Willingness-to-Pay for Blue Ecosystem Services of Natural Pools in Sri Lanka: A Discrete Choice Experiment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I have completed reviewing this article titled "Willingness-To-Pay for Blue Ecosystem Services of Natural Pools in Sri Lanka: A Discrete Choice Experiment", which needs significant improvements. The study investigated the user preferences for sustainable enhancement of recreational values in natural pools and their immediate environment. The study suggested that efforts to upgrade these natural pools should prioritize income generation, broadening recreational activities and environmental conservation, and align with respondents' inclinations. My overall feelings towards this manuscript are positive. An analysis is also appropriate and seems appropriately implemented. However, some major issues need to be addressed.

1. What is the limitation of the existing studies? In this section, the authors need to explore the originality and contribution of the study properly.

2. The introduction section lacks a research gap.  What are the research gaps in existing literature? The authors should explicitly state in this section and then draw your contributions smoothly.

3. The literature section is weak; How the existing studies related to your methods? These issues should be stated clearly in this section.

4. The data source should be stated more clearly, and how the authors pre-process the null data?

5. How could the authors solve the robustness problem in the model? The authors should state it clearly.

6. The policy recommendations are too general; the authors should focus on your results, or the recommendations should be drawn from your results directly.

Comments on the Quality of English Language

Minor English editing is  required to avoid any grammatical mistakes. 

Author Response

Reviewer 1

Overall Comment

I have completed reviewing this article titled "Willingness-To-Pay for Blue Ecosystem Services of Natural Pools in Sri Lanka: A Discrete Choice Experiment", which needs significant improvements. The study has investigated the user preferences for sustainable enhancement of recreational values in natural pools and their immediate environment. The study suggested that efforts to upgrade these natural pools should prioritize income generation, broadening recreational activities and environmental conservation, and align with respondents' inclinations. My overall feelings towards this manuscript are positive. An analysis is also appropriate and seems appropriately implemented. However, some major issues need to be addressed.

 

Response

The authors welcome the positive comments of the reviewer. We are highly grateful for the valuable comments provided by the reviewer to elevate the overall quality of this manuscript further. We have addressed all the concerns raised by the reviewer and the revisions that were made are highlighted in yellow colour.

 

• Comment 1

What is the limitation of the existing studies? In this section, the authors need to explore the originality and contribution of the study properly.

 

Response

The authors welcome the comment. This aspect was carefully addressed by the authors in the introduction section as follows.

 

“In environmental and natural resource literature, various methodologies and approaches have been employed to assess the economic value of freshwater ecosystems in general and particularly to understand how these ecosystems contribute to human well-being and the economy. The majority of these studies center around benefits such as clean water, biodiversity, flood regulation, and recreational opportunities offered by freshwater ecosystems. A recent study conducted by Sierra et al. has assessed the economic value of key natural benefits of freshwater ecosystem using a market value method considering transfer of benefits and direct uses. Results of this study has revealed that users consider ecotourism and prevention of flooding to be the most important values provided by freshwater ecosystems [32]. Since there are complex relationships in freshwater ecosystem services, the value of these ecosystem services often depends upon the other ecosystem services provided [33, 34]. A meta-analysis conducted by Brouwer et al. has found that services provided by freshwater ecosystems such as lakes are greatly valued than the values reported for wetlands by the users [35]. A recent study conducted by Ureta et al. has employed economic valuation techniques such as payment card approach to explore the WTP towards protection of blue water ecosystem services in South Carolina. According to the findings of Ureta et al. people are willing to pay more for improvements that increase recreational activities, such as better fishing, more types of species, and better access to water areas [36]. Therefore, assessment of WTP has assisted to guide the policy makers on prioritization of river protection programmes in South Carolina [36].

Another study conducted in five Kenyan counties (Migori, Siaya, Busia, Kisumu, and Homa Bay) has evaluated how much the residents are willing to pay for the conservation of the Lake Victoria Ecosystem. The findings of this study have reported that around 40.9% of respondents are willing to contribute approximately Kenyan Shilling (KES) 500 each, resulting in an estimated total annual WTP of KES 616,279,069 [37]. Using a contingent valuation approach, Bueno et al. has attempted to investigate how local communities value efforts to restore water quality in Sampaloc Lake in Philippines, amid urbanization pressures. The findings have revealed that households around the lake are willing to pay Philippine Peso (PHP) 177.09 per month, totaling PHP 7,102,017 annually, for these improvements [38].

Many studies have evidenced that people are willing to pay for services and contribute towards conservation of freshwater ecosystems, which directly benefit them or improve their quality of life [36, 38]. Further, implementing an environmental users fee system to fund restoration of such freshwater ecosystems has been identified as an effective sustainable solution for management of such sensitive ecosystems [38]. However, such attempts require coordinated efforts on elevating environmental education and comprehensive policies to manage freshwater ecosystems [36, 38]. Further, WTP for ecosystem services varies depending on numerous factors, including socio-economic status, cultural values, awareness of ecosystem benefits, and local environmental conditions [39]. Previous studies have shown that people are more likely to pay for ecosystem services when they understand their importance and when there are clear mechanisms in place to link their payments to tangible outcomes, such as improved environmental quality or increased access to resources [37].

