Healthy pond ecosystems are critical for achieving several sustainable development goals (SDG) through numerous ecosystem services (e.g., flood control, nutrient retention, and carbon sequestration). However, the socio-economic and ecological value of ponds is often underestimated compared to the larger water bodies, as per a paper in Wetlands by Shweta Yadava and V C Goyal.

Ponds are highly vulnerable to mounting land-use pressures (e.g., urban expansion, and agriculture intensification) and environmental changes, leading to degradation and loss of the pond ecosystem. The narrow utilitarian use-based conservation fails to recognize the multiple anthropogenic pressures and provides narrow solutions which are inefficient to regenerate the degraded pond ecosystem.

In this paper titled ‘Current Status of Ponds in India: A Framework for Restoration, Policies and Circular Economy’ the authors holistically examined the legal challenges (policies) and key anthropogenic and environmental pressures responsible for pond degradation in India. The country is strongly dedicated to attaining SDG and circular economy through aquatic ecosystem conservation and restoration. Considerable efforts are required at the administration level to recognize the contribution of pond ecosystem services in attaining global environmental goals and targets.

Worldwide restoration strategies were reviewed, and a framework for pond restoration and conservation was proposed, which includes policies and incentives, technologies such as environmental-DNA (e-DNA), life cycle assessment (LCA), and other ecohydrological measures. Nature-based solutions (NBS) offer a sustainable and cost-effective approach to restoring the pond’s natural processes. Furthermore, linkage between the pond ecosystem and the circular economy was assessed to encourage a regenerative system for biodiversity conservation. This study informs the need for extensive actions and legislative reforms to restore and conserve the pond ecosystems. Some recommendations include -

• A uniform waterbody classification system applicable to all the water bodies (including small ponds) is vital to ensure better administration and monitoring in all the states. Also, a comprehensive national pond database incorporating states and local bodies is required to facilitate objective policymaking and appropriate intervention at different levels.
• Integrate pond conservation into sectoral development plans and sustainable development goals. A coordinated inter-ministerial and inter-departmental approach can formulate a single comprehensive scheme to conserve and restore the ponds at the local level (top-down approach).
• Appropriate demarcation of pond boundaries and its inclusion as a municipal asset under the land records by states can be a vital step to put off pond encroachment. The No Net Loss (NNL) policy can be effectively used as a regulatory instrument to mitigate (i.e., minimize the impact) and offset (i.e., compensate) the unavoidable losses due to existing or proposed development activity (Sun et al. 2019).
• Government incentives to promote sustainable business models supporting pond restoration, conservation, and local economy. The Payment for Ecosystem Services (PES) and Collective Payment for Ecosystem Services (CPES) can be used as effective conservation tools (Jiangyi et al. 2020).
• Policies to adopt the 6R principle of circular economy in water and wastewater management which reduces the source water pollution and generate opportunity for local livelihood through reuse, recycling, and resource recovery. Please refer to Online Resource-1 (Supplementary file-1) for details on supportive policies, and action plans for aquatic ecosystem restoration, and conservation promoting a circular economy in India.
• Inclusion of local stakeholders in pond-related decision making, policy formulation, and action plans to establish a linkage between the pond ecosystem and various stakeholders (bottom-up approach) ensuring long-term conservation of ponds.

Circular economy through pond ecosystem for sustainable ecosystem services

By closing the material and energy loop and maintaining the material at its highest utility and value at all times, the circular economy strategy reduces resource input and waste (Geissdoerfer et al. 2017; Kirchherr et al. 2017). By facilitating a closed-loop system for energy and material flow through sustainable resource and waste management, the 6R framework of circular economy (i.e., reduce, reuse, recycle, reclaim, recover, and restore) lessens the demand on natural resources (van Buren et al. 2016). To manage natural resources more sustainably, a circular economy model that is restorative and regenerative is required.

