Cyanide Fishing Research Articles

An Overview of Destructive Fishing in the Philippines

The Philippines, being positioned in the center of the coral triangle, is among the major-fish producing countries globally. However, in many parts of the country, illegal fishing is rampant, particularly destructive fishing practices (DFPs). Fisheries involving DFPs cause direct ecological damage to the corals. These fishing activities threaten both natural habitats and aquatic resources. In this review paper, we reviewed available scientific literature reporting the DFPs in the Philippines from 1979 to 2022. Results revealed that most DFPs, such as dynamite fishing, cyanide fishing, and muro-ami fishing, were prevalent and remained a lingering problem in the Philippines from the 1930s up to this date. The weak enforcement of the existing laws and regulations fuels these activities, compromising the productive coral reef areas in the Philippines. Thus, it is urgently necessary to cease these DFPs as well as protect the integrity of vital and fragile ecosystems. It is therefore recommended that strict implementation of the laws and regulations at local and national levels is likely to stop or if not least, reduce the pressing issues of destructive fishing techniques.

Simulating cyanide fishing: photosynthetic effects of short-term cyanide exposure in three different hermatypic coral species

ABSTRACT Since the 1960s the demand for ornamental aquarium fish has grown steadily and consequently cyanide fishing is still a popular fishing method despite its prohibition. This poses a severe threat to coral reefs in Southeast Asia. This study aimed to investigate the short-term stress reaction on photosynthetic yield in the tissues of three different hard coral colonies (branching growth forms Pocillopora damicornis and Seriatopora hystrix, and massive Porites lobata) to initially high and then decreasing cyanide exposure, mimicking cyanide fishing by fishermen. Experiments were performed both in situ in the coral reefs of the Marine Protected Area Pulau Pieh, West Sumatra, Indonesia, and in the aquaria facilities of ZMT in Germany. A Diving-PAM fluorometer was used for in vivo stress assessment of the holobiont. While in all species the photosynthetic efficiency was significantly reduced right after cyanide application, the massive species displayed much lower ΔF/Fm’ values. After three days in cyanide-free water all three coral species recovered to initial values of Fv/Fm, except for P. lobata. No bleaching or discolouration was detected by the conclusion of the experiment after 38 days. Especially Indonesian reefs with massive corals may be therefore more severely impacted by cyanide fishing since the retention time of the water in these reefs is longer than in reefs that consist primarily of branching corals. This might have implications for the management of different reef parts of the MPA.

Fishing practices of the small scale fisheries in the selected coastal barangays of Malita, Davao Occidental

Small scale fishery is very important in many regions especially in developing countries. Their catches mostly contributed to the food being served in the table of middle to low income family. This study was conducted to identify the different fishing practices, catch composition and volume, fishing gears and the perception of the fishers in certain government restrictions implemented in the municipal waters of Malita, Davao Occidental. The researcher interviewed a total of 60 fishers in two fishing communities of the municipality barangay Tubalan and barangay Fishing Village. Based on the result of the study, majority of the fishers were male at the age bracket of 41-50 years old (Tubalan) and 31-40 years old (Fishing Village) with fishing experience of 1-10 years for Tubalan fishers and 11-20 years for Fishing Village Fishers. Most of the fishing family annual income range from 30,000 to 69,000.00 pesos. Fishers in both barangay spend their time fishing in the municipal waters of Malita and sometimes venture outside the municipal waters but within the Davao Gulf. Fishing practices were mostly passive (line fishing) with mist catch comprising pelagic fish species (scads, Tunas and squids). Fishers in both barangay agree that fishing restriction must be implemented to maintain fish catch and to sustain fish production in the area, fishing practices like blast and cyanide fishing were strongly supported by the fishers to be restricted and they know that implementation of fishing restriction in specific fishing practices is beneficial to them.

