Introduction
Illegal fishing, the act of contravening a state’s fisheries laws and regulations, has detrimental effects on coastal and marine species, ecosystems and associated services (Temple et al., Reference Temple, Skerritt, Howarth and Pearce2022). It is increasingly recognized as a widespread phenomenon threatening not only ecological balance but also food security, maritime livelihoods and the sustainability of fisheries worldwide (Mackay et al., Reference Mackay, Hardesty and Wilcox2020). Illegal fishing is estimated to account for 20% of the world’s fish catch, resulting in substantial economic losses and hindering scientific stock assessments, which then contributes to poor management (Agnew et al., Reference Agnew, Pearce, Pramod, Peatman and Watson2009; Sumaila et al., Reference Sumaila, Zeller, Hood, Palomares, Li and Pauly2020). Certain taxa, such as sharks and rays, are particularly vulnerable to illegal fishing because of their low fecundity and slow growth rate (Nijman, Reference Nijman2023). Globally, they also face heightened pressure as a result of high demand for shark-derived products, including fins, meat, liver oil and cartilage (Zhou et al., Reference Zhou, Booth, Li, Song, MacMillan, Zhang, Wang and Veríssimo2021).
Over the past 5 decades, overfishing of sharks and rays has compromised the stability of their populations (Davidson et al., Reference Davidson, Krawchuk and Dulvy2016; MacNeil et al., Reference MacNeil, Chapman, Heupel, Simpfendorfer, Heithaus and Meekan2020). For example, the global abundance of oceanic sharks and rays has declined by 71% since 1971 (Pacoureau et al., Reference Pacoureau, Rigby, Kyne, Sherley, Winker and Carlson2021) and 31% of shark species are currently at risk of extinction (Dulvy et al., Reference Dulvy, Pacoureau, Rigby, Pollom, Jabado and Ebert2021). To manage and conserve sharks better, various policies and regulations have been implemented at national, regional and international scales. These policies can be broadly categorized into target-based policies for sustainable use (e.g. fisheries quotas) and limit-based policies that completely ban specific aspects of exploitation to promote healthy shark populations without a species-specific focus (e.g. marine reserves; Shiffman & Hammerschlag, Reference Shiffman and Hammerschlag2016). For example, shark-fin bans are widespread, making possessing, selling, trading and distributing shark fins illegal (Ward-Paige & Worm, Reference Ward-Paige and Worm2017). The application of shark trade regulations through CITES also puts into place a general ban on commercial international trade or introduces trade monitoring and regulation on a species-specific basis (Friedman et al., Reference Friedman, Gabriel, Abe, Adnan Nuruddin, Ali and Bidin Raja Hassan2018). However, the efficacy of many of these measures is often limited by challenges to their implementation (Cardeñosa et al., Reference Cardeñosa, Fields, Babcock, Zhang, Feldheim and Shea2018).
Limited monitoring and surveillance capacity in many countries is a major barrier to robust implementation of shark-related policies (Doumbouya et al., Reference Doumbouya, Camara, Mamie, Intchama, Jarra and Ceesay2017), and understanding the social drivers of non-compliance is also a critical but often neglected consideration for policy success (Arias et al., Reference Arias, Cinner, Jones and Pressey2015; Collins et al., Reference Collins, Letessier, Broderick, Wijesundara and Nuno2020). Shark fins and meat often provide substantial economic benefits (Peiris et al., Reference Peiris, Kumara, Ranatunga and Liu2021; Collins et al., Reference Collins, Letessier, Benaragama, Broderick, Wijesundara, Wijetunge and Nuno2023), and shark fisheries contribute to nutritional needs (Glaus et al., Reference Glaus, Adrian-Kalchhauser, Piovano, Appleyard, Brunnschweiler and Rico2019). Policies and regulations aimed at controlling shark fisheries may thus impose multiple types of costs on fishing communities (Booth et al., Reference Booth, Squires and Milner-Gulland2019; Mizrahi et al., Reference Mizrahi, Duce, Pressey, Simpfendorfer, Weeks and Diedrich2019), leading to substantial social consequences, particularly for communities that are socio-economically vulnerable (Robinson & Sauer, Reference Robinson and Sauer2013). Effective shark conservation therefore depends on understanding the wider social context of fisheries, to enable robust policy implementation (Alabsi & Komatsu, Reference Alabsi and Komatsu2014; Collins et al., Reference Collins, Letessier, Broderick, Wijesundara and Nuno2020).
