The Environmental Assessment of an Estuarine Transitional Environment, Southern Italy

Round 1

Reviewer 1 Report

If possible, information on the ionic form of the metals such as Cr and Mn would provide the detail on the anthropogenic pressures to the aquatic environments.

Author Response

Response to Reviewer 1 Comments

 

Point 1: If possible, information on the ionic form of the metals such as Cr and Mn would provide the detail on the anthropogenic pressures to the aquatic environments.

 

Response 1: the reported concentrations of Cr and Mn do not discriminate the different oxidation state of the elements since they were determined as total concentrations.

Author Response File: Author Response.pdf

Reviewer 2 Report

My comments and changes are indicated in the pfd file, changes suggested  are easy to correct

The abstract needs information about the main conclusion of the study.

My main concern is regading the discusion section, discussion is lacking   comparisons with prevous works or other main findings and publications related to the study there is plenty of literature and info. This will make the discussion of your results strong.

Conlusion section an important part is missing regarding the quality of the estuary. please add.

 

 

 

 

 

 

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 2 Comments

 

Comment 1: Comments and changes indicated in the pfd file

Point 1: page 1 line 4: Michele Arienzo

Response 1: It is not clear the proposed amendment. Please can you clarify it?

Point 2: page 1 line 31, a brief conclusion is missing here

Response 2: We added a brief conclusion of the study;

Point 3: page 1 line 33-34:

 

Response 3: we separated keywords by semicolumns;

 

Point 4: page 2, line 60.

 

Response 4: TEs is the acronym of trace elements, thus we do believe it is appropriate to indicate these elements in this way to avoid repeating the same statement afterword.

 

Point 5: page 2 line 63

 

Response 5: we deleted the statement and replaced it with: ‘the second in the region after the Volturno River and tributary of the Tyrrhenian Sea’.

 

Point 6: page 2 line 66

 

Response 6: the word ‘and’ was deleted

 

Point 7: page 3 line 75

 

Response 7: the locations in the Figure 1 were modified to make them more readable

 

Point 8: page 4 line 93

 

Response 8: asl was replaced with above sea level

Point 9: page 4 line 109

 

Response 9: Sampling points are indicated in red circles (after Google Earth^TM Pro, 2019).

 

Point 10: line 146

 

Response 10: all the acronyms were explained

 

Point 11: line 150

 

Response 11: the statement was replaced with ‘chemical characterization’

 

Point 12: line 272

 

Response 12: the statement was amended as follows: “Concentration of total priority dangerous PAHs in sediments were <0.01 mg/kg, data not shown, at all sites, and hence below the legal limit of 0.20 mg/kg expressed by the law 152/2006”. Moreover, at line 156-157, the following statement was added to explain the meaning of dangerous priority  PAHs: “Among these NAP, ANT, BbF, BkF, BaP, BgP represent the priority dangerous PAHs and their sum is regulated by the law”.

 

Point 13: heading of Table 3

 

Response 13: the reference for the law was added in the list of references and numeration was consequently modified

 

Point 14: line 293

 

Response 14: the acronyms were explained

 

Point 15: line 325

 

Response 15: In the principal component analysis the term Factor loading is basically the correlation coefficient for the variable and factor. Factor loading shows the variance explained by the variable on that factor. So, we do believe that the use of the term is appropriate in the legend of the Table 5. Moreover, the acronyms were explained as elsewhere in the text. The results of a PCA are usually discussed in terms of component scores, sometimes called loadings. The legend of Table 5 was amended explaining the meaning of PC1, PC2 and PC3, which are the abbreviation for principal component for the first factor, second and third factor.

 

Point 16: line 356

 

Response 16: the highlighted text was replaced with ‘Water concentrations of’.

 

Point 17: lines 375-377

 

Response 17: the highlighted paragraph was replaced with ‘The data indicate that the Sele estuary is affected by significant geomorphological alteration due to erosion processes as well as by a conspicuous anthropic influence threatening the overall ecosystem’.

