A supply chain analysis of artisanal billfish fishery along the Kenyan coast

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A supply chain analysis of artisanal billfish fishery along the Kenyan coast

Damaris Njeri Kinyua

^a,*

, Dalmas O. Oyugi

^a

, Andrew Wamukota

^b

, U. Rashid Sumaila

^c

, Sarah Ater

^d

, Nelly Isigi Kadagi

^e

aPwani University, School of Pure and Applied Sciences, P.O Box 195-80108, Kilifi, Kenya

bPwani University, School of Environmental and Earth Sciences, P.O Box 195-80108, Kilifi, Kenya

cInstitute for the Oceans and Fisheries, The University of British Columbia, 2204 Main Mall, Vancouver, British Columbia, Canada

dTechnical University of Mombasa, Tom Mboya Street Tudor, P.O Box 90420-80100, Mombasa, Kenya

eWorld Wildlife Fund, 1250 24th Street, N.W., Washington, DC 20037-1193, United States

A R T I C L E I N F O Keywords:

Livelihoods Value addition Seasonality Sustainability

A B S T R A C T

The billfish industry in the Western Indian Ocean is multi-sectoral, involving artisanal, commercial and recreational sectors, exploiting billfish for food, income, sports and cultural values. However, billfish catches in the region have been declining with a number of species considered overexploited. To address gaps in sustainable billfish fisheries management, and maximize socioeconomic benefits, we explained the flow of billfish artisanal supply chain in Kenya using a mixed methods approach comprising qualitative and quantitative data. Our aim was to understand the profile of the key players, the supply chain, strengths, challenges and opportunities. Our findings revealed that the socio-demographics of actors varied by age, gender and level of formal education.

Whereas different value addition processes were recorded, billfish unit prices were influenced by the type of actors, seasonality and place. Additionally, limited capital, inadequate storage facilities, vessel and fishing equipment were major constraints. These constraints could be tackled through interventions such as financing and provision of advanced infrastructure to improve the supply chain and support livelihoods. Results from this study contribute to our understanding of billfish artisanal fisheries and provide critical insights on the supply chain that are beneficial in achieving equitable and sustainable billfish fisheries in line with national and regional conservation and fisheries management plans.

1. Introduction

The Western Indian Ocean (WIO) is home to a diverse and significant billfish fishery targeting six key species: black marlin, sailfish, striped marlin, blue marlin, short-bill spearfish, and swordfish [20,29,42].

These species are of significance to fisheries in the region and play a key role in the ecological balance within pelagic ecosystems [36]. The billfish fishery is multi-sectoral involving artisanal, commercial, and recreational fisheries exploiting billfish for food, income, sports, and cultural value [21]. Billfishes are caught as bycatch, especially, by foreign purse seiners and longline fisheries targeting tuna [16], many of its species are considered overexploited [23]. Sailfish populations, in particular, are considered overexploited in the region [31,19]. However, data for some species remain limited, making it difficult to understand their status at country and regional levels.

In the WIO, the multi-sectoral nature of the billfish fishery, often results in competition for the same stocks. Billfish stocks are therefore

shared among resource users, not only within countries but also among several national jurisdictions creating trading opportunities in billfish and associated products as well as management challenges [39,40]. In many artisanal fish landings in the WIO region, billfish has been lumped together with other tuna-like species [26]. Kadagi et al. [22], reported competing relationships between the artisanal and recreational billfish fisheries, which have a big impact on socioeconomic benefits for coastal communities and management. The trade in billfish within the WIO is influenced by factors such as availability, price, and competitive interactions among resource users [23]. Competition between recreational and commercial billfish fisheries may limit availability of billfish, and results in price fluctuations which further complicates the billfish market dynamics. The demand for billfish and its products has resulted in a complex supply chain and the development of fishing infrastructure comprising a wide range of actors, including fishers, processors, dis- tributors, marketers, and consumers [14,17,41]. While there is increasing knowledge about collaboration and coordination among this

* Corresponding author.

E-mail address: [email protected](D.N. Kinyua).

Contents lists available at ScienceDirect

Marine Policy

journal homepage: www.elsevier.com/locate/marpol

https://doi.org/10.1016/j.marpol.2025.106762

Received 27 May 2024; Received in revised form 2 April 2025; Accepted 9 May 2025

Marine Policy 180 (2025) 106762

Available online 28 May 2025

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diverse network of actors in the billfish supply chain, such studies are missing in the WIO region.