Watershed development programmes and nature-based ecosystem management projects have been proven to be sustainable and result in positive impacts on the socio-economic conditions of rural communities, including enhanced income distribution [40, 41]. Especially, participatory management programmes tend to lead into positive changes in the lives of marginal communities, while ensuring the sustainable conservation of freshwater ecosystems in different parts of the world [42]. For this, governments should facilitate policy-making, policy-lobbying and provide resources, and establish partnerships to promote integrated blue water ecosystem management [40, 42, 43]. However, designing such programmes requires an in-depth understanding on the perceptions of resource users and local communities on different values of freshwater ecosystems, alongwith their willingness to contribute towards such efforts either financially or from labour [44, 45]. To the best knowledge of the authors, no studies have valued the confounded multiple benefits of natural pools, particularly the non-market values, applying a DCE in Sri Lanka, which is a developing country. Therefore, this study provides a significant contribution to this knowledge gap in literature in this area from a developing country perspective.

Further, ecosystem services offer opportunities for diversifying livelihoods of local communities, beyond traditional sectors such as agriculture and forestry. Developing natural pool ecosystems as multi-purpose revenue generating entities can lead to environmental, economic as well as social benefits [44, 46]. Existing research on how much local stakeholders are ready to spend for the enhanced enjoyment and services from bettered recreation spots in natural pools of Sri Lanka is sparse. Hence, there's a noticeable demand to create strategies for enduring enhancement of these areas for recreation and their environs. Therefore, this study explores user preferences for improvement of recreational activities of natural pools and elicits user WTP for conservation of natural pools to ensure sustainable development. The insights from this research could inform policy-making, enabling the government to refine recreational offerings and sustainably harness the untapped potential of natural pool resources.”

 

 

• Comment 2

The introduction section lacks a research gap.  What are the research gaps in existing literature? The authors should explicitly state in this section and then draw your contributions smoothly.

 

Response

We are grateful for the comment. The contribution and research gap are highlighted in yellow in the introduction section, as mentioned below.

 

“Watershed development programmes and nature-based ecosystem management projects have been proven to be sustainable and result in positive impacts on the socio-economic conditions of rural communities, including enhanced income distribution [40, 41]. Especially, participatory management programmes tend to lead into positive changes in the lives of marginal communities, while ensuring the sustainable conservation of freshwater ecosystems in different parts of the world [42]. For this, governments should facilitate policy-making, policy-lobbying and provide resources, and establish partnerships to promote integrated blue water ecosystem management [40, 42, 43]. However, designing such programmes requires an in-depth understanding on the perceptions of resource users and local communities on different values of freshwater ecosystems, alongwith their willingness to contribute towards such efforts either financially or from labour [44, 45]. To the best knowledge of the authors, no studies have valued the confounded multiple benefits of natural pools, particularly the non-market values, applying a DCE in Sri Lanka, which is a developing country. Therefore, this study provides a significant contribution to this knowledge gap in literature in this area from a developing country perspective.

Further, ecosystem services offer opportunities for diversifying livelihoods of local communities, beyond traditional sectors such as agriculture and forestry. Developing natural pool ecosystems as multi-purpose revenue generating entities can lead to environmental, economic as well as social benefits [44, 46]. Existing research on how much local stakeholders are ready to spend for the enhanced enjoyment and services from bettered recreation spots in natural pools of Sri Lanka is sparse. Hence, there's a noticeable demand to create strategies for enduring enhancement of these areas for recreation and their environs. Therefore, this study explores user preferences for improvement of recreational activities of natural pools and elicits user WTP for conservation of natural pools to ensure sustainable development. The insights from this research could inform policy-making, enabling the government to refine recreational offerings and sustainably harness the untapped potential of natural pool resources.”

 

• Comment 3

The literature section is weak; How the existing studies related to your methods? These issues should be stated clearly in this section.

 

Response

The authors welcome the valuable comment. The following sections were added into the introduction and methodology to address this concern.

“Willingness to Pay (WTP) is a concept used to measure the value individuals place on certain goods or services, specifically in the context of enhancing recreational facilities. It is measured using contingent valuation methods and is influenced by factors such as perceived value, income levels, and alternative recreational options. Considering WTP in decision-making processes for enhancing recreational facilities can facilitate resource allocation, evaluate welfare benefits, and support sustainable development [29, 30].  Discrete Choice Experiments (DCEs) and Contingent Valuation Approach (CVA) are two of the commonly used methods to assess WTP and estimate individual choice behaviour. Both of these approaches are based on stated preference [31].

