Lake Tanganyika, the deepest and second largest lake in Africa, is shared among the Republic of Burundi in the north, the Democratic Republic of Congo in the west, the Republic of Zambia in the south and the United Republic of Tanzania in the east. Small-scale fisheries existed on the lake well before Greek fishermen introduced industrial purse seining to the Burundian part of the lake in the 1950s. In the period between 1973 and 1983, industrial production was at its peak (Petit, 1995; Mannini, 1998; Katonda, 1993; FAO, 1999; Reynolds et al., 1999; Mölsä et al.,1999; Van Zwieten et al., 2002; FAO, 2006; LTA, 2012b) when the artisanal fisheries started to develop (Van Zwieten et al., 2002; Mölsä et al., 2005). Eventually, the industrial catch rates diminished and gradually the fleet was transferred to the southern part of the lake, where in Zambia a similar phenomenon occurred and the emerging artisanal fishery outcompeted the industrial vessels. Catches of small pelagics were reliably recorded and analysed using the ARTFISH software, introduced by FAO, in Burundi. Based on these catches and the relevant fishing effort data, it could be concluded that catch rates showed considerable decline in the first decade of the millennium. Catch rates (in kg per boat) declined from 200 to 80 kg per boat per day for the Apollo-type of catamarans (fishing units characterized by their outboard engines of at least 40 HP) and from 130 to 50 kg per boat per day for ordinary catamarans (Van der Knaap, 2013).FAO (1978), Roest (1988) and Van Zwieten et al. (2002) emphasized the fluctuating natural recruitment success of the clupeids. However, the fact that two different fleets, operating in the offshore and nearshore waters respectively, showed very similar catch rate trends, it may be concluded that fish abundance in the Burundian waters was declining. Total annual production on the entire lake underwent a considerable reduction from the 1990s, when it was estimated to be between 165,000 and 200,000 tonnes (Mölsä et al., 1999; Reynolds et al., 1999), to a total fish harvest between 110,000 and 120,000 tonnes in 2012 (Van der Knaap, in press). The catch assessment on Lake Tanganyika in 2012 was unique, as the countries benefited from an FAO technical assistance project financed by the African Development Bank. FAO's software to assess artisanal fish catches (ARTFISH), as well as a cost-effective data collection system was introduced, which led to systematic coverage of many fishing unit types at the major landing sites in the four countries. Unfortunately, financial constraints caused the catch assessment survey to be halted. However, sufficient data were collected for a relatively accurate fish harvest estimate.In 2003, a reduction in primary production was predicted to have taken place, due to warming of the water column over the past century, which would have led to 30% diminishment in secondary production (O'Reilly et al., 2003). It is by chance that the reduction observed through catch assessment surveys in the four countries is of the order of 30%, while in the meantime the fishing capacity of the artisanal fleet had doubled; not only the number of fishermen, but also the number of canoes doubled between 1995 and 2011. Doubling the size of the artisanal fisheries also included an increase in illegal, unreported and unregulated (IUU) fishing (LTA Secretariat, 2012a; Van der Knaap et al., 2014a, 2014b).Despite numerous initiatives to curb the illegal fishing and other counter-productive activities in the lake basin, the overexploitation continues. These initiatives included: harmonizing of the fisheries legislation around the lake, strengthening co-management in the four countries, introducing community surveillance, unilateral closed seasons, unilateral banning of destructive fishing gear, etc.This commentary attempts to discuss the revenues of improved fisheries management versus the losses from insufficiently or unmanaged fisheries resources and the basin's natural resources.The four governments around the lake established the Lake Tanganyika Authority (LTA) in 2008, whose secretariat was put in place in Bujumbura, Burundi, in 2009. Its mandate included the management of the lake basin and its biodiversity, fisheries, pollution, etc. (LTA Secretariat, 2012b). Fisheries management in the four countries had different priorities; e.g. the fisheries acts in Burundi and the Democratic Republic of Congo date back to the 1930s, whereas the fisheries acts in Tanzania and Zambia are of much more recent dates.Although fisheries acts and laws exist in all four countries around the lake, there is no, or little, harmonization of management measures applicable to the lake. The Project to Support the Lake Tanganyika Integrated Regional Management Programme (PRODAP), financed by the African Development Fund (of the African Development Bank Group) and implemented by, among others, the Food and Agriculture Organization of the United Nations (FAO), organized the harmonization of the fisheries legislations with respect to Lake Tanganyika, in the four countries, whose recommendations have been introduced to the existing fisheries laws and have been proposed for ratification or have been ratified already (Swan, 2012). Despite these improvements to regulations, acts and laws there is still the open-access characteristic of the fishery (Van der Knaap et al., 2014a). In case of a linear relationship and applying the growth rate in the past 15 years, an increase of 20,000 fishing boats may be expected in six years’ time. Lack of complete registration and licensing systems result in enormous losses to the different administrations. According to the 2011 frame survey results (LTA, 2012a), there are over 160,000 fisheries professionals. At a relatively small annual fee of 10 USD per professional, the total (regional) revenue could be of the order of 1.6 million USD. Approximately 50% of that amount would be required for processing and administering of the transactions and providing the professionals with license badges. The entire system should be facilitated by the use of smart-money operations (transactions using smartphones); this system is operational in all four neighbouring countries.A well-organized licensing and