An in-depth investigation of the billfish supply chain is essential for gaining insights into the fishery and developing informed policy decisions and interventions to build resilient socio-economic and ecological benefits. The general consideration in billfish supply chain analysis incorporates long-term and sustainable benefits accruable from the ability of the system to adapt and recover from disturbances, ensuring the well-being of communities and the environment. Some benefits include socio-economic resilience, which ensures that the livelihoods of actors can withstand economic shocks; social wellbeing; adaptive capacity; and sustainable resource management. Ecological resilience of the targeted marine ecosystems, on the other hand, involves preserving the said marine ecosystem that supports billfish stocks ensuring biodi- versity conservation. These benefits ensure functionality and delivery of necessary ecosystem services while maintaining the diversity of species, contributing to its overall resilience and recovery from disruptions.

This study addresses gaps in the interconnection among stakeholders involved in artisanal billfish fisheries supply chain, shedding light on their activities and interactions. The study explores Kenya’s artisanal billfish supply chain as a case study to answer the following questions: 1) who are the key players in the artisanal billfish supply chain, and what are their roles? 2) how does the value of billfish products change along the supply chain? and 3) what are the billfish supply chain’s strengths, challenges and opportunities?

2. Materials and methods 2.1. Study site

This study was carried out in the Kenya coast across eight landing

sites of Ngomeni, Shella-Malindi, Watamu, Kilifi, Old Fish Market- Mombasa, Gazi, Msambweni, and Shimoni from January to December 2021 (Fig. 1). The study coincided with high and low fishing seasons of October–April, and May–September, 2021 respectively. The high season was characterized by the calm North East Monsoon (NEM) locally referred to as kaskazi, while low season occur during the rough South East Monsoons (SEM), kusi. The NEM and SEM wind patterns are known to significantly impact fishing activities along the Kenyan coast, affecting sea conditions, fish availability, and fishing strategies [20,26].

Kenya’s small-scale fisheries (SSF) are essential for livelihoods, food security, and economic contributions. The sector employs approximately 60,000 fishers and supports over 1.2 million individuals through ancillary activities [28,27,30]. The sector contributes about 0.5 % to Kenya’s GDP and generates approximately 2 % of national export earnings [24]. The total fish production for 2023 was 161,308 MT, valued at 35.9 billion Kenyan shillings ($256,744,183.38, av. exchange rate, 2023 $1= KES 139.82), with inland fisheries contributing two-thirds of the total production. Marine artisanal production increased from 37,600 MT (worth 9.8 billion shillings; $70,090,115.86, av. exchange rate,2023, 1$ =139.82) in 2022 to 39,950 MT (worth 10.0 billion shillings; $71,520,526.39, av. exchange rate, 2023, $1= KES 128.82). Marine small-scale fishery catches amounted to 36,983 MT, with demersal fish comprising 44 % (16,266 MT) of the total artisanal landings. Pelagic species contributed 26 % (9550 MT), followed by sardines (9 %, 3286 MT), crustaceans (9 %, 3245 MT), mollusks and sea cucumbers (7 %, 2696 MT), and sharks and rays (5 %, 1941 MT) (Kenya Fisheries Statistical Bulletin, [25]). In industrial fishing, swordfish (Xiphias gladius) dominated the catch at 48.02 %, followed by yellowfin tuna (Thunnus albacares) at 28.52 %. Additionally, around 14,000 vessels operate in Kenya, highlighting the extensive participation in the fisheries value chain [25].

Fig. 1.Map of Kenyan Coastline highlighting research sites of Ngomeni, Shella-Malindi, Watamu, Kilifi, Old Fish Market-Mombasa, Gazi, Msambweni, and Shimoni along the Western Indian Ocean.

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2.2. Research design and data collection

Seafood supply chains are increasingly influenced by intricate social networks that connect small-scale fisheries to broader markets, including national and international ones [7]These networks facilitate the movement of fish from local producers to consumers, with their organizational structure playing a critical role in the timely distribution of perishable goods like seafood. However, fisheries economics litera- ture has yet to fully address the impact of social interactions on market organization and behavior. Key gaps include understanding how supplier-buyer relationships shape market dynamics, why these relationships matter for strengthening supply chains, and how social contexts influence network structures and economic decisions [35].

