A Bayesian Approach to Infer the Sustainable Use of Artificial Reefs in Fisheries and Recreation

Round 1

Reviewer 1 Report

Review Report for "A Bayesian Approach to Infer the Sustainable Use of Artificial Reefs in Fisheries and Recreation"

Abstract: The abstract provides a concise overview of the study's objectives, methods, and key findings. The use of Bayesian Influence Diagrams (ID) to evaluate the effectiveness of artificial reefs (AR) in the coastal regions of southern Portugal is novel. The abstract successfully highlights the study's contribution to understanding AR's role in fisheries and recreation. However, the implications of these findings for broader ecological or economic contexts can be elaborated further.

Introduction: The introduction effectively sets the stage by discussing the historical context and significance of AR. The authors did well in outlining the gap in existing research, particularly in the monitoring and evaluation of AR's human use. The stated objectives are clear, but the introduction could benefit from a more explicit connection between the study's goals and broader sustainability context.

Literature Review: The literature review is comprehensive, covering various aspects of AR, including biodiversity, ecosystem services, and fisheries. However, integration of these elements into cohesive narratives can be improved. This review would benefit from a more critical analysis of the existing literature, specifically addressing how this study's approach differs from or builds upon previous research.

Materials and Methods: The choice of the Algarve coast as study site is justified, and the explanation of the data collection process using an Automatic Identification System (AIS) is thorough. The adoption of Bayesian modelling and the development of an influence diagram are well explained. However, a more detailed discussion of the selection of specific variables in the model and their justification would strengthen this section.

Results: The results are presented clearly, with a detailed explanation of the various scenarios analysed using Bayesian ID. The quantitative findings (utility values for catches and satisfaction) were informative. However, a discussion of these results in the context of AR sustainability could be more robust. The impact of these findings on fisheries management and recreational activities requires further elaboration.

Discussion: The discussion effectively ties the results to the research objectives and highlights the contribution of the study to the field. The authors discuss the implications of their findings for the management of AR, and their potential applications in other coastal regions. However, the discussion could benefit from a broader perspective, considering the socioeconomic and ecological implications of AR's sustainable use.

Conclusions: The conclusions concisely summarise the key findings and their implications. The alignment with the United Nations Sustainable Development Goals is a valuable addition. The acknowledgement of the study's limitations and suggestions for future research are both appropriate and valuable.

Overall Assessment

Strengths

Innovative Application of Bayesian Influence Diagrams: This manuscript demonstrates a novel and sophisticated application of Bayesian Influence Diagrams within the context of Artificial Reefs (AR). This methodological innovation provides a robust framework for analysing complex interrelationships between ecological variables and human activities, offering significant advancement in the field.

Comprehensive and Rigorous Methodology: The authors adopted a methodologically rigorous approach, characterised by comprehensive data collection and meticulous analysis. The integration of Automatic Identification System (AIS) data into the Bayesian framework is particularly commendable, reflecting a high level of detail and precision in methodological execution.

Clarity in Presentation and Implications: The presentation of research findings is exceptionally clear and well-structured, enhancing the readability and accessibility of complex analytical processes. The implications of these results for the management and sustainability of AR are elucidated with commendable clarity, thus making a tangible contribution to the field.

Weaknesses

Necessity for an Enhanced and Integrative Literature Review: The literature review, although comprehensive, lacks a critical and integrative approach that synthesises existing research with the study's novel contributions. A more critical appraisal of previous studies, particularly in terms of their methodologies and findings, would significantly strengthen the foundation of this study.

Requirement for a Detailed Discussion on Variable Selection in Bayesian Model: The selection and justification of variables incorporated into the Bayesian model are not sufficiently detailed. Expanding the foundation behind the choice of specific variables and their relevance to the study's objectives would greatly enhance the robustness and credibility of the research.

Expansion of Discussion on Socio-Economic and Ecological Implications: While the manuscript touches upon the implications of its findings, there is a notable gap in the depth and breadth of discussion regarding socio-economic and ecological impacts. More extensive exploration of how these results contribute to broader sustainability goals and their potential applications in policy and management is necessary.

Recommendation: Accept with Minor Revisions

This manuscript represents a valuable and significant contribution to the field of sustainable fisheries and recreational management using Artificial Reefs. The recommended minor revisions, focusing primarily on enhancing the critical analysis within the literature review and broadening the discussion to encompass wider socioeconomic and ecological implications, will advance the impact of the manuscript. Based on these review report and the grammatical suggestions in the attached word file, the paper can be accepted as a substantial and influential addition to the journal "Sustainability".

