When the ocean loses its breath

When the ocean starts to lose its breath, the first signs can be easy to miss.

Oxygen is invisible, but it quietly decides where marine life can live, how it behaves, and how productive ecosystems can be. In a recent study, Institute for the Oceans and Fisheries researchers Dr. Hongsik Kim and Dr. Rashid Sumaila argue that ocean deoxygenation is not only a physical, chemical, and biological crisis. It is also a socio-economic one, because the impacts do not stop underwater. They travel into fisheries, food security, and livelihoods.

Dr. Kim points to the International Union for Conservation of Nature (IUCN)’s apt description: the ocean is losing its breath. When oxygen drops low enough, hypoxia can form, which can be described as low-oxygen zones or dead zones, places where marine life can barely survive because dissolved oxygen is insufficient. The manuscript emphasizes that oxygen loss is accelerating globally and that hypoxic events are becoming more pressing. That makes this issue timely, not only because ecosystems are changing, but because the decisions we make now can determine whether fisheries face manageable disruption or critical decline.

The central message is straightforward: we cannot protect fisheries by looking only at fish biology, or only at economic outcomes. Deoxygenation reshapes both. It can alter where fish and other marine species can go, how well they grow, and how they reproduce. At the same time, those biological shifts affect what fishers can catch, what it costs to operate, how profitable fisheries remain, and what management measures are realistic. Dr. Kim puts it this way: “Deoxygenation is not just a threat to marine life, but a risk to human societies. Narrowing the gap between ocean science and economics is essential to secure the future of our fisheries and marine ecosystems.” Sumaila captures the stakes with a blunt reminder that applies across species: “Not much difference between fish and people: no oxygen, no life!!”

A major problem is what the authors call a “silo effect” between natural and social sciences. Oceanographers have strong tools for describing how warming, circulation, and biogeochemical processes influence oxygen in the sea, and they can document ecological impacts. Economists have frameworks for valuing fisheries, analyzing incentives, and evaluating trade-offs in management. However, oxygen loss often remains weakly integrated into economic valuation and decision-making. That gap matters because many fisheries tools have historically treated the environment as stable enough to simplify. When oxygen conditions become more variable and more extreme, those simplifications can break.

The paper highlights one core challenge: quantifying complex, non-linear feedback loops between ocean change and economic responses. Fish do not respond to low oxygen in a neat, linear way, and neither do people. When conditions shift, fish distributions can change, fleets can chase different areas, costs can rise, profits can fall, and management may tighten or loosen rules. Those choices feed back into ecosystems through fishing pressure and compliance. Capturing that two-way relationship is hard, but the key is opportunity. If oceanography and economics are integrated, we can move beyond simply observing change to building actionable strategies that support adaptive management and ecosystem-based management.

Who needs to do this work? Researchers, especially oceanographers and economists, need a shared foundation to build models that connect oxygen variability to outcomes people care about, like profitability and sustainability. Fisheries managers and policymakers need robust evidence to justify incorporating environmental variables such as dissolved oxygen into stock assessments and long-term plans. Without that integration, decisions risk being made with an incomplete picture of what is driving change.

The study also makes a practical point that is easy to overlook: integration fails if the basics do not line up.

Ocean data and fisheries data often come in different shapes. Oxygen can vary over hours, days, and seasons, while many economic and management decisions rely on annual summaries. Global models may be too coarse for local fisheries questions. The authors stress the importance of aligning spatial and temporal scales so that short, intense low-oxygen events are not “averaged away,” and so that regional planning reflects conditions fishers actually face. They also emphasize that different kinds of data must be treated carefully, because each dataset has limits and assumptions that can distort conclusions if used uncritically.

Just as important, the paper recognizes that collaboration is not only technical; it is cultural. Oceanographers and economists often prioritize different questions and different definitions of value. Ocean science may focus on long-term ecosystem dynamics and feedback, while economics may focus on human behaviour, markets, and trade-offs that drive real-world choices. The manuscript argues that bridging these perspectives takes interdisciplinary collaboration from the start, shared terminology, and co-designed research questions so models produce outputs that managers can actually use.

In the end, the message is not despair, it is direction. If the ocean is losing its breath, our response cannot stay siloed. Oxygen loss will shape ecosystems and economies together, and the most useful tools will be the ones that connect those realities. Integrated models that link oxygen variability to fishery outcomes can help societies anticipate risks, design smarter management, and protect both marine ecosystems and the people who rely on them.

Challenges and Opportunities in the Integrated Economic and Oceanographic Analysis of Deoxygenation Impacts on Marine Fisheries and Ecosystems was published in the Journal of Marine Sciences and Engineering.

Tags: biology, deoxygenation, faculty, Hongsik Kim, IOF alumni, IOF students, IUCN, marine ecosystems, marine science, ocean, ocean ecology, ocean economy, oxygen, Rashid Sumaila, Research