For reviewers

Articles published in Limnology and Oceanography: Methods must meet very demanding criteria. It is not enough to show that a method works, even if it appears to work perfectly. The new method must provide new opportunities to advance the science, or resolve problems with existing methods that have held back progress. The task before you is to advise the Associate Editor whether you have been persuaded that a new method has the potential to lead to new insight in the aquatic sciences.

Equally high standards apply to manuscripts that deal with reviews and syntheses. The manuscript reviewer must determine whether these syntheses do more than merely summarize the methodology. Ideally, critical reviews and syntheses will offer new perspectives on the strengths and weaknesses of the methods used in a particular discipline, and will suggest new and promising directions.

You must also critically evaluate the implementation of a proposed method. No matter how promising a method may be, it can't fulfill that promise unless it performs adequately. You must carefully examine the proofs of concept the authors have provided, and make an objective, critical decision as to whether 1) the authors have done the background work needed to understand their method's strengths and limitations, and 2) the performance of the method is sufficient to allow its potential to be realized.

Your opinion, however well founded, will not help the Associate Editor to make a decision unless you can explain the reasoning behind it. The more clearly you explain and support your opinion of a manuscript, the more likely it is that your opinion will prevail. A good review will not merely render a judgement, but will identify both positive and negative features of a manuscript, suggest ways that the manuscript could be improved, and explain the rationale behind any negative comments. Above all, a good review will encourage the authors to improve upon their work by addressing your concerns.

Both your review and the manuscript are confidential! The authors will see only the portion of your review designated for the authors. Unless you explicitly request to be identified, your name will not be revealed to the author. If the paper is subsequently revised and the revision is sent out for further review, new reviewers will receive a copy of the parts of your review that were sent to the author, together with the author's detailed responses to all reviews.

Structure of a review

Your review should be divided into three parts.

General comments (sent to the author)

This section is used to summarize your review for the authors. Briefly state what the potential impact of the method would be on the aquatic sciences. Comment on its originality, whether it is a novel approach or provides an alternative to an existing procedure, and whether the work done to assess its performance clearly supports its use. You should also comment on the probable impact of the method. How many people would it affect? If widely adopted, would it force users to rethink their perspective on the field? This section is not to include your recommendation regarding acceptance or rejection of the paper. Note that this section should be thoughtfully and carefully worded to convey your opinion without unnecessarily antagonizing the authors!

Detailed comments (sent to the author)

This section should be used to make concrete suggestions for improvement, to identify problems such as missing proofs of concept, to criticize specific paragraphs, figures, or tables, and to identify sections that could be eliminated or modified. The following questions may be of help:

1. Introduction:
   Have the authors clearly identified the need for methods development in a specific field? Have they persuasively set the stage for their description of their work?
2. Materials and procedures:
   Have the authors clearly and methodically described how to implement their method, in sufficient detail that you feel you could successfully adopt the method?
3. Assessment:
   Have the authors critically evaluated their own method in sufficient detail that you feel you understand its strengths, limitations, and performance characteristics? Do the assessments of performance support the authors' contention that the method does work under controlled conditions and should work under real-world conditions? If not, what further work would be needed to reassure you that the method works as intended?
4. Discussion:
   Have the authors made a strong case that the method, as described and with the demonstrated performance characteristics, has a strong potential to lead to new insight in the aquatic sciences? If not, what weaknesses do you see in their arguments supporting the method?
5. Potential impact:
   Methods that represent incremental progress are unlikely to be accepted for Limnology and Oceanography: Methods, even if the authors show convincing evidence that the method works as designed. Have the authors made a case for the potential impact?

Recommendation to the Associate Editor (not sent to the author)

This section should be used to recommend to the Associate Editor what you believe the fate of this paper should be. This is not the place for a detailed review. The Associate Editor needs to know what your decision would be if you were the Associate Editor handling this manuscript. Please recommend one of the following actions:

1. Conditionally accept. These manuscripts are likely to be accepted but require revision, either major or minor in scope. Manuscripts requiring more substantial revision may undergo a second round of review, often by the same reviewers, to ensure that the reviewers' concerns have been addressed. If you recommend a conditional acceptance with a major revision, please indicate to the Associate Editor whether you would be willing to re-review the revised version of the manuscript.
2. Do not accept; resubmission is invited. These manuscripts are potentially worthy of publication, but very extensive revision is needed. Resubmissions are treated as new manuscripts, and a new round of review will be required. This category should only be used if you can also make an explicit recommendation as to how the authors could restructure and revise their manuscript. You should also note the strengths of the manuscript that make you reluctant to reject it outright.
3. Do not accept; resubmission is not invited. These manuscripts may contain material worthy of publication but are unacceptable or unsuitable for Limnology and Oceanography: Methods.