Historically, various theories have been proposed to explain non-compliance (Oyanedel et al., Reference Oyanedel, Gelcich and Milner-Gulland2020). For instance, the theory of compliance suggests that individuals are rational decision-makers who seek to maximize their utility, breaking rules only when the benefits outweigh the cost (Becker, Reference Becker1968); derived from classical economic theory, this concept forms the foundation of the deterrence model. This model postulates that illegal fishing should be managed through rigorous monitoring, enforcement, prosecution and the imposition of severe penalties so that the costs outweigh the benefits (Sumaila et al., Reference Sumaila, Alder and Keith2006). However, the successful application of the deterrence model to reduce illegal fishing can be affected by its inability to integrate and account for wider factors such as detection rates, corruption, unsuitable sanctions and high enforcement costs (Sumaila et al., Reference Sumaila, Alder and Keith2006; Nunan et al., Reference Nunan, Cepić, Yongo, Salehe, Mbilingi and Odongkara2018). An alternative theoretical approach, the compliance framework (Ramcilovic-Suominen & Epstein, Reference Ramcilovic-Suominen and Epstein2012), also incorporates context-specific economic, social, cultural and institutional variables that may influence individual motivations. For example, this approach integrates legitimacy and norms to better understand what motivates compliance (Nielsen, Reference Nielsen2003).
Using illegal shark fishing by the semi-industrial fleet in Sri Lanka as a case study, we aimed to explore the social aspects of fisheries non-compliance and understand potential challenges to the success of policies designed to curb unsustainable fishing practices. Despite national and international efforts, Sri Lankan vessels have frequently been apprehended for illegal fishing in foreign waters, including the Seychelles and India, with targeting of sharks identified as a key driver of these behaviours in the Chagos Archipelago Marine Protected Area (Tickler et al., Reference Tickler, Carlisle, Chapple, Curnick, Dale, Schallert and Block2019; Collins et al., Reference Collins, Nuno, Benaragama, Broderick, Wijesundara, Wijetunge and Letessier2021). We first characterized key fishing practices and then assessed fishers’ self-reported behaviours and awareness of national shark fishing management regulations. Finally, we identified broader social aspects potentially hindering the success of these regulations.
Methods
Survey design and development
We conducted this study at three sites along the south-west, west and north-east coasts of Sri Lanka (Fig. 1) that have been associated with violations of shark fishing management regulations and illegal fishing of sharks in foreign waters, notably the Chagos Archipelago Marine Protected Area (Martin et al., Reference Martin, Moir Clark, Pearce and Mees2013; Collins et al., Reference Collins, Nuno, Benaragama, Broderick, Wijesundara, Wijetunge and Letessier2021; Fernando & Stewart, Reference Fernando and Stewart2021). In particular, we focused on the national Shark Fishing Management Regulations, 2015, which stipulate that no individual engaged in fishing operations within Sri Lankan waters shall catch any of the following species of sharks: common thresher shark Alopias vulpinus, bigeye thresher shark Alopias superciliosus, pelagic thresher shark Alopias pelagicus, oceanic whitetip shark Carcharhinus longimanus and whale shark Rhincodon typus. It also states that no person shall remove, retain on board, tranship or land fins of any shark unless such fins are naturally attached to the body of the shark (DFAR, 2015).
Fig. 1 (a) The location of Sri Lanka, its exclusive economic zone and those of neighbouring countries, (b) the provinces in Sri Lanka where the study sites were located. Precise locations of fisheries are not disclosed, to protect the anonymity of respondents.
During a preliminary investigative phase, author LGG conducted 10 site visits to engage with fishing communities informally through discussions about fishing activities, to observe shark landings and to validate study site selection. We chose to survey inboard multi-day vessels (Plate 1), which are medium-sized vessels (9–17 m) operated by a crew of 5–10 that primarily target high-value pelagic species such as tuna, sharks and billfish using gillnets and/or longlines (Collins et al., Reference Collins, Letessier, Broderick, Wijesundara and Nuno2020). Overall, 35% of the nationally registered inboard multi-day vessels land at the three selected sites (Ministry of Fisheries, 2020). Site names are anonymized here because of the sensitive data collected.
Plate 1 Medium-sized fishing vessel locally referred to as an inboard multi-day vessel.
