag reduction and improved energy efficiency [33,34]. Applications further extend to optimising hydrodynamic performance and hull forms, supporting early design estimates, enhancing component and structural optimisation, stability assessment, resistance prediction, and integration with advanced computing [35]. However, despite these potentials, explicit discussions of AI’s role in vessel design remain relatively limited, as most of the reviewed literature focuses on operational rather than design applications.

Most studies emphasise AI’s contribution to operational improvements. Digitalisation supports real-time monitoring, decision-making, and precision fishing through technologies such as VMS, AIS, and remote sensing [18,36,37]. AI enhances sustainability by reducing emissions and operational costs through data-driven optimisation [36]. Operational efficiency is strengthened through fuel prediction and reinforcement learning for route planning [38,39], while catch forecasting reduces search times and bycatch [40,41]. Onboard systems for fish identification and sizing improve compliance and stock assessment [42,43]. AI also underpins condition-based maintenance and supports the optimisation of hybrid power systems and charging infrastructures for vessel electrification [44]. The practical application of these operational technologies demonstrates their potential for sustainability, providing a bridge to the broader outcomes of technological adoption.

The application of new technologies shows potential benefits for sustainability in fishing vessels. Alternative fuels such as methanol and LNG reduce emissions, while hybrid propulsion, solar PV, hull optimisation, and advanced refrigeration increase efficiency [16,45]. Selective fishing gear reduces bycatch and discarded catches, thereby improving ecological sustainability and catch value [46,47]. In practice, digitalisation also delivers measurable outcomes, with AI-based applications supporting route optimisation, which translates into reduced CO₂ emissions and lower operational costs [40,48]. Collectively, these innovations demonstrate that technological adoption can simultaneously lower operating expenses, improve profitability, and align ecological and economic goals [29,49].

Safety and monitoring capabilities also advance through the integration of innovative frameworks. The implementation of machine learning and IoT-based systems supports accident prevention, real-time alerts, and predictive maintenance, thereby improving operational resilience [48,50]. Electronic Monitoring Systems, VMS data, and satellite-based remote sensing expand surveillance, improve traceability, and strengthen regulatory compliance [51,52]. Digitalisation enables the integration of sensors and monitoring systems on board vessels, allowing for the prediction of fuel consumption, emission control, and fisheries data collection [36,42]. Although these innovations offer significant improvements in sustainability, efficiency, and safety, they still face challenges such as high initial costs, the need to adapt regulations, and securing fisher acceptance to ensure successful implementation.

4.2. Dimensions of Sustainability Addressed in the Literature

Technological innovations in fishing vessels increasingly respond to sustainability imperatives, although the depth and integration of environmental, economic, and social dimensions vary significantly. This subsection examines how these sustainability pillars are represented in scholarly studies and highlights the trends, gaps, and future directions.

Environmental sustainability dominates the reviewed literature, primarily focusing on reducing greenhouse gas (GHG) emissions through decarbonisation. Studies have extensively explored alternative fuels, such as methanol, hydrogen, bio-LPG, and biodiesel, alongside vessel electrification and hybrid propulsion systems [16,26,53]. LCA methods frequently identify fuel consumption as a key environmental impact [22,24]. Digitalisation, particularly onboard monitoring systems, further enhances environmental performance by optimising fuel use [36]. However, technological adoption remains limited among small-scale operators due to high capital costs and inadequate regulatory frameworks, underscoring the need for inclusive and scalable solutions [46].

The ecological impacts beyond emissions, such as overfishing, habitat disruption, and bycatch, have also been widely addressed. Innovations, including selective gear and machine learning-based tools for species recognition, are needed to mitigate ecosystem pressures [42,54]. Comparative studies have reinforced the importance of context-specific assessments, revealing substantial differences in sustainability performance among fishing methods [17]. Nonetheless, waste and pollution management, particularly marine debris and biofouling prevention, requires broader methodological application [20,55].

Economic sustainability centres on operational efficiency and long-term profitability, focusing predominantly on reducing fuel costs through energy efficiency, retrofitted marine technologies and digital route optimisation [30,36,56]. Lifecycle Cost Assessment provides insights into the economic viability of innovations, although few studies have explicitly quantified savings in maintenance or vessel lifespan extension [24,57]. Selective fishing gear and improved post-harvest handling contribute positively to catch value and profitability, despite ecological trade-offs [43,58]. Structural barriers such as capital access, fluctuating fuel prices, and misaligned subsidies limit profitability and resilience, highlighting the need for innovative finance models for artisanal fisheries [29].

