- Government or intergovernmental initiatives are effective ways to establish mandatory standards for water quality and to implement legal frameworks to ban the use of harmful chemicals, mandate discharge permits or levy fines for infractions.
- The legal frameworks and policies developed by governments or intergovernmental bodies should ideally be guided by an Integrated River Basin Management (IRBM) approach.
- Industry-led initiatives, such as the Roundtable on Sustainable Palm Oil or the Better Cotton Initiative, can also be an effective way to establish industry-wide environmental standards, and members can benefit from eco-labelling and improved market access.
- NGOs and civil society can play a role in catalysing government and industry action to reduce water pollution. An effective example is the Water Stewardship approach.
Everyone has a role to play in reducing water pollution, including communities. However, the most serious sources of water pollution are linked to agriculture and industry, so here we focus on larger scale interventions. Community engagement practices are detailed in another part of this site.
How can water pollution impact river dolphins?
Rivers are particularly prone to pollution because they are often heavily exploited and close to large human populations. Human waste and household rubbish, as well as industrial and agricultural processes, are major sources of pollutants that are harmful to river dolphins. Species at the top of the food chain, such as river dolphins, are at the greatest risk of bioaccumulating pollutants since concentrations build up in each transfer of prey to predator1, 2. Pollution exposure can negatively impact dolphins in a variety of ways, including immune system suppression, reproductive issues, calf mortality, developmental abnormalities, cancer, and other diseases3, 4. Several studies have found pollution-linked population declines in cetaceans5, 6.
Many studies have found elevated concentrations of pollutants in river dolphins. One of the most pervasive and well-documented pollutants is mercury from gold mining operations, with high concentrations documented in almost every river basin hosting freshwater dolphins, including the Amazon/Orinoco7, Ganges8, Indus9, Yangtze10, Mahakam11, Mekong12, and Ayeyarwady13 river basins. Agricultural fertiliser and pesticide runoff can carry heavy metal pollutants into river systems11, 14, such as arsenic, cadmium, mercury, and lead. Butelyn compounds and organochlorines have also been found in Ganges river dolphins15, 16. The disposal of rubbish in rivers is another major source of pollution. The Ganges River and the Yangtze River discharge an estimated 115,000 and 333,000 tons of plastic into the ocean every year respectively17.
How can we reduce the impact of pollution on river dolphins?
There are several examples of best practice that have helped to significantly reduce water pollution in rivers around the world. Although there are important measures that individuals and communities can take to reduce their contributions to water pollution, the most serious sources of river pollution are linked to industry and agriculture, and effective strategies to tackle this therefore need to be large scale. Generally these strategies can be divided into government/intergovernmental-led initiatives, and industry-led initiatives.
These initiatives are often most effective where policies and regulations are required to ban harmful practices or mandate best practice. Policies can be implemented on a local or national scale, or, in the cases of rivers that traverse multiple national jurisdictions, on a transboundary or regional scale. Governmental and intergovernmental led initiatives should ideally aim to achieve Integrated River Basin Management (IRBM) or Integrated Water Resource Management (IWRM). Both are approaches that seek to achieve more sustainable (environmentally and socio-economically) use of fresh water21. Operationalisation of this approach can be measured by the IWRM indicator framework laid out in Using Indicators for Improved Water Resources22. For freshwater ecosystem to be managed effectively at the river basin scale, there needs to be:
- Integration of policies, decisions and costs across sectoral interests such as industry, agriculture, urban development, navigation, fishery management and conservation;
- A long-term vision for the river basin, agreed by all the major stakeholders, with strategic decision-making at the river basin scale and active participation by all relevant stakeholders in well-informed and transparent planning and decision-making processes; and
- A solid and shared basis of knowledge of the river basin and the natural and socio-economic forces that influence it.
- The implementation of the Surface Waters Pollution Act in the Netherlands in 1970, which has provided a legal framework that requires the issue of discharge permits and the use of levies or fines for discharges. The impacts of this framework have significantly improved the quality of freshwater bodies throughout the country18.
- In Brazil, the National Water Agency (ANA in Portuguese) establishes standards for freshwater quality throughout the country, and collaborates with other agencies to conduct monitoring. The government coordinates with a wider range of stakeholders to develop and monitor water use and policy development19, 20.