We used questionnaire-based interviews and focus group discussions to collect data. We designed these instruments using evidence on potential factors related to fishers’ non-compliance (e.g. Gelcich et al., Reference Gelcich, Edwards-Jones and Kaiser2005; McClanahan et al., Reference McClanahan, Davies and Maina2005; Pita et al., Reference Pita, Pierce and Theodossiou2010; Karnad et al., Reference Karnad, Gangal and Karanth2014; de Andrade & de Oliveira Soares, Reference de Andrade and de Oliveira Soares2017; Maynou et al., Reference Maynou, Gil, Vitale, Giusto, Foutsi and Rangel2018) and factors identified during preliminary field visits (Table 1). We included the following sections in the questionnaire: fishers’ socio-economic characteristics (e.g. years of fishing experience, main occupation), spatial data (e.g. fishing area), vessel characteristics (e.g. licence category, vessel length), awareness of shark fishing regulations (including also the perceived purpose of these regulations), compliance with regulations (including self-reported compliance, perceived level of compliance by others, consequences for non-compliance), and perceived effectiveness of the regulations on shark fishing (Supplementary Tables 1 and 2).
Table 1 Variables obtained from the questionnaire responses to characterize behaviours and perceptions regarding national regulations on shark fishing management among fishers, skippers and boat owners.
We used focus group discussions to collect broader qualitative data around the issues we discussed amongst respondents. Focus group discussion guidelines comprised 26 open-ended questions and related prompts to understand fishing practices, awareness of national shark fishing management regulations and perceived effectiveness in terms of compliance and protecting shark populations (Supplementary Tables 3 & 4). We also designed interactive activities such as asking fishers to sort sharks according to their protection status, to stimulate and generate discussion.
Data collection
Target respondents (fishers, skippers or boat owners) were recruited using convenience (where respondents are approached randomly at suitable sites) and snowball sampling (where respondents are asked to recommend suitable additional respondents; Newing, Reference Newing2010). A pilot study was conducted with 27 fishers across different sites, primarily to identify potential methodological improvements. Face-to-face questionnaire-based interviews were conducted during February–June 2023 by LGG, and OD and DB, who were trained on-site for > 1 month prior to data collection. We also conducted a pilot focus group at one of the study sites to determine any changes needed in the focus group discussion guidelines. Based on this, more prompt questions were added to encourage discussion.
At the start of interviews and focus group discussions, we explained the purpose of the research, highlighting anonymity and data confidentiality and emphasizing that respondents could skip questions or end their participation at any time. We collected the data only after obtaining their verbal consent to participate and be audio recorded. We conducted all data collection in Sinhalese, audio-recorded our interactions with respondent permission, and then transcribed the responses and translated them into English.
Data analysis
We summarized responses to closed questions as frequencies. Some response categories had limited counts and were grouped for more robust distinctions (Table 2). We used Pearson χ 2 test of independence and Fisher’s exact test (if any of the categories had ≤ 5 counts) to explore potential differences in socio-economic and vessel characteristics amongst landing sites. Statistical analyses were conducted in R 4.3.2 (R Core Team, 2023), with significance at P < 0.05.
Table 2 Summary of the key characteristics (Table 1) of the 254 questionnaire respondents, their fishing vessels, practices and perceptions.
Answers to open questions in the questionnaires and focus group discussion transcripts were imported into NVivo 14 (NVivo, 2023) and analysed together. We used a hybrid approach of both inductive and deductive reasoning to conduct a thematic framework analysis (Fereday & Muir-Cochrane, Reference Fereday and Muir-Cochrane2006). Firstly, we created a thematic analysis framework (Table 3) based on a targeted literature review and data familiarization. Key literature focused on the potential impacts of fishers’ perceptions, knowledge of management policies and perception of their effectiveness on compliance (e.g. Gallic & Cox, Reference Gallic and Cox2006; Le Page & Radomski, Reference Le Page and Radomski2006; Dimech et al., Reference Dimech, Darmanin, Smith, Kaiser and Schembri2009; St John et al., Reference St John, Keane and Milner‐Gulland2013; Karnad et al., Reference Karnad, Gangal and Karanth2014; Thomas et al., Reference Thomas, Milfont and Gavin2016; Bennett, Reference Bennett2019). Secondly, data were coded against the thematic analysis framework in an iterative manner, where new codes were added or modified as needed, and existing ones were deleted to ensure they matched the data (Bryman, Reference Bryman2016). We arranged codes in a hierarchical structure, with codes and sub-codes rearranged during the iterative coding process. Within the Results, illustrative quotes are used to further explain the codes.
Table 3 Thematic analysis framework used to code qualitative data to describe perceptions of the fishing community in Sri Lanka of national shark fisheries management regulations and aspects of compliance. Quotes are taken from discussions held with focus groups (Supplementary Table 3).