Social sustainability, although critical, is the least represented dimension. Fisher safety remains central, given the high fatality rates of commercial fishing [59]. Advanced analytical methods, such as Bayesian networks, increasingly identify accident causes and preventive strategies; however, safety frameworks often neglect small-scale vessels [48,60]. Additionally, the absence of standardised accident reporting hampers effective risk management [27,61]. Labour conditions, workforce demographics, and gender equity also remain underexplored, despite growing concerns over exploitation, an ageing workforce, and insufficient onboard living conditions [24,38]. Addressing these gaps requires cross-disciplinary collaboration and targeted capacity-building initiatives to ensure an equitable and holistic sustainability.

Overall, the reviewed literature demonstrates an increasing methodological sophistication in addressing sustainability challenges. However, substantial implementation challenges persist, particularly concerning the integration of social sustainability measures and equitable technological adoption. Future research should develop holistic frameworks and integrated metrics that can simultaneously advance environmental, economic, and social sustainability in fisheries.

4.3. Technology Readiness Levels and Implementation Status

Technological readiness critically influences the implementation of sustainability innovations in fishing vessels. Most reviewed technologies are situated in mid-range TRLs, notably TRL 6 (operational demonstrations) and TRL 5 (prototype validation), indicating an ongoing transition from conceptual phases to broader field testing. However, many have not yet reached commercial deployment. Innovations at these levels, including selective gear modifications, electrification, and AI-based monitoring, often lack market standardisation [23,29]. Only a limited number of studies have reported fully integrated, commercially proven technologies (TRL 8–9), such as lifecycle carbon assessments and carbon tracking platforms [17,62]. Established technologies such as AIS, VMS, electronic logbooks, and bycatch mitigation devices have widespread adoption, yet conventional, less environmentally friendly refrigeration systems persist owing to cost and familiarity [31].

Progress through TRLs faces multiple barriers, including regulatory drivers, technical constraints, and economic challenges. Environmental policies accelerate innovation, but the lack of standardised datasets and operational challenges in real-world conditions constrain the implementation of emerging technologies, such as AI [42,63]. High upfront costs limited retrofit compatibility, and insufficient infrastructure further hindered adoption, compounded by social resistance due to privacy concerns or mistrust [36,64]. These factors highlight the need for integrated context-sensitive roadmaps.

The regional context significantly shapes TRLs’ progression, with developed maritime nations such as Norway, Japan, Spain, and the United States primarily associated with higher TRLs (7–9), supported by robust innovation ecosystems and regulatory frameworks. In contrast, developing countries face structural constraints, including limited funding, fragmented governance, and weaker regulatory enforcement, often confining technologies to TRL 4–6. Large-scale operations more readily adopt innovations, such as hybrid propulsion and digital technologies, whereas small-scale fisheries (SSFs) encounter significant barriers, including retrofit costs and institutional mistrust, which limit even basic system adoption.

Economic considerations critically affect the scalability and adoption of sustainable technologies. Innovations, such as vessel electrification and selective gear modifications, offer long-term economic benefits through fuel cost reductions and improved catch value [17,38]. However, high initial investments, complex technical integration, and operational constraints limit their broad adoption, particularly in small-scale fisheries (SSFs) [30]. Limited access to suitable financing mechanisms exacerbates these barriers, particularly in developing regions. Addressing these financial gaps through targeted instruments such as microcredit, public–private partnerships, and market incentives could significantly enhance technology adoption and commercial viability [31,65].

Advancing sustainable fishing vessel technologies from intermediate TRLs to full-scale deployment requires overcoming interconnected technical, financial, and institutional barriers. Stakeholder collaboration, compliance frameworks, and suitable financing instruments are essential for bridging this gap and aligning innovation pathways with sector-specific operational and socio-economic contexts. Equally important is the training of specialists capable of effectively operating and maintaining these new technologies. Successful integration of innovations depends not only on technical readiness but also on well-structured training, education, and capacity development.

