An Overview of Atlantic Bluefin Tuna Farming Sustainability in the Mediterranean with Special Regards to the Republic of Croatia

Round 1

Reviewer 1 Report

The document is generally well written and referenced. The work is a bit descriptive and reads like a literature review, but there is some data analysis and it does represent a decent summary of the state of play of BFT aquaculture in the Med. The pdf has some queries and clarifications that should be addressed. In addition, the conclusion should be fairly extensively redone as it is currently just a copy and paste of text found elsewhere in the document and doesnt really include any conclusions or synthesis of the information. Some consistency in citation style is required as is the use of a hyphen in sushi-sashimi. As stated, other comments are in the pdf

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 1,

We would like to thank you for your quick evaluation. Your suggestions helped us a lot to improve the work. We have considered all your suggestions and we hope that we have managed to answer all your questions. All changes and comments made by the authors can be found in the revised manuscript titled REV1 & REV3 & REV4 & REV5 sustainability-2139437 (tracked changes). If you have any further questions, please feel free to ask. Thank you again.

Yours sincerely,

The Authors

REV1

The document is generally well written and referenced. The work is a bit descriptive and reads like a literature review, but there is some data analysis and it does represent a decent summary of the state of play of BFT aquaculture in the Med.

• The pdf has some queries and clarifications that should be addressed.
• In addition, the conclusion should be fairly extensively redone as it is currently just a copy and paste of text found elsewhere in the document and doesnt really include any conclusions or synthesis of the information.

This conclusions chapter is basically just cut and paste text from previous sections of the document. Im not sure what that adds to the document. It should be modified to reflect only the main findings and be reworded accordingly to avoid dull repetition.

• Some consistency in citation style is required as is the use of a hyphen in sushi-sashimi. As stated, other comments are in the pdf

Comments in pdf version:

1. This statement seems a bit out of place here. It should rather come near the beginning of the paragraph or be left out.

Deleted at the suggestion of reviewer 1

2. Different citation format... also quite an old reference. A lot may have changed since 2008.

Corrected and a newly dated reference added at the suggestion of reviewer 1

3. This again is a change in referencing format

Corrected at the suggestion of reviewer 1

4. Formatting issues

Corrected at the suggestion of reviewer 1

5. As a European Union (EU) Member country...

Corrected at the suggestion of reviewer 1

6. The Legal Framework...

Corrected at the suggestion of reviewer 1

7. when mature fish are reared..

Corrected at the suggestion of reviewer 1

8. is are reared for an extended…

Corrected at the suggestion of reviewer 1

9. I get what the authors are saying, but this isnt a very clear description or justification. Why has their historical experience resulted in only Croatia being allowed to farm juvenile ABFT?

Rewritten at the suggestion of reviewer 1: According to [14], Croatia is allowed to farm juvenile tuna based on historical data on the size composition of Croatian ABFT catches, and the fact that Croatia, a pioneer in tuna farming, produces relatively small quantities of tuna.

Authors’ comment: A new subchapter 2.1 ABFT fishing in Croatia has been added to clarify for readers why the minimum size for ABFT caught in the Adriatic for farming purposes is 8 kg.

10. This is the first time a hyphen has been used between sushi-sashimi. I would say this is correct, but should be consistent throughout the document. Corrected (throughout the document) at the suggestion of reviewer 1
11. Comment of reviewer 1 for Figure 2: If I understand correctly the Blue line represents all production, Orange represents EU production and Grey represents Croatian production. If the authors are trying to prove the point that the statistics dont match, a comparison using only the Croatian data from each dataset would be more informative.

Authors’ comment: : We are not trying to prove here that the statistics do not match. Figure 2 shows only the comparison between Mediterranean production, EU production and Croatian production.

12. Comment of reviewer 1: Clarify what you mean by "free" in: In 2022, there are 4 ICCAT registered 262 FFBs in Croatia with 10 different locations/fields, while the total FFBs allocated capacity 263 is 7092 t (788 t are free) and the maximum input quantity of wild caught ABFT is 2947 t 264 (Figure 3) according to ICCAT Record of farms (2022).

Added at the suggestion of reviewer 1:

In 2022, there are 4 ICCAT registered FFBs in Croatia with 10 different locations/fields, the tuna farming capacity available to the Republic of Croatia is 7880 t, the total FFBs allocated capacity is 7092 t (90% of the tuna farming capacity available to the Republic of Croatia and 10% or 788 t is not allocated) and the maximum input quantity of wild caught ABFT is 2947 t (Figure 3) according to ICCAT Record of farms (2022).