1National Aquatic Resources Research and Development Agency.
Results
Characteristics of the study population and their fishing practices
For the questionnaire-based survey, we approached 273 individuals of whom 19 (7%) declined to participate because of limited available time or concerns about discussing illegal fishing activities. Overall, 254 people participated (84, 84 and 86 from site 1, 2 and 3, respectively) in surveys that took, on average, 17 min. Respondents were primarily skippers (149, 59%), followed by fishers (83, 33%) and boat owners (22, 8%). Skippers were perceived to have more knowledge about fishing practices and were frequently identified by others as suitable respondents for the survey. Although boat owners typically have ultimate authority and are responsible for managing fishers and skippers, they may not always be aware of what happens on board. As a result, boat owners directed us to skippers for data collection, recognizing their key role in managing fishing operations and their detailed understanding of practices at sea. Overall, 97 (38%) of survey respondents had > 20 years of experience in fisheries. A summary of the main characteristics of respondents, fishing vessels and practices is presented in Table 2.
Vessel length averaged 12.8 ± SD 1.7 m (range 8.5–18.0) and the majority (172, 68%) of vessels had a high-seas operation licence. Most (79%) of the smaller vessels (< 10.7 m long) only held local-water operation licences, whereas larger vessels (≥ 10.7 m) mostly (75%) had a high-seas operation licence. Overall, 80 (32%) of respondents reported they operated only on the high seas, and 95 (37%) operated on both high seas and in local waters, with the remaining 79 (31%) fishing only in local waters. Based on self-reported fishing areas and licences, six (2%) vessels fished non-compliantly on the high seas without a high-seas operation licence.
Most respondents used more than one type of fishing gear, with longline being the most common (142, 56%), followed by gill net (110, 43%), purse seine (66, 19%) and other types of gear (33, 9%), including flying fish nets.
The following socio-demographic and vessel characteristic variables differed significantly between sites: education level, licence type, vessel length, types of fishing gear and fishing area (high seas, local waters; see Supplementary Table 5 for statistics). For example, the majority of the respondents from one of the sites had larger vessels and high-seas operation licences, in contrast to the other two sites.
A total of 34 respondents, including fishers and skippers, participated in the six focus group discussions conducted across three sites. On average, each focus group discussion lasted 25 minutes.
Awareness about regulations, and self-reported behaviours
To assess awareness about shark fishing management regulations, survey respondents were asked to identify banned shark species: thresher sharks (all three thresher shark species collectively), oceanic whitetip sharks and whale sharks. Overall, 245 (97 %) named ≥ 1 banned species but only 23 (9%) identified all banned species and had relatively high awareness levels (Table 2). The most common perceived reasons for the bans were extinction threat for sharks (141, 56%), low reproduction rates (54, 21%), and ensuring their functional roles within the wider ecosystem such as protecting coral reefs and cleaning the ocean (26, 10%). Fifty respondents (22%) did not know why these bans were in place. Awareness of regulations and associated punishments were reported to come primarily from social networks, especially from people who had previously faced consequences for landing sharks illegally.
Most respondents (221, 87%) reported they release banned sharks caught incidentally. However, 30 (12%) reported retaining them and either landing them as whole carcasses (12), dried fish (11) or using them for food (7). When asked about the behaviour of other fishers, 168 respondents (66%) said their friends always released banned sharks, 42 (17%) said friends either consume them onboard or land banned sharks as whole carcasses or dried fish, and the remaining said they did not know what other fishers did with sharks. In addition, 120 (47%) said they think other fishers at their harbour (not their friends) land banned sharks and 28 (11%) said that the prevalence of illegal shark landings was relatively high (> 40% of other fishers engaging in this behaviour; Table 2).
Drivers and deterrents of illegal shark fishing
Economic importance of shark fishing
Respondents cited economic reasons (122, 48%) and the role of sharks as a food source both whilst on board and on land (17, 7%) as the main reasons for landing banned shark species. Thematic analysis supported this, indicating that the perceived high income from shark fishing, relative to other occupations, was a substantial driver of non-compliance. Respondents indicated that shark fishing was their only viable means of economically supporting their families, particularly given the rising cost of living. They also cited the need to cover the high operating costs of their fishing vessels, such as fuel and food, driven by the country’s economic crisis. One fisher stated: ‘Most of the time, people bring those sharks to land to cover only the cost of the boat…[which] is around LKR 20 lakhs [USD 6,500–7,000; lakh refers to LKR 100,000]. So, though we bring in LKR 10 lakhs worth of fish, it is not enough’.
