3.1 Relevance of river processes to SDG 14
The SDGs do not recognize inland fisheries explicitly, and certainly do not recognize overfishing in lakes and rivers (Allan et al., Reference Allan, Abell, Hogan, Revenga, Taylor, Welcomme and Winemiller2005; Elliot et al., Reference Elliot, Lynch, Phang, Cooke, Cowx, Claussen, Dalton, Darwall, Harrison, Murchie, Steel and Stokes2022; Lynch et al., Reference Lynch, Cowx, Fluet-Chouinard, Glaser, Phang, Beard, Bower, Brooks, Bunnell, Claussen, Cooke, Kao, Lorenzen, Myers, Reid, Taylor and Youn2017), despite fisheries from freshwater ecosystems (connected or unconnected to the marine environment) provide food security, primary protein and nutrition supply to some of the world’s least developed nations and roughly 158 million people (Ainsworth et al., Reference Ainsworth, Cowx and Funge-Smith2021; Funge-Smith & Bennett, Reference Funge-Smith and Bennett2019; McIntyre et al., Reference McIntyre, Liermann and Revenga2016). It is important to point out that this issue also affects developed countries for a variety of fishery types (Driscol, Reference Driscol2015; Embke et al., Reference Embke, Rypel, Carpenter, Sass, Ogle, Cichosz, Hennessy, Essington and Zanden2019). Often inland fisheries are highly dispersed, lack infrastructure and management capacity, consist of artisanal or small-scale fishing, are lower in economic value and result in a subsistence-oriented harvest. The combination of these factors makes understanding impacts difficult (Bartley et al., Reference Bartley, Graaf, Valbo-Jørgensen and Marmulla2015). Progress towards improving inland fisheries, as suggested by the United Nation’s Rome Declaration (Cooke et al., Reference Cooke, Nyboer, Bennett, Lynch, Infante, Cowx, Beard, Bartley, Paukert, Reid, Funge-Smith, Gondwe, Kaunda, Koehn, Souter, Stokes, Castello, Leonard, Skov and Taylor2021), has become constrained by these limitations and in many cases freshwater fisheries are heavily fished (Lynch et al., Reference Lynch, Bartley, Beard, Cowx, Funge-Smith, Taylor and Cooke2020). Most recently, a 10-year fishing moratorium for the Yangtze river was put into effect on 1 January 2021, which affects roughly 250,000 fishers according to mainstream media (Xiaoyi & Yameng, Reference Xiaoyi and Yameng2021). Drastic management actions, such as fishery closures, can help restore biodiversity and combat overfishing, but can work against the livelihoods and rights (e.g. ancestral, cultural, access arrangements, food security) of small-scale and subsistence fishers.
The construction and removal of water infrastructure (i.e. dams, water diversions, power plants and levees) is an example of a drastic ecosystem intervention that poses both opportunities and challenges for inland fisheries (Grill et al., Reference Grill, Lehner, Thieme, Geenen, Tickner, Antonelli, Babu, Borrelli, Cheng, Crochetiere, Macedo, Filgueiras, Goichot, Higgins, Hogan, Lip, McClain, Meng, Mulligan and Zarfl2019). On the one hand, fishery production of a reservoir can provide ways to increase capture and develop aquaculture, although it rarely replaces the lost river fisheries. On the other hand, barriers may generally result in reductions in fish catches, loss of biodiversity and interruption of ecosystem processes (Hughes, Reference Hughes2021; Petts, Reference Petts1984). They may also prevent migration of diadromous and potadromous fishes if appropriate fish passage facilities are not installed (Winemiller et al., Reference Winemiller, Mcintyre, Castello, Fluet-Chouinard, Giarrizzo, Nam, Baird, Darwall, Lujan and Harrison2016). In extreme cases, large-scale water diversions could both fundamentally change flows within river systems and contribute to water scarcity (Shumilova et al., Reference Shumilova, Tockner, Thieme, Koska and Zarfl2018).