13. This is the authors opinion and not based on the science or preceding information. Im not sure its appropriate here. Also what awards have been won and when? This statement should have some justification if its to remain (for…although the award-winning Croatian tuna is a good example of the direction Croatian ABFT farming should take).

Deleted at the suggestion of reviewer 1

14. Just clarify does the reference only refer to the Japanese success or does it also list the various projects initiated in the Med? Just make sure both aspects are covered as only one citation is provided and its a pretty generic one at that.( Since the 2000s, there have been many closed-cycle aquaculture projects of ABFT in 285 the Mediterranean Sea, encouraged by successfully spawned and reared Pacific bluefin 286 tuna in captivity at Kinki University Fisheries Laboratory (Japan) from 2002 to 2004 [6].

Authors’ comment: The reference refers both to the Japanese success and to the various projects initiated in the Mediterranean.

15. Inconsistent citation style

Corrected at the suggestion of reviewer 1

16. See highlight in line 351. The citation style is inconsistent again.

Corrected at the suggestion of reviewer 1

17. Klinčić et al. (2020)

Corrected at the suggestion of reviewer 1

18. This sentence is somewhat repetitive of the previous sentence. (The constant availability of food near farms can alter 358 wild fish feeding behaviour and migration patterns)

Deleted at the suggestion of reviewer 1

19. End of the first sentence and the second sentence are directly contradictory... Nevertheless, wild 363 organisms can easily entangle in caging nets, and there is a high risk of two-way pathogen 364 transmission between farmed and wild animals (cross-contamination). According to [43], 365 there is no evidence of disease transmission between wild and farmed ABFT.

Deleted (the first sentence) at the suggestion of reviewer 1

20. Im not sure I follow the logic. The reared tuna are caught in the wild normally fairly close to where they are reared and therefore may well be from the same population that would have naturally bred in the wild had these individuals not been captured. I see that citations have been used to justify this statement but I think a bit more explanation is required as it is counter intuitive unless the reared tuna come from a separate population (for which there is no evidence in the Med for ABFT) (and gene flow [77].)

Added at at the suggestion of reviewer 1:

According to [77]., the dynamics and structure of ABFT stocks in the Atlantic and Mediterranean are not fully understood and it is not clear whether spawning sites separate the gene pool, especially in the Mediterranean, which offers a large number of spawning sites.

Authors’ comment: According to [77], there is an ongoing debate on whether ICCAT a two-unit stock structure was accurate to capture the actual global ABFT population genetic structure or possibly even meta-populations. The diversity of results has not explained the full dynamics and structure of ABFT stocks in the Atlantic Ocean and the Mediterranean Sea. It is not clear if and to what extent spawning sites separate the gene pool especially for the Mediterranean Sea, which offers a large number of spawning locations.

21. I would say "reduced" is more accurate. not sure they can be avoided completely.

Corrected at the suggestion of reviewer 1

22. See previous comment on the use of the hyphen.

Corrected at the suggestion of reviewer 1

23. Repetition of lines 401 and 402.

Deleted (lines 405-407) at the suggestion of reviewer 1

24. This conclusions chapter is basically just cut and paste text from previous sections of the document. I am not sure what that adds to the document. It should be modified to reflect only the main findings and be reworded accordingly to avoid dull repetition.

Rewritten at the suggestion of reviewer 1:

Conclusions

ABFT is the most important commercial tuna species in the Mediterranean. The lucrative Japanese market has encouraged the fattening of adult ABFT (Australian-style) in Spain and other Mediterranean countries and the farming of juveniles in Croatia since 1996. In the Mediterranean, tuna farming and fattening are very profitable, provide full year-round employment, contribute to the preservation of cultural heritage, and can also promote tourism development. Unfortunately, the environmental viability of ABFT farming and fattening is questionable, as both farming and fattening are completely dependent on wild stocks, both for stocking and feeding. Although there has been success in closing ABFT life cycle in captivity, and environmentally friendly feeds are available, hatchery-produced juveniles and new efficient commercial feeds are still insufficient and costly for commercial use. Further investment in research and innovation is needed to conserve wild stocks and ensure sustainable development of ABFT farming industry.