A mixed-methods research approach comprising qualitative and quantitative methods was used to examine the billfish supply chain following [6]. In-depth individual interviews were undertaken, which lasted an average of 40 min, targeting key actors; fishers, small-scale traders, large-scale traders, and fish processors referred herein as fishmongers. The interviews comprised semi-structured questionnaires focusing on; (i) actors’ socio-demographics, (ii) main activities at each node of the supply chain, (iii) landing price per unit kilogram of billfish and at different nodes, (iv) social arrangements and forms of coordination among actors, and (v) the respondents’ perspectives regarding the strengths, weaknesses, and challenges of the production chain in the billfish fishery. A total of 81 respondents comprising 20 fishers, 30 traders, and 31 fishmongers were purposively selected and interviewed as key informants. To identify and map out the key actors in the artisanal billfish supply chain, paths involving billfish marketing channels at the local, national, and international levels were established and summarized in a flow chart. The billfish supply chain was mapped to identify who participates in the chain, how the actors interact and coordinate among themselves, and how the billfish prices change across the chain.

In each case, the actors were identified and their characteristics defined, including working conditions, social interactions, and forms of business coordination, e.g., binding by formal agreements.

2.3. Data analysis

Data from questionnaires focusing on strengths, challenges, and prospects in billfish fishery were coded and thematically summarized.

Social-demographic variables such as age, gender, education, and marital status were analyzed by calculating frequencies and presented as percentages. The most common path in the billfish supply chain was determined by identifying the highest frequency of responses (in per- centage) for each path. Proportions of each path at each level of the market system, local, national or international were calculated based on the number of responses. Directed Acyclic Graphs (DAG) were created using the grViz function from the Diagramme Package in R [18]. These DAGs were used to visualize the specific paths involved in the flow of billfish and billfish products across the supply chain. Social arrangements were identified as the informal and formal relationships govern- ing interactions among supply chain actors, deduced from responses regarding the presence of formal contracts or agreements. Forms of coordination were analyzed by examining the mechanisms through which roles and responsibilities were structured, including market linkages and value addition processes [15]. Variables, including the price of billfish at landing site and in the market were summarized as median with interquartile range (IQR). Progressive product value changes along the production process were examined using Generalised Linear Regression Models (GLM). GLMs were generated with price at the market as the outcome variable, and actors (fishers and traders) as the predictor variable [32]. The model was adjusted to reduce effects of other related value-addition processes. The relationship between the price at landing site and market, and determinants of billfish price was evaluated using GLM. Price at landing site and market in low/high season were considered as dependent variables, while determiners of

billfish price were used as independent variables. Student t-test compared means of price variation between actors. Least square tech- nique was performed in SPSS (version 14) to assess the relation between fish prices at the landing sites and at the markets, during high and low fishing seasons. Here, r²>0.5 with a p-value <0.05 was considered as a significant relationship. Descriptive statistics evaluated and results presented as summaries of strengths, challenges, and opportunities.

3. Results

3.1. Social demographics characteristics of artisanal billfish fishery Most of the age of the respondents ranged between 20 and 45 years, across all actor groups. Fishing and trading were male dominated (100 %), while processors (fishmongers) were all females (100 %). 55 % of fishers and 42 % fishmongers had primary level education, while half of fish traders had secondary education. None of the fishmongers attained secondary education (Table 1).

3.2. Billfish supply chain, actors and their roles

Three key nodes of actors were identified as fishers, traders (who doubled up as dealers and middle-persons), and fishmongers (who are the local and small-scale processors). In the coastal local market, 27.16 % of the respondents configured the billfish supply chain as;

Fisher → Dealer →Fishmonger (locally known as mama karanga) → Consumer. In the national market (that extends beyond the landing site but within the country), 45.68 % of the respondents described the flow as; Fisher → Dealer →Wholesaler → Retailer → Consumer. Majority (i.e., 85.19 %) of the respondents did not have information regarding the international market system, with the remaining indicating the supply moving from the fisher through the dealer and wholesaler to the exporter (Fig. 2). The study reveals that social arrangements in the billfish supply chain are mainly informal, relying on trust-based agreements, shared norms, and community networks, especially for women fishmongers, and coordination mechanisms involve direct interactions at landing sites. The study reveals that social arrangements in the billfish supply chain are mainly informal (100 %), relying on trust-based agreements, shared norms, and community networks, especially for women fishmongers. Coordination mechanisms involve direct interactions at landing sites. For example, prices are negotiated on the spot without prior contract, with the buyer and seller engaging in real time bargaining. Additionally, the actors have pre-arranged verbal credit systems or reciprocal exchanges, where fishers get financial or material support in exchange for priority access to their catch.