In environmental and natural resource literature, various methodologies and approaches have been employed to assess the economic value of freshwater ecosystems in general and particularly to understand how these ecosystems contribute to human well-being and the economy. The majority of these studies center around benefits such as clean water, biodiversity, flood regulation, and recreational opportunities offered by freshwater ecosystems. A recent study conducted by Sierra et al. has assessed the economic value of key natural benefits of freshwater ecosystem using a market value method considering transfer of benefits and direct uses. Results of this study has revealed that users consider ecotourism and prevention of flooding to be the most important values provided by freshwater ecosystems [32]. Since there are complex relationships in freshwater ecosystem services, the value of these ecosystem services often depends upon the other ecosystem services provided [33, 34]. A meta-analysis conducted by Brouwer et al. has found that services provided by freshwater ecosystems such as lakes are greatly valued than the values reported for wetlands by the users [35]. A recent study conducted by Ureta et al. has employed economic valuation techniques such as payment card approach to explore the WTP towards protection of blue water ecosystem services in South Carolina. According to the findings of Ureta et al. people are willing to pay more for improvements that increase recreational activities, such as better fishing, more types of species, and better access to water areas [36]. Therefore, assessment of WTP has assisted to guide the policy makers on prioritization of river protection programmes in South Carolina [36].

Another study conducted in five Kenyan counties (Migori, Siaya, Busia, Kisumu, and Homa Bay) has evaluated how much the residents are willing to pay for the conservation of the Lake Victoria Ecosystem. The findings of this study have reported that around 40.9% of respondents are willing to contribute approximately Kenyan Shilling (KES) 500 each, resulting in an estimated total annual WTP of KES 616,279,069 [37]. Using a contingent valuation approach, Bueno et al. has attempted to investigate how local communities value efforts to restore water quality in Sampaloc Lake in Philippines, amid urbanization pressures. The findings have revealed that households around the lake are willing to pay Philippine Peso (PHP) 177.09 per month, totaling PHP 7,102,017 annually, for these improvements [38].

Many studies have evidenced that people are willing to pay for services and contribute towards conservation of freshwater ecosystems, which directly benefit them or improve their quality of life [36, 38]. Further, implementing an environmental users fee system to fund restoration of such freshwater ecosystems has been identified as an effective sustainable solution for management of such sensitive ecosystems [38]. However, such attempts require coordinated efforts on elevating environmental education and comprehensive policies to manage freshwater ecosystems [36, 38]. Further, WTP for ecosystem services varies depending on numerous factors, including socio-economic status, cultural values, awareness of ecosystem benefits, and local environmental conditions [39]. Previous studies have shown that people are more likely to pay for ecosystem services when they understand their importance and when there are clear mechanisms in place to link their payments to tangible outcomes, such as improved environmental quality or increased access to resources [37].

Watershed development programmes and nature-based ecosystem management projects have been proven to be sustainable and result in positive impacts on the socio-economic conditions of rural communities, including enhanced income distribution [40, 41]. Especially, participatory management programmes tend to lead into positive changes in the lives of marginal communities, while ensuring the sustainable conservation of freshwater ecosystems in different parts of the world [42]. For this, governments should facilitate policy-making, policy-lobbying and provide resources, and establish partnerships to promote integrated blue water ecosystem management [40, 42, 43]. However, designing such programmes requires an in-depth understanding on the perceptions of resource users and local communities on different values of freshwater ecosystems, alongwith their willingness to contribute towards such efforts either financially or from labour [44, 45]. To the best knowledge of the authors, no studies have valued the confounded multiple benefits of natural pools, particularly the non-market values, applying a DCE in Sri Lanka, which is a developing country. Therefore, this study provides a significant contribution to this knowledge gap in literature in this area from a developing country perspective.”

 

“Analytical Framework of the Choice Experiment

This study employed a DCE to elicit the respondent's preference by presenting sets of choices with varying attributes and the choice set's corresponding price vehicle. WTP is a concept used to measure the value individuals place on certain goods or services, specifically in the context of enhancing recreational facilities. The DCEs allow for estimation and forecasting of individual choice behaviour and provide a way to measure preferences for nonmarket goods. Further, DCEs can generate more precise preference estimates compared to traditional "pick the best" approaches, since it captures decision-rule heterogeneity, allowing for a more accurate representation of respondent behaviour [47]. 

Choice experiments are survey-based valuation methods used to estimate the marginal values of individual elements in environmental resources. Choice modeling provides decision-makers with richer information on economic values, enhancing the quality and sustainability of natural resources at local, national, and global levels [48, 49]. Often, DCE designs consist of a small number of choice sets with a limited number of alternatives to increase response efficiency. Optimal designs, also known as orthogonal designs, are used when prior information about population preferences is not available. The orthogonalization procedure works in the context of choice card attributes and levels, by introducing column vectors for alternative-specific attributes and forcing their values to be orthogonal with other generic attributes within the same alternative. This maintains orthogonality within individual alternatives but not necessarily across alternatives [47, 50].

Although several non-market valuation techniques have been used to estimate the monetary value of ecosystem services, stated preference approaches are increasingly used as they rely on preferences or values as stated by individuals [29, 49]. The major advantage of the stated preference methods is that they possess flexibility to capture both use and non-use values. Choice experiment models allows for the estimation of the relative importance of multiple environmental attributes and their levels [37]. Conditional logit model can be effectively used to relate the probability of a choice among the alternatives to the characteristics of the attribute levels defining those alternatives, which is consistent with the random utility theory. Further, unlike other regression models, the Conditional logit model avoids sparse data biases, leading to more accurate interpretations [49].”