Dams are designed for many purposes, which results in a complex array of impacts for both freshwater and diadromous fishes (Barbarossa et al., Reference Barbarossa, Schmitt, Huijbregts, Zarfl, King and Schipper2020). Often, such infrastructure development involves neither fishing communities in the planning nor discussions around needs for fish passage or other mitigation measures. For example, floodplain fisheries in the Mekong river basin that depend on annual flood regimes have encountered conflict with rice farmers as their levees and water management structures are used to convert floodplains into rice production (Lynch et al., Reference Lynch, Baumgartner, Boys, Conallin, Cowx, Finlayson, Franklin, Hogan, Koehn, McCartney, O’Brien, Phouthavong, Silva, Tob, Valbo-Jørgensen, Vu, Whiting, Wibowo and Duncan2019). Similar conflicts among inland fisheries and irrigation needs have been shown in the Murray–Darling basin (Lynch et al., Reference Lynch, Baumgartner, Boys, Conallin, Cowx, Finlayson, Franklin, Hogan, Koehn, McCartney, O’Brien, Phouthavong, Silva, Tob, Valbo-Jørgensen, Vu, Whiting, Wibowo and Duncan2019). Tributaries that are unobstructed by dams can still be affected by main stem rivers that are dammed because of the backwater effects of inundation and disconnection of migratory fish pathways (swimways) (Worthington et al., Reference Worthington, van Soesbergen, Berkhuysen, Brink, Royte, Thieme, Wanningen and Darwall2022). Riverine capture fisheries, such as the Murray–Darling basin, Brazilian Amazon and the Columbia river, are minimizing further deterioration by supporting science-based management and adapting governance for a shared water body (Cooke et al., Reference Cooke, Nyboer, Bennett, Lynch, Infante, Cowx, Beard, Bartley, Paukert, Reid, Funge-Smith, Gondwe, Kaunda, Koehn, Souter, Stokes, Castello, Leonard, Skov and Taylor2021).
Systems that cannot overcome the challenges associated with existing capture fisheries have also considered further development of aquaculture (Valenti et al., Reference Valenti, Barros, Moraes-Valenti, Bueno and Cavalli2021). Aquaculture is an independent production system that has the potential to increase the economic benefits of these fisheries, but has many economic limitations and risks for inland fishing communities as well (Lynch et al., Reference Lynch, Cowx, Fluet-Chouinard, Glaser, Phang, Beard, Bower, Brooks, Bunnell, Claussen, Cooke, Kao, Lorenzen, Myers, Reid, Taylor and Youn2017). Eutrophication from aquaculture may work against ecosystem management goals intended to reduce excess nutrients and algal blooms in rivers (Wang et al., Reference Wang, Beusen, Liu and Bouwman2020). Lack of regulations, inspections and monitoring can result in the escapement of non-native aquaculture farmed species, which threaten native biodiversity (Nobile et al., Reference Nobile, Cunico, Vitule, Queiroz, Vidotto-Magnoni, Garcia, Orsi, Lima, Acosta, da Silva, do Prado, Porto-Foresti, Brandão, Foresti, Oliveira and Ramos2020). Opportunities to address some of these issues can be seen in Chinese freshwater aquaculture where dramatic changes to reach long-term sustainability initiatives are occurring: eliminating fertilizer application for fish culture, combining aquaculture with rice culture systems, increasing emphasis on aquaponics use, prioritizing culture of indigenous fish species, and increasing regulation (Wang et al., Reference Wang, Li, Gui, Liu, Ye, Yuan and De Silva2018). Subsidies geared to enhance more sustainable practices of freshwater aquaculture can also increase economic benefits and profitability without jeopardizing ecosystem integrity (Aheto et al., Reference Aheto, Acheampong and Odoi2019; Guillen et al., Reference Guillen, Asche, Carvalho, Fernández Polanco, Llorente, Nielsen, Nielsen and Villasante2019).
For marine systems, ending harmful subsidies that enable illegal, unreported and unregulated fishing practices is critical to prevent overfishing and promote sustainability of fish stocks. Conversely, in freshwater systems, fisheries can be harmed by subsidies or incentives that enable barrier construction, unsustainable aquaculture production, sand mining and other undesired by-products, which can alter natural flow regimes, reduce biodiversity and decrease the productivity of fish communities (Ainsworth et al., Reference Ainsworth, Cowx and Funge-Smith2021; Arantes et al., Reference Arantes, Fitzgerald, Hoeinghaus and Winemiller2019; Hackney et al., Reference Hackney, Darby, Parsons, Leyland, Best, Aalto, Nicholas and Houseago2020; Kano et al., Reference Kano, Dudgeon, Nam, Samejima, Watanabe, Grudpan, Grudpan, Magtoon, Musikasinthorn, Nguyen, Praxaysonbath, Sato, Shibukawa, Shimatani, Suvarnaraksha, Tanaka, Thach, Tran, Yamashita and Utsugi2016; Pelicice et al., Reference Pelicice, Azevedo-Santos, Vitule, Orsi, Lima Junior, Magalhães, Pompeu, Petrere and Agostinho2017). Subsidies for detrimental developments on rivers directly contribute to the degradation of ecosystem resilience and productivity, jeopardizing any existing fishing enterprises. For example, Badcock and Lenzen (Reference Badcock and Lenzen2010) found that global financial subsidies for hydropower totalled 116 billion USD between 1960 and 2007. The total subsidies for all dams, not just hydropower, during this time period is unclear, but recent estimates of large hydroelectric projects (over 50 MW) was 16 billion USD in 2018 (United Nations Environment Programme & Frankfurt School-UNEP Centre, 2019) and for small hydropower development it was approximately 170 million euros in 2018 (Gallop et al., Reference Gallop, Vejnović and Pehchevski2019).