3.3. Product supply chain and pricing

The forms of value addition processes identified were gutting, scaling, cutting, frying, deep frying, and smoking. Most fishers (85 %) and traders (60 %) sell their fish unprocessed (no value addition), whereas majority (97 %) of fishmongers deep-fry their fish as a form of value addition (Fig. 3). Billfish unit prices varied significantly between fishers and traders with traders fetching higher prices by at least by at least US$ 1.47 kg⁻¹) (t=10.71, df =49, p<0.05). There was also a significant variation in unit price between landing site and local and national market. (Table 2). Average price pooled for all the landing site (8 study sites) was only significantly influenced by season (t=2.76, p<0.05), but not demand (t=-1.18, p>0.05), nor size of the billfish (t=-1.89, p>0.05). Whereas in the local and national market, price was significantly influenced by both demand (t=-4.88, p<0.05) and season (t=-2.82, p<0.05). Size of the billfish as a factor, did not influence price (t=-0.45, p>0.05). The price at the landing site did not influence the price at the markets during high season (October–April, 2021) (r²=-0.00001, n=79, p>0.05), however, during low season (May–September, 2021), there was a significant positive correlation

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between billfish price at the market and the landing site (r²= 0.5, n=70, p<0.001) (Fig. 4).

Determination of the price varied across the supply chain actors’

nodes. At the fishmongers’ node, 96 % of the billfish prices were determined by the fishmongers, while at traders’ node, the price was mainly (70 %) determined by the traders. At the fishers’ node, fish prices were mainly (68 %) determined by agreements between the fisher and the buyer (Fig. 5). The Beach Management Unit (BMU)¹– which is the lowest (community) legal fisheries governance structure - was found to influence the pricing of billfish for fishmongers (5 %), who purchased

billfish through the BMU.

3.4. Constraints, their effects and prospects in artisanal billfish supply chain

This study identified several issues along the billfish supply chain, they were classified as a) key constraints, b) effects of the constraints, and c) proposed interventions by the actors. Majority of the fishers (75 %) identified inefficient fishing vessels and equipment as a major challenge, while the traders’ primary (46.7 %) constraint was limited capital. Among the fishmongers (54.8 %), reported lack of adequate storage facilities (Fig. 6a) as their main challenge. Additionally, most actors, reported reduced income level as one of the major effects of the constraints (Fig. 6b). To address these constraints, respondents sug- gested provision of advanced vessels (75 %), improved access to loans (46.5 %) and better storage facilities (48.4 %) as key solutions (Fig. 6c).

4. Discussion

Our study examined profile of key players in the billfish supply chain, the value transformation of products, as well as the strengths, challenges, and opportunities within the artisanal billfish value chain in Kenya. We also highlight the complexities of the artisanal billfish fishery supply chain along the Kenyan coast, focusing on the roles, interactions, and challenges faced by various actors. Although women dominate the fishmongers’ node in the supply chain, their ability to navigate systemic challenges and effcetively exercise autonomy in this space is hindered by several factors, as our findings demonstrate.

4.1. Age, gender and formal education in billfish coastal fisheries The Kenyan billfish supply chain primarily involves actors aged between 20 and 45 years, similar to the general age structure in small-scale fisheries in Kenya, where 45 % of participants are under 40 years [28, 27]. This age range aligns with other artisanal fisheries, such as Fiji’s lobster fishery [43]and Sri Lanka’s shark value chain [5]. In Kenya, older fishers often face physical challenges, limiting their ability to engage in demanding activities like fishing and hauling. This may lead them to transition to less physically demanding roles or retire, impacting productivity in artisanal fisheries. In contrast, younger fishers may bring energy and adaptability but often lack the experience needed for sustainable fishing operations. Globally, an aging fisher population is a growing concern, particularly where succession planning is lacking. The loss of experienced fishers can harm fisheries management [11]. At the same time, young fishers face challenges like limited access to resources and training, leading to underemployment or migration to urban areas [10]. In Kenya, this mirrors global trends, with an aging workforce and declining youth participation in the sector, raising concerns about the long-term sustainability of artisanal fisheries.

