The main aim of this paper is to introduce the newly developed Starfish Barometer, which will be updated and published annually at the World Ocean Day. The Barometer is intended to provide a comprehensive yet accessible summary of the current state of the ocean, combining scientific evidence with a format that is approachable to the general public. Using the symbolic framework of a starfish, the Barometer addresses five key thematic areas: the condition of the ocean, human pressures, societal harms, protective efforts, and opportunities for humanity. The 2025 edition highlights both persistent challenges and notable progress.

I find the concept of the Starfish Barometer highly commendable. Its focus on a selected number of key issues each year—rather than attempting an exhaustive overview—is both pragmatic and effective. While the content is based on existing scientific literature and reports, the Barometer succeeds in synthesizing the complex and fragmented data across multiple dimensions of ocean health into a clear and engaging narrative.

I have outlined below a set of minor but important comments that should be addressed prior to recommending this paper for publication. I look forward to seeing this inaugural edition of the Starfish Barometer published soon.

Minor Comments and Suggestions

General:

It remains unclear whether the paper itself will be updated annually, or if only the data and visualizations on the accompanying website will be revised each year. Is the intention to maintain a ‘living document’—similar to the Global Carbon Project (GCP)—that evolves over time? I strongly recommend implementing such a model to ensure transparency and traceability across editions.

Abstract:

Given that the ocean reached record-high surface temperatures in 2023 and 2024, it would strengthen the abstract to mention this explicitly, as it contextualizes the urgency of the findings.

Line 16: The phrase “only 8.34%” introduces a value judgment. I suggest removing "only" to maintain a more objective tone appropriate for the abstract.

Introduction:

It may be useful to acknowledge that the selection of focus areas—represented by the starfish arms—inevitably involves some degree of subjectivity. Stating this openly would reinforce the transparency of the framework.

Section 2.1:

Consider including more detail on the record increase in global sea surface temperature in 2023/2024, which surpassed the 2015/16 record by approximately 0.25°C. This was a very unusual but not entirely unexpected event. While El Niño contributed, it was not sufficient to explain the jump alone. Terhaar et al. (2025, Nature) provide evidence countering claims that current models fail to capture such changes. Including this reference would strengthen the section.

Clarify the term “acidity” or “acidification.” If the reported 30% increase refers to [H⁺] concentration, this should be stated explicitly to avoid confusion with other metrics such as changes in aragonite saturation (Ω).

More clearly link the fourth global coral bleaching event to ocean warming, as this connection is currently implied but not explicitly stated.

Figure 1:

The symbols on the individual arms of the starfish appear meaningful. Will these themes (i.e. symbols) serve as a recurring structure in future Barometer editions, or are they illustrative only? Clarification would help readers understand the role of this visual design.

Section 2.2:

Consider mentioning that international shipping emissions contribute approximately 1.6% of total global fossil fuel CO₂ emissions. While this share is relatively small, the localized health and environmental impacts—particularly near ports and coastal communities—are significant and not currently discussed. Including these could enhance the ‘Societal Harms’ section/paragraph.

The figure of 37.7% for unsustainable fishing may appear overly precise. If the underlying uncertainty is substantial, consider rounding or contextualizing the number. This comment also applies to other numbers in the text.

The phrase “dramatic rise in nearshore macroalgal blooms” would benefit from quantification. What constitutes “dramatic” in this context—10%, 100%, more?

Section 2.3:

It is unclear whether the reported loss of life relates to ocean-induced migration (e.g., from sea-level rise or climate variability) or to other causes. If data are available on total ocean-related mortality, it may be valuable to include here.

Section 2.4:

While the text notes that MPAs expanded by only 0.007% between 2023 and 2024, it would be helpful to include figures showing the change over a longer timescale (e.g., the past decade) to give readers a sense of long-term progress.

Although I am not an expert in ocean governance, I believe the International Tribunal for the Law of the Sea (ITLOS) recently ruled that CO₂ emissions constitute marine pollution under UNCLOS, requiring states to take preventative measures. This is a significant legal development and should be mentioned in this section.

