Status of Coral Reef Communities on the Caribbean Coast of Costa Rica: Are We Talking about Corals or Macroalgae Reefs?

Round 1

Reviewer 1 Report

Review of Quezada-Peres et al.

This is a pretty good study, in a part of the Caribbean that has been sort of neglected over the past decades. It will need some modifications.

First of all, ditch the cutesy title. Reduce to "Status of coral-algal reefs etc."

The 14% coral cover cited in the Abstract will only be for selected parts of those “reefs”. There will be no part larger than a few football fields with values that high.

In the Intro-never forget that the fish depend on the coral structure, not the other way around. When talking of some reefs (as re Lester et al) that maintain high fish with low coral cover: it takes several years for bioerosion to reduce the topographic complexity, so some estimates will be a snapshot of a moving target.

L159-it would be sporting of au to cite the first use of the chain technique, which was Risk 1972. Then they would be able to link to the parts of that paper that discuss the relationship between topography and fish.

L193 and ff: there is entirely too much talk of Diadema here. Later on in the MS au ‘fess up and admit that the real issue is nutrients, but in between, there is a whole lot of wasted space chasing zombies. I urge au to read Gardner, which much to my amazement is not cited. Take a look at the figure there, showing reef decline in the Caribbean over time. There is no nickpoint, no sharp decline, at the time of the Diadema dieoff. I am afraid that the hard evidence is, that dieoff had little to zero affect on Caribbean reefs, and the fact we still talk about it is testimony to the doggedness of the top-down crowd.

The community descriptions are on the whole well done, and a valuable addition to our knowledge in this area.

The Discussion needs work. The “reefs” described herein are isolated little patches. Go easy on drawing large conclusions about lack of ecosystem services related to coral, etc-Cahuita was never a GBR. The reasons for the decline are sediments and sewage, that much is clear-and was clear 40 years ago. Instead of taking up so much time waffling about Diadema, au should address the real problem. What, in their data, points to higher nutrients here than there? One factor, which is not even mentioned in the text, is bioerosion. This accelerates with elevated nutrients-C. caribbaea is abundant at Cahuita, and I am sure elsewhere. Au need to at least touch on this. Also-there is a HUGE, curious omission. The 1991 earthquake dropped part of that coastline by some metres. It was a huge impact on the reefs, and would have come with greatly increased sediment yield. It changed the whole aspect of that coast. It should at least be mentioned.

Author Response

Thank you for your suggestions. Please see the attachment to see our response to your notes.

Author Response File: Author Response.docx

Reviewer 2 Report

Reefs are the result of geological processes over long periods of time and thus it is hard to imagine that recent changes will immediately affect some of the services associated with the 3D complex structure of the reef. Although in your case you have evidence of coral cover loss, your rugosity results suggest that the reef growth has not been very active in the last 9000 years or so. It would be good if you could comment on the size of the corals present: are we talking of mostly small colonies that probably have a high replacement rate and do not reach large sizes that will contribute to reef accretion and tridimensional complexity? (See Perry and Larcombe 2003. Marginal and non-reef-building coral environments). A few photos of the reefs will also be welcome. More specific comments: 

Line 21. I guess you mean < 10%

Line 171. I find it difficult to have a 5 cm accuracy in the estimation of total fish length, could you be more specific on how to achieve this?

Line 193. Sea urchins tend to prefer shallow environements where they seek refuge during the day and are active during night. Unless you searched for the urchins in their preferred habitat I wonder how good this indicator might be. 

Line 196. Estimating fish richness is not easy as they move around, have different activity hours, etc. Given that fishery valueis your main ecosystem service and is based on a good estimation of fishes I would like to see some rarefaction curves or other indicators of how sufficient is you sample size to estimate fish richness.  

Line 258. Why are you testing for homogeneity if you already decided to use Kruskal-Wallis and Mann-Whitney (line 254)?

Line 260. I find the name "dark spots" a little confusing because there is a coral disease called "dark spots". 

Line 274 Millepora complanata

Line 232 Specie is not the singular of species. 

Line 392. What ecosystem functions and services are you referring to? please be specific. 

Line 394. Lower or higher?

English is mostly ok. 

Author Response

Thank you for yor suggestions. Please see the attachment to see our reponse.

Author Response File: Author Response.docx

Reviewer 3 Report

In general the manuscript written fairly well and it has a good potential. It provides useful information about the sate of the reefs on the Caribbean side of Costa Rica. However, there are some changes that needs to be done before being ready for publications.

Most sections need to be shortened and re-organized. Your data is the current state of the reefs. So this what needs to be the center of the study. In several sections the emphasis seems to be on the competition of corals and algae, even this can be seen in the title. There is no historical data on the studied sites, therefore you can’t make any conclusion about functions and coverage over time. Please focus on what you have and adjust and organize the text based on your data.

Title: Not clear why the focus is on the Algae.

Material and methods: It needs a bit of organizations and editing. I suggest some sub-headlines. Please include few images of the different reefs you surveyed.

Below are some minor comments:

Lines 64-91: it is too much here, please make it shorter and use part in the discussion.

Lines 107-108: There should be no results here.

Material and methods: How reefs were chosen or detected? How did you know about them ? if previous studies please include them all. 

Lines 169-174: How did you measure the fish size accurately without having scale?

Lines 183-225: This section needs to be shortened. There is no need to define all these metrics if has been used before. You can list what you did and refer to the original paper.

Data analyses: Again, needs a bit of organization and shortening. This section needs to be accurate and clear. I suggest breaking into different paragraphs that each describe a specific method or procedure.

Line 301: “bright spots” and “dark spots” etc. Please clarify.

Figure 5: It is too complicated and too much information in one image. I suggest breaking this up into at least two.

Results: This section should follow your material and method’s order.

Figure 6: Check this figure. If you have box and whiskers plot then for example, the data in E and D are overlapping so not clear how the difference became significant. If you are comparing the means, why not using a chart that is cantered around the mean rather than median?

Discussion: This needs to be focused around your data. Need more organization. Please follow same chronological order based on your material methods and results.

Some English editing is required. 

Author Response

Thank you for your suggestions. Please see the attachment to see our response to your notes

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I have read the revision, au did a good job. MS is ready to go.

Reviewer 2 Report

Just a minor detail  in line 282, the rugosity index can´t be >1.