 

• Comment 4

The data source should be stated more clearly, and how the authors pre-process the null data?

 

Response

All the data used for the current study were collected using a pre-tested interviewer administered structured questionnaire and choice cards. Null data were treated as missing data and appropriately removed during the analysis. This fact was clearly mentioned in the manuscript under following sections.

 

“Data Collection and Survey Design

The proportionate random sampling technique was employed in selecting a total of 320 locals, whom were utilizing the natural pools in the two study areas for different purposes. A pre-tested structured questionnaire along with a choice experiment was administered to collect the primary data. The survey instrument focused on three major sections, 1) demographic characteristics; 2) knowledge, awareness, and perception of resource users on conservation and amenity improvement of natural pools; 3) Choice experiment and value elicitation. The perception, awareness and knowledge related questions established a baseline for how much the respondents know about the ecological terminology and its relation to the economic and well-being improvement. Furthermore, it also elicited their position on some potential actionable issues relevant to implementing conservation interventions.

 

Data Analysis and Interpretation

All the collected data were double-checked and verified on the same day for completeness and consistency before entering into for Microsoft Excel data sheets (version, 2016). Cross-tabulations and logical checks were done to ensure the accuracy of the data. Any null data were treated as missing data and appropriately removed during the analysis.”

 

• Comment 5

How could the authors solve the robustness problem in the model? The authors should state it clearly.

 

Response

The authors welcome the comment. We followed several approaches to address the robustness of the conditional logit model in order to validate the stability and reliability of the model results. Initially, the data set was tested for multicollinearities and outliers. Subsequently, alternative models such as Mixed Logit and Multinomial Logit Models were also fitted for the data along with the Conditional Logit model. Several goodness of fit measures such as AIC (Akaike Information Criterion), BIC (Bayesian Information Criterion) and McFadden R squared values were used for model selection to identify the model that fits best and addresses the complexity of data. Based on the preliminary analysis, Conditional Logit model was selected as the best model, which agrees with the recommendation of Green (2012). In addition, bootstrapping was performed along with empirical confidence intervals (95%) to address the robustness of the model.

 

Reference

Greene WH. Econometric analysis 4th edition. International edition, New Jersey: Prentice Hall. 2000:201-15.

 

• Comment 6

The policy recommendations are too general; the authors should focus on your results, or the recommendations should be drawn from your results directly.

 

Response

The comment is welcome. Policy recommendations mentioned in the conclusion section were revised carefully, based on the suggestions of both reviewers. The revisions are highlighted in yellow colour.

 

“The study findings indicate that visitors of the natural pools place a significant value on higher economic improvements, high availability of recreational activities and environmental damage reduction. There is a clear WTP for these enhancements, as evidenced by positive coefficients and MWTP values. For example, the value attached to further improvements tends to be influenced by diminishing returns, as the MWTP for a 50% damage reduction is more than double that of a 20% reduction. When it comes to paying, visitors believe that the community should be made better-off through higher income generation. One of the reasons for this perception could be that they believe, improved income generation could boost greater benefits, facilities and amenities for visitors as well.

The findings of this study revealed that users were also willing to pay through labour contribution. Hence, these findings can be effectively used to guide co-management-based initiatives for freshwater ecosystem management, which are found to be sustainable in the long run. Users were also willing to accept a payment for certain income generation activities which could be through direct cash or in-kind measures. Moreover, the significantly higher preference for environmental damage reduction exhibits the user affinity and inclinations towards conservation. This is an indication of the potential for implementing nature-based solutions for ecosystem conservation. If implemented, such programmes should be voluntary and perhaps incentivized with discounts or other benefits. It's essential to consider the negative utility of increased funds per adult per visit. The Willingness to Pay indicates the maximum price consumers are willing to pay for the ecosystem service which helps derive the demand for a environmental good or service. Therefore, such pricing strategies should be carefully evaluated to ensure that they do not become a barrier to entry or visitation. Considering tiered pricing, discounts for advance booking, or membership programmes that offer added value without significantly increasing the single-visit cost are few strategies that can be recommended. Consumer surplus can be estimated as a measure to understand the gains and losses of price setting.

Further studies should be conducted to understand quantified trade-offs between conservation, water quality improvement and economic development of natural freshwater ecosystems such as natural pools. Multidisciplinary studies are warranted to understand how monetary valuation of these ecosystems can be integrated in to national policy making. Understanding these aspects better could help in drafting policies that align visitor experiences with conservation and community goals. Strategies that can enhance community income is more likely to gain strong public support. Additionally, initiatives should focus on improving environmental conditions and providing education on conservation, as these are also highly valued. In contrast, while still important, spiritual and cultural benefits are seen as less immediate priorities and could be integrated into broader programmes that primarily address the more pressing economic and environmental concerns.”

 

• Comment 7

Minor English editing is required to avoid any grammatical mistakes.