Potentiometry for Cyanide Detection Applied to Fisheries Regulation

Illegal cyanide fishing is practiced by some fishers to capture agile and otherwise inaccessible reef fishes easily. Economic incentives had prevented discontinuation of the practice despite regulations present. Aside from the well-known toxicity of cyanide, it is a concern whether the fish is for ornamental purposes or human consumption that cyanide is being used because of the environmental damage it can cause by killing off non-target species. Currently, the cyanide content of fish is determined using an ion-selective electrode (ISE), with distillation as the mode of extraction of cyanide from tissues. This paper reports a modification of ASTM Method 500-CN-E, a method originally used to test for cyanide content in the wastewater. This paper outlines the process of determining the applicability of the method modification for analysis of fish tissue samples, in which no standard method was designed specifically for the matrix mentioned above. Although percent recoveries for cyanide at 0.05-10 mg/L range in spiked distilled water matrices are in line with the American Society of Testing and Materials (ASTM) results (90-105%), cyanide recoveries in spiked fish tissue matrices at the same concentration range are appreciably lower (~60-80%). For regulatory purposes, it serves as a temporarily acceptable method to detect cyanide-laden fish until a suitable method can be validated on international standards. However, to be accepted as a standard method, additional modifications may be needed or proven in inter-laboratory tests that the recovery of cyanide in fish is consistently low.

The determination of thiocyanate in the blood plasma and holding water of Amphiprion clarkii after exposure to cyanide.

The illegal practice of cyanide fishing continues throughout the Indo-Pacific. To combat this destructive fishing method, a reliable test to detect whether a fish has been captured using cyanide (CN) is needed. We report on the toxicokinetics of acute, pulsed CN exposure and chronic thiocyanate (SCN) exposure, the major metabolite of CN, in the clownfish species, Amphiprion clarkii. Fish were pulse exposed to 50 ppm CN for 20 or 45 s or chronically exposed to 100 ppm SCN for 12 days and blood plasma levels of SCN were measured. SCN blood plasma levels reached a maximum concentration (301–468 ppb) 0.13–0.17 days after exposure to CN and had a 0.1 to 1.2 day half-life. The half-life of blood plasma SCN after chronic exposure to SCN was found to be 0.13 days. Interestingly, we observed that when a fish, with no previous CN or SCN exposure, was placed in holding water spiked to 20 ppb SCN, there was a steady decrease in the SCN concentration in the holding water until it could no longer be detected at 24 hrs. Under chronic exposure conditions (100 ppm, 12 days), trace levels of SCN (∼40 ppb) were detected in the holding water during depuration but decreased to below detection within the first 24 hrs. Our holding water experiments demonstrate that low levels of SCN in the holding water of A. clarkii will not persist, but rather will quickly and steadily decrease to below detection limits refuting several publications. After CN exposure, A. clarkii exhibits a classic two compartment model where SCN is eliminated from the blood plasma and is likely distributed throughout the body. Similar studies of other species must be examined to continue to develop our understanding of CN metabolism in marine fish before a reliable cyanide detection test can be developed.

Leaky bodies: masculinity and risk in the practice of cyanide fishing in Indonesia

Dive fishing with cyanide is known as a risky fishing practice, as it pushes or lures divers to the limits of what their bodies can take. Its association with physical danger is linked to a culture of machismo and a coming-of-age process in which young men prove their bravery and become part of a shared manhood. What often remains implicit in the understanding of risk-seeking activities is the notion of body and masculinity that such practices entail and produce. Understanding risk and how it relates to masculinity in native terms requires conceptual tools to think beyond the self-contained body that navigates an external environment. Based on long-term ethnographic fieldwork in Indonesia, this article explores cyanide dive fishing in the context of risky practice in relation to the body as contingent, permeable and leaky. Drawing from situated narratives and post-human phenomenology, the article makes room for masculinities beyond the self-contained man by describing dive fishing as a transformative process of becoming fluid to a submerged world of currents and spirits. By showing how this process brings bodies to or beyond their threshold of endurance, the article sheds light on the situated vulnerabilities of dive fishers in an environment of exploitation.

Synergistic Effects of Ocean Warming and Cyanide Poisoning in an Ornamental Tropical Reef Fish

