Niche Analysis of the Main Fish in the Lhasa River Basin

Round 1

Reviewer 1 Report

I have evaluated this second version on the system, in which some corrections were inserted. The text is well written and objective. My comments must be considered for text improvement and clearness. Figure 1 is ok, but it must be completed with a macro spatial context (minor maps together allowing to focus the river on the whole context). An international reader needs to access other sources to precisely the studied area. The use of different fishing gears is understandable. Nevertheless, different selectivity implies in text if this data can be joined or not for analysis. Some authors recommended the use of Kruskal Wallis and Levene tests to ascertain the possibility of combining samples from different fishing gears. Vaz-dos-Santos and Silveira (Available from: https://www.researchgate.net/publication/352453667_Idade_e_crescimento_de_peixes_de_riacho_metodos_e_desafios_para_a_obtencao_de_estimativas_robustas) proposed the use of ANOVA two way (fish length = response, fixed factor = size class, random factor + fishing gear) to test this possibilty for combine samples. In relation to fish, it is important to present them considering the current taxonomic status. In this way, in each first citation, present the complete name (not abbreviated) and include the author following Eschemeyer catalog (Eschmeyer's Catalog of Fishes | California Academy of Sciences (calacademy.org)). You can describe the 25 species in an appendix (Order, famliy, author). Other important information that is missed  is the size structure of catches, an information that must be inserted in this table at the appendix. My last concern is related to the IRI application. When studying fish diet, composite indices (such as IRI) are not recommended, due to bias caused in its calculation. It is important to discuss and highlight this, either many people could not read the text or lost interest in it due to methods applied.

Reviewer 2 Report

Please see the attached comments.

Comments for author File: Comments.pdf

Author Response

First of all, I am very grateful for the valuable advice provided by Dr.Sun Ming!!! This is treasure of my progress and article revision. The following is my reply.

After half a day of consideration, although a little uneasy, but I still think that there is not much nonsense to write so. This will not waste too much time for you, so no longer refer to the online reply template, but a direct reply. If not, please understand.

I have undergone extensive English revisions of my manuscript,I used the “Track Changes”,so any changes to the manuscript can be easily viewed.

Abstract

• Reviewer: Starting the Abstract with one or two sentences introducing the Lhasa River geographics and ecosystem help readers learn more about the background.

Reply：In the abstract part, the introduction of the geographical environment and ecosystem of the Lhasa River is added. （line10-15）“The Lhasa River is one of the five tributaries of the Yarlung Zangbo River. It is the main industrial, agricultural and animal husbandry area in Tibet. It plays an important ecological security barrier role in regulating regional climate and maintaining biodiversity.

• Reviewer: The abstract did not offer a capture of research highlights. There were too many quantitative results, without summarized key findings. Simply compiling them made the abstract very boring and not enlightening. I suggest only keep the key quantitative results, interpret their meanings (e.g., high niche breadth indicates ….) and supplement some implications for management and conservation. I am personally a quantitative fisheries scientist, but I would care for more take-away messages instead of bunch of non-informative numbers.

Reply：At the beginning, I increase the purpose of our work.（In order to understand the dis-tribution pattern and competition relationship of fish in Lhasa River and provide basic data for the protection and sustainable utilization of fish diversity in Lhasa River…）.

I simplified the description of quantitative results and added summary language. （line32-41）

Introduction

• Reviewer: Lines 45-53: This paragraph should be the major background for conducting such analysis. I personally am very interested in learning the river ecology in Tibet. Based on my naïve understanding, the local ecosystem is very vulnerable and poorly understood, despite the strong conservation initiative proposed by national and local administrations. I would streamline the introduction with the following elements: local geographics and ecosystem overview, management/conservation policy background, pervious conservation efforts and their challenges due to lack of knowledge.

Reply: I address your proposed ' local geography and ecosystem profiles, management / conservation policy background, previous conservation efforts and the challenges they face due to lack of knowledge’. It was modified. ( line66-71,74-83 )

Materials and methods

• Reviewer: Line 68: Are the survey approaches and gears eco-friendly and representative of the fish community? Some justifications are needed here.