Comments for author File: Comments.pdf

Quality of English Language should be improved.  

Author Response

Answers to Referee

Dear Reviewer:

We are very grateful for reviewing this manuscript and providing us with comments and suggestions to consolidate a review that will allow for a much better understanding of what is written. After studying the comments carefully, we tried our best to make corrections and adjustments as suggested.

We hope that the new manuscript is now in compliance to be approved. Responses to review comments are provided below in this document.

REVIEWER 1

Abstract: The abstract provides a concise overview of the study's objectives, methods, and key findings. The use of Bayesian Influence Diagrams (ID) to evaluate the effectiveness of artificial reefs (AR) in the coastal regions of southern Portugal is novel. The abstract successfully highlights the study's contribution to understanding AR's role in fisheries and recreation. However, the implications of these findings for broader ecological or economic contexts can be elaborated further.

We appreciate reviewer’s supportive comment very much.  A further elaboration as suggested was added, as follows: “An adequate interpretation based on the use of these tools implies being able to safeguard the ecological balance and economic sustainability of the communities operating in these areas”.

Introduction: The introduction effectively sets the stage by discussing the historical context and significance of AR. The authors did well in outlining the gap in existing research, particularly in the monitoring and evaluation of AR's human use. The stated objectives are clear, but the introduction could benefit from a more explicit connection between the study's goals and broader sustainability context.

Thank you for the constructive comments. We also appreciate this suggestion. We addressed it by establishing the connection between both parts of the goals and sustainability, as follows: “Regarding the data collection itself, this approach is carried out in a more sustainable way as it does not require many energy resources.”

Literature Review: The literature review is comprehensive, covering various aspects of AR, including biodiversity, ecosystem services, and fisheries. However, integration of these elements into cohesive narratives can be improved. This review would benefit from a more critical analysis of the existing literature, specifically addressing how this study's approach differs from or builds upon previous research.

We would like to thank the reviewer for this comment, which really seems quite relevant to us. In this sense, we add the following: “The potential of ID is great, and it is a tool that we believe is very useful for approaching the monitoring of reef use in relation to different human activities. There are few applications with these Bayesian tools, in the context that we decided to explore in this research”.

Materials and Methods: The choice of the Algarve coast as study site is justified, and the explanation of the data collection process using an Automatic Identification System (AIS) is thorough. The adoption of Bayesian modelling and the development of an influence diagram are well explained. However, a more detailed discussion of the selection of specific variables in the model and their justification would strengthen this section.

We are grateful to the reviewer for pointing out this issue. Table 1 succinctly is an attempt to describe the nodes found in the ID. However, we have improved the description a little towards objectives according to the reviewer. The following was added: “The main objective of the ID was to infer which combinations of reef use and surrounding areas, where the usefulness of human activities can be maximized, namely in the capture of living resources (professional fishing) and in the satisfaction of the practice of recreational activities (recreational fishing and diving)”.

Results: The results are presented clearly, with a detailed explanation of the various scenarios analysed using Bayesian ID. The quantitative findings (utility values for catches and satisfaction) were informative. However, a discussion of these results in the context of AR sustainability could be more robust. The impact of these findings on fisheries management and recreational activities requires further elaboration.

The suggestions made by the reviewer are very valuable. To address what the reviewer pointed out, we decided to add some explanatory text and an additional Table in the Results section. The text was: “Decision and chance nodes were determined from the AIS data and the ratio between human activities (i.e., the presence of fisheries and recreation boats in different spatial-temporal setting combinations). Based on these primary data sources, it was possible to construct the condition probability tables (CPT) for the nodes included in the ID. For instance, the values selected for the CPT of the decision node “Time spent” consisted in finding probabilities for boats spending their recorded activity time according to three discretization states, i.e., less than one hour, between 1 and 4 hours, and over 4 hours (Table 2).”

Discussion: The discussion effectively ties the results to the research objectives and highlights the contribution of the study to the field. The authors discuss the implications of their findings for the management of AR, and their potential applications in other coastal regions. However, the discussion could benefit from a broader perspective, considering the socioeconomic and ecological implications of AR's sustainable use.

We appreciate the suggestion and have made some changes accordingly.

Conclusions: The conclusions concisely summarise the key findings and their implications. The alignment with the United Nations Sustainable Development Goals is a valuable addition. The acknowledgement of the study's limitations and suggestions for future research are both appropriate and valuable.

We appreciate very much the comments.

