Mechanical Removal of Minnows (Gila bicolor) to Improve Water Quality in a Hydropower Impoundment, Lemolo Lake, Oregon, USA

Round 1

Reviewer 1 Report

This is interesting manuscript; experimental approach might attract scientific community since at all parts of the globe native fish diversity is primarily threatened by alien and invasive fish species. In numerous standing water bodies (not only impoundments, but also natural one), aliens already took over. Beside debased, experimental approaches, seem that this is an issue very difficult to be managed.

The integrated experimental approach considering different components within ecosystem is the right one, but there are couples of lacking:

·         The study has been undertaken 10 years ago, whether the tui chub has been recovered again within Lemolo Lake, or fish structure was changed. In many examples ones intervention is happen just in two year, in sequence years the invasive become more invasive.

·         Under the Method section (lines 183-184) it is noted that: “Tui chub removal was con-ducted by staff from Lemolo Lake Resort deploying three Oneida trap nets (3/8 inch mesh size), typically beginning in June and proceeding through August, with nets generally checked on a daily basis”. This need to be expanded a bit more explaining: Onieda trap nets dimensions (apart of mesh size), fished area, time of efforts, etc.

·         Although, authors at the end of the manuscript (lines 514-517) address the topic: “…. Studies such as this one of Lemolo Lake illustrate that even as we learn about the connection between fish biomass and water quality, management activities by resource managers have yet to fully appreciate these processes and incorporate this knowledge into fisheries management”. I think this is a general one, but not a conclusion driven from the experimental approach. In nowadays, readers would be more interested to know whether this experiment was successful, can be replicated, is it sustainable, is it economically costly, etc.

Author Response

1. We can't address the gap in years.  Data collection ceased in 2013 and we have no additional data.
2. We have added additional details regarding the dimensions of the nets and described the deployment strategy.
3. We deleted lines 514-517 and substituted statements that are supported by the data.

Reviewer 2 Report

COMMENTS ON MANUSCRIPT ID: hydrobiology-2478930

The manuscript presents “Mechanical Removal of Minnows (Gila bicolor) to Improve  Water Quality in a Hydropower Impoundment, Lemolo Lake, Oregon, USA”, which is remarkable. The subject addressed is within the scope of the journal.

However, the manuscript, in its present form, contains several weaknesses. Appropriate revisions to the following points should be undertaken in order to justify recommendation for publication.

The abstract section starts with too much general information and remove the first 4-5 sentences.

Keywords: please mention the study area in keywords as “Lemolo Lake” or “Hydropower Impoundment” or “ Oregon”

 “Figure 1. Lemolo Lake showing inlets and outlets.” Showing the inlets and outlets is far from reflecting the location of workspace. It is too simple. Neither its place in the world nor its place in the country is clear.

 There are too many descriptive words in the results and discussion part. It is obvious that the author's discussion is not deep enough. It is suggested that further in-depth discussion should be conducted.

The discussion section in the present form is relatively weak and should be strengthened with more details and justifications.

Author Response

1. the first lines of the abstract have been deleted.
2. the reviewer suggests adding several words to the keyword list.  However, these words are included in the title and search engines include the title in addition to the keywords, which would make these additions redundant.
3. We have offered a revised Figure 1 that addresses the critique offered by the reviewer.
4. We have deleted several descriptive words in the text and in some cases substituted quantitative descriptors.
5. we have added a paragraph discussion the increase in nitrate loading from Lake Creek and tied it to the model simulation.