- IRBM has been applied on a regional scale through the European Union’s Water Framework Directive, Environmental Quality Standards Directive and the Groundwater Directive Directives, as well as in the International Commission for the Protection of the Rhine and Rhine Action Programme.
- The effective banning of artisanal gold mining in the Mekong River basin by the Cambodian government, which led to at least a temporary decrease in mines23, although these may have increased again once effective surveillance and monitoring decreased24.
Industry-led initiatives can be very effective in reducing water pollution, as they can act on a local scale, or harness the collaboration of industry members around the globe and in multiple river basins. Examples of industry-led initiatives include:
- The Roundtable on Sustainable Palm Oil (RSPO), through which palm oil producers and other stakeholders must meet specific standards to become certified. These standards include the minimal use of approved pesticides, the recording and monitoring of fertilizer use, and maintaining waste management protocols. Their published Best Management Practices for Riparian Areas includes a mandate to maintain buffer zones on river banks. There are over 4,000 companies certified by the RSPO, accounting for 19% of global palm oil production. Companies certified by the RSPO benefit in return by being in demand by consumers conscious of the impacts of unsustainable palm oil production.
- The Better Cotton Initiative (BCI), uses a similar model to promote sustainable practices underpinned by their principles and criteria. In the 2018-2019 season alone, the BCI trained 2.3 million farmers on sustainable farming practices and produced 5.6 million tonnes of BCI approved cotton – an estimated 22% of the global cotton production.
- Industries can also play a role in addressing pollution caused by sources other than their own activities. For example, in India, Hindustan Zinc developed a solution for treating domestic wastewater/sewerage that would otherwise pollute rivers and lakes. Pipelines take waste to a treatment plant to the company’s industrial complex, which then uses the treated/recycled water for its processes, thus reducing its own water consumption, while also generating a fertiliser by-product which is marketable for local horticulture industries.
In many instances NGOs and other civil society organisations can help to catalyse and support good practice at government or industry level. Examples include:
- The Alliance for Water Stewardship (AWS) standard provides a guidance framework to implement water stewardship on the ground. As an example, WWF-Pakistan has facilitated different stakeholders to implement the AWS standard in Pakistan, including multinational corporations such as Nestlé, as well as small and medium-sized enterprises.
- WWF has applied a system of Basin Report Cards to assess the status of the Orinoco River in Colombia, the Kwando River in Angola, Zambia, Botswana, and Namibia, and the Tuul River in Mongolia. A guide to developing these Basin Report Cards can be downloaded here.
- Cossaboon, J. M. et al. Apex marine predators and ocean health: Proactive screening of halogenated organic contaminants reveals ecosystem indicator species. Chemosphere 221, 656-664, doi:https://doi.org/10.1016/j.chemosphere.2019.01.050 (2019).
- Gui, D. et al. Bioaccumulation and biomagnification of persistent organic pollutants in Indo-Pacific humpback dolphins (Sousa chinensis) from the Pearl River Estuary, China. Chemosphere 114, 106-113, doi:http://dx.doi.org/10.1016/j.chemosphere.2014.04.028 (2014).
- Genov, T. et al. Linking organochlorine contaminants with demographic parameters in free-ranging common bottlenose dolphins from the northern Adriatic Sea. Science of The Total Environment 657, 200-212, doi:https://doi.org/10.1016/j.scitotenv.2018.12.025 (2019).
- 4 Wells, R. S. et al. Integrating life-history and reproductive success data to examine potential relationships with organochlorine compounds for bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida. Science of the Total Environment 349, 106-119, doi:https://doi.org/10.1016/j.scitotenv.2005.01.010 (2005).
- 5 Jepson, P. D. et al. PCB pollution continues to impact populations of orcas and other dolphins in European waters. Scientific Reports 6, 18573, doi:10.1038/srep18573 https://www.nature.com/articles/srep18573#supplementary-information (2016).
- Desforges, J.-P. et al. Predicting global killer whale population collapse from PCB pollution. Science 361, 1373-1376, doi:10.1126/science.aat1953 (2018).