Overall Assessment

Strengths

Innovative Application of Bayesian Influence Diagrams: This manuscript demonstrates a novel and sophisticated application of Bayesian Influence Diagrams within the context of Artificial Reefs (AR). This methodological innovation provides a robust framework for analysing complex interrelationships between ecological variables and human activities, offering significant advancement in the field.

Comprehensive and Rigorous Methodology: The authors adopted a methodologically rigorous approach, characterised by comprehensive data collection and meticulous analysis. The integration of Automatic Identification System (AIS) data into the Bayesian framework is particularly commendable, reflecting a high level of detail and precision in methodological execution.

Clarity in Presentation and Implications: The presentation of research findings is exceptionally clear and well-structured, enhancing the readability and accessibility of complex analytical processes. The implications of these results for the management and sustainability of AR are elucidated with commendable clarity, thus making a tangible contribution to the field.

Weaknesses

Necessity for an Enhanced and Integrative Literature Review: The literature review, although comprehensive, lacks a critical and integrative approach that synthesises existing research with the study's novel contributions. A more critical appraisal of previous studies, particularly in terms of their methodologies and findings, would significantly strengthen the foundation of this study.

Requirement for a Detailed Discussion on Variable Selection in Bayesian Model: The selection and justification of variables incorporated into the Bayesian model are not sufficiently detailed. Expanding the foundation behind the choice of specific variables and their relevance to the study's objectives would greatly enhance the robustness and credibility of the research.

Expansion of Discussion on Socio-Economic and Ecological Implications: While the manuscript touches upon the implications of its findings, there is a notable gap in the depth and breadth of discussion regarding socio-economic and ecological impacts. More extensive exploration of how these results contribute to broader sustainability goals and their potential applications in policy and management is necessary.

Recommendation: Accept with Minor Revisions

This manuscript represents a valuable and significant contribution to the field of sustainable fisheries and recreational management using Artificial Reefs. The recommended minor revisions, focusing primarily on enhancing the critical analysis within the literature review and broadening the discussion to encompass wider socioeconomic and ecological implications, will advance the impact of the manuscript. Based on these review report and the grammatical suggestions in the attached word file, the paper can be accepted as a substantial and influential addition to the journal "Sustainability".

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

the paper “A Bayesian approach to infer the sustainable use of artificial reefs in fisheries and recreation” provides an interesting perspective for evaluating artificial reefs. However, the paper has some weaknesses and there is a potential for strengthening certain parts. Regarding the mentioned, I propose to work on the following items to improve the quality of the paper:

General remarks:

Introduction: Please check, in the Instruction for Authors, if the journal requires a literature review as a separate chapter. Concerning the overall length of the paper and the disproportion in the length of the introductory part and results – I propose merging/integrating the present Literature chapter within the Introduction and condensing it to make a page and a half at most.

Material and methods: Could you provide more description of artificial reefs? For example, describe their shape/dimensions, density; the distance from the coast; mention at what dept they are submerged, the area occupied by the ARs, etc. 

Describe the main goals of the application of ID. Especially, the terms “catches” and “satisfaction”.

Results: While the chapter Material and Methods is extensively exposed, results are presented modestly. There are many interesting data, readers might be interested in, but so far, these cannot be found in the text. It would be interesting present more data about observed boats and their dynamics – e.g. to amend lines 270-281 by providing more numbers, or maybe presenting thses in a table, where sorting a total number of boats/vessels observed during the period, no. of boats by year and by season; according to their category, etc.  

In short, provide concrete numbers as inputs for the model required by the nodes in table 1. At least for the baseline scenario, while for other scenarios, these might be placed as supplementary files.

Discussion: Some parts are already elaborated in detail in the text, e.g. in lines 316-329, while discussion about the concrete results of the scenarios is missing. Please improve the discussion to balance the mentioned parts.

Conclusion:  Outline the results obtained and recommendations for the further use of ARs according to the most optimal scenario for the case of the investigated AR. In addition, you can continue with the possibilities of further application of ID in this domain.

Suggestions for improving details: 

Figure 5. – Nodes’ titles might be larger.

I propose careful checking of the English language for some minor mistakes.

Author Response

Answers to Referee

Dear Reviewer:

We are very grateful for reviewing this manuscript and providing us with comments and suggestions to consolidate a review that will allow for a much better understanding of what is written. After studying the comments carefully, we tried our best to make corrections and adjustments as suggested.

We hope that the new manuscript is now in compliance to be approved. Responses to review comments are provided below in this document.

REVIEWER 2

The paper “A Bayesian approach to infer the sustainable use of artificial reefs in fisheries and recreation” provides an interesting perspective for evaluating artificial reefs.

