Bioeconomic Analysis of In-Pond Raceway System Production of Foodsize and Stocker Hybrid Catfish (Channel Catfish Ictalurus punctatus ♀ × Blue Catfish, I. furcatus ♂)
Round 1
Reviewer 1 Report
The scientific article is original and brings a lot of important information. The article is extensive, but does not detract from the quality of the information. The authors present enough numbers (data) to support fish farmers in making decisions, this is the strong point of the study. In my opinion, the article has great potential to be published in Fishes journal.
Author Response
We would like to thank the reviewers for the detailed comments and suggestions for the manuscript. We believe that the comments have identified important areas which require improvement. After completion of the suggested edits, the revised manuscript has benefitted from an improvement in the overall presentation and clarity.
Answer: Thanks for reviewing our article. Our goal was to show the costs of producing catfish using IPRS and as you pointed out to support fish farmers with their decisions!
Reviewer 2 Report
The study is an exciting and applied bioeconomic research combining actual growth and economic performance of channel catfish in IPRS. The study was well described and very detailed in presentation. A key challenge with the study is the presentation of the economic performance of the stocker fingerlings. I will recommend that the growth performance of the stocker fingerlings be left. However, the financial performance be removed as it is irrelevant and doesn't make economic sense from the study design. The economic performance of the stocker would have made sense if the stocker were raised to produce fingerlings for sale or restocking.
I also noticed that the cost of carp fingerlings was added to the economic analysis. However, there was nowhere in the introduction or methodology that carp was introduced or stated as part of the study.
Finally, the authors need to concisely recommend the best bioeconomic scenario based on the study that will help farmers maximise yield and economic returns if they adopt the IPRS for channel catfish production.
Other comments and corrections are included in the attached manuscript.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
We would like to thank you for the detailed comments and suggestions for the manuscript. We believe that the comments have identified important areas which require improvement. After completion of the suggested edits, the revised manuscript has benefitted from an improvement in the overall presentation and clarity. Attached, you will find a point-by-point description of how each comment was addressed in the manuscript.
Author Response File: Author Response.pdf
Reviewer 3 Report
Bioeconomic analysis of aquaculture production is a very important field of research for aquaculture. However, there not many studies analysing the economic impact of different production system investments, and less made a pilot scale.
The design of the trial is in my opinion the main weakness of the work. It seems contradictory that the RW1/RW2 made of stainless Steel (more expensive and thus requiring a higher investment) are bigger than RW3/RW4. I do not understand why all RW doesn’t have the same m3. The analysis of results becomes complicated, as authors should then compare an investment decision (two RW materials), with a zoo-technical decision (RW of different m3 with two different fish densities). I understand that pilot trials are very expensive, but it would have been better to make two different trials.
A second key criticism is the lack of information about the causes of mortality, and the very high impact that mortality has on economic results. Nothing is said about diseases, and for the data presented those should have happened. The authors tried to correlate that with DO concentration and as pond 4 have low values in the mornings and it had heavy phytoplankton blooms. However, pond 1 has the highest mortality on Growout fish and nothing is comment about this. On average mortality is higher on Stocker fish (80.55% survival) than on Growout fish (90.15% survival). That should be discussed.
As the pilot study is as it is. If similar performance (growth and survival) can be gotten with RW of different dimensions as it seems, that authors could compare (hypothesizing) the investment of two RW made of different materials and cost but of the same size/volume.
With the information that authors have, they could try to study the profitability of a given IPRS (better the RW with low cost material) facility with different mortalities, trying to look for a breakeven value. It is well know that feeding is the higher cost in aquaculture, but there are few economic studies that show the impact of mortality. Investment if disease prevention is probably one of the most profitable business decisions that a farmer can make.
Other correction/suggestions:
Abstract: please make it more synthetic and conceptual. Lines 13 to 23 are full of data and over descriptive, which make the abstract difficult to understand.
Introduction, 1st paragraph: all catfish production references should be updated to the latest year at possible, to provide production information of 2020 (and not of 2018, 2019 and 2020, as it is now).