For the future provision of natural resources (such as water, food, and nutrients), energy (such as biomass, biofuel), and ecosystem services, it is crucial to link circular economy and aquatic ecology. The upsurge in economic development and consumerism exert pressure on the already limited natural resources leading to resource depletion and ecosystem degradation (Priyadarshini and Abhilash 2020). Unlike developed countries, India has a high resource extraction rate of 1580 tonnes/acre and a low recycling rate of 20–25% (NITI-Aayog 2019).

Consequently, many critical raw materials are imported into the country. The country’s dependency on imports is 90% for phosphate as raw material or as finished fertilizer (Ministry of Mines—https://www.mines.gov.in/). The transition to a zero-carbon economy, clean and green economy further exerts pressure on natural resources such as biofuels, and biodiesel through increased demand (Mehrabadi et al. 2016; Darda et al. 2019).

The rich biodiversity of ponds provides numerous natural resources (Kumar 2018). Increased demand for natural resources by local industries, agriculture, and households increases the stress on the pond ecosystem. The simple living behavior and 6R framework of circular economy can reduce the demand for natural resources. The waste and wastewater disposed of in ponds can be a potential source of energy through waste-to-energy initiatives which reduce fossil fuel dependency and pollution to the aquatic ecosystem (Kalyani and Pandey 2014). As the recovery of secondary materials requires less energy than the raw ones, the energy-saving opportunity is highly likely through circular economy practices.

Wastewater can also be a source of biofertilizers through nutrient recovery which reduces the dependency on phosphorus imports (Kumar 2018; Shukla et al. 2020a). Under the circular economy scenario, the use of synthetic pesticides and fertilizers would be 45% lower by 2030 (EllenMacArthur-Foundation 2016). Farm pond biomass valorization and its use as an organic fertilizer in the United States provided economic sustainability to farmers through phosphorus recycling (50%-70%) and reduced the phosphorus treatment and energy cost.

The application of organic fertilizers further enhances the carbon sequestration in the soil thus contributing directly to crop productivity and climate change mitigation (Shukla et al. 2020a). Mixed land use patterns in India also provides an opportunity for the reuse and recycling of resources fairly easily with limited infrastructural development (Kakwani and Kalbar 2020).

Restoration and management of the pond ecosystems further promote biodiversity richness, ecosystem health, and livelihood through nature-based solutions (Crawford 1979; Jurczak et al. 2018). NBS can be better integrated with circular economy for sustainable natural resource management and biodiversity conservation. Government policies encourage the 6R framework of circular economy in ecosystem-related action and management plans. The interaction between the pond ecosystem, natural resources, and energy is illustrated in Fig. below.

A restored, and well-managed pond/tanks directly or indirectly contribute to the three circular economy principles, (a) Regenerating natural capital (i.e., biodiversity, water cycle, nutrient cycle, and water quality); (b) Keep resources in use (i.e., enhance resource use efficiency of material and energy); and (c) Design out waste externalities (i.e., reduce environmental impacts, waste reduction, and economic sustainability) (EllenMacArthur-Foundation 2016).

Conclusions

Pond ecosystem underpins economic prosperity, social wellbeing, and environmental sustainability through a range of ecosystem services predominantly to the agricultural developing economies. The negative repercussions of uncontrolled developmental activities, land-use alterations, and constrained conservation policies threaten the existence of a biodiverse pond ecosystem.

The study highlighted the major physical, chemical, and biological pressures along with the legal challenges which are needed to be addressed systematically. The study revealed pond ecosystem lags behind other aquatic water bodies in research and policy integration. A framework for pond restoration and conservation was presented suggesting the policy reforms, technologies, and other locally accepted conservation measures to attain sustainability through ponds.

The study further showcases a linkage between the pond ecosystem and the circular economy principles, promoting a more regenerative system to lessen the burden on its natural resources and avoid biodiversity loss. The study further highlights the need for better governance and institutional arrangements to encourage various stakeholders for pond conservation and restoration thereby boosting the water security of the region which supports the attainment of SDG 2030 targets.

The full paper can be accessed here