Review Reports - The Pierpaoli’s Herbarium MBMP: A Historical Window into Marine Biodiversity of the Ionian Sea

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Figure 2. Improve symbology, it is not clearly

pag. 12. Reference 78 after Thompson R.; correct punctuation

Comments for author File: Comments.pdf

Author Response

Dear reviewer,

We appreciate your suggestions for improving our manuscript. Below you find our answers. The changes in the latest manuscript version uploaded are highlighted in yellow

Figure 2. Improve symbology, it is not clearly

To fulfill this request, the dimension of the character in the figure legend was increased. You can find it on page 5, line 170 of the latest manuscript version

pag. 12. Reference 78 after Thompson R.; correct punctuation

Corrected. Now you find it on page 14, line 565 of the latest manuscript version

Reviewer 2 Report

Comments and Suggestions for Authors

This study examines changes in macroalgal flora over the past century in the enclosed coastal waters around Taranto, Italy (Mar Piccolo, Mar Grande) using herbarium in a museum, old literatures, and recent survey results. By elucidating temporal changes of the flora, the authors tried to bring to light to the coastal environmental changes during the century. I think this is a very important work which demonstrates the significance of preserving seaweed specimens and making effective use of them.

However, specific data are only shown in Fig. 2, and temporal appearance (and disappearance) of each species are only explained in the text. I think the following improvements are needed to provide reliable information and make readers to be more attracted:

L147-152: It is better to create a list (table) of species found in Mar Piccolo, clearly indicating which species appeared in Periods I, II, and III.

L154-160: Please provide supporting literature for the biogeographical grouping of species found (Atlantic, Mediterranean, Indo-Pacific, Circumtropical, Cosmopolitan). I would also like the table mentioned above to indicate the groups to which each species belongs.

L161-164: As with Mar Piccolo, it is better to create a list (table) of species that appear in Mar Grande and the periods of their appearance.

If possible, it is better to provide graphs or timelines showing environmental changes in Mar Piccolo and Mar Grande, such as temporal variations of water temperature, transparency, or nutrient concentrations, as well as the history of coastal modifications (e.g., reclamation and artificial seawall construction, etc.).

L193-195: This sentence is difficult to understand. Does it mean that shade-adapted plants were once (during Period I) collected at depths deeper than the growth zone currently observed? Please provide more details.

L197: It is understandable that the decline in epiphytic macroalgae is due to the decline in their host canopy-forming species, but what are some possible reasons for the decline in understory algae?

L.205-210 Here, it is said that environmental deterioration has prevented sexual reproduction of some red algae, and that vegetative reproduction has become an alternative. Please show the basis for this and explain what specifically happened to which species.

Author Response

Dear reviewer,

We appreciate your suggestions for improving our manuscript. Below you find our answers. The changes in the latest manuscript version uploaded are highlighted in green

L147-152: It is better to create a list (table) of species found in Mar Piccolo, clearly indicating which species appeared in Periods I, II, and III.

The list was created and added as supplementary material (Table S1)

The chorological element's reference has been added to the text (page 5, line 159 of the latest manuscript version). This reference was already present in the bibliographic list (it was quotation 66, now 36 of the latest manuscript version). Furthermore, the chorological element for each listed species has been included in Table S1.

L161-164: As with Mar Piccolo, it is better to create a list (table) of species that appear in Mar Grande and the periods of their appearance.

The list was included as Table S2.

We are unable to fulfill this request because the data were published in other papers for which we are not the authors. However, we have included the bibliographic citations necessary to retrieve this information from its original source

We modified the sentence to provide a clearer explanation (page 6, lines 199-204 of the latest manuscript version).

L197: It is understandable that the decline in epiphytic macroalgae is due to the decline in their host canopy-forming species, but what are some possible reasons for the decline in understory algae?

A brief explanatory paragraph was added (page 6, lines 206-209 of the latest manuscript version)

A brief explanatory paragraph was added (page 7, lines 222-230 of the latest manuscript version)

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript by Petrocelli et al. focuses on a comparative study of the marine macroalgal flora of the Adriatic and Ionian Seas over a century, using the historical Pierpaoli herbarium vouchers, as well as data from the bibliography and the most recent explorations, as sources of information. Since the data could be standardized in their nomenclature, it has been possible to highlight the floristic changes that occurred during this time. The manuscript is a good example of a well-done work that has taken advantage of a historical herbarium. It is well written, and the results are presented in an appropriate manner. The discussion of the results raises the most likely causes of the floristic changes that have occurred over the past century.