 

Comment 2: The abstract needs information about the main conclusion of the study.

Response 2: the main conclusion was added: ‘All these data reveal the fragility of the estuary and the need of urgent remediation actions.

Comment 3: My main concern is regading the discusion section, discussion is lacking   comparisons with previous works or other main findings and publications related to the study there is plenty of literature and info. This will make the discussion of your results strong.

Response 3: as stated in the introduction there is a lack of data in the literature concerning the environmental statement of this estuary, thus it is not possible to compare our data with those of previous studies performed in the area and to state the temporal evolution of the environmental conditions. This makes our study as milestone for future assessment of the environmental quality of the estuary as well of the entire course of the river.

Conclusion section 4: an important part is missing regarding the quality of the estuary. please add.

Response 4: the conclusions were modified in their final part adding the following statement: “The data indicate that the Sele estuary is affected by significant geomorphological alteration due to erosion processes as well as by a conspicuous anthropic influence threatening the overall ecosystem”.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript by Arienzo and colleagues entitled, "The Environmental Assessment of an Estuarine Transitional Environment, Southern Italy," is an excellent example of a carefully considered multi-disciplinary study to assess human impacts on coastal environments.

I recommend that this manuscript undergo MINOR REVISIONS before publication. Most of my comments relate to the presentation of data and that is why I consider them to fall in the "minor revision" category. There are some improvements to be made to the English writing, and to save the authors time, I have attached a Word document with Tracked Changes. I have edited line by line to maximize the readability of the manuscript, because this is a robust dataset and I am eager to see it reach maximum readership in JMSE.

The methodology and rationale are sound. That said, I strongly recommend that the authors address my comment about sampling site selection to illustrate that their samples are representative and not biased by sampling location along the Sele River channel and mouth. Energy and grain size (and thus other measures tied to the fine fraction) are very closely related and controlled by location within the river and estuary. Therefore, this rationale needs to be explained explicitly in the methods and the results/discussion too.

The statistical analysis appears to be sound.

I have also highlighted areas in the Word document in which further citations are needed, where figure captions are needed, and where methodology could use more detail (especially including standards, calibration, and error of measurements in geochemical proxy analyses).

This paper will benefit from another section that integrates and discusses the data presented. Here, the “Results and Discussion” section is really results with some basic interpretations. There is no real discussion of the data or how you came to these conclusions. This makes it very difficult to assess the significance of the study.

Further, a hypothesis and clear explanation of how you will test it in the introduction will help create a thread from which you can build the discussion. I think this is an essential element to improving this manuscript.

Finally, add concluding sentences to tell us why studies like this are important, and what we can learn from them. For example, this information could be used by resource managers and conservation groups to protect the vulnerable ecosystems of the Tyhrrenian Sea/Mediterranean Sea, upon which the local and state economy rely (for fishing/seafood and tourism).

My comments are listed here, but REFER TO THE WORD DOCUMENT for line references of each comment, and please review the tracked changes I have made to the manuscript:

I think it is best to simplify terminology in the abstract to attract broad readership.

Avoid relative terms. Higher than what?

Remove IE and OE throughout. Refer to the inner as proximal and the outer as distal.

What limit? Please define it.

What hierarchical analysis? You have not introduced this method

I suggest a less definitive term here, because the data shown may not give enough information to make this determination.

Organisms or nutrients? What are the “forms” measured from? The last two sentences are difficult to understand and may need to be rewritten.

See if you agree with my edit here; make sure I have not changed your meaning in trying to interpret & revise the sentences.

Instead of explaining what estuaries are, which should be pretty common knowledge, why not start by saying how estuaries are complex and vulnerable to human influences? That would set up the reader for your main message.

I don’t think this is particularly useful to the presentation of your thesis… it is common knowledge. Consider removing or reworking.

This sentence is more to the point of what you plan to test. Perhaps build up to this important point with a transition from discussing natural gradients and variability to human impacts on the system.

Consider alternate wording that may be more accessible to the diverse audience of JMSE: ecosystem response to eutrophication?

