What Climate-Ready Fisheries Can Teach Us About Trade-Offs

When Being Climate-Ready Means Making Hard Choices

We've heard a lot about making fisheries "climate ready"—updating management rules to keep pace with warming oceans and shifting fish populations. It sounds straightforward: use the best available science, adapt as conditions change, and everyone benefits.

Our new study in PLOS Climate suggests it's not that simple.

My colleagues and I modeled what happens when climate gradually changes two fundamental aspects of a fish population: its productivity (how fast it can grow) and its carrying capacity (how many fish the environment can support). We compared business-as-usual management—where harvest rules stay fixed—against climate-adaptive management that updates targets as conditions shift.

The results consistently showed a trade-off, not a win-win.

When climate caused productivity to decline, adaptive management maintained larger populations but reduced cumulative harvest. When productivity increased, adaptive rules captured more fish but kept populations smaller—in some scenarios, cumulative harvest was over 100% higher, but populations ran 40% smaller.

Changes in carrying capacity created similar tensions. When carrying capacity dropped, adaptive management increased harvest by 36% but reduced population biomass by 22%. The pattern reversed when carrying capacity increased.

These aren't hypothetical scenarios. We looked at stock assessments for three major West Coast groundfish species: Pacific hake, petrale sole, and sablefish. Between 2005 and 2022, estimated unfished biomass (essentially carrying capacity) changed by 25-65% for these stocks as new data came in. Every time assessments update—which happens every 1 to 4 years—managers implicitly choose between conservation and harvest objectives, though we rarely discuss it that way.

Both fixed and adaptive strategies prevented populations from becoming overfished in our models. But they diverged sharply on other objectives. Fixed management was more likely to maintain the conservation benchmark we tested (population biomass 20% above the level that produces maximum sustainable yield). Adaptive management was better at avoiding overfishing rates.

Here's what this means practically: There's no universally "better" approach to climate adaptation in fisheries. The right strategy depends on what a community values—stable populations, maximizing catch, precautionary buffers, or something else entirely.

The technology and medical sectors have shown that gradual, responsive adjustments often outperform rigid rules. But in fisheries, those adjustments come with explicit trade-offs. You can see this playing out in Pacific salmon management, where reference points have stayed largely fixed despite documented declines in age structure and productivity. Our models suggest this fixed approach likely maintains lower biomass but higher harvest than an adaptive strategy would.

The path forward isn't about choosing the "correct" management philosophy. It's about being transparent with fishing communities, Indigenous nations, conservationists, and other stakeholders about what gets prioritized when climate forces populations to change. These conversations are already happening implicitly every time a stock assessment updates. We should make them explicit.

Climate-ready fisheries aren't just technically adaptive—they're socially deliberate about the trade-offs that adaptation requires.

Read the full open-access paper: https://journals.plos.org/climate/article?id=10.1371/journal.pclm.0000624