Meridionalization as a Possible Resource for Fisheries: The Case Study of Caranx rhonchus Geoffroy Saint-Hilaire, 1817, in Southern Italian Waters
Round 1
Reviewer 1 Report
Please provide explanations of meridionalization in text for readers. (Please see Azzurro 2008, 2010)
Authors declared that false scad has increased its abundance in Italian waters. Is it a personal observation or is there any commercial data?
Lines
30: recorded
35: dimensions
36: is strongly
51: Lessepsian
55-58: In my opinion, van Rijn et al. did not mention the morphological similarity between Sparus aurata and N. randalli . It is sold as a common pandora (please see: https://doi.org/10.12681/mms.19658 - however, please not cite this reference). Please replace Sparus aurata to native Sparids.
32 and 59: Authors used both thermophiles and thermophilic. Please standardize it.
Additionally, please check the grammar of the Abstract section
Author Response
Please provide explanations of meridionalization in text for readers. (Please see Azzurro 2008, 2010)
Original draft: Due to its biogeographical characteristics, the Mediterranean Sea recording faster water temperature warming than other marine areas with even more dramatic effects favouring the spread of (sub)tropical species (NIS, non-indigenous and thermophiles species) [1,2]. The increase in water temperature has triggered quickly shifts in the range distribution of species [3,4,5].
Revises draft: The Mediterranean Sea is one of the most vulnerable areas to climate change, with dramatic effects favouring the spread of non-indigenous and thermophilic native species [1,2]. In particular, the range shift of species in the Mediterranean Sea is caused by two distinct phenomena: tropicalization, with non-indigenous species introduced by human activities (e.g. Suez Canal and ballast waters) [1], and meridionalization, whit northwards expansion of species usually restricted to the warmer southern part of the Mediterranean Sea [3].
Authors declared that false scad has increased its abundance in Italian waters. Is it a personal observation or is there any commercial data?
There is currently no direct commercial data showing an increase in the abundance of the species Caranx rhonchus. Our assertion is based on direct observation of Sicilian fish markets, fish landings and comparison with scientific experts and artisanal fishermen in southern Italy
Lines
30: recorded
Done
35: dimensions
Done
36: is strongly
Done
51: Lessepsian
Done
55-58: In my opinion, van Rijn et al. did not mention the morphological similarity between Sparus aurata and N. randalli. It is sold as a common pandora (please see: https://doi.org/10.12681/mms.19658 - however, please not cite this reference). Please replace Sparus aurata to native Sparids.
Original draft: Another example is the species Nemipterus randalli Russell, 1986 first recorded in the Mediterranean in 2005 [31]. This species, however, was readily incorporated into markets as it is very similar in morphology and size to the common gilthead seabream Sparus aurata Linnaeus, 1758 [18]
Revised draft: Another example is the species Nemipterus randalli Russell, 1986 first recorded in the Mediterranean in 2005 [31]. This species, however, was readily incorporated into markets as it is very similar in morphology and size to the native Sparids [18]
[18] Yapici, S., Filiz, H. (2019). Biological aspects of two coexisting native and non-native fish species in the Aegean Sea: Pagellus erythrinus vs. Nemipterus randalli. Mediterranean Marine Science, 20(3), 594-602.
32 and 59: Authors used both thermophiles and thermophilic. Please standardize it.
Done
Additionally, please check the grammar of the Abstract section
Done
Reviewer 2 Report
The manuscript deals with an interesting subject of applied ichthyology. The authors have proven similar nutritional profile, as well as heavy metals contamination between C. rhonchus and T. trachurus, two species also similar in their external morphology but ordinarily valued differently in the Italian fish markets. The information included is not entirely new; the methodology followed is also time-tested. Before being publishing, some issues have to be improved, in order to obtain maximum strength.
Please provide some information about an established increase of population density concerning C. rhonchus. The citation provided (35) does not include directly such information.
M&M
Why only male samples were used? Is this a certain methodology? Were all used scad specimens also male? Do you expect to have the same results as if using females also?
DISCUSSION
Some statements show unsupported generalization, e.g.: “In this study, we have observed through the study of C. rhonchus how the phenomenon of meridionalization can provide benefits to fisheries.”
Concerning the species as negligible market object is also a generalization, since only Italy is mentioned from the Northern Mediterranean. What is the situation e.g. in France, Spain, Greece, even in Turkey?
General comments: It is not entirely clear, if the authors consider C. rhonchus as native or alien in the Mediterranean Sea. In some cases they discuss the incorporation of alien species in local fish communities, as well as fish markets. This is not the case of C. Rhonchus, which is assumed as native, despite the fact that is increasing its Mediterranean population (https://www.fishbase.de/Country/CountryList.php?ID=1899&GenusName=Caranx&SpeciesName=rhonchus). This should be taken into account, so as to change the text of introduction/discussion accordingly.
Author Response
The manuscript deals with an interesting subject of applied ichthyology. The authors have proven similar nutritional profile, as well as heavy metals contamination between C. rhonchus and T. trachurus, two species also similar in their external morphology but ordinarily valued differently in the Italian fish markets. The information included is not entirely new; the methodology followed is also time-tested. Before being publishing, some issues have to be improved, in order to obtain maximum strength.
Please provide some information about an established increase of population density concerning C. rhonchus. The citation provided (35) does not include directly such information.
There is currently no direct commercial data showing an increase in the abundance of the species Caranx rhonchus. Our assertion is based on direct observation of Sicilian fish markets, fish landings and comparison with scientific experts and artisanal fishermen in southern Italy
M&M
Why only male samples were used? Is this a certain methodology? Were all used scad specimens also male? Do you expect to have the same results as if using females also?
We preferred not to present the data of the female specimens because they were too few compared to the male specimens. In addition, the nutritional qualities of female specimens can change according to season, reproductive cycle and change of diet. Therefore, we decided to conduct another study focused on females and to concentrate this study only on male specimens of Caranx rhonchus and to compare them with male specimens of T. trachurus.
DISCUSSION
Some statements show unsupported generalization, e.g.: “In this study, we have observed through the study of C. rhonchus how the phenomenon of meridionalization can provide benefits to fisheries.”
Concerning the species as negligible market object is also a generalization, since only Italy is mentioned from the Northern Mediterranean. What is the situation e.g. in France, Spain, Greece, even in Turkey?
Unfortunately, there is few information on the species Caranx rhonchus. The only information that can be found are studies conducted in the waters of North Africa. In the future, it would be useful to understand the real abundance and distribution of C. rhonchus by conducting a study in collaboration with several Mediterranean countries (e.g. Turkey, France, Greece, Spain, Cyprus ecc…)
General comments: It is not entirely clear, if the authors consider C. rhonchus as native or alien in the Mediterranean Sea. In some cases they discuss the incorporation of alien species in local fish communities, as well as fish markets. This is not the case of C. Rhonchus, which is assumed as native, despite the fact that is increasing its Mediterranean population (https://www.fishbase.de/Country/CountryList.php?ID=1899&GenusName=Caranx&SpeciesName=rhonchus). This should be taken into account, so as to change the text of introduction/discussion accordingly.
Thank you very much for your observation.
The species Caranx rhonchus is native to the southern Mediterranean basin and due to the phenomenon of meridionalization is migrating to northern Mediterranean areas increasing its abundance. This shift caused by meridionalization is similar to tropicalization but with the arrival of southern species in new areas in the northern Mediterranean. According to our point of view, this shift of species (tropicalization and meridionalization) can cause the same effect on ecosystems and the human dimension and can offer new positive opportunities. The two phenomena observed from the side of the human dimension can be equated and therefore treated in the same way for some aspects.