Croatian ABFT breeding is less profitable than fattening practices in other Mediterranean countries, but is very important for the Croatian economy and society. Croatian ABFT farming also contributes to the development of a number of accompanying activities, such as fishing for small pelagic fish, and can help reduce the trend of depopulation of vulnerable island communities. Due to good environmental status, availability of small pelagic fish, availability of highly qualified and well-organised labour force, good cooperation between producers and researchers and application of modern farming technologies, ABFT farmed in Croatia have high quality and good reputation on the market. ABFT farmed in Croatia have high quality and good reputation on the market. The main weakness of Croatian tuna farming is that the entire industry is dependent on the Japanese market, but this can be overcome by the possibility of product diversification for new markets, including the tourism industry. The Croatian National Strategic Plan for Aquaculture Development until 2027 emphasises that the full potential of Croatian tuna farming has not yet been exploited. Therefore, further investigation is needed.

25. Repetition of a previous statement. See previous comment for lines 270 - 271. (Comment 13) Deleted at the suggestion of reviewer 1

Reviewer 2 Report

The MS is worth interest and represent a significant contribution to the field. THe MS is well organized and structured and, in my opinion, can be considered for publication in this form. 

Author Response

Dear Reviewer 2,

We would like to thank you for your quick evaluation. Reviewers’ suggestions helped us a lot to improve the work. All changes and comments made by the authors can be found in the revised manuscript titled REV1 & REV3 & REV4 & REV5 sustainability-2139437 (tracked changes). Thank you again.

Yours sincerely,

The Authors

 

Reviewer 3 Report

Sustainability

An overview of Atlantic bluefin tuna (Thunnus thynnus, Linnaeus, 1758) farming sustainability in the Mediterranean with special regards to the Republic of Croatia.

Gorana Jelić Mrčelić, Vedrana Nerlović, Merica Slišković, Ivana Zubak Čižmek

 

Line 83-84. … been in force since 1981, E-BFT TAC since 1998, while Atlantic-wide ABFT size limit of 6.4 kg (10 kg and 30 kg afterwards) since 1975 [18]. The 6.4 kg conservation measure was violated for decades in the East Atlantic and Mediterranean fisheries, resulting in the death of millions of fish (Cort & Abaunza, 2019).

Reference:

Cort, J. L. and Abaunza, P. 2019. The bluefin tuna fishery in the Bay of Biscay. Its relation with the crisis of catches of large specimens in the East Atlantic fisheries from the 1960s. Springer Briefs in Biology, 123 p. Available on line at: The Bluefin Tuna Fishery in the Bay of Biscay | SpringerLink

 

Line 94. Please, make the figure bigger and with a larger Y-axis scale to be able to see the fluctuations of the Croatia landings.

 

Line 110. The Recommendation 21-08 sets E-BFT TAC at 36000 t for 2022, and the 108 minimum E-BFT size is 30 kg or 115 cm fork length, while minimum size for E-BFT caught in the Adriatic Sea for farming purposes is 8 kg or 75 cm fork length, the same as in the Bay of Biscay and some artisanal fisheries.

 

Line 116.

Note. In order for the readers to know the characteristics of the ABFT fishery in Croatia, the authors should have to insert the following subchapter:

 

2.1 ABFT Fishing in Croatia 

Note. In this subchapter, authors should describe the ABFT fishery in Croatia on the basis of the following articles:

 

Morovic, D. 1969. La pêche des thonidés sur les côtes yugoslaves de l´Adriatique. Biljeske-Notes, Split, 24.

 

Alegria, V. 1984. Preliminary analyses of tuna catches along the eastern Adriatic coast. Bilješke-Note of Institute of Oceanography and Fisheries – Split; 57.

 

Tièina, V., Kataviæ, I. and Fanièeviæ, V. 2002. Croatian bluefin tuna catches in the Adriatic during 1999 through 2001 by year/month/size structure. Col. Vol. Sci. Pap. ICCAT, 54(2): 465-471.

 

Note. This description will help readers understand why the minimum size for ABFT caught in the Adriatic Sea for farming purposes is 8 kg or 75 cm length.

 

Line 140  … transport cages and towed by a tugboat at a speed of 1 to 1.5 knots to the rearing site [14]. In the western Mediterranean, tuna have been shown to spawn inside transport cages (Gordoa et al., 2009).