An array of anthropogenic pressures is affecting tropical ecosystems, posing major conservation challenges for scientists, stakeholders and populations. Illegal cyanide fishing is one of the major threats to Indo-Pacific coral reefs, targeting a multitude of colorful species for the marine aquarium trade as well as large-sized groupers and wrasses for the food fish trade. Ultimately, the continued use of this destructive practice as oceans warm may overload tropical ecosystems and result in irreversible ecological damage. Here we show that the impact of cyanide poisoning in ornamental tropical marine fish is magnified under increased temperatures. A sole pulse exposure of 60 seconds to 50 mg L-1 of cyanide under current temperature (26 oC) caused substantial mortality (50-100 %) in eight species of Pomacentridae. The clownfish Amphiprion ocellaris was the most resilient, especially medium-sized fish (average total length and weight of 38 mm and 1.12 g; LC50 (95% CI) = 50.00 (46.76 – 53.24) mg L-1) that showed shorter recovery times and higher survival rates (%) when compared to small-sized ones (average total length and weight of 25 mm and 0.30 g; LC50 (95% CI) = 28.45 (20.17 – 36.72) mg L-1). However, when the most resistant size-class was concomitantly exposed to a sub-lethal dosage of cyanide (25 mg L-1 instead of 50 mg L-1) and ocean warming scenarios for 2100 (+3 oC and heat wave +6 oC), survival rates (%) decreased to 60 % and 20 %, respectively and recovery times increased in the worst case scenario. Mortality outbreaks, as well as vulnerability to predation, will likely expand in fish inhabiting coral reefs exposed to cyanide fishing unless stronger conservation measures are taken in tropical reefs to limit this destructive practice now and in the oceans of tomorrow.

Detecting illegal cyanide fishing: Establishing the evidence base for a reliable, post-collection test

Ornamental fish have been legally harvested since the 1930's but in the 60's, cyanide fishing was first documented. Target fish exposed to the chemical are temporarily paralysed making them easier to catch, but with high post-capture mortality and significant ecological impacts, its use is banned in most exporting countries. To differentiate illegally caught fish from those sustainably collected, efforts to develop a post-collection detection test began nearly 30 years ago. However, even the most promising approach has been questioned by other researchers as unrepeatable under different experimental conditions. In this paper we summarise the evidence-base for establishing a cyanide detection test for live fish by evaluating current approaches. We describe the key knowledge gaps which continue to limit our progress in implementing a screening programme and highlight some alternative solutions which may provide greater short to medium term opportunities to prevent the illegal practise before fish enter the supply chain.

Destructive Fishing Practices

The objective of this study is to find out and explain the destructive fishing practices occurred in Taka Bonerate National Park area and the factors that caused it. Data retrieval was conducted with in-depth interview techniques, literature studies and documents. The results showed that destructive fishing practices were still prevalent in the Taka Bonerate National Park area, both using chemicals (cyanide) and those using explosives (bombs) in fishing activities. The conclusions from this study are that fisheries destructive activities are generally not carried out individually but in groups, namely 3-4 people led by a captain. There are several contributing factors to the proliferation of destructive fishing practices in the small islands of Taka Bonerate National Park. Where they are still under guarded, and the conflicts of authority among the Taka Bonerate National Park management authorities, conflicts between fishermen, and availability of bombs and cyanides raw materials. The other are strong position of retainer and weak position of mustard in patron client relations between punggawa-sawi. The last factor but not least, that there are markets for them to sell the bombs and cyanide fishing.

Defining research priorities to detect live fish illegally collected using cyanide fishing in Indo-Pacific coral reefs

Indo-Pacific coral reefs face an unprecedented level of anthropogenic pressure. Cyanide fishing is a highly destructive method employed to capture live fish from Indo-Pacific coral reefs and supply the live fish food trade in Asia and the global marine aquarium trade. To allow the development and implementation of an effective and reliable testing platform to screen live reef fish for cyanide poisoning, without their sacrifice, and thus contribute to the ban of this practice from Indo-Pacific coral reefs, the following research topics must be urgently addressed: 1) selection of a suitable model species; 2) standardization of experimental methodologies; 3) exclude the possibility that the target compound(s) being monitored to detect live reef fish illegally collected using cyanide originate from other sources than cyanide poisoning; 4) clarification of the excretion physiology and cyanide pharmacokinetics in marine fish; and 5) evaluate interspecific differences in excretion physiology and cyanide pharmacokinetics in marine fish.

On the half-life of thiocyanate in the plasma of the marine fish Amphiprion ocellaris: implications for cyanide detection.