The study also identifies gendered roles in the supply chain, with males predominantly in fishing and trading. Our findings indicate that women play a significant role in dominating the fishmonger node in the fisheries supply chain. However, further investigations are necessary to assess their effectiveness and challenges, particularly in price control and information flow within the supply chain. Several studies have Table 1

Social-demographic characteristics of actors in artisanal billfish supply chain along the Kenyan coast.

Actors Actors’ Characteristics

Age Gender Education

<20 20–45 46–65 >65 F M Madrassa Primary Secondary None

(Numerical) (Numerical)

Fishers, n ¼20 5 % 55 % 25 % 15 % 0 20 0 % 55 % 30 % 15 %

Traders, n ¼30 20 % 40 % 40 % 0 % 0 30 27 % 10 % 50 % 13 %

Fishmongers, n ¼31 23 % 48 % 26 % 3 % 31 0 29 % 42 % 0 % 29 %

Fig. 2. Structural value chain according to different actors across billfish supply chain along the Kenyan coast: a) local market systems, and b) national market systems.

1Beach management unit are a co management unit established under the Fisheries Act (Cap 378) – The functions of a beach management unit includes strengthening of management of fish-landing stations, fishery resources and the aquatic environment; supporting sustainable development of the fisheries sector; ensuring the achievement of high-quality standards regarding fish and fishery products; and preventing or reducing conflicts in the fisheries sector. To ensure the safety of fish and fishery products, a specific area of the fish landing station is delineated, marked and assigned for the exclusive purposes of landing and selling fish and fishery products

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Fig. 4. Correlation between fish price at the market (Pm) and at landing during (Pl) during: (a) high season; and (b) low season, along the Kenyan coast for the period between January and December 2021.

Fig. 5. Knowledge of who determines billfish price across different supply chain nodes of fishmongers, traders and fishers along the Kenyan coast.

Fig. 3. Forms of value addition across different actors in the billfish supply chain, (a) Fishmongers, (b) Traders, and (c) Fishers along the Kenyan coast.

Table 2

Mean estimates of billfish prices at different nodes of value chain at the landing site, national market and international markets (Exchange rate US$ 1=KES 110, November 2021).

Nodes Fishers (n=20)

price average estimates (US$) Traders (n=30)

price average estimates (US$) Fishmonger (n=31) price average estimates (US$)

Landing sites 2.5 1.8 1.7

National Markets 3.6 4.5 3.6

International 3.9 9.1 9.1

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shown that women experience discrimination in pricing and access to fish, especially during low fishing seasons [28,27]. This, therefore, un- derscore the need for examining gender-disaggregated data to fully comprehend the challenges [4]. The observations show that fishmongers had limited primary and secondary level of formal education, compared to their traders and fishers in the supply chain. Education significantly impacts the supply chain such as agriculture. Farmers can analyze costs, benefits, and risks, making them better negotiators and responsive to market demands [44,9]. Similarly, our findings noted fishmongers, typically had lower levels of formal education, thus may face limitations in decision-making, financial planning, and market adaptability. The lack of secondary education in fishmongers suggests they may also struggle with price negotiations, value addition, and business expansion.

Limited education can also hinder access to market information, quality standards, and formalized business operations. Higher-educated traders and fishers can navigate complex supply chain processes, adopt new technologies, and capitalize on profitable market opportunities. This disparity in education levels in the fisheries supply chain underscores the need for targeted capacity development and sharing programs, such as financial literacy training and business skills development, to empower fishmongers. Enhancing their education and training can in- crease competitiveness, reduce exploitation, and contribute to a more efficient and equitable fisheries supply chain.