Reference:

Gordoa, A., Olivar, M. P., Arevalo, R., Viñas, J., Molí, B. and Illas, X. 2009. Determination of Atlantic bluefin tuna (Thunnus thynnus) spawning time within a transport cage in the western Mediterranean. ICES Journal of Marine Science, Volume 66, Issue 10, December 2009, Pages 2205–2210, https://doi.org/10.1093/icesjms/fsp211

 

Line 379

ABFT aquaculture is attractive to investors because of the high returns, but it is also important to the general population because of the high export value and employment [6]. It is also a source of income from the tourist point of view, such is the case of the Catalan company Balfegó, which has a catamaran to visit the tuna farms in l'Ametlla de Mar (Tarragona, Spain).

 

Line 441

... but it is also important to the public because of its high export value and employment and for tourism.

Author Response

Dear Reviewer 3,

We would like to thank you for your quick evaluation. Your suggestions helped us a lot to improve the work. We have considered all your suggestions and we hope that we have managed to answer all your questions. All changes and comments made by the authors can be found in the revised manuscript titled REV1 & REV3 & REV4 & REV5 sustainability-2139437 (tracked changes). If you have any further questions, please feel free to ask. Thank you again.

Yours sincerely,

The Authors

REV3

• Line 83-84. … been in force since 1981, E-BFT TAC since 1998, while Atlantic-wide ABFT size limit of 6.4 kg (10 kg and 30 kg afterwards) since 1975 [18]. The 6.4 kg conservation measure was violated for decades in the East Atlantic and Mediterranean fisheries, resulting in the death of millions of fish (Cort & Abaunza, 2019). Cort, J. L. and Abaunza, P. 2019. The bluefin tuna fishery in the Bay of Biscay. Its relation with the crisis of catches of large specimens in the East Atlantic fisheries from the 1960s. Springer Briefs in Biology, 123 p. Available on line at: The Bluefin Tuna Fishery in the Bay of Biscay | SpringerLink
• Line 94. Please, make the figure bigger and with a larger Y-axis scale to be able to see the fluctuations of the Croatia landings.
• Line 110. The Recommendation 21-08 sets E-BFT TAC at 36000 t for 2022, and the 108 minimum E-BFT size is 30 kg or 115 cm fork length, while minimum size for E-BFT caught in the Adriatic Sea for farming purposes is 8 kg or 75 cm fork length, the same as in the Bay of Biscay and some artisanal fisheries.
• Line 116. In order for the readers to know the characteristics of the ABFT fishery in Croatia, the authors should have to insert the following subchapter:

2.1 ABFT Fishing in Croatia 

Note. In this subchapter, authors should describe the ABFT fishery in Croatia on the basis of the following articles:

Morovic, D. 1969. La pêche des thonidés sur les côtes yugoslaves de l´Adriatique. Biljeske-Notes, Split, 24.

Alegria, V. 1984. Preliminary analyses of tuna catches along the eastern Adriatic coast. Bilješke-Note of Institute of Oceanography and Fisheries – Split; 57.

Tièina, V., Kataviæ, I. and Fanièeviæ, V. 2002. Croatian bluefin tuna catches in the Adriatic during 1999 through 2001 by year/month/size structure. Col. Vol. Sci. Pap. ICCAT, 54(2): 465-471.

Note. This description will help readers understand why the minimum size for ABFT caught in the Adriatic Sea for farming purposes is 8 kg or 75 cm length.

Authors’ comment: Added at the suggestion of reviewer 3:

2.1. ABFT fishing in Croatia

As European Union (EU) Member country, Croatian fishery is under the Common Fisheries Policy (CFP). Legal Framework governing Croatian marine fisheries includes Ma-rine Fisheries Act (OG 56/10, 127/10, 55/11) and Act on structural support and market organiza-tion in fisheries (OG 153/09, 127/10), as well as special regulations on E-BFT fishing (in-cluding purse seine fishing, recreational fishing for trophy tuna, etc.) [24].