Respondents said strong demand and high prices for sharks, particularly shark fins and dried shark, which have stable prices compared to other fish, was driving non-compliance. For example, the price of shark fins remained consistently high over the study period at USD 12–40/kg (LKR 7,000–12,000). One fisher stated: ‘We are also going for sharks the next trip. Those fish prices don’t fluctuate like in yellow fin tuna. They have a good market’. Prohibited oceanic whitetip sharks were mentioned as the most expensive fish sold in harbours, mainly because of the high value of their notably long fins.
Fishers believe there is a higher availability of shark species in offshore foreign waters than in traditional local fishing grounds as a result of overfishing, which reportedly encourages illegally crossing borders of other countries’ waters. One fisher explained: ‘No fish in our seas now; we have to go to other borders to catch them’.
Consequences of non-compliance
When asked about perceived punishments for landing banned shark species, 194 respondents (76%) mentioned fines (estimates were LKR 25,000–100,000; USD 76–305), and 97 (38%) said skipper licences are revoked (for 3, 6 or 12 months). Some respondents thought that fines were relative to the weight of illegal landings, and others said half the fine was payable by the vessel owner and the other half by the crew.
Other consequences reported were: court cases (81, 32%), custodial sentences (21, 8%), boat confiscation (9, 4%) and fishing bans (6, 2%). Fishers mentioned that specific sanctions vary depending on the nature of the illegal activity. Respondents reported that repeated regulation violations incur severe penalties, including fines of LKR 5,000,000–6,000,000 (USD 16,000–20,000), boat confiscation, extended jail time and a fishing ban if a skipper’s licence is revoked three times. However, when asked to score the perceived level of punishments, four (2%) replied that there were no punishments, with one fisher stating, ‘No matter how severe the punishments are, they are not enforced’. For the remaining 250 (98%) who perceived there were some punishments, these were generally perceived to be ‘relatively strong or severe’ by 62% and ‘weak or moderate’ by 23%.
Perceptions of the likelihood of capture and corruption
Perceptions regarding the likelihood of being caught landing a banned shark varied widely, ranging from 0 to 100%. Overall, 48 (19%) respondents believed there was no chance of being caught, and 49 (19%) perceived a relatively high likelihood (> 60%), most of whom (45) felt there was a 100% chance of being caught (Table 2). The likelihood of being caught varied depending on information leaks or someone informing the coastguard about the presence of banned sharks. As a result, fishers typically sold banned sharks directly to the same shark seller to prevent information reaching the coastguard through third parties. One stated, ‘Let’s say we bring a banned shark and promise to sell it to one person for LKR 1,000. Another person comes and offers to buy it for LKR 1,200. We cannot sell it to the second person…if we do so, the first person gives a hint to some officer and betrays us. That’s why we give those sharks to the same person as agreed upon’.
It was noted by fishers that the coastguard faces challenges with the taxonomic identification of sharks as well as the feasibility of inspecting cold rooms filled with ice, leading to increased opportunity for non-compliance and a decreased likelihood of being caught. They explained that individuals landing banned sharks typically remove the gut, head and fins, making identification difficult. Respondents stated that banned sharks are unloaded daily by at least 2–3 vessels at different locations, without getting caught. One fisher said, ‘To get caught, Navy officers should be there when we unload these sharks. They only inspect us just after we return to the harbour. Furthermore, those officers lack the knowledge and are unable to distinguish between banned and non-banned shark species’.
A perceived key reason behind non-compliance is bribery, with officers accepting monetary bribes or a share of the fish catch, and favouring fishers with personal connections, leading to distrust in law enforcement. Fishers explained that vessels they perceived as poorer are more frequently punished for non-compliance, while wealthier vessels, particularly those owned by individuals with multiple vessels, often evade any consequences for illegal shark landings, creating an unfair situation. One fisher said, ‘Normally, fishers don’t get caught unless someone provides a hint. However, if we do get caught, there are ways to escape. For instance, if I contact a specific officer or offer bribes, I can be safe. There are rules and regulations in Sri Lanka, but they are not implemented’.
Wider drivers of non-compliance
Some fishers (66, 26%) believe discarding banned shark catches is wasteful. For example, one fisher stated: ‘If a banned shark gets entangled in our nets and is already dead, throwing it away into the sea is useless. It is not beneficial for us fishers or the sea.’ Fishers explained they felt it was unfair to be told to release banned sharks, especially after working hard to earn a living. For example, one fisher said: ‘For instance, someone might have caught only oceanic whitetip sharks but is still required to remove them because of the law’.