I suggest changing some of your wording here, adding terms that are “hot topics” and may increase your readership and ultimate impact.

How can you link the erosion that you just talked about to sediment build ups? I think a sedimentologist may infer the connection, but remember you will have a diverse readership that may be confused… make sure you are clear and precise in your explanations. I recommend if the example is too complicated and not immediately relevant to your argument, cut it.

Emphasize this point. “Also” makes it sound like an add on, when this is a pollution effect that is important to ecosystem and human health. This is unclear, please elaborate.

I recommend to avoid another acronym and to be consistent in how you refer to the estuary throughout the text and figure captions.

By what method? Is there a hypothesis you plan to test?

FIGURE 1: The city names are not legible in dark black due to the dark brown background. Please make the symbol a light color and reposition the label so it can be read. Label legend with geologic units on the map as well (there is room). I do not see #6 on the map- is that because it is transparent over the mountains? Adjust the legend color so it can be seen on the map. Cite the geologic map and papers that were used to construct this map.

ADD BACKGROUND SECTION (FROM MATERIAL IN THE END OF INTRODUCTION): I believe the following paragraphs are not introduction but rather background information. Therefore, I suggest making a new section header for the background section here (follow the Guide to Authors for appropriate header titles and numbering).

REMOVE INNER/OUTER ESTUARY TERMS AND USE PROXIMAL/DISTAL ESTUARY, WITHOUT ACRONYMS: This is another reason why you should not make an acronym for the Sele Estuary (SE). Could be confused with cardinal directions!

This is a new and different idea not supported by the topic sentence of the paragraph… Therefore, you should start a new paragraph.

FIGURE 2: This is a good figure. Is there a land use map that you could also show to demonstrate agricultural, urban, and/or industrial runoff in the watershed? Preferably one that includes the entire watershed to include upstream influences. Can you also draw and label the boundary that you define as inner and outer (or proximal and distal) estuary? That would help the reader in connecting the sampling sites with discussion in the main corpus.

PUT FIGURES/TABLE CITATIONS IN PARENTHESES: Generally figure and table captions are in parentheses. While JMSE seems to publish both ways, this style is more interesting to read.

METHODS: How were samples split? It is not clear from this phrase.

What was the fine fraction analyzed for?

Need to cite seminal paper on grain size moment statistics: Folk and Ward 1957

Change the word choice is changed from “by” to “using”. (The scientist, not the microscope, analyzed the samples.)

Please provide magnification of microscope.

Did you count ostracod valves that were incomplete or <half of a valve preserved? How did you ensure that you did not over-count?

What was the calibration method? What is the detection limit and error for each element? You could put this information into Supplementary.

Consider the flow of the methods: field work then lab work, and/or sample type (sediment then water) and organize the methods accordingly.

What is the laboratory precision, calibration, and error?

What datasets were included in the PCA? That needs to be stated in methods.

RESULTS/DISCUSSION: You need to give a general topic sentence before providing details. Starting with details will lose the reader, because the detail is not put into meaningful context. You also need to make sure you are citing figures, especially the map, when you refer to features and sample sites.

Again, change terminology to proximal estuary

'Further analysis with LPSA may help evaluate whether there is significant clay fraction. In any case, high energy environments will sort out the clay. It will largely depend on where in the river channel you sampled. Did you expect to find clay?

Is this new information? Seems pretty standard sediment dynamics. Can you elaborate why this is an important finding?

This is not clear. Re-write sentence.

This is unclear what “remainder samples” means. Please clarify.

Pull in more literature discussion to evaluate the problem of progradation and erosion of the shoreline. I am hesitant to evaluate claims about river channel erosion and progradation of the beach with grab samples alone. You really need seismic and sediment cores to evaluate whether the beach is prograding… do you have aerial images/historical maps before and after dam construction that could illustrate lateral migration of the shoreline? That may help make the case in absence of other datasets.