The following minor changes are suggested for improving the manuscript:

The title could specify the geographical area for which the "historical window" is opened (i.e., the Adriatic and Ionian).2. The abbreviation for non-indigenous species (NIS) is defined on line 152 and again on line 263. However, it appears for the first time on lines 78-79, and the abbre
viation is not defined here. Furthermore, as there are several abbreviations specific to the manuscript, it would be helpful to include a list of abbreviations after the keywords.
The labels in Fig. 2 are not as sharp as the rest of the figure.
It is suggested that Cheney's index (1977. R and C/P—new and improved ratio for comparing seaweed floras. Journal of Phycology 13, pp. 12-12) be used to compare the floristic catalogs from the three periods being compared throughout the century.

Author Response

Dear reviewer,

We appreciate your suggestions for improving our manuscript. Below you find our answers. The changes in the latest manuscript version uploaded are highlighted in pale blue

1. The title could specify the geographical area for which the "historical window" is opened (i.e., the Adriatic and Ionian).

In the title, “of the Ionian Sea” has been introduced, since this is the area analysed in the manuscript. Herbarium MBMP also includes specimens from the Adriatic, but their analysis was performed by other authors in other papers, which are quoted in the Discussion section (page 9, lines 325-331 of the latest manuscript version)

2. The abbreviation for non-indigenous species (NIS) is defined on line 152 and again on line 263. However, it appears for the first time on lines 78-79, and the abbreviation is not defined here. Furthermore, as there are several abbreviations specific to the manuscript, it would be helpful to include a list of abbreviations after the keywords.

As suggested, a section Abbreviations was added before the References section, as reported in the Guide to Authors (page 10, lines 373-375 of the latest manuscript version)

3. The labels in Fig. 2 are not as sharp as the rest of the figure.

As already answered to Reviewer 1, the dimension of the character in the figure legend was increased. You can find it on page 5, line 170 of the latest manuscript version

It is suggested that Cheney's index (1977. R and C/P—new and improved ratio for comparing seaweed floras. Journal of Phycology 13, pp. 12-12) be used to compare the floristic catalogs from the three periods being compared throughout the century

Based on the Cheney's ratio, the flora in the Mar Piccolo showed a mixed affinity during periods I and III, with ratios of 4.0 and 5.1, respectively. In contrast, period II had a ratio of 8.0, which indicates a tropical flora.

However, this shift towards a seemingly more tropical flora during period II is likely not a true representation of the environment. Instead, it's probably an artificial result of the significant decrease in brown seaweeds. Brown seaweeds, which are characteristic of temperate waters, were less than half as abundant in period II compared to the other two periods. This decline was most likely caused by high eutrophication, which can negatively affect certain species. Because the ratio is based on the proportion of different seaweed types, the drastic loss of temperate brown seaweeds artificially inflated the ratio, making the flora appear more tropical than it actually was.

Therefore, the Cheney's ratio wasn't included in the paper because it didn't provide a reliable or accurate picture of the floral changes in the Mar Piccolo due to the confounding effect of eutrophication.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Additional comments

L 156

“Figure 3” →　“Figure 2”

L272-274　“So, the light increase of the percentage of these species in II compared to I, could be ascribed to the increase of pollution and the need of higher adaptability for chances of species survival.”

　Does ‘these species’ in this sentence mean cosmopolitan (eucosmopolitan) or neocosmopolitan? If the case is former, the percentage of cosmopolitan species exhibited a light decrease from the period I to II (Fig. 2) and it seems to be contradictory.

Author Response

L156: “Figure 3” →　“Figure 2”.

The mistake was in the Figure number (page 6 line 171 of the latest manuscript version). We have changed the number in the figure caption

L272-274　“So, the light increase of the percentage of these species in II compared to I, could be ascribed to the increase of pollution and the need of higher adaptability for chances of species survival.”

That’s right. We apologize for the oversight. The numbers changed due to the previous revision, so we forgot to change “increase” to “decrease”. We have changed now (page 8 lines 281-284 of the latest manuscript version)