Disagreement among stakeholders has made it unclear whether hydropower should be expanded to assist with efforts to decarbonize energy production and whether subsidies, such as the Kyoto Protocol’s clean development mechanism, should be used to support this initiative (Ascher, Reference Ascher2021; Fearnside, Reference Fearnside2015; Zarfl et al., Reference Zarfl, Lumsdon, Berlekamp, Tydecks and Tockner2015). As the cost of installing wind, solar and battery storage decreases, developing countries must decide on which renewable energy sources to invest (Thieme et al., Reference Thieme, Tickner, Grill, Carvallo, Goichot, Hartmann, Higgins, Lehner, Mulligan, Nilsson, Tockner, Zarfl and Opperman2021). Construction of hydropower dams is not only considered a viable means to meet SDG 7 (ensure access to affordable, reliable, sustainable and modern energy for all), but is a key investment goal for both hydropower developers and some global funding agencies (World Commission on Dams, 2000). Figure 2 highlights hydropower financing flows from 2000 to 2019, and according to the International Renewable Energy Agency (2022), total transactions reached 92.51 billion USD. The top five recipients were Brazil, Nigeria, Pakistan, Lao PDR and Ethiopia, and the largest donor was China. The implications for global financing of hydropower projects are directly linked to the future resilience of river systems, environmental flows and fishing-related targets of SDG 14, and many other food security-related SDGs as well as energy-related SDGs. The accessibility and increase of water security may provide opportunities for SDG 2 (end hunger, achieve food security and improved nutrition and promote sustainable agriculture) if agricultural development is pursued at the cost of SDG 14. Synergies between SDG 14, SDG 2 and SDG 3 (ensure healthy lives and promote well-being for all at all ages) become more realistic if a healthy river ecosystem is maintained. Tradeoffs and synergies among SDGs is not a new issue but solutions are often case-by-case specific where there is potential for conflict among stakeholders (Thieme et al., Reference Thieme, Tickner, Grill, Carvallo, Goichot, Hartmann, Higgins, Lehner, Mulligan, Nilsson, Tockner, Zarfl and Opperman2021).
3.2 Evaluating SDG 14 indicators and identifying mutual opportunities
Fishing at sustainable levels, implementing policies to restrict harmful fishing subsidies, increasing economic output of fisheries, and providing support for small-scale fishers (targets 14.4, 14.6 and 14.B) could be readily adapted to inland fisheries. One of the greatest challenges lies in the international characteristics of many of the world’s large rivers. These transboundary rivers may have complex socio-ecological relationships concerning fishing, which may lead to conflict among different stakeholders (Ainsworth et al., Reference Ainsworth, Cowx and Funge-Smith2021). For example, water abstraction from adjacent aquifers may also have multinational dimensions, issuing another series of challenges. Polycentric-governance is a potential opportunity that can supplement or even replace existing state-based governance systems to better accommodate transboundary issues in a flexible manner (Baltutis & Moore, Reference Baltutis and Moore2019). Improving science-based management for these systems may be challenging for migratory species that cross political boundaries and ecosystems. The likely suspects framework is one potential approach that attempts to unify management of Atlantic salmon (Salmo salar) across its life history, which includes both marine and freshwater systems (Bull et al., Reference Bull, Gregory, Rivot, Sheehan, Ensing, Woodward and Crozier2022). The ‘swimway’ management approach is a recommendation for freshwater migratory fish species that span multiple basins and political jurisdictions (Pracheil et al., Reference Pracheil, Pegg, Powell and Mestl2012; Worthington et al., Reference Worthington, van Soesbergen, Berkhuysen, Brink, Royte, Thieme, Wanningen and Darwall2022). Similarly, creating agreements for sustainable societal developments may require cooperation at multiple scales throughout a river basin to avoid power hierarchies (e.g. upstream and downstream socio-political dynamics).