4.2. Value addition and pricing of billfish commodities

The study identified a variety of post-harvest value addition processes, including gutting, scaling, cutting, frying, deep frying, and smoking. However, it did not analyze price variations across different product presentations. We recommend that future studies incorporate an economic analysis to address this gap. Most of the fishmongers in the coastal billfish industry are predominantly retailers, targeting piecemeal

buyers, whose purchasing time are unpredictable. Thus, the fishmongers deep fry their fish commodities, as a value addition to avert spoilage and add flavor. Few traders may gut and smoke their fish commodities as a means of preserving them should buyers not show up going into late in the dusk. Only special instances, and threat of prominent loss due to spoilage should buyers not show up, fishers occasionally gut and scale their fish usually to take home for subsistence. This study highlights the crucial role of women in the billfish supply chain, particularly in value addition processes like cleaning, deep frying, and marketing. Women accounted for over 60 % of participants in post-harvest activities, ensuring a steady supply of value-added products. Their involvement not only enhances product quality but also supports household incomes and community livelihoods. Their involvement fosters sustainability by bridging the gap between fishers and consumers, ensuring timely processing and delivery of high-quality products. Legal recognition by the government, including quantification of women’s labor in the national statistics, and supporting women’s roles is essential for the overall ef- ficiency and equity of the billfish supply chain.

The study also established that fish traders had more exposure and knowledge especially on local billfish market operations and compared to fishers and fishmongers in the supply chain. Further, the results show that billfish prices tend to be higher in regional markets outside Kenya.

The general lack of awareness on regional and international billfish markets among fishmongers and fishers may imply potential limitations in information flow, or access to market information and opportunities for certain actors within the supply chain. While similar trend has been observed elsewhere [13]and confirmed the general lack of knowledge on regional and international billfish markets, knowledge on market dynamics is critical given the transboundary nature of billfish, and the need for regional cooperation on their sustainable management. The findings align with previous studies showing that the fishing season typically depicted the how demand and supply determine price in fish Fig. 6.Summary of: (a) key constraints in the billfish supply chain, (b) effects of the constraints, and (c) proposed interventions by the actors for an efficient billfish supply chain along the Kenyan coast.

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markets [2,28,27,37]. For instance, the decline in fish production during low fishing season drives higher billfish prices at both landing sites, as well as at offsite market outlets. Here, the two prices (i.e., at landing sites and at the market) positively correlated. That is, the higher prices at the landing sites are reflected in the consequent higher prices at the market. Conversely, during the high fishing season, when there is rela- tively more abundant landing of billfishes, prices offered at the landing sites had minimum influence on the market. This pattern has also been reported by [1]. The study indicated that different actors at particular nodes of artisanal billfish supply chain operate on trust. The actors do not have any formal contracts or regulatory oversight and operate purely on mutual trust and informal agreements. These informal, trust-based relationships are vital for the smooth operation of the supply chain, compensating for the lack of formal agreements. However, this reliance on trust also makes the system vulnerable to issues like price manipulation and inconsistent supply when relationships are strained [34,38].

4.3. Constraints and opportunities in artisanal billfish supply chain The billfish supply chain in Kenya presents unique strengths and untapped opportunities. These include the resilience and adaptability of fishmongers, particularly women, and the potential for targeted interventions to enhance equity and sustainability. This study further reveals that a lack of suitable fishing vessels and equipment may hinder the ability of fishers to maximize their returns. Addressing this issue requires collaborative efforts among the government, NGOs, and private sector stakeholders to enhance access to modern fishing technologies.

This includes facilitating links to funding programs for acquiring advanced equipment and implementing capacity-building initiatives to ensure effective adoption and utilization of these technologies. Initia- tives such as NGO-supported equipment grants or public-private partnerships can empower fishers to adopt more efficient and sustainable fishing practices, reducing their operational constraints. Our findings highlight the limited financial capital available to fishers and fishmongers, a challenge also emphasized by Kimani et al. [28,27], Gardner et al. [12], and Odebiyi et al. [33], who identify financial capital as a primary constraint across fisheries supply chains. While fish traders and fishmongers had capital to expand their operations, such as increasing their capacity to handle, process, and distribute fish more efficiently, the overall lack of accessible financial resources diminishes returns for all actors in the supply chain. Successful case studies, such as community-based savings and credit cooperatives or microfinance in- stitutions, demonstrate the potential to provide financial support to small-scale actors. For instance, Bennett [3] highlighted that cooperatives can play a crucial role in improving the livelihoods of small-scale fishers while also contributing to sustainable resource management. Establishing targeted credit schemes or subsidies, possibly supported by development organizations, can help bridge this gap and promote economic empowerment within the supply chain.

Additionally, improved access to market information and strength- ened communication channels between fishers and fishmongers repre- sent another opportunity. Establishing cooperatives or networks that facilitate information exchange, training, and collective bargaining can empower stakeholders. These structures can help reduce disparities, enhance pricing transparency, and enable fishmongers to make informed decisions, ultimately boosting their market competitiveness.

