Co-Culture of Gracilariopsis longissima Seaweed and Penaeus monodon Shrimp for Environmental and Economic Resilience in Poor South-East Asian Coastal Aquaculture Communities

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper investigates the benefits of monoculture and co-culture of shrimp with seaweed and conducts large-scale field experiments, which require the cooperation of local farmers. The researchers deserve to be commended for their efforts. This study has the potential to enhance the income of local farmers and promote environmentally friendly aquaculture practices. I recommend that this manuscript be accepted for publication after minor revisions.

 

Here are specific suggestions for improvement:

L120–121: Figure 1 is not shown in the manuscript. If possible, a satellite image indicating the location of each experimental pond and the surrounding environment should be included.

L124: What is the depth of these ponds?

L250: Was the incidence of viral diseases assessed in shrimp monoculture versus co-culture with seaweed?

Table 1: What caused the salinity differences between ponds?

Table 3: The numbers and text appear quite "crowded." I recommend reformatting the table to improve readability.

L411–412: How could future studies address this issue? Please elaborate to assist future researchers.

The authors should attempt to discuss possible reasons for the significant water quality differences between the ponds.

Author Response

Dear reviewer 1

Thank you so much for your favorable judgement regarding our submission and for your helpful comments and questions. With all three reviews and suggestions by the assistant editor we have made many important improvements to the paper. We are very grateful for all your input.

Here is our response to your specific queries:

Comment 1: L120–121: Figure 1 is not shown in the manuscript. If possible, a satellite image indicating the location of each experimental pond and the surrounding environment should be included.

Answer: Yes indeed. We have now inserted figure 1.  (please see line 149)

Comment 2: L124: What is the depth of these ponds?

Answer: It was roughly 75 cm. We have inserted that into  the text (please see line 122)

Comment 3: L250: Was the incidence of viral diseases assessed in shrimp monoculture versus co-culture with seaweed?

Answer: Unfortunately no. We only assessed bacterial loads.

Comment 4: Table 1: What caused the salinity differences between ponds?

Answer: Natural hydrological processes due to some sites being closer to the seawater canals affected salinity (please see line 253).

Comment 5: Table 3: The numbers and text appear quite "crowded." I recommend reformatting the table to improve readability.

Answer: Yes, you are right. We have simplified table 3 (please see line 301) greatly without loss major of information.

Comment 6: L411–412: How could future studies address this issue? Please elaborate to assist future researchers.

Selection of the ponds and the treatments designated to them was fully dependent on the willingness of the farmers. Being able to increase replications as well as randomization of the treatments would improve the strength of proving differences between treatments (please see lines 371 and 372). Clearly more studies are needed to validate the potential of co-culture for different settings and different combinations of species (please see line 401) So basically a larger study or more control over the farmers. Also, working with ponds for which the characteristics are previously known (research test ponds) would also have been easier.

Comment 7: The authors should attempt to discuss possible reasons for the significant water quality differences between the ponds.

Yes. There were 4 parameters which differed significantly (Table 1) (on line 275). These were total solids and salinity, both of which we ascribe to position in relation to the main marine tidal canals in the village (please see line 253), dissolved oxygen, for which we have no suitable explanation but suggest it may be a sampling artifact as dissolved oxygen was very dependent on the time of day. Finally  differences in turbidity seem to be especially related to shrimp bioturbation (please see line 270).

Reviewer 2 Report

Comments and Suggestions for Authors

Most parts of this manuscript are good. However, there are still some places for improvement.

1) What is the main difference between shrimp in Southeast Asia vs other regions in the world.

2) What about quality parameters for other seafoods besides seaweed and shrimp?

3) Previously researchers already studies of Co-culture of seaweed and shrimp, what innovations does this manuscript make?

4) It is obviously that shrimp can survive with other plants, and what about results of these co-cultures?

 

5) How does species of shrimp influence the result?

Author Response

Dear reviewer,

Thank you so much for your favorable judgement regarding our submission and for your helpful comments and questions. With all three reviews and suggestions by the assistant editor we have made many important improvements to the paper. We are very grateful for all your input.

Comment 1) What is the main difference between shrimp in Southeast Asia vs other regions in the world.