We appreciate your supportive comment very much.

However, the paper has some weaknesses and there is a potential for strengthening certain parts. Regarding the mentioned, I propose to work on the following items to improve the quality of the paper: 

General remarks:

Introduction: Please check, in the Instruction for Authors, if the journal requires a literature review as a separate chapter. Concerning the overall length of the paper and the disproportion in the length of the introductory part and results – I propose merging/integrating the present Literature chapter within the Introduction and condensing it to make a page and a half at most.

We are grateful for the reviewer's suggestion on this pertinent issue. In fact, the journal does not require a literature review section, but after an analysis of other papers published in this journal (and the “Resources and Sustainable Utilization” section) it appears that it is somewhat frequent practice to do so, for example when the authors address case studies. As ours is a methodological approach applied to a concrete case study, we decided to include, in addition to the introduction, a literature review section before the materials and methods. The idea of including a brief literature review is reinforced by the fact that it allows the reader to easily follow the lines of investigation that will be developed throughout the paper, reinforced by the literature consulted.

Regarding the disproportion between the introductory part and the results, we decided to lengthen the results part a little more, which was very modest. Thus, the results part was developed, as suggested.

Material and methods: Could you provide more description of artificial reefs? For example, describe their shape/dimensions, density; the distance from the coast; mention at what dept they are submerged, the area occupied by the ARs, etc. 

We greatly appreciate the reviewer's suggestion in this regard. In fact, although previously published literature describes much of what is required by the reviewer here, the present manuscript lacked some of these descriptions. Therefore, and in order to fill the gap pointed out by the reviewer, we added the following: “The artificial reefs in the study sites are modular porous concrete structures with cubic and octagonal shapes and occupy areas of approximately 6 km2 (Oura and Vilamoura) [14 ] and 12.2km2 (Faro-Ancão) [36]. The ARs are found between 16-40m deep [35], and their distance from the coast varies depending on the slope but can be up to almost 6.5km [14].”

Describe the main goals of the application of ID. Especially, the terms “catches” and “satisfaction”.

We are grateful to the reviewer for pointing out this issue. Table 1 succinctly is an attempt to describe the nodes found in the ID. However, we have improved the description a little more. The following was added: “The main objective of the ID was to infer what are the combinations of reef use and surrounding areas where the usefulness of human activities can be maximized, namely in the capture of living resources (professional fishing) and in the satisfaction of the practice of recreational activities (recreational fishing and diving).”

Results: While the chapter Material and Methods is extensively exposed, results are presented modestly. There are many interesting data, readers might be interested in, but so far, these cannot be found in the text. It would be interesting present more data about observed boats and their dynamics – e.g. to amend lines 270-281 by providing more numbers, or maybe presenting thses in a table, where sorting a total number of boats/vessels observed during the period, no. of boats by year and by season; according to their category, etc.  

The suggestions made by the reviewer are very valuable. To address what the reviewer pointed out, we decided to add some explanatory text and an additional Table in the Results section. The text was: “Decision and chance nodes were determined from the AIS data and the ratio between human activities (i.e., the presence of fisheries and recreation boats in different spatial-temporal setting combinations). Based on these primary data sources, it was possible to construct the condition probability tables (CPT) for the nodes included in the ID. For instance, the values selected for the CPT of the decision node “Time spent” consisted in finding probabilities for boats spending their recorded activity time according to three discretization states, i.e., less than one hour, between 1 and 4 hours, and over 4 hours (Table 2).”

In short, provide concrete numbers as inputs for the model required by the nodes in table 1. At least for the baseline scenario, while for other scenarios, these might be placed as supplementary files.

We took the reviewer's suggestion into consideration. Instead of adding some scenario results as supplementary files, we not only added what was described above, but also improved the discussion section by adding some text on scenario analysis, as also suggested by the reviewer.

Discussion: Some parts are already elaborated in detail in the text, e.g. in lines 316-329, while discussion about the concrete results of the scenarios is missing. Please improve the discussion to balance the mentioned parts.

 Thank you for this suggestion. We addressed it by describing more on the scenarios, as follows:

“The base case adjusts to the situation where fishing vessels occur three times more often than recreational vessels - regardless of the season of the year or time of day -, and that seiners correspond to a little more than half of the eligible observations. This situation assumes that AR areas are used in a relatively low proportion - i.e., 10% of the total area under analysis is assumed (Figure 6) - and that these recreational activities are practiced in an identical proportion (i.e., half angling and half diving). This base case also assumes that most activities - whether fishing or recreation - primarily use areas further away from reef areas. Most of the time, vessel activity time is relatively short (i.e., most spend less than 1 hour in the same location). This base case assumes a relatively low utility in catches (tangible), presenting the lowest value of all, when compared to the scenarios that were evaluated.