Further, consider that your samples might be completely different if they were collected in a different part of the river channel or mouth, or even at a different time of the year. It is hard to make big claims on what the sedimentology tells you about evolution of the system from just a few grab samples in one field season. I suggest scaling back your claims of erosion and progradation, or suggesting it and saying that further data collection is necessary to confirm. This may also help you in justifying future field campaigns to funding agencies. It is certainly an important point that you raise (and it is pretty universal that dams will trap coarse sediment and change the downstream dynamics), but more data are needed to justify these interpretations.

FIGURE 3: The axis labels are too small. Please increase font size. Please make the symbols a little larger in the ternary diagram too. The Particle diameter is usually shown in phi and microns in articles today. Many only show microns anymore! Go ahead and put both scales on your x-axis. Introduce the paleo-dunes again in the caption.

Not quite clear why this comparison is important. Pull in the geologic background here, refer to the geologic map (fig. 2) and make a stronger case for this. Again, I don’t think you have enough data to say this unilaterally. You can suggest it, however. Otherwise fall back on literature and cite appropriately.

You should cite the tables and figures, instead of calling them out in this fashion. I have rewritten several sentences like this to help give examples of how this can be done. Please check throughout.

If formations containing the older Q forams are reworked by the river, then the material is coming from terrestrial sediments. Please elaborate or explain more explicitly.

Are they all Holocene in age, free of abrasion, and not likely reworked? State so here.

I think when you write “main” you mean “dominant”. Is that right? It is best to be explicit in your word choice to reduce ambiguity.

Why are ostacod species listed, but not the foram species? Is it because the forams are mostly reworked?

Proximal/distal terminology again.

Since you have sampled spatially (different sites) and not temporally (with different cores or at different times), this word choice is not appropriate.

I do not think you can say that it is progressive without time series data or sediment cores that record environmental change. Remove this word and add justification for marine intrusion conclusion. Are there other published datasets to support this idea?

Start the paragraph with a topic sentence that introduces what you will present.

Write present tense when presenting data, and past tense when you describe what you did to collect it.

How much of the TOC and the TN values have to do with sampling site and water energy, which would winnow fines and reduce organic matter? For example, the river channel should have highly variable sedimentary environments due to slight sinuosity… how did you account for this natural variability and test that your results are meaningful? On another note, if you had analyzed stable isotopes, perhaps you could speculate more on source change- from arboreal and plankton sources to agricultural, sewage and other contaminants.

Is this local or national law? Since an international audience will be reading, you should elaborate/define it.

I agree, but still would like to consider how the sampling strategy may have biased your samples. Where you sample within the channel and mouth of the river will be the biggest control on grain size; how did you make sure your samples are representative? This rationale must be included, both in methods and reiterated in the results.

Instead of showing all statistics in table form, it would be more useful to formulate an image showing statistical results… and how they relate spatially with your sample sites

Due to what? Explain the reasoning a little more. Which human activities would cause TE enrichment?

This has not been defined. What is SQA?

Not sure it is appropriate to include the Antarctic Peninsula reference [55], but the point holds regardless.

How significant is that difference? How significant are the assemblage results with this number of samples?

This paper will benefit from another section that integrates and discusses the data presented. Here, the “Results and Discussion” section is really results with some basic interpretations. There is no real discussion of the data or how you came to these conclusions. This makes it very difficult to assess the significance of the study. Further, a hypothesis and clear explanation of how you will test it in the introduction will help create a thread from which you can build the discussion here.

Add concluding sentences to tell us why studies like this are important, and what we can learn from them. For example, this information could be used by resource managers and conservation groups to protect the vulnerable ecosystems of the Tyhrrenian Sea/Mediterranean Sea, upon which the local and state economy rely (for fishing/seafood and tourism).

Was this work funded? If not, I am truly impressed by the amount of work and careful analysis that went into this. It must have been a very robust collaboration, and certainly yielded fruitful results!