The purse seine is the most important fishing gear in Croatian ABFT fishery and the Regulation on fishing opportunities and the allocation of the state quota in 2022 for fishing for bluefin tuna (Thunnus thynnus) (OG 16/2022) set quota for ABFT purse seine fishing at 833.46 t for 2022 [25]. Purse seine fishing for ABFT is allowed in the Eastern Atlantic and the Mediterranean from 26 May to 1 July, while for fish farmed in the Adriatic Sea, the season may be open from 26 May to 15 July in the Adriatic Sea (FAO fishing area 37.2.1) [22]. The minimum size for ABFT caught in the Adriatic Sea for farming purposes was set at 8 kg or 75 cm fork length based on historical data on the size composition of Croatian ABFT catches. Purse seine tuna fishing in the Croatian Adriatic began in 1929, when only one purse seiner was registered, but by 1954 there were 36 boats [26]. Commercial tuna fishing in Croatia has developed significantly since the World War II. The first phase of development, which lasted from 1947 to 1964, ended with the disappearance of traps. In the second phase, the Croatian ABFT fishery has been dominated by purse seine fishing since 1965 [27].

Based on an analysis of the size composition of Croatian (Yugoslav) ABFT catches, [26] found that tuna in the 4-5 kg weight class and the 9-10 kg weight class accounted for 70% of catches in the period from 1947 to 1969, while specimens weighing more than 25 kg were very rare. Analysis of the size composition of ABFT purse seine catches from 1978 to 1981 showed that the 8-15 kg weight class dominated at 80% [27]. According to [28] [29], tuna weighing 7-15 kg dominated Croatian catches in the period 1990-1997 with 86%

• Line 140. … transport cages and towed by a tugboat at a speed of 1 to 1.5 knots to the rearing site [14]. In the western Mediterranean, tuna have been shown to spawn inside transport cages (Gordoa et al., 2009). Gordoa, A., Olivar, M. P., Arevalo, R., Viñas, J., Molí, B. and Illas, X. 2009. Determination of Atlantic bluefin tuna (Thunnus thynnus) spawning time within a transport cage in the western Mediterranean. ICES Journal of Marine Science, Volume 66, Issue 10, December 2009, Pages 2205–2210, https://doi.org/10.1093/icesjms/fsp211
• Line 379. ABFT aquaculture is attractive to investors because of the high returns, but it is also important to the general population because of the high export value and employment [6]. It is also a source of income from the tourist point of view, such is the case of the Catalan company Balfegó, which has a catamaran to visit the tuna farms in l'Ametlla de Mar (Tarragona, Spain).
• Line 441... but it is also important to the public because of its high export value and employment and for tourism.

 

Reviewer 4 Report

Although I read this paper with interests, it does not acceptable in its present form. Following comments for your reference.

1.       Title, “ (Thunnus thynnus, Lin- 2 naeus, 1758)” this piece of of formation is confusing. It would be better to present this information in the main content and explain what does this mean? As it does not make any sense to me.

2.       Abstract, poorly drafted. You need to tell the reader what is your main research question? How are you going to solve the issues? What have you achieved?

3.       P.2, “e [10] (Ottolenghi, 2008)” I do not understand why did you incorporate two different citation styles in one paper?

4.       Introduction, it would be helpful if you could provide the overall structure of this paper at the end of this section.

5.       P.4, “[12] (Katavić et al., 2003)” Again, two citation styles. Confusing!

6.       P.5, “In 2016, 196 farmed ABFT from Croatia (ToroCro Maguro, Sashimigrade) won the Superior Taste 197 Award [33].” So what? What follow from this result?

7.       P.5, lines 214-221, data is nothing to do with Croatia. This is the biggest problem for this paper. This paper is focusing on the practice in Croatia but the data and practice that you provided are largely based on other EU states. You need to in some way link to Croatia and make sure every single section of this paper link to Croatia.

8.       P.6, “As in the Mediterranean region as a whole, data on ABFT aquaculture production in 252 Croatia were not harmonized in the FAO database (FishstatJ), in the EUROSTAT database, 253 and in the national database, so the data in FishstatJ and EUROSTAT differ until 2004 254 (minimum 0 t in 1996 and 1997 and maximum 782 t in 2003).” What is the reason behind this situation? You need to explain!

9.       P.8, “environment ^[55] (Casadevall et al. 2021)” Confusing, fix this.

       10. P.8, “s (Posidonia oceanica (Linnaeus) Delile, 1813)”Confusing, further explanation needed.

Author Response

Dear Reviewer 4,

We would like to thank you for your quick evaluation. Your suggestions helped us a lot to improve the work. We have considered all your suggestions and we hope that we have managed to answer all your questions. All changes and comments made by the authors can be found in the revised manuscript titled REV1 & REV3 & REV4 & REV5 sustainability-2139437 (tracked changes). If you have any further questions, please feel free to ask. Thank you again.

