Bloom of Prorocentrum cordatum in Paracas Bay, Peru

Round 1

Reviewer 1 Report

Review for the paper "Expansion of the potentially toxic dinoflagellate Prorocentrum cordatum in Paracas Bay, Peru" by Cecil Tenorio, Gonzalo Álvarez, Melissa Perez-Alania, Jose Luis Blanco, Carlos Paulino, Juan Blanco Eduardo Uribe submitted to "Diversity".

 

General comment.

 

Coastal ecosystems display a pronounced seasonal succession in community structure, function and productivity due to the prominent seasonality in environmental conditions. Still, the majority of studies on pelagic primary production have focused on the peak productive periods in spring and/or summer seasons. Outbursts of phytoplankton are one of the main events occurring in the pelagic realms over the years. Phytoplankton communities play a pivotal role in aquatic ecosystems transforming solar energy into chemical compounds and transferring synthesizing substances to the higher trophic levels. Therefore, investigations focusing on the dynamics and physiology of microalgae may be considered as relevant in modern hydrobiology. The present study focused on the dinoflagellate Prorocentrum cordatum. The authors revealed the presence of this species in Paracas Bay but they found no tetrodotoxin in the strain culture of P. cordatum. In the present form, however, the scope of the study is too narrow to be interesting to a wide audience. The paper is not well structured and organized; it must be re-drawn partly focusing on the ecological consequences and possible implications for future monitoring. Additionally, the authors claimed no presence of tetrodotoxin in the cultured P. cordatum strain but they provide no data regarding the presence of this toxin in the seawater that makes their main conclusions speculative. In my opinion, the paper is more focused on the morphology of P. cordatum rather than on the expansion of the species off Peru. If so, the aim and title of the study must be re-done. Other parts of the paper also need to be corrected (see major concerns).

 

Major concerns.

 

1. Abstract.

The main results of the study must be indicated in the Abstract according to the aim of the study.

 

2. Introduction.

I suggest the authors emphasize why their study is important in the field. Please, pay more attention to the ecology of the toxic microalgae and their possible impacts on the natural ecosystems (community structure, productivity etc) and various human activities including aquaculture, tourism, coastal engineering, and sustainable development of the inshore waters.

 

3. Material and methods.

Procedures to determine phytoplankton abundance must be described in the ms. Additionally, the authors must explain why they used a conical net to collect phytoplankton. During a spring bloom, concentrations of the microalgae may be extremely high and may lead to clogging of planktonic nets and, therefore, to underestimations of plankton abundance. In this case, using of bottles to sample phytoplankton seems to be more preferable.

 

4. Results.

The description of environmental conditions must be placed at the beginning of the section.

 

5. Discussion.

Environmental conditions during the study period must be discussed in the beginning of the section.

Ecological implications and consequences must be discussed more carefully.

 

 

Specific remarks.

 

L26. Consider replacing "In the winter of 2017" with "In the austral winter of 2017".

 

L27. '6' and '-1' must be in the upper index.

 

L28. Consider replacing " performed to perform" with " made to perform ".

 

L86-87. Please indicate the period of the study and the number of phytoplankton samples.

 

L149. Insert bracket after ‘centrifuge’.

 

L163. Consider replacing "2.4. Environmental parameters" with "2.5. Environmental parameters".

 

L168 and below. ‘chlorophyll A’ must be replaced with ‘chlorophyll a’ (‘a’ must be italicized).

 

L187, 196. Please, correct the units for long, wide and apical collar emerge.

 

Fig. 2. A scale bar must be added to the Figure.

 

L270. Consider replacing "has presented" with "was presented".

Author Response

Please see the attachment with replies 

Author Response File: Author Response.docx

Reviewer 2 Report

This article was well written, it is original, and of great importance, since it is a potentially toxic species. On the other hand, it is a work of utmost importance for the area, since on the one hand, there are no reports of many harmful algal blooms in the area, and because they occur in areas with great fishing potential. In general, the results obtained were well described, not only graphically, but textually.

 

This research addresses the bloom of a potentially toxic dinoflagellate, Prorocentrum cordatum, which poses a risk to aquaculture activities. In the same way, they sought to relate the development of this bloom with the availability of nutrients.  The research was well approached methodologically, obtaining the type of samples for it. The authors not only sought to make a correct identification of the responsible species. Likewise, the authors carried out a corroboration of the identification of the species through molecular analyses.  This is important since morphologically very similar species can occur, but not be producers of toxins. 

 

The discussion needs to be improved. They seem to be different paragraphs united, without spinning, that is, a mixture of results with conclusions. The conclusions are partial. I think that a conclusion about the effect of the nutrients and the development of the bloom of P. cordatum was lacking and left open the question if the presence of certain types of nutrients can affect the presence or not of the toxins analyzed.

 

I think that this article should be published, once the observations made throughout the text have been considered.

 

The discussion needs to be improved. They seem to be different paragraphs united, without spinning, that is, a mixture of results with conclusions.

 

Author Response

Please see the attachment with  replies

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have revised the manuscript according to my suggestions.