The illegal practice of using cyanide (CN) as a stunning agent to collect fish for both the marine aquarium and live fish food trades has been used throughout the Indo-Pacific for over 50 years. CN fishing is destructive to all life forms within the coral reef ecosystems where it is used and is certainly one of many anthropogenic activities that have led to 95% of the reefs in the Indo-Pacific being labeled at risk for degradation and loss. A field-deployable test for detecting fish caught using CN would assist in combating the use of this destructive practice, however, no reliable and robust test exists. Further, there is little toxicokinetic data available on marine fish to support the development of such a test, yet such data is critical to establishing the concentration range and time scale over which such a test would be viable. This study presents the first direct measurement of the half-life of the metabolite thiocyanate (SCN) after pulsed exposure to CN in a marine fish. SCN was measured in the plasma of Amphiprion ocellaris after exposure to 50 ppm CN for three exposure times (20, 45, and 60 s) using HPLC-UV and a C30 column pre-treated with polyethylene glycol. Plasma SCN levels observed are dose-dependent, reflecting a longer time for conversion of CN to SCN as the dose of CN increases. SCN plasma levels reached a maximum concentration (1.2–2.3 ppm) 12–20 h after exposure to CN. The half-life for the elimination of SCN was 1.01 ± 0.26 days for 45 s exposure and 0.44 ± 0.15 days for 20 s exposure. Fish were also directly exposed to SCN (100 ppm for 11 days) and the observed half-life for SCN elimination was 0.35 ± 0.07 days. Plasma SCN levels did not return to control levels, even after 41 days when exposed to CN but did return to control levels after 48 days when exposed to SCN. The similar half-lives observed for CN and SCN exposure suggests that SCN exposure can be used as a proxy for measuring the rate of SCN elimination following CN exposure. In order for plasma SCN to be used as a marker for CN exposure, these results must be extended to other species and endogenous levels of SCN in wild caught fish must be established.

Acute toxicity of cyanide (KCN) on two types of marine larvae: Acropora sp. planulae and D-veliger larvae of Tridacna squamosa

Cyanide fishing has been intensively used to catch aquarium fishes and fish for human consumption around coral reefs in the South East Asian countries, such as Indonesia. There is little known about the lethal effect of cyanide on the early life stages of marine organisms. We assessed mortality and morphological changes of Acropora sp. planulae and fluted giant clam (Tridacna squamosa) D-veliger larvae exposed to potassium cyanide (KCN) concentrations closed to those used in cyanide fishing. The KCN concentration exposure treatments for coral planulae were 50, 100, 300, 600, and 1000 mg L−1; and those for giant clam D-veliger larvae were 18.875, 37.5, 75, 300, and 600 mg L−1. The 24 hour static-acute toxicity test was used with four replicates for each concentration. The 24h-LC50 was calculated based on Finney’s Probit Analysis Method, and the 24 h-LC50 for coral planulae and giant clam veliger were 121.854 and 84.421 mg L−1, respectively. The D-veliger larvae of Tridacna squamosa were more sensitive to KCN exposure than Acropora sp. planulae. In addition to mortality, we observed that, in both the planulae and D-veliger larvae, morphological abnormalities increased in frequency and severity with increasing KCN concentration, even at the lowest KCN concentrations.

Fisher perceptions of threats and fisheries decline in the heart of the Coral Triangle

Larsen SN, Leisher C, Mangubhai S, Muljadi A, Tapilatu RF. 2018. Fisher perceptions of threats and fisheries decline in the heart of the Coral Triangle. Ocean Life 2: 41-46. The Coral Triangle contains the most species-diverse coral reefs in the world, and at its center is the Raja Ampat archipelago in West Papua, Indonesia. The marine resources of Raja Ampat are an important source of food and livelihood for thousands of people, but overfishing and destructive fishing practices threaten its coral reefs and fisheries. To better understand the threats, we surveyed the ‘most knowledgeable fishers’ in all 88 of Raja Ampat’s coastal villages (n = 495) in 2003-2005. We analyzed the links between declines in fish catch and threats to marine resources as perceived by fishers. Blast fishing, cyanide fishing, and ‘outsiders’ were perceived to be the causes of the fish declines and the greatest ongoing threats to fisheries resources. We also found evidence of inter-generational differences in perceptions on the health of local fisheries. For fishers who had over 15 years of fishing experience, 77% reported a decrease in fish catch. For fishers who had less than 5 years of experience, only 41% reported a decrease in catch. Education and outreach on illegal fishing practices and the benefits of healthy coral reef ecosystems are likely to be ongoing needs in communities in Raja Ampat.Coral reefs

SEAMANCORE: A spatially explicit simulation model for assisting the local MANagement of COral REefs