Other factors that led to the perceived unfairness of regulations included the inability to selectively target permitted shark species; other countries, such as India, continuing to target banned species in high-sea areas; and regulations preventing fishers from drying sharks onboard (a traditional practice). Some fishers emphasized the poor communication regarding why only some shark species are banned. Similarly, some felt that species-specific bans were the Sri Lankan government’s response to international pressure to enact shark conservation. Fishing strategies and social-cultural drivers (Supplementary Table 6) were also identified as factors that affect the non-compliance behaviour of respondents.
Discussion
Social dimensions are often overlooked in shark management and policy design, undermining their effectiveness (Booth et al., Reference Booth, Squires and Milner-Gulland2019; MacKeracher et al., Reference MacKeracher, Diedrich and Simpfendorfer2019). Our research provides new insights into the drivers of non-compliance in Sri Lankan shark fisheries operating inboard multi-day vessels. Our findings reveal that fishers of these vessels engage in both forms of non-compliance, landing of banned shark species and fishing in other countries’ exclusive economic zones to target sharks to varying degrees, influenced by factors such as awareness of regulations, social networks and perceived penalties. These findings highlight the importance of considering social dimensions in designing management strategies to address non-compliance.
Occurrence of non-compliant behaviour
Although asking questions about illegal behaviour is likely to generate non-response and response biases (Nuno & St John, Reference Nuno and St John2015), and the estimates reported here are conservative, our data provide evidence of the occurrence of non-compliant behaviour among Sri Lankan fishers operating inboard multi-day vessels. This confirms previous studies that found banned species, including thresher sharks and oceanic whitetip sharks, at markets in Sri Lanka (Collins et al., Reference Collins, Nuno, Benaragama, Broderick, Wijesundara, Wijetunge and Letessier2021; Peiris et al., Reference Peiris, Kumara, Ranatunga and Liu2021). In addition to reporting illegal shark landings by themselves and their friends, respondents also mentioned vessels entering other countries’ exclusive economic zones to target sharks. Respondents reported that declines in sharks in local waters are prompting them to venture into high seas and areas where, according to their perception, shark populations are higher. This supports other studies that suggested fishers tend to fish in foreign waters when sharks in traditional, local waters are heavily exploited (Schiller et al., Reference Schiller, Bailey, Jacquet and Sala2018; Collins et al., Reference Collins, Nuno, Benaragama, Broderick, Wijesundara, Wijetunge and Letessier2021). Our findings also indicate ongoing instances of landing prohibited species of sharks, primarily from bycatch in tuna fisheries (Balawardhana et al., Reference Chaturika Balawardhana, Randika Dalpathadu and Sisira Kumara Haputhantri2018), with a few vessels directly targeting sharks. This contradicts previous claims (Hasarangi et al., Reference Hasarangi, Maldeniya and Haputhantri2012) that Sri Lankan fishers no longer target sharks.
Drivers of non-compliance
Economic incentives have been widely identified as a key driver of non-compliance in other studies (Sumaila et al., Reference Sumaila, Alder and Keith2006; Agnew et al, Reference Agnew, Pearce, Pramod, Peatman and Watson2009), a finding supported by our research. Although the international market for shark fins in East Asia has traditionally been identified as the primary driver of shark harvests (Clarke et al., Reference Clarke, Milner-Gulland and Bjørndal2007; Cardeñosa et al., Reference Cardeñosa, Fields, Babcock, Zhang, Feldheim and Shea2018), our data highlight the importance of strong demand and high, stable prices for shark meat and dried fish within the domestic market. Our data suggest some fishers were driven to illegal behaviours by the economic crisis in Sri Lanka, which accelerated in 2022 as a result of the country’s depletion of foreign reserves, and led to shortages of food, fuel, medication and other essential goods (George et al., Reference George, George and Baskar2022; Sharma et al., Reference Sharma, Anawade and Sahu2022). This is supported by other studies that show how socio-ecological shocks, such as an economic crisis, can have negative effects on compliance (Quimbayo et al., Reference Quimbayo, Silva, Barreto, Pavone, Lefcheck and Leite2022). Nevertheless, our findings indicate these fishers target sharks primarily to obtain additional income, underscoring that while poverty may drive some resource users to engage in shark fishing for basic needs, it is not the sole economic motivation resulting in non-compliance.