The literature emphasises various training methods and global best practices that support this transition. ISSF Skippers Workshops exemplify participatory knowledge exchange, combining scientific expertise with fishers’ experiential insights to promote gear selectivity, bycatch reduction, and conservation [58]. Scalable “train-the-trainer” models, successfully applied in Indonesia and extended to longline fisheries, expand reach in geographically dispersed contexts, while localised gear-specific training in France has facilitated the adoption of new technologies such as the Danish seine [49]. Targeted initiatives like Norway’s CoolFish project and training programmes in Oman further demonstrate the importance of knowledge transfer for energy-efficient refrigeration and fuel-saving practices [31,62]. Beyond initial instruction, continuous support, participatory policy frameworks, and international certification standards strengthen adoption while addressing skill gaps in marine engineering, alternative fuels, and safety [28,29]. Integrating traditional knowledge and ICT-based analyses also reinforces adoption and local ownership [66]. Preparing fishing specialists is thus a dynamic and context-specific process, requiring participatory strategies that align human capacity with technological, environmental, and socio-economic objectives.

4.4. Integration of CE Principles

CE principles are increasingly being recognised as vital for advancing sustainability. While the fishing vessel sector has historically lagged in circularity compared to other maritime industries, the recent literature reveals a growing interest in both conceptual and operational integration. This section synthesises the findings across three themes: resource efficiency and waste minimisation, life cycle thinking, and value retention and recovery.

Resource efficiency efforts in fishing vessel operations have mainly focused on fuel consumption and gear management. Abandoned, Lost, or Otherwise Discarded Fishing Gear (ALDFG) has been identified as a significant contributor to marine debris, with gear types such as purse seines and Danish seines exhibiting higher recyclability than gillnets or longlines [23]. Material Flow Analysis in Norway estimates 300 tons of plastic gear waste annually [55]. Policy instruments such as the EU Circular Economy Action Plan and Extended Producer Responsibility (EPR) schemes have emerged as key drivers, yet domestic recycling capacities remain limited [67]. Similarly, fuel efficiency is a critical area for reducing emissions and costs, with strategies including hull and propulsion optimisation and the adoption of alternative fuels or hybrid propulsion systems. However, the design of durability or onboard closed-loop systems remains largely underexplored [68].

LCA plays a central role in aligning vessel innovation with CE goals by assessing the cradle-to-port impacts. Studies have consistently shown that fuel consumption during operation accounts for more than 90% of the total environmental burden [22,26]. Alternative fuels and hybrid propulsion technologies offer significant mitigation potential [46]. Although vessel renewal is sometimes proposed, systemic strategies focusing on fuel efficiency and operational design yield more effective results. Although the end-of-life impacts are smaller, material recovery (e.g., steel and wood) is essential for closing loops [68]. Broader adoption of LCA approaches that incorporate economic and social metrics would further enhance circular assessments [24].

Value retention is primarily addressed through fishing gear recycling and, to a lesser extent, through digital monitoring tools that optimise operational inputs. Initiatives to recycle gear materials such as polypropylene and nylon, though hampered by limited domestic capacity, illustrate growing momentum [55]. Circular business models, such as recycling discarded tuna purse-seine nets, highlight viable paths for material recovery [67]. Nonetheless, remanufacturing of vessel components and reuse-oriented system design remain largely absent from the literature. Similarly, the onboard processing of fishery by-products and the recovery of waste are underexplored, despite their potential to support circularity. Technologies such as predictive energy management and real-time monitoring indirectly support circular objectives with improved efficiency [36].

While the literature reflects the promising integration of CE principles in the operational and end-of-life phases, key gaps persist in vessel-level designs, particularly in terms of durability, remanufacturing, and integrated waste recovery systems. Strengthening these dimensions is essential for advancing next-generation fishing vessels aligned with the circulatory and decarbonisation goals.

4.5. Technical Dimensions of Fishing Vessel Innovation

Innovations in fishing vessels have so far mainly focused on sustainability outcomes, including emission reductions, improved operational efficiency, and enhanced safety. However, the reviewed literature also indicates that technical design aspects are increasingly being considered, although with varying levels of scope and depth. The development of vessel design is strongly influenced by the need for sustainability, which involves striking a balance between technological advancement, economic viability, and environmental responsibility. In this context, several technical features are experiencing significant innovation.