Reply: Thank you for your proposal, here really need to add(line100-119):

 Add 1:  Field work was approved and supervised by the Agriculture and Rural Affairs Department of Tibet Autonomous Region.

Add 2:  In order to make the catches representative, three-layer gill nets (for pelagic fish) and cages (for demersal fish) were used to catch fish in the Lhasa River Basin (gill nets: length × height: 20m × 1.2m, mesh size: 2-8 cm; cage size: length × width × height: 10m × 0.3m × 0.5m), and the placement time is 12 hours.

Add 3: The catches captured at each site were quickly anesthetized, packed into sample bags, numbered and recorded.

Revise1: The fish resources were investigated in strict accordance with the Inland Waters Fishery Natural Resources Survey Manual

• Reviewer: Figure 1: Legend is broken here. I supposed the black triangles refer to stations.

Reply:I‘m sorry about that, but your guess is right. 

Result

• Reviewer: Overall, I hate to say that but listing a ton of Latin names is very discouraging for readers unfamiliar with the local taxonomy. I suggest 1) adding photos for key species,2) any chances using common names that are widely known, and 3) maybe group them by life history types, predator preys, or any other groupings that make sense to general audiences.

Reply: I made a slight modification to your opinion - adding pictures of major fish. I 'm so sorry, but I decided to use the Latin name for the reader 's accurate knowledge of the species.

Discussion

• Reviewer: Discussion on the quantitative results is quite necessary. Solid and nothing to pick here. But I am still not sure what are the key conclusions underlying these results. I suggest organizing the discussion based on key conclusions, instead of focusing on the analyses themselves.

Reply: I have made a lot of modifications to the discussion section, adding conclusions drawn from the research results and related literature.（line229-369）

• Reviewer: Any comparisons can be made to other studies for the Lhasa River. If this is the first paper, then please highlight this point as much as possible in the Abstract, Introduction, and Discussion.

Reply: Through modification, I emphasized in the abstract, preface and discussion section of the article that this is the first article to introduce the niche analysis of major fish in the Lhasa River.

• Reviewer: Section 4.3: I like this section is individually put here as part of the research highlights. But my biggest concern is why we are talking about “fisheries management” in the Lhasa River instead of conservation. First of all, I am not sure if there are considerable fisheries or other human impacts in the river (should be explicitly mentioned in the introduction). Second, I believe environmental changes could be more significant stressors to the ecosystem due to altered river flow volume, seasonality, and temperature etc. The authors mentioned in the results that many species were endemic to the river, so readers would naturally incline to learn their current status and conservation challenges. This study actually offered very valuable baseline data for spatio/temporal conservation planning, which is very different from fisheries management. With fisheries management we try to address how to exploit the fish more sustainability but may be exploitation is not quite the case here. I may be wrong on this perspective, but authors should make the overall background more clear.

Reply: Thank you for your valuable comments, I looked up the information, the word “conservation” is indeed more suitable for this article, I have made changes. （line376-406）

Emm,I have to say: your proposal has made me great progress, thanks again!!! I’ll keep trying!!!

Please see the attachment

 

Author Response File: Author Response.docx

Reviewer 3 Report

The paper “Niche Analysis of Main Fish in Lhasa River Basin”  deals with an original and useful topic for the journal.

The space and time two-dimensional niche method is very interesting for ecological studies and relatively new  for the aquatic systems.

Change the following words:

line 16     ”There”  edit as “there”

line 82     "IRI = (N+w) x F" edit as "IRI 0 (N + W) x F"

line 88     “1 000”  edit as “1000”

Modify the following parts in the manuscript:

line119   (table 1)

line  135  delete table

line 143   delete figure

Author Response

Thank you very much for your valuable comments. I have made changes.
I have undergone extensive English revisions and some other revisions of my manuscript,I used the “Track Changes”,so any changes to the manuscript can be easily viewed.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The revision looks good. There are some grammar issues (probably due to the track change mode). But they do not interfere with my understanding. And they can be readily fixed during proofreading.