Despite the challenges, the dominance of women in the fishmongers’

node highlights their crucial role in ensuring fish distribution. Targeted capacity-building programs can enhance their skills in financial literacy, negotiation, and value addition, enabling them to command greater influence within the supply chain. Moreover, promoting gender- sensitive policies and practices can address inequities and support women’s participation and leadership. Promoting sustainable practices within the billfish supply chain is essential for its long-term viability.

Encouraging responsible fishing methods, reducing post-harvest losses,

and integrating climate-resilient practices can enhance the ecological and economic outcomes of the fishery. Partnerships with conservation organizations and government bodies can play a pivotal role in achieving these goals. In line with Crona et al. [8], targeted interventions and policies applicable to the fisheries supply chain are essential to enhance sustainable billfish fisheries in Kenya and the region.

5. Conclusion

Our findings highlight the need for targeted interventions that could involve increasing financial access through microfinance programs and development of cold storage facilities, markets infrastructure, and access to local, national, and export markets. The study recommends enhancement of value addition by training in fish processing and fostering research partnerships.

Moreover, the study underscores the importance of capacity development and sharing programs on sustainable fishing practices, entre- preneurship, and inclusion of women in supply chain. It also emphasizes the role played by socio demographic variables such as age, gender and education in influencing the supply chain dynamics, revealing that fishmongers and traders have more control over the prices than the fishers. By documenting diverse value addition processes and identifying key determinants for optimizing resource use and management, this study demonstrates the significant potential of the billfish supply chain for income generation and food security especially for coastal communities.

Our work contributes to marine policy by providing actionable insights and recommendations to address the challenges faced by Kenya’s artisanal billfish sector. Additionally, the findings inform policy development by advocating for increased support for supply chain actors through microfinance programs, and capacity development and sharing, as well as emphasizing the importance of inclusivity for women. Un- derstanding the characteristics, constraints and opportunities calls for investments in infrastructure, such as cold storage and market facilities, which reduce losses and improve market access. We advocate for policies that encourage training, and research partnerships to enhance value addition. We propose integrating artisanal fisheries into marine spatial planning, strengthening governance frameworks; alignment of local practices to national and regional conservation strategies, and balancing socio-economic areas with sustainable fisheries management.

From the key aforementioned findings, it is reasonably necessary to extend this work across different sectors and countries with billfish populations. This is anticipated to achieve equitable and sustainable billfish fisheries in line with national and regional billfish conservation and management plans.

CRediT authorship contribution statement

Damaris Njeri Kinyua: Writing – review & editing, Writing – original draft, Validation, Methodology, Investigation, Funding acquisition, Formal analysis, Data curation, Conceptualization. Dalmas O. Oyugi:

Writing – review & editing, Supervision, Formal analysis, Data curation, Conceptualization. Andrew Wamukota: Writing – review & editing, Supervision, Project administration. U. Rashid Sumaila: Supervision, Project administration. Sarah Ater: Writing – review & editing, Vali- dation, Project administration. Nelly Isigi Kadagi: Writing – review &

editing, Project administration, Funding acquisition, Conceptualization.

Acknowledgments

This study was made possible with financial support from the WWF’s Russell E. Train Education for Nature Program (EFN) Grant RK66a, and Western Indian Ocean Marine Science Association (WIOMSA) - Marine and Coastal Science for Management (MASMA) Grant MASMA/OP/

2019/01. The authors appreciate technical support from the Kenya

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Fisheries Service, the BMUs from the eight sites of Ngomeni, Shella- Malindi, Watamu, Kilifi, Old Fish Market-Mombasa, Gazi, Msambweni, and Shimoni. We would also like to thank Shakila Muendo (Pwani University), for assistance during field works, George Aike (The Nature Conservancy) for developing the study site map, and Evans Mudibo (Wageningen University), for his contribution to data analysis.

Author Agreement Statement

We the undersigned declare that this manuscript is original, has not been published before and is not currently being considered for publi- cation elsewhere.

We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us.

We understand that the Corresponding Author is the sole contact for the Editorial process.

He/she is responsible for communicating with the other authors about progress, submissions of revisions and final approval of proofs.

Data availability

Data will be made available on request.

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