Prohibiting certain fishing activities and river development subsidies that contribute to unsustainable practices and less resilient marine and freshwater systems will require different strategies. Many large rivers intersect with multiple countries that may have competing interests in regards to both energy and food production (e.g. the Mekong river intersects China, Myanmar, Thailand, Lao PDR, Cambodia and Vietnam). Implementation of international instruments focused on dam development incentives – particularly for developing and least developed countries – may need to operate at a transnational scale to avoid conflict over downstream water requirements. Unless mechanisms are in place to override activities in the watershed, there is always the risk that countries will act independently. For example, proposed dam development projects in free-flowing rivers over 500 km are focused in Asia, South America and Africa, which have the potential to: (1) affect some of the world’s largest river basins and deltas; (2) involve multiple countries and (3) have implications for estuaries and marine environments (Thieme et al., Reference Thieme, Tickner, Grill, Carvallo, Goichot, Hartmann, Higgins, Lehner, Mulligan, Nilsson, Tockner, Zarfl and Opperman2021). Where aquaculture is being developed, careful consideration should be warranted to ensure artisanal fisheries are not substituted by aquaculture production. In the case of sand mining, regulating and monitoring, which is often not conducted, is just beginning to understand longitudinal impacts on the river system and the connected marine system (Hackney et al., Reference Hackney, Darby, Parsons, Leyland, Best, Aalto, Nicholas and Houseago2020).
Application of legal, regulatory, policy or institutional frameworks for riverine small-scale fisheries can be improved by developing inclusive adaptive management programmes that incorporate fisher values and knowledge. Emphasis is particularly focused on full and equal participation of small-scale fishing communities and associated cultures for all parts of the governance process: planning, assessment, implementation, monitoring and management. This approach may present opportunities to subsidize sustainable development projects that can directly increase economic benefits from river fisheries. This co-development approach also provides a straightforward opportunity in making the planning process gender-inclusive, which has met resistance historically, despite high proportions of the workforce being women (Bartley et al., Reference Bartley, Graaf, Valbo-Jørgensen and Marmulla2015; Biswas et al., Reference Biswas2018; Harper et al., Reference Harper, Adshade, Lam, Pauly and Sumaila2020).
For riverine or reservoir capture fisheries, opportunities exist to optimize dam operations to integrate with fish life history requirements. However, such options are often hard to design and even harder to predict (Holtgrieve et al., Reference Holtgrieve, Arias, Ruhi, Elliott, Nam, Ngor, Rasanen and Sabo2018; Olden et al., Reference Olden, Konrad, Melis, Kennard, Freeman, Mims, Bray, Gido, Hemphill, Lytle, McMullen, Pyron, Robinson, Schmidt and Williams2014; Richter & Thomas, Reference Richter and Thomas2007; Sabo et al., Reference Sabo, Ruhi, Holtgrieve, Elliott, Arias, Ngor, Rasanen and Nam2017; Williams, Reference Williams2018). The Brisbane Declaration suggests environmental flows should be assessed well before the development of new dams, and actively incorporated within the planning process once development commences (Arthington et al., Reference Arthington, Bhaduri, Bunn, Jackson, Tharme, Tickner, Young, Acreman, Baker, Capon, Horne, Kendy, McClain, Poff, Richter and Ward2018). Adopting an adaptive management approach for existing large infrastructure may also help promote environmental flows in a cost-effective manner (Olden et al., Reference Olden, Konrad, Melis, Kennard, Freeman, Mims, Bray, Gido, Hemphill, Lytle, McMullen, Pyron, Robinson, Schmidt and Williams2014). For systems where reservoir development is appropriate, consideration of multi-purpose operation and optimization could increase co-benefits as opposed to single-purpose implementation (Bhaduri et al., Reference Bhaduri, Bogardi, Siddiqi, Voigt, Vörösmarty, Pahl-Wostl, Bunn, Shrivastava, Lawford, Foster, Kremer, Renaud, Bruns and Osuna2016). Dams have broad socio-ecological impacts upstream and downstream of their reservoir (Richter et al., Reference Richter, Sandra, Carmen, Thayer, Bernhard, Allegra and Morgan2010), and this issue persists well after the lifespan of the dam has surpassed and restoration is needed (Bellmore et al., Reference Bellmore, Pess, Duda, O’Connor, East, Foley, Wilcox, Major, Shafroth, Morley, Magirl, Anderson, Evans, Torgersen and Craig2019; Hansen et al., Reference Hansen, Forzono, Grams, Ohlman, Ruskamp, Pegg and Pope2019; Perera et al., Reference Perera, Smakhtin, Williams, North and Curry2021; Tullos et al., Reference Tullos, Collins, Bellmore, Bountry, Connolly, Shafroth and Wilcox2016). Broader discussion and debate now concern how funds and subsidies are allocated for dams and their anticipated impacts (Hirsch, Reference Hirsch2010; Thieme et al., Reference Thieme, Tickner, Grill, Carvallo, Goichot, Hartmann, Higgins, Lehner, Mulligan, Nilsson, Tockner, Zarfl and Opperman2021).