Simulation models have a broad potential as decision-support tools for resource management by mechanistically representing and projecting complex ecological processes. In the case of socioeconomically and biologically important coral reef ecosystems, models have been used to address important questions regarding the effects of human impacts on their ecological dynamics and to inform management approaches. However, few of the models integrate benthic and fish dynamics with the influence of external anthropogenic stressors, and virtually none is available as a user-friendly platform for non-scientist managers to easily access. We propose a new ecological model to assess the effects of simultaneous stressors on coral reef ecosystems which includes a dynamic representation of benthic and fish spatial processes, linked by their ecological feedbacks. SEAMANCORE is a two-dimensional model representing the dynamics of local coral reefs which can be used to explore the influence of bleaching, eutrophication, and fishing, including destructive fishing such as bomb and cyanide fishing. The model is coupled with a menu-based interface that allows users with no programming experience to simulate numerous scenarios in specific contexts that can be customized with depth profile maps and initial coral reef conditions of fish and benthos functional group abundance. This study includes SEAMANCORE’s description and shows the model’s sensitivity to its parameters by means of sensitivity analyses. Its utility is exemplified by exploring various scenarios of no stressors, fishing and bleaching regimes in a theoretical coral reef. We expect that linking fish demographics with changing habitat quality will prove insightful for fisheries management.

Can excreted thiocyanate be used to detect cyanide exposure in live reef fish?

Cyanide fishing, where a solution of sodium or potassium cyanide is used to stun reef fish for easy capture for the marine aquarium and live fish food trades, continues to be pervasive despite being illegal in many countries and destructive to coral reef ecosystems. Currently, there is no easy, reliable and universally accepted method to detect if a fish has been exposed to cyanide during the capture process. A promising non-invasive technique for detecting thiocyanate ions, the metabolic byproduct excreted by exposed fish, has been reported in the literature. In an effort to validate this method, four cyanide exposure studies on Amphiprion ocellaris (common clownfish) were carried out over three years. Fish were either exposed to the same (25 ppm) or twice the concentration (50 ppm) as the previsouly published method. Over 100 water samples of fish exposed to cyanide were analyzed by reverse phase HPLC with a C30 column treated with polyethylene glycol and UV detector operating at 220 nm. No thiocyanate was detected beyond the analytical standards and positive controls prepared in seawater. As an alternate means of detecting thiocyanate, water samples and thiocyanate standards from these exposures were derivatized with monobromobimane (MBB) for LC-MS/MS analysis. Thiocyanate was detected in standards with concentrations as low as 0.6 μg/L and quantified to 1 μg/L, but thiocyanate could not be detected in any of the water samples from fish exposed to cyanide with this method either, confirming the HPLC results. Further, we calculated both the mass balance of thiocyanate and the resultant plausible dosage of cyanide from the data reported in the previously published method. These calculations, along with the known lethal dosage of cyanide, further suggests that the detection of thiocyanate in aquarium water is not a viable method for assessing fish exposure to cyanide.

Destructive fishing and fisheries enforcement in eastern Indonesia

A simple bioeconomic leader-follower model was constructed to simulate snapper (family Lutjanidae) and grouper (family Serranidae) fisheries in Raja Ampat, Indonesia, an area of significant coral and fish biodiversity. We developed a leader-follower game, wherein the Regency government as the leader chooses an enforcement model to discourage illegal fishing. Fishers are then given a choice to fish using legal gears, such as handlines, or to fish with illegal gears, e.g. dynamite (for snapper) or cyanide (for grouper). Given prices and costs of legal and illegal fishing, the status quo simulations with no Regency enforcement result in a large amount of illegal catch throughout the 50 yr simulation, which agrees with expert opinion that destructive illegal fishing is occurring in the region. In an attempt to include ecosystem-based management principles into Raja Ampat governance, we introduce an enforcement regime in the form of detecting and punishing illegal fishing. Results suggest that current fishing practices do not account for the disproportionate ecosystem effects of destructive fishing, and that elimination of dynamite fishing may be easier for the government due to the high profitability of the live fish trade connected with cyanide fishing.