registration system may be an important tool in addressing and harnessing the fishing capacity (Pomeroy, 2011; Van der Knaap, 2013), which was also one of the recommendations in the unpublished and non-implemented RPOA (Regional Plan of Action).The lack of enforcement of the measures against the use of illegal fishing gears and fishing methods condones the utilization of beach seines, monofilament gillnets, mosquito nets, and nets with undersized mesh. Alternatives for the fishermen using these gears and methods are limited. Buy-back systems are not realistic options; however, replacing illegal with regular gear is an option, but this may be costly. The users of prohibited gear are numerous and as such it will be difficult to generate alternative employment for all of them (e.g. operating a beach seine may require up to 20 persons, thus removing one such gear requires 20 alternative sources of income). In the late nineties the annual fish production was estimated between 165,000 and 200,000 tonnes, whereas the production in 2012 was estimated between 110,000 and 120,000 tonnes. The estimated reduction in catches amounts to a total between 55,000 and 90,000 tonnes. The average lake wide price of fish is about 1.00 USD per kg; thus the loss of revenue on the beach is then calculated at a value between 55 and 90 million USD per year.Post-harvest losses at the lakeside have been estimated for DR Congo alone at 20,000 tonnes of fish, which could fetch a total of 20 million USD per year if properly processed, stored and transported. Van der Knaap et al. (2014a) reported over 23,000 fish processors in DR Congo, who could with limited means reduce these losses enormously. A one-time investment could assist many households and turn the losses into gains.Taking into account the reduced catches due to overexploitation, the estimated losses could be of the order of at least 55 million USD per year. The application of fisheries management measures could reduce these losses, thus earning 55 million USD and at the same time contributing to a sustainable fishery by targeting the appropriate fish sizes of the different commercial species. Added to this amount the income at regional level from low-fee licenses of 1.6 million, may result in 56.6 million USD per year.Such revenues do not appear automatically. Such an amount should suffice to encourage the riparian countries to undertake monitoring, control and surveillance (MCS) cruises on a regular basis to combat IUU fishing, particularly with the patrol vessels already supplied by PRODAP. Certain investments will have to be made from the Governments’ sides (with or without external financial support) like additional presence of fisheries officers and other relevant authorities at landing sites; training and sensitization of these officers with respect to prohibited gears and methods; means of communication for these officers; transport; etc. Also, the fishing communities require funding for training and sensitization of beach and landing site representatives; for networking; demarcation of ecologically vulnerable areas; community surveillance.Different co-management systems exist in the four countries with varying rates of success. The Burundian federations of fisheries associations conduct community surveillance, which in the first year led to increased fish landings and subsequently attracted fishers from other areas to take their share of the resource. As fish in the inshore waters were no longer exploited certain cichlid species re-occurred in the catches in deeper waters. Also, the larvae of clupeids recruited to the fishery after an undisturbed period in the inshore waters.AU-IBAR (2016) reported that Burundi had already designated 20 areas in the lake as protected. The Nature Conservancy (TNC) supports the Tuungane Project in Tanzania, which contributes significantly to strengthened co-management in the waters of and around the Maahale National Park, by demarcating fish spawning and nursery areas, identified by the fishing communities themselves. Lessons learned from this experience should be emulated elsewhere.Burundi has a reasonably well-maintained road network along the lake shores and thus the ndagala (Stolothrissa tanganicae and Limnothrissa miodon) can be transported to the capitol city Bujumbura with relative ease. The fish of high quality may find their way to Rwanda where good prices are fetched. In the 1990s the fish consumption in Burundi was 6 kg/year per capita, which has been reduced to 2 kg/year in 2012, according to FAO (Van der Knaap, in press). As a result the demand for cheap fish is high and an illegal fish trade has developed from the Tanzanian part of Lake Victoria to Burundi. Undersized Nile Perch (Lates niloticus) smaller than 50 cm, which, by law, cannot be processed by the exporters, find their way to Burundi, as well as the larger rejected fish from which the swim bladders were removed. Processed Nile Perch carcasses from processing factories around Lake Victoria find their way to the Democratic Republic of Congo, where they arrive across Lake Tanganyika and find their way to many fish markets in eastern DR Congo. These low-quality fisheries products are sold cheaply to the local Burundian and Congolese populations as well as dried Dagaa from Lake Victoria. As such, the demand for cheap fish in the Lake Tanganyika basin encourages illegal fishing in the Lake Victoria basin.By chance, the total fish production has reduced between the late nineties and 2012 by approximately 30%. The question remains whether this is due to climate change or overexploitation.Much has been published on climate change effects on Lake Tanganyika's primary and secondary production. According to O'Reilly et al. (2003) and Cohen et al. (2016) the fisheries production reduced by 30% due to warming up of the water column. That would be a costly effect of climate change of between USD 50 and 60 million. There is continuing discussion about the warming up, stratification and wind patterns in relation to upwelling of lake water (Langenberg et al., 2003; Van der Knaap, in press). It is clear that monitoring and research have to continue and ideally be strengthened to link climate change and overfishing to the reduction of fish harvests. As a