 

Response

The comment is welcome. The entire manuscript was carefully edited to avoid such grammatical issues.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

water-3134106

Title: Willingness-To-Pay for Blue Ecosystem Services of Natural Pools in Sri Lanka: A Discrete Choice Experiment

 

Comments:

The paper represents a relevant contribution to the literature on this matter. The authors aimed to investigate the user preferences for sustainable enhancement of recreational values in natural pools and their immediate environment. However, there are some aspects in the paper that can be revised / improved before being considered for publication, for example:

·       The abstract is well presented, however some improvements can be added, for example including more achievements;

·       Concerning keywords, there are other words could be included, for example, “Ecosystem Services”;

·       Introduction can be improved for example highlighting the novelty and contributions to the literature on this matter;

·       In the end of the introduction, the organization of the paper should be presented (the different sections of the paper);

·       In the introduction, the theory could be separated and be included in a new chapter for ‘methodological approach’. But I will leave this to better judgment of the authors.

·       In the literature review, there are other aspects and studies related to willingness to pay (see Marque et al., 2016);

·       All the abbreviations must be presented in the text;

·       Regarding the methodology, the model must can better justified, and including the limitations;

·       According to table 2, the results show “Willingness to improve sustainable recreational services”. The authors can explain better what are reasons beyond this results. Among the different regions of the country the results can be different among them? There is a limit for this willingness?

·       Figure 2 should be better explained;

·       How the authors see the future research of willingness to pay. This can be included in the discussion;

·       Explain better the statistical significance of the variables and its meaning;

·       The authors can also explain better how regulation can play a more important role on this matter;

·       The limitations of the study and future research can be highlighted in the conclusions;

·       Authors can improve the conclusions with more recommendations for decision makers (for example, how willingness to pay can be considered in price setting).

References:

MARQUES, R.; CARVALHO, P.; PIRES, J.; FONTAINHAS, A. (2016). Willingness to pay for the water supply service in Cape Verde–how far can it go. Water Science and Technology: Water Supply. IWA. ISSN: 1606-9749. Vol. 16, no. 6, pp 1721-1734.

Comments on the Quality of English Language

Well written

Author Response

Reviewer 2

Title: Willingness-To-Pay for Blue Ecosystem Services of Natural Pools in Sri Lanka: A Discrete Choice Experiment

 

• Overall Comment

The paper represents a relevant contribution to the literature on this matter. The authors aimed to investigate the user preferences for sustainable enhancement of recreational values in natural pools and their immediate environment. However, there are some aspects in the paper that can be revised / improved before being considered for publication, for example:

 

Response

The authors welcome the positive comment of the reviewer. We are highly grateful for the valuable comments provided by the reviewer to elevate the overall quality of this manuscript further. We have addressed all the concerns raised by the reviewer and the revisions that were made are highlighted in yellow colour.

 

• Comment 1

The abstract is well presented, however some improvements can be added, for example including more achievements.

 

Response

The authors welcome the comment. Abstract was revised to better reflect the results (more achievements) as highlighted in yellow.

“Ecosystem services offered by freshwater ecosystems, in the form of natural pools have not been fully realized by the public, which has led to limited attention on the conservation of these pools.  This study therefore was conducted to investigate the user preferences for sustainable enhancement of recreational values of natural pools and their immediate environment. A total of 320 local users of natural pools located in Rangala and Nillambe were surveyed as the sample. A Discrete Choice Experiment (DCE) was employed to elicit the preference and user willingness to pay. The Marginal Willingness to Pay (MWTP) for the improvement of recreational values of natural pools was estimated using a Conditional Logit Model. Outcomes of the WTP disclosed a clear preference hierarchy for various enhancements and contributions. Users were willing to pay LKR 297.6 to reduce the environmental damage by 50% and LKR 84.4 to raise the community income by 20%. The option to have a higher number of recreational activities was highly valued. Respondents were willing to pay a value of LKR 554.8 per year for the multiple benefits provided by the pool ecosystems. Conclusively, the study suggested that efforts to upgrade these natural pools should prioritize income generation, broadening of recreational activities and environ-mental conservation, in line with respondents’ inclinations.”

 

• Comment 2

Concerning keywords, there are other words could be included, for example, “Ecosystem Services”

 

Response

The comment is welcome. “Ecosystem Services” was added as a key word.

 

• Comment 3

Introduction can be improved for example highlighting the novelty and contributions to the literature on this matter;

 

Response

The authors welcome the comment. This aspect was carefully addressed by the authors in the introduction section as follows.

“In environmental and natural resource literature, various methodologies and approaches have been employed to assess the economic value of freshwater ecosystems in general and particularly to understand how these ecosystems contribute to human well-being and the economy. The majority of these studies center around benefits such as clean water, biodiversity, flood regulation, and recreational opportunities offered by freshwater ecosystems. A recent study conducted by Sierra et al. has assessed the economic value of key natural benefits of freshwater ecosystem using a market value method considering transfer of benefits and direct uses. Results of this study has revealed that users consider ecotourism and prevention of flooding to be the most important values provided by freshwater ecosystems [32]. Since there are complex relationships in freshwater ecosystem services, the value of these ecosystem services often depends upon the other ecosystem services provided [33, 34]. A meta-analysis conducted by Brouwer et al. has found that services provided by freshwater ecosystems such as lakes are greatly valued than the values reported for wetlands by the users [35]. A recent study conducted by Ureta et al. has employed economic valuation techniques such as payment card approach to explore the WTP towards protection of blue water ecosystem services in South Carolina. According to the findings of Ureta et al. people are willing to pay more for improvements that increase recreational activities, such as better fishing, more types of species, and better access to water areas [36]. Therefore, assessment of WTP has assisted to guide the policy makers on prioritization of river protection programmes in South Carolina [36].