Materials and Methods: there is a lack of information about the materials of the two IPRS, their characteristics, price per m2, required maintenance and expected lifespan. First comment about that appears on lines 226.
As for tables 4 and 5, I propose authors give the stocking density in kg/m3. Same that at harvest, and not in fish/m3 or fish/ha (these are no necessary).
Author Response
Dear Reviewer,
We would like to thank you for the detailed comments and suggestions for the manuscript. We believe that the comments have identified important areas which require improvement. After completion of the suggested edits, the revised manuscript has benefitted from an improvement in the overall presentation and clarity. Attached, you will find a point-by-point description of how each comment was addressed in the manuscript.
Author Response File: Author Response.pdf
Reviewer 4 Report
Review of ‘Bioeconomic analysis of in-pond raceway system production of foodsize and stocker hybrid catfish (Channel catfish Ictalurus punctatus ♀ x Blue catfish, I. furcatus ♂)’ by Leticia Fantini-Hoag, Terry Hanson and Jesse Chappell.
The authors conducted a study aimed to reveal different stocking regimes on profitability of in-pond raceway systems producing foodsize and stocker hybrid catfish. They described in detail their system and methods. The authors analyzed data financially and found that positive financial net returns occurred when farm level investment decreased because of reduced payback periods, increased net present values, and higher internal rates of return. In general, the authors used standard approaches to treat the data but additional analysis is recommended. The authors discussed their results and concluded that initial raceway cost and cost of materials for raceways had a large impact on the long-term feasibility of the in-pond raceway system. In general, the paper is well-written and I can recommend this manuscript for publication after minor revisions.
Abstract
The abstract is wordy and overloaded with unnecessary information. The authors should reduce this section.
Introduction
Pg 1 Ln 35: Suggest changing ‘metric ton, 27%’ to ‘metric tons, 27%’
Pg 1 Ln 40: Suggest changing ‘137 thousand metric ton’ to ‘137 thousand metric tons’
Pg 2 Ln 62: Suggest changing ‘allow for more’ to ‘allows for more’
Methods
Pg 5 Ln 147: Suggest changing ‘sizes’ to ‘sized’
Pg 5 Ln 176: Please, explain your choice of the 5.0% discount rate.
Pg 5 Ln 182: Suggest changing ‘softwares’ to ‘software’
Pg 7 Ln 222: Why did you use "$2.44 (base), $2.44"? Was the latter incorrectly inserted?
Pg 7 Ln 230: Suggest changing ‘larger sized’ to ‘larger-sized’
Results
Pg 8. Table 3. The authors should include mean values for water quality parameters and should compare statistically these values among different ponds and raceways.
Pg 11. Table 4. The authors should apply a statistical analysis to test the mean values for differences and provide relevant p-values.
The same concern is for Pg 12, Table 5.
Pg 17 Ln 385: Suggest changing ‘The lowest total costs’ to ‘The lowest total cost’
Pg 18 Ln 457: Suggest changing ‘a scenario 4’ to ‘scenario 4’
Discussion.
The authors should compare the thermal regime observed during the study period with multi-year conditions for this region and should discuss possible risks associated with situations when unfavorable conditions exist due to fluctuations in environmental variables.
Pg 24 Ln 569: Suggest changing ‘of 72 to’ to ‘from 72 to’
Pg 26 Ln 689: Suggest changing ‘different sized’ to ‘different-sized’
Pg 26 Ln 696: Suggest changing ‘indicates’ to ‘indicate’
The authors use the terms ‘IPRS systems’ and ‘IPRS system’. This is redundant because IPRS means ‘in-pond raceway system’.
Author Response
Dear Reviewer,
We would like to thank you for the detailed comments and suggestions for the manuscript. We believe that the comments have identified important areas which require improvement. After completion of the suggested edits, the revised manuscript has benefitted from an improvement in the overall presentation and clarity. Attached, you will find a point-by-point description of how each comment was addressed in the manuscript.