Comments for author File: Comments.docx

Reviewer 4 Report

The manuscript "The Environmental Assessment of an Estuarine Transitional Environment, Southern Italy" describes the data collected from a thorough assessment of many physical, chemical and biological parameters of sediment and water of the Sele estuary. Samples were collected from the inner and outer estuary and analyzed to evaluate the health of the waterway.

I believe these types of studies are necessary to evaluate the health of watersheds and surface waters and view this as a significant contribution. However, the presentation is weak, even sloppy in places, and difficult to read.  For example, the numbers in many chemical formulas are not subscripted, there are incomplete sentences and several acronyms are not described. The Introduction lacks coherence and possibly contains information that is better placed in the Methods section. The section describing the geological characteristics of the area is very long and does not seem completely relevant. The work lacks a clear conclusion or organized assessment of the sediment and water.

Were the water and sediment sampled only one time?  Are there seasonal variations? How many samples/replicates were analyzed?  Where is the dam located?  

What does it mean "most of the samples are bimodal and multi-modal?" (Line 188) What is the Gromola Synthem?

For the sediment chemical data, I would argue that the TOC and TN are similar, except for S9. On the other hand, many of the metal concentrations seem notable. Is Mn expected to be significantly higher than the other metals?

The figure and table captions should be improved.

 

Author Response

Response to Reviewer 3 Comments

Point 1: the numbers in many chemical formulas are not subscripted

Response 1: the numbers in the chemical formulas were subscripted, please see lines 25, 338 and all the chemical formulas in Table 6.

Point 2: there are incomplete sentences and several acronyms are not described.

Response 2: All the incomplete sentences and acronyms were explained as also requested by reviewer 2.

Point 3: The Introduction lacks coherence and possibly contains information that is better placed in the Methods section.

Response 3: The part describing the site was moved from the introduction to the Material and Method section (lines 84-105). In this way the introduction appears more linear and logically ordered.

Point 4: the section describing the geological characteristics of the area is very long and does not seem completely relevant.

Response 4: We do agree with the reviewer and we deleted the following non relevant part: “The innermost sector of the plain is characterized by hills, up to 400 m asl, formed by uplifted alluvial fans. The river plain hilly areas, with steeper slopes, are generally formed by siliciclastic deposits, while the reliefs, with sub-vertical slopes, mainly show limestone outcroppings belonging to the Appennine Chain formations. Generally, the top of these reliefs is mantled by volcanoclastic deposits, partly pedogenized, pertinent to the volcanic centers of Phlegrean Fields and Mt. Somma-Vesuvius, some 70 and 50 km to the northwest, respectively”.

Point 5: The work lacks a clear conclusion or organized assessment of the sediment and water.

Response 5: the conclusion section was ameliorated as also requested by reviewer 2

Point 6: Were the water and sediment sampled only one time? 

Response 6: the water and sediment samples were taken one time. Sediments normally express the history of a specific site and their composition does not change in the short-term period.

Point 7: Are there seasonal variations? How many samples/replicates were analysed?  Where is the dam located?  

Response 7: It was not the scope of our study to evaluate any temporal variation of the environmental conditions of the estuary. Our main objective was to give a first comprehensive picture of the actual conditions of the estuary. This could to be useful for future studies for comparison purposes. Methods section was modified adding the statement:’ A total of nine sites in three replicates (line 105). Regarding the location of the dam the text was modified as follows (see line 66): ’ However, the presence of the Dam of Persano, 16.2 linear km far from the river mouth, built between 1929 and 1932…’

Point 8: What does it mean "most of the samples are bimodal and multi-modal?" (Line 188). What is the Gromola Synthem?

Response 8: the text at line 185-186 was modified as follows: bimodal and multi-modal, S3, S4, S5, S7, S8, S9, that is composed by two or more mixed granulometric classes’. The text, see line 222, was modified as follows: ‘Quaternary sediments of the Gromola Synthem geological formation [40] and transported by…’.

Point 9: For the sediment chemical data, I would argue that the TOC and TN are similar, except for S9. On the other hand, many of the metal concentrations seem notable. Is Mn expected to be significantly higher than the other metals?