Another study conducted in five Kenyan counties (Migori, Siaya, Busia, Kisumu, and Homa Bay) has evaluated how much the residents are willing to pay for the conservation of the Lake Victoria Ecosystem. The findings of this study have reported that around 40.9% of respondents are willing to contribute approximately Kenyan Shilling (KES) 500 each, resulting in an estimated total annual WTP of KES 616,279,069 [37]. Using a contingent valuation approach, Bueno et al. has attempted to investigate how local communities value efforts to restore water quality in Sampaloc Lake in Philippines, amid urbanization pressures. The findings have revealed that households around the lake are willing to pay Philippine Peso (PHP) 177.09 per month, totaling PHP 7,102,017 annually, for these improvements [38].

Many studies have evidenced that people are willing to pay for services and contribute towards conservation of freshwater ecosystems, which directly benefit them or improve their quality of life [36, 38]. Further, implementing an environmental users fee system to fund restoration of such freshwater ecosystems has been identified as an effective sustainable solution for management of such sensitive ecosystems [38]. However, such attempts require coordinated efforts on elevating environmental education and comprehensive policies to manage freshwater ecosystems [36, 38]. Further, WTP for ecosystem services varies depending on numerous factors, including socio-economic status, cultural values, awareness of ecosystem benefits, and local environmental conditions [39]. Previous studies have shown that people are more likely to pay for ecosystem services when they understand their importance and when there are clear mechanisms in place to link their payments to tangible outcomes, such as improved environmental quality or increased access to resources [37].

Watershed development programmes and nature-based ecosystem management projects have been proven to be sustainable and result in positive impacts on the socio-economic conditions of rural communities, including enhanced income distribution [40, 41]. Especially, participatory management programmes tend to lead into positive changes in the lives of marginal communities, while ensuring the sustainable conservation of freshwater ecosystems in different parts of the world [42]. For this, governments should facilitate policy-making, policy-lobbying and provide resources, and establish partnerships to promote integrated blue water ecosystem management [40, 42, 43]. However, designing such programmes requires an in-depth understanding on the perceptions of resource users and local communities on different values of freshwater ecosystems, alongwith their willingness to contribute towards such efforts either financially or from labour [44, 45]. To the best knowledge of the authors, no studies have valued the confounded multiple benefits of natural pools, particularly the non-market values, applying a DCE in Sri Lanka, which is a developing country. Therefore, this study provides a significant contribution to this knowledge gap in literature in this area from a developing country perspective.

Further, ecosystem services offer opportunities for diversifying livelihoods of local communities, beyond traditional sectors such as agriculture and forestry. Developing natural pool ecosystems as multi-purpose revenue generating entities can lead to environmental, economic as well as social benefits [44, 46]. Existing research on how much local stakeholders are ready to spend for the enhanced enjoyment and services from bettered recreation spots in natural pools of Sri Lanka is sparse. Hence, there's a noticeable demand to create strategies for enduring enhancement of these areas for recreation and their environs. Therefore, this study explores user preferences for improvement of recreational activities of natural pools and elicits user WTP for conservation of natural pools to ensure sustainable development. The insights from this research could inform policy-making, enabling the government to refine recreational offerings and sustainably harness the untapped potential of natural pool resources.”

 

• Comment 4

In the end of the introduction, the organization of the paper should be presented (the different sections of the paper).

 

Response

We are grateful for the suggestion. The following sentence was included at the end of the introduction section. 

“This paper is presented under separate sections highlighting the materials and methods, which emphasize the theoretical background of the study, along with the study design, data collection and analysis. The subsequent sections present the results of the analysis, along with a comprehensive discussion and conclusions.”

 

• Comment 5

In the introduction, the theory could be separated and be included in a new chapter for ‘methodological approach’. But I will leave this to better judgment of the authors.

 

Response

We are grateful for the valuable suggestion. However, based on some comments of the reviewer 1 and authors judgement, we kept the aforementioned theory aspects in the “Introduction section”. However, the “Analytical Framework of the Choice Experiment” and “Theoretical Background” sections in the methodology were expanded based on your suggestion to provide a better understanding.

 

• Comment 6

In the literature review, there are other aspects and studies related to willingness to pay (see Marque et al., 2016).

 

Response

We are thankful for the suggestion. This reference was cited in the manuscript as reference 46.

“46. Marques, R; Carvalho, P.T.; Pires, J. & Fontainhas, A. Willingness to pay for the water supply service in Cape Verde - How far can it go?. Water Science and Technology: Water Supply 2016, 16(6), 1721-1734.”

 

• Comment 7

All the abbreviations must be presented in the text.