Determining the suitable size of a fishing vessel is a fundamental design factor, affecting operational capacity, economic efficiency, environmental impact, and safety standards [17,29,69]. Vessel size is closely linked to fishing methods, target species, and geographical locations. Larger vessels provide greater range and catch capacity, but they also require more fuel and increase the risks of over-exploitation when capacity exceeds quotas [22]. Conversely, small-scale vessels under 7 GT, such as those in Indonesia, remain essential to local economies and are increasingly being targeted for electrification initiatives [70]. Significantly, scale goes beyond physical size to include quota allocation, regulatory requirements, and ecological constraints. Norwegian rules enforce stricter compliance on ships over 80 m, and accident studies confirm length as a safety factor [27,46]. Thus, defining scale requires a multi-criteria approach that balances efficiency, compliance, and conservation to ensure sustainable use of resources.

The next crucial decision is selecting the engine horsepower and propulsion system, as these affect capacity, fuel efficiency, emissions, and safety. Fishing vessels generally allocate 70–75% of their energy to propulsion, with the remaining 25–30% used by auxiliaries such as refrigeration, illumination, and net hauling [36]. While higher horsepower enhances range and resilience, it also increases fuel use, CO₂ emissions, and accident risks [17,22]. Diesel engines remain dominant, but sustainability pressures are increasing interest in hybrid and electric systems. Diesel-electric configurations with smaller diesel units, electric motors, and batteries enhance efficiency across various operational modes, particularly in low-speed operations where diesel engines tend to be less efficient [44]. These developments highlight the trade-offs between performance, emissions, and safety, naturally leading to considerations of vessel profile design.

The optimisation of fishing vessel profiles extends beyond aesthetics to encompass hydrodynamic efficiency, stability, spatial use, and sustainability. Hull form is critical, as reducing resistance directly cuts fuel consumption and environmental impact [26]. Modern design employs tools for lines plan development [70], alongside alternative materials such as laminated bamboo composites, which offer sustainable and low-cost solutions with favourable mechanical properties [19]. Digitalisation enables real-time monitoring, supporting models for fuel prediction, route planning, and species distribution, while numerical methods help track biofouling to maintain hull efficiency [36]. Profile design must also accommodate space for fishing gear and on-board processing facilities, as handling, chilling, and freezing significantly impact product value [31,71]. Increasingly, route optimisation is viewed as a multi-objective challenge that balances fuel consumption, catch requirements, and safety. These considerations highlight how profile optimisation integrates hydrodynamic, structural, and operational factors in pursuit of sustainability.

Overall and detailed design in fishing vessels are closely interconnected, forming a continuous process where high-level decisions influence technical specifications, and detailed results feedback to refine broader concepts. Overall design determines vessel dimensions, layout, propulsion type, and mission profile, while detailed design translates these into concrete solutions such as battery layouts, LNG pipelines, fishing gear, or digital sensors [36,45,54]. Feedback from detailed design can lead to revisions of overall strategies. This linkage shows that sustainable vessel performance depends on continuous interaction between overall concepts and detailed engineering.

The transition to new energy fishing vessels signals the beginning of efforts to reduce emissions and reliance on fossil fuels. Research highlights methanol, LNG, biofuels, and hydrogen, each with technical challenges such as cryogenic storage for LNG or high costs and safety issues for hydrogen [26,32,45]. Hybrid and diesel-electric systems with batteries are developing, while fully electric vessels connected to renewable grids are an emerging alternative [30,72]. Batteries are central, requiring optimisation of size, charging, and regenerative energy recovery [73]. Complementary measures include solar PV for auxiliary power, energy-efficient refrigeration with natural refrigerants, and waste heat recovery [15,31]. Hull optimisation and advanced monitoring systems further reduce energy demand and improve reliability [16]. These technical aspects illustrate the move towards more sustainable and economically viable fleets.

Balancing economic, technological, and environmental considerations remains a central challenge in fishing vessel design. Profitability depends on reducing major costs such as fuel and labour [22,29], while digital tools like route optimisation and fish-finding reduce searching time and emissions [38,39,40]. However, environmentally friendly technologies often involve high initial costs, requiring long-term returns or policy incentives [26,29,44]. Technological advances provide efficiency and emission reduction benefits, though they are limited by integration complexity and uneven practicality. Environmental imperatives, supported by global climate agreements and policies such as the Common Fisheries Policy, drive reductions in carbon footprints, bycatch, and seabed damage, supported by gear innovations [71,74]. Tools including LCA and Fishery Performance Indicators integrate ecological, economic, and social dimensions to identify context-specific solutions. The technical dimensions of fishing vessel innovation thus demonstrate that sustainable fisheries require integrated design approaches that connect environmental stewardship, economic resilience, and technological feasibility.