In the case of scenario 1, it is evaluated when there is no recreational activity and only purse seine fishing, practiced exclusively in the reef area, where the fishing trip(s) last up to 4 hours. Here there is a slight increase in catches as well as satisfaction (intangible). This scenario assumes that there is no interference between activities, but there is a limitation - carrying capacity - of the AR area itself that offers limited possibilities in the case of seine catches (generally pelagic fish species) and the slight increase in satisfaction for being given the possibility of having living resources for future recreational activities (namely species not targeted by purse seine gear).

In the case of scenario 2, everything is similar to the previous scenario, with the difference that multigear fishing is passive. In this scenario, the behavior of the vessels is different, as the vessel will launch the gear for a relatively brief period, leave the gear fishing continuously for some time and some hours later haul the gear on board. Generally, it is in the during the hauling process that fish from catch are counted. In this type of passive gear, there is generally greater selectivity. Therefore, the satisfaction of fishing in these areas is greater than in the case of boats with active gear (e.g., seiners). In this scenario, despite the gear remaining permanently in the reef zone under continuous fishing, the utility in terms of satisfaction for recreational activities is identical to that in scenario one.

In the third scenario it is assumed that in fisheries there are only purse seine activities, and in recreational activities both angling and diving are present. Under these conditions, it seems that this is the scenario where recreational activities obtain the least satisfaction, as there is some competition for space.”

Conclusion:  Outline the results obtained and recommendations for the further use of ARs according to the most optimal scenario for the case of the investigated AR. In addition, you can continue with the possibilities of further application of ID in this domain.

Thank you for the suggestions. In this sense, we outlined the results obtained and added the following recommendations: “The use of Bayesian influence diagrams is recommended as a feasible and com-prehensive approach, for cases that present some evidence of human activities in coastal areas, regardless of whether they are AR areas or not. Thus, the use of ID, particularly when exploring several use scenarios, requires caution due to several adjustments to the models and their constant plausibility checks.”

Suggestions for improving details: 

Figure 5. – Nodes’ titles might be larger.

Previously we have used the original printout/output from the software, where both definition and nodes’ headings/titles were not highly visible. Given this comment, it was decided to improve the figure by drawing a better one (i.e., both with better definition and larger node titles).

Author Response File: Author Response.pdf

Reviewer 3 Report

1.      In general, this paper is well researched and written with new insight into the current literature.

2.      At the end of 1. Introduction, it would be helpful to provide a brief introduction concerning the overall structure of this paper.

3.      Some of the relevant references should be cited: “Maritime Dispute Settlement Law towards Sustainable Fishery Governance: The Politics over Marine Spaces vs. Audacity of Applicable International Law”, Fishes, (2022), Vol. 7.

Author Response

Answers to Referee

Dear Reviewer:

We are very grateful for reviewing this manuscript and providing us with comments and suggestions to consolidate a review that will allow for a much better understanding of what is written. After studying the comments carefully, we tried our best to make corrections and adjustments as suggested.

We hope that the new manuscript is now in compliance to be approved. Responses to review comments are provided below in this document.

REVIEWER 3

1. In general, this paper is well researched and written with new insight into the current literature.

We appreciate your supportive comment very much.

2. At the end of 1. Introduction, it would be helpful to provide a brief introduction concerning the overall structure of this paper.

This comment is greatly appreciated. Done accordingly.

We added the following at the end of the introduction: “After this introduction, there is a literature review section covering the four topics considered important in this study. Next comes the material and methods section covering the study site, data collection, data mining, vessel typology and behavior and Bayesian modeling with influence diagrams. Later we have the results considering the base case and some analyzed scenarios. Afterwards comes the discussion of the results obtained and the potential of using Bayesian networks for similar studies. Finally, conclusions are drawn up and some recommendations are included.”

3. Some of the relevant references should be cited: “Maritime Dispute Settlement Law towards Sustainable Fishery Governance: The Politics over Marine Spaces vs. Audacity of Applicable International Law”, Fishes, (2022), Vol. 7.

As suggested, we have included the reference.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Dear Authors,

I am glad that you have put in additional effort to improve the paper.
According to my opinion, the paper is ready to be published in the Sustainability Journal.

Reviewer 2