 

Response

The authors carefully read the entire manuscript and all the abbreviation were presented under declarations as follows.

Abbreviations: CL: Conditional Logit; CVA: Contingent Valuation Approach; GDP: Gross Domestic Production; DCE: Discrete Choice Experiments; KES: Kenyan Shilling; MWTP: Marginal Willingness-to-Pay; LKR: Sri Lankan Rupees; PCA: Principal Component Analysis; PHP: Philippine Peso; WTP: Willingness to Pay.

 

• Comment 8

Regarding the methodology, the model can be better justified, and including the limitations.

 

Response

The comment is welcome. Following section was added under the “Analytical Framework of the Choice Experiment” title in the methodology to address this concern.

“Although several non-market valuation techniques have been used to estimate the monetary value of ecosystem services, stated preference approaches are increasingly used as they rely on preferences or values as stated by individuals [32, 49]. The major advantage of the stated preference methods is that they possess flexibility to capture both use and non-use values. Choice experiment models allows for the estimation of the relative importance of multiple environmental attributes and their levels [42]. Conditional logit model can be effectively used to relate the probability of a choice among the alternatives to the characteristics of the attribute levels defining those alternatives, which is consistent with the random utility theory. Further, unlike other regression models, the Conditional logit model avoids sparse data biases, leading to more accurate interpretations [49].”

 

Comment 9

 According to table 2, the results show “Willingness to improve sustainable recreational services”. The authors can explain better what are reasons beyond this result. Among the different regions of the country the results can be different among them? Is there a limit for this willingness?

 

Response

We are grateful for the comment. The following paragraph was added into the Discussion section to address this comment.

“The findings of the current study revealed a higher willingness among the local community to improve sustainable recreational services of the studied natural pools. This could be caused by a variety of factors such as the higher education level and monthly income, followed by higher environmental awareness [36, 38]. Further, positive attitudes of local communities on the importance of these natural pools for their income, health and wellbeing could also contribute to this tendency [41, 42]. However, previous studies have suggested that this WTP for sustainable recreational services can vary significantly among different regions of the country due to several factors such as proximity to the freshwater ecosystem of interest, cultural differences across regions, local environmental conditions and regional income differences [38, 39, 65, 66]. Further, studies are recommended to evaluate the regional differences among the WTP to improve sustainable recreational services and to estimate the maximum limits. This will be of immense importance in making policy decisions regarding the community-based conservation of these ecosystems.”

 

• Comment 10

Figure 2 should be better explained.

 

Response

Authors welcome the comment. Following revisions were done to elaborate the Figure 2, as highlighted in yellow colour.

“The association of ecosystem services is illustrated by the Principal Component Analysis (PCA) plot, as shown in Figure 2.  This ordination biplot is based on the relative importance of services as perceived by the respondents.  The two-dimensional plane of the biplot captures the variance and trade-offs of ecosystem services. PCA₁ and PCA₂ explains a combined variance of 93.5% of the total variance. The variables, labeled A to L, correspond to different recreational perception-related indicators. The spread of the variables along PCA₁ (88.9%), suggests that most variables are strongly associated with this component. Variables closer to the circumference of the circle are well represented in the PCA space. For instance, variable K which is community income generation closely aligns with PCA1, indicating it's a dominant factor in the dataset. Variable A (waste disposal and recycling methods) also extends farther in PCA1, indicating a significant influence. Variables J (security) and L (advertising) extend towards PCA2, which captures a relatively smaller portion of the variance (4.6%), suggesting these factors contribute uniquely to the dataset's variability.

Factors D, C and E lie closer to each other, suggesting a possible correlation among those (Figure 2). Hence providing knowledge and awareness on the importance of natural pool conservation in the forms of education programmes can have significant implications in inculcating positive attitudes and values among users. This shows a clear spatial pattern of tradeoffs between different ecosystem services. Further, all variables were clustered in the positive quandrant of PCA1 indicating a strong association. Therefore, factors such as cultural benefits, spiritual benefits and adverstising seemd to be correlated indicating the potential for developing the natural pools in such a way to attract the visitors seeking such ecosystem services.”

 

• Comment 11

How the authors see the future research of willingness to pay. This can be included in the discussion. Explain better the statistical significance of the variables and its meaning.  

 

Response

The authors welcome the valuable suggestions of the reviewer. After considering the comments of both reviewers following revisions were done.

In case of the future research of WTP, this section was added into the conclusion.

“Further studies should be conducted to understand quantified trade-offs between conservation, water quality improvement and economic development of natural freshwater ecosystems such as natural pools. Multidisciplinary studies are warranted to understand how monetary valuation of these ecosystems can be integrated in to national policy making. Understanding these aspects better could help in drafting policies that align visitor experiences with conservation and community goals. Strategies that can enhance community income is more likely to gain strong public support. Additionally, initiatives should focus on improving environmental conditions and providing education on conservation, as these are also highly valued. In contrast, while still important, spiritual and cultural benefits are seen as less immediate priorities and could be integrated into broader programmes that primarily address the more pressing economic and environmental concerns.”