4.6. Research Gaps and Future Directions

Although research on sustainable fishing vessel technologies has expanded in recent years, several critical gaps remain across the thematic, methodological, and implementation domains. These gaps hinder a comprehensive understanding of innovation in this sector. Technical advancements have occurred in various areas, but key subsystems such as waste recovery, ergonomic design, and circular vessel architecture remain insufficiently explored. For example, laminated bamboo composites offer promise for sustainable hull construction [19]. However, validation studies on water absorption, durability under marine exposure, and joint configurations are still lacking. Similarly, although natural biocides such as phlorotannins demonstrate potential as eco-friendly antifouling agents [21], their performance under real-world operating conditions has not been sufficiently evaluated.

Alternative propulsion systems and fuels, including hydrogen, LNG, biodiesel, ammonia, and LPG, are in their early development stages (TRLs 1–3), with limited design standards, operational data, and infrastructure support. In particular, hydrogen lacks probabilistic failure models and field-based risk assessment. Although vessel electrification has progressed in pilot-scale studies [44], scaling up remains difficult owing to the high energy demands, limited charging infrastructure in remote areas, and insufficient analysis of long-term battery degradation and maintenance needs. Emerging innovations, such as regenerative energy recovery from winches or cryogenic cold recovery in LNG propulsion, are promising but remain largely theoretical.

In the context of fishing gear, circular design principles, such as reparability, modularity, and extended product lifespan, are seldom applied. Tools such as NetLights and Juvenile and Trash Fish Excluder Devices (JTEDs) hold ecological potential, and further field trials are required to assess their operational impacts, debris interference, and selectivity. The durability and recyclability of biodegradable gear materials, especially the fastening strength of ropes, are yet to be systematically assessed. Post-harvest systems also lack adequate research, particularly concerning the onboard valorisation of fish by-products such as viscera and frames. This area has the potential for waste minimisation and value creation, especially in SSFs with limited shore-based processing facilities.

Beyond technical gaps, the literature often overlooks human-centred and socio-cultural dimensions. Ergonomics, habitability, and occupational health are rarely integrated into vessel design despite their importance for crew well-being and retention. Gender roles in post-harvest activities and intergenerational knowledge transfer are underrepresented in both policy and academic discourse. Likewise, indigenous ecological knowledge systems, such as the Lombada tradition, remain marginalised despite offering culturally embedded and ecologically sound practices for vessel operation and design.

Methodological limitations further constrain evidence-based research. Many studies rely on small sample sizes, such as single-vessel case studies, which limits their generalisability. Simulation-based approaches are often disconnected from field validation, particularly in the assessment of wind propulsion, hydrogen systems, or solar-powered equipment. Self-reported data and expert elicitation introduced subjectivity and memory bias, particularly when long recall periods were involved. These issues are compounded by short study durations that fail to capture seasonal variability or long-term socio-economic transitions.

Data limitations are also prevalent in quantitative modelling and life-cycle assessments. AIS and VMS data often exclude vessels with <30 GT and suffer from signal loss or manipulation. EM systems face technical constraints such as low video resolution and time-intensive manual annotation. LCA studies frequently omit critical phases, including construction, maintenance, and end-of-life treatment, and rarely account for benthic carbon emissions from bottom trawling, leading to an underestimation of climate impacts. Additionally, many LCAs rely on uncertain or non-transparent background data, thus reducing comparability across studies. The lack of integration between LCA and tools such as material flow analysis (MFA) or lifecycle costing further weakens their applicability in CE transitions.

Similarly, the economic dimensions are underexplored. Cost–benefit analyses, business models, and long-term investment scenarios have rarely been addressed in sufficient depth. Studies often rely on aggregated financial data that obscures vessel-level variability. Accident analyses lack standardised frameworks and fail to differentiate between technical and human factors, thus limiting evidence-based policy development. Furthermore, inconsistent sustainability indicators, such as fuel consumption per unit catch or embodied energy, hinder benchmarking, policy transfer, and cross-national comparisons.