- Mosquera-Guerra F., Trujillo, F., Herrera, D. C., & Callejas, S. M. (2015). Indicios de biomagnificación de Mercurio total (Hg) en las especies del género Inia (Cetartiodactyla: Iniidae) en los ríos Amazonas y Orinoco (Colombia). Momentos de Ciencia, 12(2).
- Paul D. (2017) Research on heavy metal pollution in Ganga: a review. Annals of Agrarian Science 15 (2017) 278 – 286.
- Riaz, A., Khan, S., Muhammad, S., & Shah, M. T. (2019). Mercury contamination in water and sediments and the associated health risk: a case study of artisanal gold-mining. Mine Water and the Environment, 38(4), 847-854.
- Wei-Wei D., Ying X., Ding W., & Yu-Jiang H. (2006). Mercury concentrations in Yangtze Finless Porpoises (Neophocaena phocaenoides asiaeorientalis) from eastern Dongting Lake. China. Fresenius Environmental Bulletin 15(5):446–453.
- Kreb, D. & Budiono. (2018). Protecting critical Mahakam River dolphin habitat through sustainable fisheries, monitoring and raised awareness in East Kalimantan, Indonesia. Final technical report for Keidanren Nature Conservation Fund.
- Murphy, T. P., Irvine, K. N., Sampson, M., Guo, J., & Parr, T. (2009). Mercury contamination along the Mekong River, Cambodia. Asian Journal of Water, Environment and Pollution, 6(1), 1-9.
- Smith, B. D., & Tun, M. T. (2007). Review of the Status and Conservation of Irrawaddy Dolphins Orcaella brevirostris in the Ayeyarwady River. Status conservation of freshwater populations of Irrawaddy dolphins, 21.
- Gachal, G. S., Slater, F. M., Nisa, Z., & Qadri, A. H. (2006). Ecological effects on the status of the Indus Dolphin. Pakistan Journal of Biological Sciences, 9(11), 2117-2121.
- Kannan, K., Sinha, R. K., & Tanabe, S. (1993). Heavy Metals and Organochlorine Residues in Ganges River Dolphins from. Marine Pollution Bulletin, 26(3), 159-162.
- Kannan, K., Senthilkumar, K., & Sinha, R. K. (1997). Sources and accumulation of butyltin compounds in Ganges river dolphin, Platanista gangetica. Applied Organometallic Chemistry, 11(3), 223-230.
- Lebreton, L.C.M., Van Der Zwet, J., Damsteeg, J.W., Slat, B., Andrady, A., & Reisser, J. (2017). River plastic emissions to the world’s oceans. Nat. Commun. 8, 1–10. https://doi. org/10.1038/ncomms15611.
- Warmer, H & Van Dokkum, R. 2002. Water pollution control in the Netherlands; Policy and practice 2001. RIZA report 2002.009, ISBN 9036954290.
- Agência Nacional de Águas e Saneamento Básico (ANA) https://www.ana.gov.br/ANA/, accessed in February 2021.
- Conselho Nacional de Recursos Hídricos (CNRH) https://cnrh.mdr.gov.br/, accessed in February 2021.
- Bandaragoda DJ, Babel MS (2010) Institutional development for IWRM: an international perspective. Int J River Basin Manag 8(3–4):215–224. doi:10.1080/15715124.2010.496707.
- Bertule, M., Bjørnsen, P.K., Costanzo, S.D., Escurra, J., Freeman, S., Gallagher, L., Kelsey, R.H. and Vollmer, D. (2017). Using indicators for improved water resources management – guide for basin managers and practitioners. 82 pp. ISBN 978-87-90634-05-6.Using indicators for improved water resources management Guide for basin managers and practitioners.
- Smith BD, Tun MT. Review of the status and conservation of Irrawaddy dolphins Orcaella brevirostris in the Ayeyarwady River of Myanmar. In: Smith BD, Shore RG, Lopez A, eds. Status and Conservation of Freshwater populations of Irrawaddy dolphins: Wildlife Conservation Society; 2007:21-40.
- Wang Z-T, Duan P-X, Akamatsu T, Wang K-X, Wang D. Passive acoustic monitoring of the distribution patterns of Irrawaddy dolphins (Orcaella brevirostris) in the middle reaches of the Ayeyarwady River, Myanmar. Marine Mammal Science 2020;36:1241-53.