 

The statistical significance of the variables and their meaning were further elaborated under the results section.

 

• Comment 12

The authors can also explain better how regulation can play a more important role on this matter.

 

Response

We are grateful for the valuable suggestion. The conclusion section was revised as follows, highlighting the importance of regulations on the conservation of these freshwater ecosystems.

“The findings of this study revealed that users were also willing to pay through labour contribution. Hence, these findings can be effectively used to guide co-management-based initiatives for freshwater ecosystem management, which are found to be sustainable in the long run. Users were also willing to accept a payment for certain income generation activities which could be through direct cash or in-kind measures. Moreover, the significantly higher preference for environmental damage reduction exhibits the user affinity and inclinations towards conservation. This is an indication of the potential for implementing nature-based solutions for ecosystem conservation. If implemented, such programmes should be voluntary and perhaps incentivized with discounts or other benefits. It's essential to consider the negative utility of increased funds per adult per visit. The Willingness to Pay indicates the maximum price consumers are willing to pay for the ecosystem service which helps derive the demand for a environmental good or service. Therefore, such pricing strategies should be carefully evaluated to ensure that they do not become a barrier to entry or visitation. Considering tiered pricing, discounts for advance booking, or membership programmes that offer added value without significantly increasing the single-visit cost are few strategies that can be recommended. Consumer surplus can be estimated as a measure to understand the gains and losses of price setting.

The findings of this study revealed that users were also willing to pay through labour contribution. Hence, these findings can be effectively used to guide co-management-based initiatives for freshwater ecosystem management, which are found to be sustainable in the long run. Users were also willing to accept a payment for certain income generation activities which could be through direct cash or in-kind measures. Moreover, the significantly higher preference for environmental damage reduction exhibits the user affinity and inclinations towards conservation. This is an indication of the potential for implementing nature-based solutions for ecosystem conservation. If implemented, such programmes should be voluntary and perhaps incentivized with discounts or other benefits. It's essential to consider the negative utility of increased funds per adult per visit. The Willingness to Pay indicates the maximum price consumers are willing to pay for the ecosystem service which helps derive the demand for a environmental good or service. Therefore, such pricing strategies should be carefully evaluated to ensure that they do not become a barrier to entry or visitation. Considering tiered pricing, discounts for advance booking, or membership programmes that offer added value without significantly increasing the single-visit cost are few strategies that can be recommended. Consumer surplus can be estimated as a measure to understand the gains and losses of price setting.”

 

• Comment 13

The limitations of the study and future research can be highlighted in the conclusions. Authors can improve the conclusions with more recommendations for decision makers (for example, how willingness to pay can be considered in price setting).

 

Response

We are grateful for the valuable suggestion. The conclusion section was revised as follows, highlighting the limitations and future research as highlighted in yellow.

“The study findings indicate that visitors of the natural pools place a significant value on higher economic improvements, high availability of recreational activities and environmental damage reduction. There is a clear WTP for these enhancements, as evidenced by positive coefficients and MWTP values. For example, the value attached to further improvements tends to be influenced by diminishing returns, as the MWTP for a 50% damage reduction is more than double that of a 20% reduction. When it comes to paying, visitors believe that the community should be made better-off through higher income generation. One of the reasons for this perception could be that they believe, improved income generation could boost greater benefits, facilities and amenities for visitors as well.

The findings of this study revealed that users were also willing to pay through labour contribution. Hence, these findings can be effectively used to guide co-management-based initiatives for freshwater ecosystem management, which are found to be sustainable in the long run. Users were also willing to accept a payment for certain income generation activities which could be through direct cash or in-kind measures. Moreover, the significantly higher preference for environmental damage reduction exhibits the user affinity and inclinations towards conservation. This is an indication of the potential for implementing nature-based solutions for ecosystem conservation. If implemented, such programmes should be voluntary and perhaps incentivized with discounts or other benefits. It's essential to consider the negative utility of increased funds per adult per visit. The Willingness to Pay indicates the maximum price consumers are willing to pay for the ecosystem service which helps derive the demand for a environmental good or service. Therefore, such pricing strategies should be carefully evaluated to ensure that they do not become a barrier to entry or visitation. Considering tiered pricing, discounts for advance booking, or membership programmes that offer added value without significantly increasing the single-visit cost are few strategies that can be recommended. Consumer surplus can be estimated as a measure to understand the gains and losses of price setting.

Further studies should be conducted to understand quantified trade-offs between conservation, water quality improvement and economic development of natural freshwater ecosystems such as natural pools. Multidisciplinary studies are warranted to understand how monetary valuation of these ecosystems can be integrated in to national policy making. Understanding these aspects better could help in drafting policies that align visitor experiences with conservation and community goals. Strategies that can enhance community income is more likely to gain strong public support. Additionally, initiatives should focus on improving environmental conditions and providing education on conservation, as these are also highly valued. In contrast, while still important, spiritual and cultural benefits are seen as less immediate priorities and could be integrated into broader programmes that primarily address the more pressing economic and environmental concerns.”

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed all the comments and significantly improved the manuscript. Therefore, I recommend the manuscript for publication.