compromise both are deemed to have an impact on this reduction. However, the community management experience in Burundi seems to indicate that appropriate fishing methods and gears lead to increase in harvest immediately. It should be taken into account that this may also be caused by the fluctuating natural recruitment success of the clupeids (FAO, 1978; Roest, 1988; Van Zwieten et al., 2002).On Lakes Victoria and Malawi/Nyassa/Niasa1 similar developments have been observed with respect to strongly increased fishing capacity over the past decades. Interesting observations for these lakes are that (despite climate change effects) the productivity and production of small pelagic species, like dagaa/mukene/omena (Rastrineobola argentea) in Lake Victoria and usipa (Engraulicypris sardella) in Lake Malawi, increased spectacularly (Ojwang et al., 2014; Jamu et al., 2011). The production of small pelagics in Lake Tanganyika seems to have decreased although no proper estimates exist. The above-mentioned fish harvest figures are for all species combined, however, discussions with fishermen and representatives of cooperatives corroborate the observation that the clupeid production declined (Van der Knaap, personal observations).Apart from the increased fishing intensity on the three Great African Lakes, also the human population pressures increased around them with commensurate uncontrolled pollution with human waste, as well as the run-off of fertilizers and pesticides, the destruction of wetlands and underwater habitats by sand and gravel mining in the lake and deforestation in the basin. Also, the development of cage culture in the lake could have negative impacts on the water quality of the lake, although at first glance it would be a good opportunity for employment, investment and increased fish production (provided that the cultured species remain the endemic ones, like the Giant Tanganyika Tilapia, Oreochromis tanganicae). A sudden development of cage culture (as experienced on Lake Victoria according to LVEMP [2016]) should be prevented. LTA approved cage culture to a certain extent, but there is no policy or strategy in place to dictate zoning, capacity of farms, prevention of pollution and of escaping fish, water quality monitoring, etc.It has been observed that fish larvae of the Nile tilapia (O. niloticus) were imported from Asian countries, despite the clear agreement in the Lake Tanganyika Convention (LTA, 2003) that exotic and invasive species may not be introduced into the lake's basin. Presently there is another risk threatening tilapias, the Tilapia Lake Virus (TiLV), and as such special care should be taken when displacing live fish from one site to the other (Jansen and Mohan, 2017).The losses in fish harvest and revenues are mainly caused by overcapacity in the fishery and illegal fishing. Climate change may have an effect as well, but this is presently considered having a much lower impact than the overexploitation. If properly managed, the fishery could harvest the same quantity as in the late nineties, but with a much higher value than in those years. To achieve this serious adaptations have to be made to the existing fisheries management measures, regionally harmonized, and with collaboration from the riparian communities. Many tools have been provided by various interventions of development partners and are ready to be used. Political will, relevant investments and continued support to the Lake Tanganyika Authority are required to reinstate sustainable fisheries as well as food and nutrition security for the riparian communities. The losses due to inaction are estimated at more than USD 55 million per year. Regional action will cost much less than that figure. Harmonized action at regional level will yield that amount of funds for continuation of management and sustainable fish harvest.Since the establishment of the Lake Tanganyika Authority in 2008, a considerable number of achievements may be listed which form the basis for rational management for the lake and its basin. Recommendations for regional harmonized fisheries legislation have been prepared and partly followed up. Harmonized monitoring of the fisheries started with the regional frame survey and the catch assessment survey (although this monitoring ceased after 2012). A fisheries information system was prepared and co-management structures promoted. Through sensitization community surveillance was developed, which started to bear fruit immediately by burning illegal fishing gear. With all these harmonized management measures it still remains impossible to manage the fishery.The following reasons could have led to failing fisheries management: continuation of the use of illegal fishing gear and methods; the lack of functional licencing systems for the regulation of access to the fisheries resources; lack of sensitization programs to inculcate (community) surveillance methods; fisheries monitoring that ceased; remote fisheries authorities in three out of four capitol cities; lack of alternative income generating activities and livelihoods; inappropriate fish processing techniques (smoking as well as drying).With the conclusion that states and communities are not satisfactorily and sustainably capable of co-managing Lake Tanganyika's fisheries resources, a new strategy is proposed. It is recommended that the LTA select a co-management “champion” in each country. This might be a Beach Management Unit in Tanzania, a Federation of Fishermen in Burundi, a Village Conservation and Development Committee in Zambia or a Fishermen's Committee in the Democratic Republic of Congo. Ideally a champion be located near a protected area or reserve. However, such a champion could also be an NGO (e.g. the Nature Conservancy in Tanzania) or any other organization. The idea is to convince these possible champions to contribute to appropriate management, which have positive effects on them. These champions should then be actively involved in sharing their positive experiences with their partner organizations and networks through the Lake Tanganyika Authority's institutions. There is an estimated amount of at least 50 million USD to be gained annually. That should be a realistic incentive for the way forward for Lake Tanganyika.