Enforcement is crucial for ensuring compliance, with weak enforcement often linked to low compliance (Alabsi & Komatsu, Reference Alabsi and Komatsu2014). However, several studies have indicated that the perceived impact of sanctions may differ based on various factors, including social context (Collins et al., Reference Collins, Letessier, Broderick, Wijesundara and Nuno2020) and prior experience such as previous interactions with enforcement personnel or processes (Battista et al., Reference Battista, Romero-Canyas, Smith, Fraire, Effron, Larson-Konar and Fujita2018). Similarly, respondents in our study reported instances of corruption, such as monetary bribes or sharing catches with monitoring officers, with these behaviours reportedly more commonplace amongst individuals of better economic standing, leading to negative perceptions of sanctions among other fishers. Booth et al. (Reference Booth, Milner-Gulland, Bang, Bull, Moreno-Ternero and Squires2024) discuss this issue in the context of distributive justice, highlighting how the unequal distribution of costs can result in poor social and biodiversity outcomes, thereby fostering non-compliance. Additionally, some respondents believed that punishments are insufficient compared to the gains from illegal shark fishing, further supporting the economic rationale for engaging in this behaviour.
Other social drivers of non-compliance were identified, including legitimacy. We found that fishers perceived unfairness in regulations, particularly the requirement to discard banned sharks and also the lack of consequences for Indian fishers who, according to respondents, face no punishments under their own country’s regulations for illegally fishing for sharks in the same fishing grounds (e.g. Chagos Archipelago Marine Protected Area). Additionally, as some fishers perceived that regulations were created to comply with international guidelines rather than for genuine ecological or conservation reasons, this led to reduced perceptions of legitimacy regarding regulations. This is likely to jeopardize the current measures given that natural resource users are more likely to feel obliged to comply if they perceive regulations as fair and legitimate, even when non-compliance could benefit them personally (Nielsen, Reference Nielsen2003; Turner et al., Reference Turner, Addison, Arias, Bergseth, Marshall, Morrison and Tobin2016). Relatedly, we found that both fishers and monitoring officers lacked sufficient knowledge of the regulations and their ecological justification. Lack of knowledge regarding the environmental justification for regulations has also been identified as a driver of non-compliance (Jagers et al., Reference Jagers, Berlin and Jentoft2012).
Previous studies have suggested that social networks influence the perceived acceptability of non-compliance (Arias & Sutton, Reference Arias and Sutton2013). Similarly, we found some evidence of the importance of social networks in both facilitating the transmission of information regarding non-compliance and influencing perceived social norms around the acceptability of it. Given that compliance can be determined by the extent to which rule-breaking is negatively perceived by peers and the fishing community (Jagers et al., Reference Jagers, Berlin and Jentoft2012), the relatively high perceived rates of non-compliance among friends of study respondents may contribute to rule-breaking becoming normalized, particularly within specific networks, leading to increased non-compliance.
Wider fisheries management implications
Effective fisheries management typically requires a policy framework with clear objectives, a set of laws and regulations to govern resource users’ behaviour, and robust enforcement mechanisms to ensure compliance (Alabsi & Komatsu, Reference Alabsi and Komatsu2014). Non-compliance is framed in previous studies as an interaction between motivated actors and opportunities (Clarke, Reference Clarke1980; Oyanedel et al., Reference Oyanedel, Gelcich and Milner-Gulland2020); addressing it thus requires a robust understanding of drivers. Our findings emphasize the role of various drivers in affecting compliance (e.g. economic factors, legitimacy and perceived fairness) and, although their importance may vary, these should be carefully considered when planning the design of potential incentive programmes. For example, financial incentives for compliance with shark regulations can be more effective than traditional regulatory methods with penalties (Booth et al., Reference Booth, Ramdlan, Hafizh, Wongsopatty, Mourato and Pienkowski2023). When monetary value is not the sole determinant of fisher behaviour, financial incentives can be integrated with community-led initiatives, such as cooperative management systems, where traditional practices and social norms are recognized and reinforced alongside monetary benefits to enhance intrinsic motivations for compliance (Grillos et al., Reference Grillos, Bottazzi, Crespo, Asquith and Jones2019). However, such incentive programmes need to be tailored to specific local conditions, considering ecological, socio-economic and institutional factors (Börner et al., Reference Börner, Baylis, Corbera, Ezzine-de-Blas, Honey-Rosés, Persson and Wunder2017; Booth et al., Reference Booth, Ramdlan, Hafizh, Wongsopatty, Mourato and Pienkowski2023). This approach could be trialled in Sri Lanka, although financial constraints may pose a barrier, requiring additional funding sources.