The manuscript presents a timely and important initiative which seeks to assess and communicate the status and trends of ocean health and related societal dimensions. The concept is commendable and the presentation is generally clear. My understanding is that this is intended for non-technical readers. However, several areas require further clarification, elaboration, and stronger connection between sections to improve coherence and rigor. 

I provide below specific comments and suggestions for improvement directly on the manuscript.

Major Comments

1. Intended Audience and Positioning

• It would be beneficial for the authors to clearly indicate the main audience of the initiative early in the manuscript. Identifying whether the intended readership includes policymakers, the general public, the scientific community, or all of the above will help tailor the messaging and focus (both in the abstract and in the introduction)
• Introduction: I suggest acknowledging similar existing initiatives (e.g., Ocean Health Index) and clearly articulating how the Starfish Barometer differentiates itself in scope, methodology, or application.

2.   Framework and Rationale

• A paragraph explaining the rationale behind the choice of focal topics for 2025 should be included. If the focal topics are intended to change with each assessment cycle, this adaptive approach should be explained
• A brief summary of the assessment methods should be presented in the main text, with detailed methodologies referenced in the supplementary materials.
  
     

3.  Scientific Accuracy and Completeness

• Line 60: When discussing ocean warming, providing an estimated rate of warming would strengthen the context.
• Line 69: Statements about changing risk levels of species could be strengthened by quantifying both the number of species increasing in risk and those decreasing, as available from the Red List Index for marine species.
• Line 74: The impacts on deep-sea ecosystems can mention multiple stressors, including climate change, deep-sea mining, and bottom trawling.
• Line 78: The discussion on extreme conditions should briefly define or exemplify these conditions

4.    Linking Drivers and Pressures

• Line 84-87: The manuscript should more clearly explain the linkages between CO₂ emissions and associated oceanic pressures, including climate change and acidification.
• Line 88-89: The use of “sustainable level” is currently narrow, defined primarily as maximum sustainable yield (MSY). It would be helpful to acknowledge that fisheries can be unsustainable even at MSY levels due to ecological complexities such as trophic disruptions and bycatch.
• Line 103-104: It would be useful to briefly mention the main pathways of impacts here - through pollution, habitat destruction, increased risks of marine pathogens, parasites and invasive species.

5.    Integration Across Sections

• The manuscript could benefit from integrating between sections. Currently, the selection topics in 2.2, 2.3 and 2.4 does not fully align.  For example, E.g., 2.3 does not have any mention of the impacts of over-exploitation or the lost of coast habitats on the society - topics that are highlighted in 2.2 . Also, pollution focuses on plastic only, but coastal hypoxia is discussed in 2.2, much of which is driven by excessive nutrients, leading to coastal hypoxia. It would be useful to discuss the implications of the pressures highlighted in 2.2 for the society in 2.3. Similarly, it would be useful to strengthen the linkages between the responses (2.4) to 2.2 and 2.3.

6.    Others

• Efforts to address pollution and climate change should be explicitly mentioned in the management response sections.
• LineL 199-207: The discussion of small-scale fisheries should also emphasize their importance in promoting equity and sustainability. They provide livelihoods, cultural value, and critical nutrition, especially for vulnerable societal groups, in contrast to large-scale industrial fisheries. Generally, they contributes more to sustainable development. 
• The anticipated benefits of marine protected areas (MPAs) should be clearly articulated.
• Line 180:  A note on the importance of ensuring sustainability in marine biological products would also strengthen the narrative.

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Minor Comments

• Line 6: Phrases like “ocean-related developments” need further clarification. It is important to define such terms to avoid ambiguity for readers from diverse backgrounds.
• Line 29: Suggest rephrasing as lastest availability information on historical changes and current status and trends, instead of "facts".. currently, it makes "predicted futures" sound unscientific.
• Line 97: Specific terms such as “struggling” should be clarified (e.g., does it mean species are being impacted?).