Author Response File: Author Response.pdf
Reviewer 5 Report
Overall writing style is good but there are several incidences of typos, such as ‘m3’ instead of the correct superscript, or the use of acronyms without description (i.e. DO). Captions and notes are repetitive and lengthy.
In terms of the analysis, it seems that too many parameters were tested back and forth without a logic flow or rationale. Focusing on one parameter at the time and making it clear the reasons why each parameter is tested, would make it for an easier flow. It is also not clear the reasons for defining scenarios of investment. A simple comparison of percentage of fixed costs to total costs for different (feed and fish) price scenarios would tell the same story. As in the flow of the analysis, the focus of the study in general is not clear. While the goal of this study was defined as to evaluate the growth performance and economic efficiency of two sizes of IPRS units using two stocking density approaches raising stocker and foodsize hybrid catfish in IPRS units and testing whether density would affect efficiency, discussion focuses on adoption of alternative production technologies. Finally, the most interesting finding of the study is the point of highest (only) profitability, occurred in the high-density RW3 raceway, coinciding with lowest FCR and yet, highest biomass. That finding deserves much more attention.
Specific suggestions:
On line 59, that last sentence seems disconnected to its paragraph.
Figure 1 caption: incorporate the detailed description in the text if not already there and provide a concise caption.
Line 112: can you make clear that all growout ponds received the same feeding regime?
Line 126: does that mean that zero feed loss was assumed in the process?
Line 138 the word “cost” is missing.
Table 1: third column heading is cost ($) per unit but half of the table reports quantities. Which prices were chosen for those items and what was used as a reference price for each component? What was the source of average prices? Does blue catfish attract a premium price?
Table 2: RW1 and RW2 are larger than RW3 and RW4 (line 87 : “RW1/RW2 and RW3/RW4 plus stocker units represented 1.5% and 1.2% of the 0.4 ha pond surface area, respectively”). Hence the different density. However, investment on land occupied is the same. Also, WWU in large and small RWs appears in both small and large RWs. Please check and explain.
Figures 2 and 3: Why is this information only relevant to growout raceways? What about stockers?
Section 2.3: it is not clear whether this is a sensitivity analysis that identifies the effect of each particular variable, or a ‘what if’ scenario analysis, please choose one. Also, the reader will benefit from a table describing parameters of each scenario. Section 2.3 describes two sensitivity analyses but it seems that what is described as second sensitivity analysis is actually the estimation of economic results from changes in feed and fish prices. Scenario structures are confusing.
Table 4: does the stocking density in fish/ha take into account the measures “1.5% and 1.2% of the 0.4 ha pond surface area” described before?
Net FCR is smaller in smaller ponds, is this a consequence of higher density and a result of reduced feed loss?
Line 271: section 3.1 states “no fish mortalities occurred.” Right after, in section 3.2, survival varies from 90.7% and 91.6%. Can you infer where mortality comes from?
Table 4: what was the percentage harvested of small and premium size fish?
Tables 6 and 7: these are the only times Carp appears in the manuscript. Explain why it is included there and what is its effect.
Correct me if I’m wrong but I could not find the part of the manuscript where authors describe what is a ‘stocker’ fish and why they carry the same price/kg as foodfish. A brief description is only offered in the discussion at the end of the paper.
Tables 11 and 12 and 13 and following figures: No need to repeat all over again the description of scenarios. Build a table to describe scenarios and refer to it when necessary.
Table 12: by ‘effect’ do you mean a reduction from a base scenario or are these tables reporting actual net return in each combination? Define MT.
Figure 5 Notice that the graph is cut in Fig 5.a.
Line 595: EBITA or EBITDA?
Author Response
Dear Reviewer,
We would like to thank you for the detailed comments and suggestions for the manuscript. We believe that the comments have identified important areas which require improvement. After completion of the suggested edits, the revised manuscript has benefitted from an improvement in the overall presentation and clarity. Attached, you will find a point-by-point description of how each comment was addressed in the manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
The authors have well responded to all comments and suggesttions made in the previous revision: therefore and I thus accepting the paper for its publication.