Fishers in our study mentioned that some monitoring officers (although not all) cannot distinguish prohibited species from other shark species, which undermines management of shark conservation. Similar to other areas (Wosnick et al., Reference Wosnick, Prado, Giareta, da Cruz, dos Santos and Leite2019), evisceration, decapitation and finning prior to landing can be particularly problematic for proper monitoring, impairing the correct identification of species. However, improving monitoring is costly for developing countries (Doumbouya et al., Reference Doumbouya, Camara, Mamie, Intchama, Jarra and Ceesay2017), requiring more cost-effective collaborative approaches (Iwane et al., Reference Iwane, Leong, Vaughan and Oleson2021). Peer monitoring, or placing the burden of proof on fishers, can be an effective strategy. Although a reward-based approach such as incentives for live shark releases can encourage compliance (Wosnick et al., Reference Wosnick, Giareta, Leite, Hyrycena and Charvet2023), implementing these incentive-based tools may have financial implications for Sri Lankan authorities. Their suitability is also uncertain for an offshore fleet where incidental capture of sharks is frequent, which may lead to high numbers of claims and increased administrative burden. Partnering with NGOs to pilot schemes could decrease the financial burden and support transitioning to community-driven management. Furthermore, ensuring fair enforcement of regulations for all fishers, regardless of economic status, can foster distributive justice and uphold the shared responsibilities of compliance.
Fishers also reported instances of corruption among monitoring officers, potentially driven by personal motivation, which undermines enforcement efforts and requires urgent attention. As suggested by Moreto et al. (Reference Moreto, Brunson and Braga2015), strategies such as building internal organizational capacity, enhancing leadership integrity, establishing internal affairs units, and strengthening supervisory oversight can help to mitigate corruption. However, the Sri Lankan context needs to be further researched to identify the root causes of corruption and to tailor interventions to address underlying motivations effectively.
Ensuring that fishers are sufficiently aware of regulations is essential for the success of regulatory efforts (Islam et al., Reference Islam, Shamsuzzaman, Mozumder, Xiangmin, Ming and Jewel2017). Efforts to enhance access to information and conduct targeted campaigns for fishers, aimed at addressing relevant perceptions and improving regulatory knowledge, have been shown to motivate behaviour change (Butler et al., Reference Butler, Green and Galvin2013; Battista et al., Reference Battista, Romero-Canyas, Smith, Fraire, Effron, Larson-Konar and Fujita2018). Moreover, the social networks used by fishers play a crucial role in motivating their participation in conservation projects (Iwane et al., Reference Iwane, Leong, Vaughan and Oleson2021). In Sri Lanka, social networks and key community actors could be more effective in improving awareness of regulations amongst fishers and securing their support in managing shark fishing. Future research could seek to assess monitoring and the awareness of enforcing officers, perceptions of the effectiveness of national shark fishing management regulations and challenges in implementing the regulations.
Finally, our results highlight the persistent non-compliance of shark fisheries in Sri Lanka, which undermines conservation efforts. This underscores the importance of understanding social dimensions and integrating them into policy frameworks to manage non-compliance effectively. Furthermore, we advocate adoption of a collaborative and inclusive fisheries management approach that could achieve sustainable outcomes for both shark populations and reliant communities (Angel et al., Reference Angel, Edwards, Hawkshaw, Wor and Parlee2019). This would ensure a holistic strategy in which conservation objectives are integrated with socio-economic considerations, balancing conservation goals with fisheries’ socio-economic needs (Booth et al., Reference Booth, Squires and Milner-Gulland2019; Mizrahi et al., Reference Mizrahi, Duce, Pressey, Simpfendorfer, Weeks and Diedrich2019).
Supplementary material
The supplementary material for this article is available at doi.org/10.1017/S0030605325000432
Author contributions
Study design: LGG, CC, AdV, MFMF, AN; data collection: LGG, OD, DB; data analysis: LGG; writing: LGG, CC, AdV, AN, MFMF.
Acknowledgements
We acknowledge the fishers, skippers and boat owners who generously provided their time; and we thank Dulari Harsha for transcription and Tharusha Neththipola for assistance with map preparation. This research was supported by funding from the Bertarelli Foundation as part of their Marine Science Programme.
Conflicts of interest
None.
Ethical standards
This research was reviewed and approved by the Zoological Society of London (Reference: ZSLHEC-003) and abided by the Oryx guidelines on ethical standards.
Data availability
The data collected in this study are strictly confidential, to protect the anonymity of the research participants. Requests to access the fully anonymized datasets should be directed to the corresponding author, LGG.
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