Yours sincerely,

The Authors

REV4

1. Title: “(Thunnus thynnus, Linnaeus, 1758)” this piece of formation is confusing. It would be better to present this information in the main content and explain what does this mean? As it does not make any sense to me.

Authors’ comment: The scientific name (Latin name with author) was removed from the title at the suggestion of reviewer 4.

2. Abstract, poorly drafted. You need to tell the reader what is your main research question? How are you going to solve the issues? What have you achieved.

Authors’ comment: Rewritten at the suggestion of reviewer 4:

Atlantic bluefin tuna (Thunnus thynnus) is the most important tuna species in Mediterranean tuna fishery and a valuable commodity on the global fish market. Croatia is a pioneer in tuna farming in the Mediterranean and the only country that has the exclusive right to farm wild-caught juvenile tuna (8 to 30 kg). The paper identifies key challenges to the sustainability of current farming and fattening practices, primarily economic and environmental, and possible solutions to over-come these challenges. The paper analyses data on tuna catch and aquaculture production (FAO FishStatJ and EU-Eurostat database) and updates the latest literature on farming practices, production challenges related to biotechnical, economic and environmental issues, the market and current legislation in Croatia, as well as fattening in other Mediterranean countries. Tuna capture based aquaculture is attractive to investors because it promises high returns, but the sustainability of intensive tuna farming and fattening is questionable and raises many ethical issues. Tuna farming and fattening relies on wild fish for stocking and feeding, and further expansion of tuna farming and fattening is limited by the size of wild tuna and small fish populations. To meet the growing global demand for tuna and to conserve wild tuna stocks, further investments are needed. The knowledge gained in Croatian tuna farming is valuable for future sustainable close-cycled tuna farming in the Mediterranean. Due to good environmental status, availability of small pelagic fish, availability of highly qualified and well-organised labour force, good cooperation between producers and researchers and application of modern farming technologies, ABFT farmed in Croatia have high quality and good reputation on the market. The main weakness of Croatian tuna farming is that the entire industry is dependent on the Japanese market, but this can be overcome by the possibility of product diversification for new markets, including the tour-ism industry.

P.2, “e [10] (Ottolenghi, 2008)” I do not understand why did you incorporate two different citation styles in one paper?

Authors’ comment: Corrected at the suggestion of reviewer 4.

3. Introduction, it would be helpful if you could provide the overall structure of this paper at the end of this section.

Authors’ comment: Added at the suggestion of reviewer 4:

The paper consists of five chapters: Introduction; ABTF fishing in the Mediterranean; ABFT fattening/farming in the Mediterranean; Fattening/farming challenges; Sustainable ABFT farming and Conclusions.

4. 4, “[12] (Katavić et al., 2003)” Again, two citation styles. Confusing!

Authors’ comment: Corrected at the suggestion of reviewer 4.

5. 5, “In 2016, farmed ABFT from Croatia (ToroCro Maguro, Sashimigrade) won the Superior Taste Award [33].” So what? What follow from this result?

Authors’ comment: Added at the suggestion of reviewer 4:

The award-winning Croatian tuna is an example of how farming tuna from the juvenile stage onwards can be very profitable even with small tuna sizes due to the high fat content.

6. 5, lines 214-221, data is nothing to do with Croatia. This is the biggest problem for this paper. This paper is focusing on the practice in Croatia but the data and practice that you provided are largely based on other EU states. You need to in some way link to Croatia and make sure every single section of this paper link to Croatia.

Authors’ comment: As stated in the introduction, the aim of the paper is to provide an overview of the sustainable farming/fattening industry in the Mediterranean, with special attention to Croatian tuna farming and not only to Croatian tuna farming. It is important to note that the production data of all countries that farm/fatten ABFT are closely linked, as the tuna price is highly dependent on market supply. Therefore, all countries producing ABFT are direct competitors. In addition, at the suggestion of reviewer 3 (2.1. ABFT fishing in Croatia) and reviewer 4 (5.1. Sustainability of Croatian ABFT farming), new subchapters dedicated exclusively to Croatian ABFT farming were added.

7. 6, “As in the Mediterranean region as a whole, data on ABFT aquaculture production in Croatia were not harmonized in the FAO database (FishstatJ), in the EUROSTAT database, and in the national database, so the data in FishstatJ and EUROSTAT differ until 2004 (minimum 0 t in 1996 and 1997 and maximum 782 t in 2003).” What is the reason behind this situation? You need to explain!

