Review of the Manuscript DDI-2024-0246: "Continental-scale assessment of climate-driven marine species range extensions using a decade of citizen science data."
This manuscript addresses an important and timely topic: leveraging citizen science to monitor climate-driven range shifts in marine species. The study is innovative and makes valuable contributions to marine ecology and the broader discourse on participatory science.
Major comments:
This paper is well-structured and well-written. It presents a significant advance in leveraging citizen science for large-scale ecological monitoring, demonstrating its utility in detecting range extensions in marine species across Australia's coastline. The methodological approach and emphasis on community engagement are particularly commendable. The work is particularly relevant given the accelerating pace of climate-driven changes in marine ecosystems.
Having participated in smaller-scale citizen science initiatives, I am impressed by the scale of this study, which offers a comprehensive framework adaptable to other regions. I hope it serves as a model and inspiration for similar initiatives worldwide. The concept of "virtuous cycles" between participation and conservation outcomes is compelling, and the development of the ‘report cards’ for public dissemination (redmaps) produced in this work is an excellent example of effective science communication.
That said, the manuscript does not fully address how potential biases in citizen science data, such as uneven geographic coverage or species detectability, might affect the findings. A more quantitative assessment of these biases would enhance the study's robustness. Even if such an analysis is not feasible, acknowledging these limitations in greater detail would strengthen the discussion.
Additionally, while the benefits of citizen science are well-articulated, the manuscript could benefit from a discussion of strategies to sustain participant engagement. For instance, how can reporting consistency be maintained as "novel" species become more commonplace?
Minor comments:
- line 40: “species are […] in pursuit of suitable habitat” – please replace the anthropomorphism. Species do not pursue anything.
- lines 249 -251: “Secondly, a list of iNaturalist users known to be 250 experts of identified taxa (professional biologists, museum curators, taxonomists, etc.) was 251 developed, with advice from the Australasian Fishes project curator. ” – it would be great to have that list in suppl. material, to give credit to these people.
- line 456: Typo in “Determining the the spatial...”
- This is a detail, but Fig.1 could be improved by highlighting or calling attention to the starting point.
- in Fig. 1, I could not find the footnotes for 1 and 2.
- starting on page 43, the supplementary materials lost formatting, making it difficult to understand the information.

I am happy with the modifications to the MS