Response 9: TOC and TN are quite similar for most of the sites except site 9 which is significantly affected by industrial wastewater discharges. Our data clearly show that sediment metal concentrations are lower than the law limits. Mn is expected to be higher than other metals since it is an important component of terrestrial crust.

Point 10: The figure and table captions should be improved.

Response 10: Figures and Tables captions were improved throughout the text as also asked by reviewer 2.

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

in Tables:  change to .... total organic carbon (TOC), Total nitrogen (TN)...mean size (MZ).. do the same in  all tables

 

Table 6:  ......in ug/L      "(delete parenthesis)"

Author Response

Response to reviewer 2 comment:

Comment: in Tables:  change to .... total organic carbon (TOC), Total nitrogen (TN)...mean size (MZ).. do the same in all tables

 Response to comment: All the proposed changes were made

Comment: Table 6:  ......in ug/L      "(delete parenthesis)"

Response: caption of Table 6 was amended as proposed.

Author Response File: Author Response.pdf

Reviewer 4 Report

I still find parts of this manuscript difficult to read. There is also a lack of balance between the introduction, collection of data and conclusions.

 “The plain is characterized by the presence of Quaternary alluvial deposit, mostly sandy and conglomeratic, and is formed by the aggradation of a Plio-Quaternary tectonic depression located along the western Tyrrhenian margin of the southern Apennine Chain [14].” WAS?

It still seems that the detailed background on the geology of the area is not fully relevant to the study.

From the authors' responses, this one was incomplete since it did not address the single water sampling concern:

Point 6: Were the water and sediment sampled only one time? 

Response 6: the water and sediment samples were taken one time. Sediments normally express the history of a specific site and their composition does not change in the short-term period.

For Figure 1, what do the blue lines represent?  I do not find the caption number 6 color in the figure. Figure 2, S2-S5 are not clear. 

Why is S5 associated with the data characteristics of S6-S9?

How was inorganic carbon differentiated from organic carbon for the sediment samples?

Author Response

Response to reviewer 3 comments

Comment: “The plain is characterized by the presence of Quaternary alluvial deposit, mostly sandy and conglomeratic, and is formed by the aggradation of a Plio-Quaternary tectonic depression located along the western Tyrrhenian margin of the southern Apennine Chain [14].” WAS?

It still seems that the detailed background on the geology of the area is not fully relevant to the study.

Response to comment: this part was deleted since as argued is not relevant.

Point 6: Were the water and sediment sampled only one time?

Response: Water samples were taken in three replicates in a single collection for each of the nine studied sites. As stated in the introduction this study represents the first comprehensive picture of the environmental status of the Sele estuary. We do have in mind to continue our research to monitor a more extended period and a larger set of samples the conditions of the estuary as well of the river.  

For Figure 1, what do the blue lines represent?  I do not find the caption number 6 color in the figure. Figure 2, S2-S5 are not clear. 

Response: the explanation for the blue lines is already contained in the legend of the figure: 1, isobath (m bsl); the colour of the caption number 6 of the legend of Figure 1 has been changed to match with that of the carbonate and terrigenous geological formations. In Figure 2, the symbols indicating the locations have been reduced in size to make them more distinguishable.  

Comment: Why is S5 associated with the data characteristics of S6-S9?

Response: The sampling site S5 is located very close to the outer part of the estuary. However, its global characteristics makes that it is more associated to the samples of the inner estuary as also revealed by the cluster analysis.

How was inorganic carbon differentiated from organic carbon for the sediment samples?

Response: at line 131 the following paragraph was added: Total organic carbon was determined by difference of Total Carbon (TC) and Inorganic Carbon (IC) concentration. TC was determined by catalytic oxidation of the sample at 1100 °C, converting the carbon to CO₂, which was detected by the NDIR detector. IC was determined by acidification of the sample with phosphoric acid solution (20% v/v), which converts the IC to CO₂ which was detected by the NDIR detector.

 

Author Response File: Author Response.pdf