Authors’ comment: Added at the suggestion of reviewer 4:

The quality of the statistics contained in the FAO database depends mainly on the accuracy and reliability of the data provided by countries. Although FAO member countries should provide statistics to the government on a regular basis, this is not always the case, either due to erroneous reporting (inconsistencies between data compiled by different institutions), political reasons or sometimes due to communication problems (e.g. change of responsible official, etc.). There is also a tendency for most ICCAT member states to under-report their catches to ICCAT and FAO in order to support their national finishing fleets. When they under-report landings, they also under-report catch-based aquaculture production levels to maintain consistency in reporting figures.

8. “environment [55] (Casadevall et al. 2021)” Confusing, fix this.

Authors’ comment: Corrected at the suggestion of reviewer 4.

9. 8, “s (Posidonia oceanica (Linnaeus) Delile, 1813)”Confusing, further explanation needed.

Authors’ comment: Rewritten at the suggestion of reviewer 4:

The physical presence of caging installations and increased sedimentation of organic material from the farm may reduce water transparency and alter the composition, distribution, and diversity of benthic communities, particularly the very sensitive Posidonia communities.

Reviewer 5 Report

Dear Authors,

It was an interesting pool of information on fattening and farming of ABFT. The manuscript was well written in a good flow of information. Very few comments were given in the manuscript attached here with for your reference.

Line 54 and 55 – Need some changes to this sentence for its improvement. A suggestion has mentioned in the attached manuscript.

Line 83 – Specify the type of size limit  

Line 95 – ‘’N” must be a block letter

Line 236 – Consider the given suggestion in the manuscript to improve the figure title.

Line 244 – Add region/sea to complete the sentence.

It is much better, if authors can include an analysis of present legislations on farming and fattening of BFT in Croatia and how those regulations impact on the sustainability of the industry. Authors also can incorporate a SWOT analysis on Croatian BFT fattening and farming in relation to the sustainability of the industry. Because the review built on the common information available for the region. As the title specified the “special regards to the Republic of Croatia’’ the paper must have an in-depth analysis related to the Croatian BFT industry.

 

Thank you

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 5,

We would like to thank you for your quick evaluation. Your suggestions helped us a lot to improve the work. We have considered all your suggestions and we hope that we have managed to answer all your questions. All changes and comments made by the authors can be found in the revised manuscript titled REV1 & REV3 & REV4 & REV5 sustainability-2139437 (tracked changes). If you have any further questions, please feel free to ask. Thank you again.

Yours sincerely,

The Authors

REV5

It was an interesting pool of information on fattening and farming of ABFT. The manuscript was well written in a good flow of information. Very few comments were given in the manuscript attached here with for your reference.

• Line 54 and 55 – Need some changes to this sentence for its improvement. A suggestion has mentioned in the attached manuscript.

Changed at the suggestion.

• Line 83 – Specify the type of size limit

Added at the suggestion:

W-BFT TAC has been in force since 1981, E-BFT TAC since 1998, while the minimum size limit for ABFT caught in the Atlantic of 6.4 kg (10 kg and 30 kg thereafter) has been in force since 1975 [18].

• Line 95 – ‘’N” must be a block letter

Changed at the suggestion.

• Line 236 – Consider the given suggestion in the manuscript to improve the figure title.

Changed at the suggestion.

• Line 244 – Add region/sea to complete the sentence.
• It is much better, if authors can include an analysis of present legislations on farming and fattening of BFT in Croatia and how those regulations impact on the sustainability of the industry. Authors also can incorporate a SWOT analysis on Croatian BFT fattening and farming in relation to the sustainability of the industry. Because the review built on the common information available for the region. As the title specified the “special regards to the Republic of Croatia’’ the paper must have an in-depth analysis related to the Croatian BFT industry.

Added at the suggestion:

5.1. Sustainability of Croatian ABFT farming

Croatian ABFT farming is an important and promising sector in the Croatian economy and society. In 2015, the Croatian ABFT industry employed about 500 people and exported products worth US$ 239 million, mainly farmed ABFT for the Japanese market [86]. Further development of ABFT farming could create new jobs and regular income for hundreds of people, especially on depopulated Croatian islands, and provide a high-quality local food supply for responsible tourism [85] [87]. Croatia has done much to improve the administrative and legal framework for aquaculture and to implement integrated coastal zone management and marine spatial planning [86]. According to the experience of Croatian farms, ABFT farming of juveniles is feasible but less efficient than ABFT fattening of adults. Nevertheless, the experience and knowledge gained in Croatian ABFT farming can be useful for future close-cycled ABFT farming in the Mediterranean region.