Shared Space, Conflicting Perceptions, and the Degradation of an Indonesian Fishery

AbstractThis article takes as its subject the degradation, through blast and cyanide fishing, of one of the world's largest and most species diverse coral reefs. Drawing attention to the role of culturally founded spatial models in orienting local perceptions and practices, it provides a case study of how such degradation can proceed unchecked when the social meanings inscribed upon a seascape by those who rely upon it as an economic resource find themselves at the intersection of conflicting cultural models of natural spaces. It is based upon ethnographic fieldwork carried out for over two decades on the small Indonesian island of Balobaloang. Relying upon indigenous cognitive models of both the fishery itself and apposite features of the social structure, including reciprocity and hierarchy, this article demonstrates how, even as they engage with the forces of global capital and universalist models of development, individual actors may continue to privilege social relationships over economic considerations and reciprocity over individual interests.

The Fishery Potential of Freshwater Gobies in Mandulog River, Northern Mindanao, Philippines

Freshwater gobies, particularly fry and some adult species, have been used as an alternative fishery resource. Mandulog River in Iligan City, northern Mindanao, Philippines, is one of the areas known for goby-fry fishery. This study described the potentials of the goby population in Mandulog River in terms of its fishery aspects. Households along the Mandulog River were the respondents of the survey. Results show that most of the freshwater gobies were caught as alternative food while goby-fry were sold in the market. Goby fishing was done five times a year using nets and traps. The maximum catch per fishing session was one to three kilograms and sold at more or less PHP 10 (Philippine Peso) (USD 0.23) per kilogram. Monthly income from goby fishing was from PHP 100 to PHP 200 (USD 2.35 to USD 4.71) only. Goby species such as Sicyopterus lagocephalus, Oxyeleotris lineolata, Awaous melanocephalus, A. ocellaris, Giuris margaritacea, and Rhyacichthys aspro were the preferred prey species. Findings suggest that goby fishing was not a major source of livelihood as fishers were not earning much from it. However, as a bycatch, the goby population is under threat, with their economic and ecological benefits not utilized. Destructive fishing methods such as cyanide fishing, electric fishing, and use of fine mesh nets might also adversely affect the goby population, despite being non-target species. Therefore, protection of target species from overexploitation would also benefit the goby species.

Caught in the Act: How the U.S. Lacey Act Can Hamper the Fight Against Cyanide Fishing in Tropical Coral Reefs

AbstractCyanide fishing is one of the most destructive techniques employed to collect live reef fish. While national laws of most source countries ban this practice, cyanide is still widely employed to capture live reef fish for human consumption and marine aquariums. The United States is one of the largest importers of live reef fish, and the implementation of new approaches to screen for fish caught with cyanide is urgently needed. A fast and reliable noninvasive and nondestructive approach to screen live reef fish for cyanide poisoning was recently developed, yet deployment of this test may be obstructed by U.S. law. The Lacey Act prohibits the import, export, transport, and acquisition in interstate or international commerce of fish taken in violation of any foreign law. Therefore, if a fish tests positive for cyanide poisoning, the testers could expose themselves to liability for potential Lacey Act violations, as they are “knowingly” engaging in an illegal act. To eliminate this disincentive, the U.S. government should help conservationists develop protocols on how to test for cyanide poisoning without violating the Lacey Act.

Indigenous Goby Population in Mandulog River System and its Conservation by Communities in Iligan City, Philippines

Threats of water pollution, unregulated extraction of resources, and sprawling urbanization are some of the common issues of Mandulog River, a home for indigenous freshwater gobies. This study was conducted to assess the status of freshwater gobies and how the resident communities exert conservation efforts to the river and the inhabiting gobies. Standard method of collection of gobies was done. Interviews with semi-structured questionnaires were used to know the conservation measures of the residents. Ten goby species belonging to three families namely, Family Eleotridae (Belobranchus belobranchus), Giuris margaritacea, and Oxyeleotris lineolata, Family Gobiidae (Awaous melanocephalus), Awaous ocellaris, Glossogobius celebius, Glossogobius giuris, Periophthalmus barbarus and Sicyopterus lagocephalus, and Family Rhyacichthyidae (Rhyacichthys aspro), can be an alternative source of food and livelihood. They were caught by-catch, while employing some destructive fishing methods like cyanide fishing, electric fishing, and use of fine mesh nets. The awareness of the residents to the adverse impacts of water pollution, unregulated human activities, and destructive fishing had strengthened their conservation measures. A multi-stakeholder management approach is created through concerted proactive conservation measures like protection of the goby population, the river-riparian ecosystems, enhanced scientific information, and the legal intervention of the local government.