Answer: Not much  difference is there as especially P. vannamei, a hardy species, is cultivated around the world. Even so P. monodon is the species of preference in our study area due to larger size and better meat color.

Comment 2) What about quality parameters for other seafoods besides seaweed and shrimp?

Answer: These parameters were not assessed. However also for shrimp there are other key parameters such as size , texture, flavour  and colouration that jointly determine quality. For seaweed, especially those sold for fresh consumption, antioxidant, minerals and vitamins, flavour and texture are also key determinants of quality. The species considered here was mainly used for industrial extraction of  agar and those criteria were not so relevant.

Comment 3) Previously researchers already studies of Co-culture of seaweed and shrimp, what innovations does this manuscript make?

In Indonesia seaweed culture and shrimp culture in ponds largely occurs side by side. This work shows that they can be combined with significant benefit to both.

Most studies on co-culture are from highly controlled settings but field validation for farmers is also critical. That is maybe the most important contribution of this study (please see line 367). However, we would not call such basics an innovation. Most studies on co-culture look only at culture biology and fail to do a realistic cost-benefit analysis. However, the latter, as we have provided, is critical for co-culture to achieve wider application.  Other points are that this study focused on P. monodon, whilst most work focusses on L. vannamei and that no additional feed was used to feed the shrimp. Consequently, our results are relevant to extensive aquaculture which is important to many small forgotten farmers but of little interest to the larger commercial operations to which most aquaculture research is directed.

Comment 4) It is obviously that shrimp can survive with other plants, and what about results of these co-cultures?

 Answer: Specifically looking at pond culture, there are only a very limited number of seaweeds co-cultured largely experimentally with shrimp. Ulva spp., have been tested especially for remediation purposes (e.g., Goa et al. 2022, Cruz et al., 2010) such as also Gracilaria tenuistipitata (e.g, Das et al. 2022, An et al. 2020, Anh et al. 2018), G. verrucosa (Susilowati et al. 2014), ) Gracilaria vermicophylla  and Dyctyota (Anaya-Rosas et al (2019). All of this has been done in the context of bioremediation and disease prevention. Finally, Gao et al. (2022) showed that cultivation of Ulva linza with L. vannamei reduced nutrients, enhanced shrimp growth and survival, improved content composition of both shrimp and seaweed. All of these references have been cited in the introduction under the different purposes for co-culture.

Comment 5) How does species of shrimp influence the result?

To use P. monodon affected the income in such a way that this species is more profitable per kilogram than L. vannamei (esp due to larger size and appetizing colour). Therefore, use of the chosen species positively affected the revenues of the farmers. Nonetheless, P. monodon is more susceptible to poor water conditions and infections as well as it grows less fast, making it a more risky species to cultivate.

 

Reviewer 3 Report

Comments and Suggestions for Authors

 

Review of manuscript

Co-culture of Gracilariopsis longissima seaweed and Penaeus monodon shrimp for environmental and economic resilience in poor South-East Asian coastal aquaculture communities by
Reinier W. Nauta, Romy A. Lansbergen, Restiana W. Ariyati, Lestari L.Widowati, and Sri Rejeki & Adolphe O. Debro

 

 

Controlled laboratory studies indicate that mechanisms exist by which low-cost co-culture of seaweed and shrimp reduces ecological impact and facilitates increasing income to the many pond farmers. The authors studied extensive co-culture of Gracilariopsis longissima seaweed and Penaeus monodon shrimp on pond production output. Their results showed increased production compared to monoculture. Thus, it increased profit, and unexpectedly reduced heavy metals concentrations in shrimp.

 

I thick it is a very interesting and important manuscript.

Ther results deserve practical application and should be published.

 

Just check the text once again to avoid misprints as line 20

Here we here studied extensive

Comments on the Quality of English Language

Just check the text once again to avoid misprints 

Author Response

Dear reviewer,

Thank you so much for your favorable judgement regarding our submission and for your helpful comments and questions. With all three reviews and suggestions by the assistant editor we have made many important improvements to the paper. We are very grateful for all your input.

 

Comment 1: Please extensively review the text to avoid misprints (as line 20)

Answer: Yes. Good suggestion. Done.

The text has been extensively revised and improved. We hope you will be happy with the many improvements.