In addition to the already mentioned Croatian Law on Aquaculture (OG 130/2017, 111/2018; 144/2020), the following legislation for ABFT farming has been enacted in the Republic of Croatia:

The Regulation on marking of breeding installations, monitoring of operations on breeding grounds and traceability during the breeding of bluefin tuna (Thunnus thynnus) (OG 63/2022) - this regulation imposes the obligation to notify the plan of FFB, the procedure for the identification of the farming facilities, the conditions and procedure for the placing of tuna in the cages, the procedures for the catching of tuna from the cages, the transfer of tuna within the farm, the implementation of conducting random controls, the verification of the transfer of tuna, the transfer of tuna between farms, the handling of dead tuna during farming and tuna below the minimum size in the catch, the obligation to keep documentation, regional observers and  scientific research.

The Regulation on the disposal of tuna farming capacity and permitted input quantities of caught wild tuna (Thunnus thynnus) on farms (OG 22/2021) and Amendments to Regulation (OG 9/2022) - this Regulation regulates the ways of disposing of tuna farming capacity and the way of disposing of the allowed input quantity of caught wild tuna.

The legislation is harmonized with the Regulation (EU) 2016/1627 of the European Parliament and of the Council of 14 September 2016 on a multiannual recovery plan for bluefin tuna in the eastern Atlantic and the Mediterranean and repealing Council Regulation (EC) No 302/2009 as well as with the Recommendation 21-08 by ICCAT, and has a positive environmental impact by ensuring rational management and conservation of ABFT. On the other hand, it restricts to some extent the growth of farming capacity and employment.

The Croatian National Strategic Plan for Aquaculture Development 2014-2020 (the NSPA) has set the goals and priorities for aquaculture development of in the period from 2014 to 2020. This strategic document contains an analysis of Croatian mariculture, including ABFT farming, for the period from 2003 to 2012. According to [88]  the strengths of Croatian ABFT farming are as follows: a long tradition of farming, favorable environmental conditions, numerous experts contributing to the development of ABFT farming, wide acceptance in local communities, and the availability of natural resources. Almost all ABFT caught by the Croatian purse seine fleet are used in farming cages, and a large part of small pelagic fish caught by the Croatian fleet is used as feed in ABFT farming. The fact that tuna production is almost exclusively for the Japanese market is listed as a strength, but this dependence on the Japanese market could also be a weakness. Weaknesses also include insufficient collaboration between science and the sector, and a lack of applied science and research projects. The major threat to ABFT farming is dependence on natural resource availability (small pelagic fish and tuna TACs). The opportunities are as follows: contribution to the development of island communities (employment, related activities), better use of farming capacities, the possibility of further implementation of Integrated Coastal Zone Management, and the possibility of support from EUSAIR (Pillar I, Topic II: scientific cooperation and sustainable fisheries management).

In November 2022, a new National Strategic Plan for Aquaculture Development until 2027 (the NPRA) (OG 133/22) was adopted. The NPRA is harmonized with European Commission Strategic guidelines for a more sustainable and competitive EU aquaculture for the period 2021 to 2030 COM (2021) 236 final. The NPRA includes a SWOT analysis of Croatian ABFT farming for the period from 2015 to 2020. According to [89] , the strengths of Croatian ABFT farming are the following: good reputation on the world market, high product quality, availability of highly skilled labour, application of modern farming technologies, availability of baitfish from the catch, good organisation of farmers, good cooperation with research institutions, active participation in EU activities, good social acceptance, cooperation with local communities, and the viability of a good environmental status. Weaknesses include the fact that tuna production is dependent on quotas, the entire industry depends on one market, and prices depend on market supply. The main opportunity is the diversification of production for new markets, especially the European and Croatian markets, including the tourism sector. Threats include the likelihood of sudden disease outbreaks, tuna escaping from cages in adverse weather conditions, possible feed restrictions, and rising feed prices.

 

Round 2

Reviewer 4 Report

I am happy with the revision. Accept!