Although CE is being increasingly discussed conceptually, its empirical application in vessel design, operation, and end-of-life management remains limited. Most current studies have focused on post-use gear recovery [23], with little attention given to the circularity in hulls, propulsion systems, or integrated onboard waste and energy loops. Strategies such as modular design, reparability, and remanufacturing are rarely addressed, and the valorisation of fish waste into secondary products remains underexplored in real-world contexts. Although LCA is widely used to assess environmental performance, it seldom reflects systemic trade-offs or includes the social and economic dimensions essential for CE thinking.

Barriers to CE integration are multifaceted. Technically, most older vessels are not designed for retrofitting and spatial constraints limit the adoption of modular components or separate waste streams. Economically, fragmented value chains, high capital costs, and limited access to credit deter long-term investments, particularly among artisanal fleets. Socially, adoption is hindered by resistance to digital monitoring, generational disconnection from fisheries, and inadequate recognition of traditional practices. Regulatory barriers also persist; global frameworks, such as those from the IMO, often exclude small vessels, while enforcement in the Global South is hampered by weak institutional capacity and data infrastructure.

Addressing these challenges requires transdisciplinary research and context-sensitive frameworks that reflect the diversity of vessels and operational realities. Future studies should link engineering and materials science to governance, economics, and community engagement. Inclusive collaboration among academia, industry, and fishing communities is essential for developing adaptable design standards that are accessible to small-scale operators. Crucially, the integration of CE principles should move beyond isolated technological innovations and contribute to broader transitions toward equity, ecological resilience, and cultural continuity in the fishing sector.

This review also has limitations related to the review process itself. Firstly, only English-language studies published in peer-reviewed journals and conference proceedings were included, which may have introduced language and publication bias. Secondly, although multiple databases were searched, excluding grey literature and regional reports means some relevant evidence might have been overlooked. Thirdly, no formal risk-of-bias tool was used, which limits the ability to systematically assess the quality of the included studies. These process-related limitations should be considered when interpreting the findings of this review.

5. Conclusions

The systematic literature review conducted in this study explored technological innovations aimed at enhancing the sustainability of fishing vessels. Through a rigorous analysis of 105 peer-reviewed articles published between 2020 and 2024, technological innovations were categorised into ten functional domains, such as propulsion systems, fishing gear, post-harvest handling, and digital monitoring tools. Most innovations were found to focus on environmental sustainability, particularly emissions reduction, energy optimisation, and minimising ecological disturbances through increased gear and vessel efficiency. Meanwhile, the economic and social aspects of sustainability are discussed less frequently, indicating an imbalance in research focus on all facets of sustainability.

An assessment of technological readiness revealed that a large portion of innovations in the literature fall into higher TRL categories, suggesting their maturity and potential for near-term adoption. However, uptake remains constrained by systemic barriers, such as capital costs, policy fragmentation, and institutional capacity, particularly in small-scale and developing fisheries. However, alignment with CE principles, such as waste reduction, lifecycle efficiency, and material reuse, remains partial and largely underexplored, with most studies being limited to energy savings or end-of-life gear recycling.

This review identifies several priorities for future research and practices to accelerate the sustainable transformation of the global fishing fleet. For practice, there is a need to accelerate investment in underexplored areas such as onboard waste recovery, ergonomic vessel design, and remanufacturable components, alongside the deployment of standardised sustainability metrics that enable comparisons across fleets. For policy, appropriate regulatory frameworks, certification schemes adapted to local contexts, and inclusive financing mechanisms are critical to support the adoption of low-emission technologies, particularly among small-scale operators. For research, stronger interdisciplinary collaboration is needed, linking engineering, economics, environmental science, and social studies, while future work should deepen CE integration and adopt more comprehensive life cycle assessments.

Technological advances in fishing vessels alone are not enough to ensure the sustainability of the fishing industry. Vessel designs and systems must meet fishermen’s needs, incorporate local knowledge, and provide equitable benefits to all parties. Circular economy principles should be applied from the beginning of vessel construction until it is no longer in use. All of this needs to be protected by appropriate regulations and certifications tailored to local conditions, so that vessels and fisheries can continue to operate effectively while preserving the ocean for the future. While this review provides a comprehensive synthesis of current innovations, its findings should be interpreted with caution, given the exclusion of grey literature, the restriction to English-language sources, and the lack of a formal risk-of-bias assessment.