# Grade-set: S1_fishery — Coastal fishery on a collapse trajectory

SCENARIO (given verbatim to both reasoning methods):
A coastal fishery harvesting a single demersal stock has shown three years of declining catch-per-unit-effort and shrinking average fish size. The biologist's stock assessment estimates that current harvest exceeds maximum sustainable yield (MSY) by ~20% and that, on the current trajectory, the stock will cross a recruitment-collapse threshold within 4-7 years. The fishery is open-access in practice (no enforced individual quotas); ~120 small-boat operators across 5 villages depend on it for income, with fish-processing buyers downstream. A regulator has authority to set total allowable catch but has historically deferred to the industry.

Decision required: What intervention design preserves the stock without destroying the livelihoods that depend on it?

Success criteria: Stock biomass returns to MSY-supporting range within 10 years AND <20% drop in aggregate fisher income (averaged across the cohort, not per-boat). Failure = stock collapse OR a regulatory regime that pushes the bottom quartile of operators below subsistence.

There are 6 candidate recommendations below, labeled R1, R2, R3, R4, R5, R6.

## Recommendation R1
The core failure is open access: each boat captures the full value of every extra fish but bears only a sliver of the depletion it causes, so collectively rational restraint never emerges and the stock slides toward a recruitment threshold that, once crossed, is far harder to climb back from than it was to fall past. The intervention must do three things at once — cap total take below the danger zone, route the consequences of each boat's harvesting back onto that boat, and do both without pushing the weakest operators below subsistence. None of these works alone; sequencing and legitimacy are everything.

Begin by setting a binding total catch limit that is genuinely enforced, not advisory. Set it deliberately below maximum sustainable yield for the first recovery phase — target roughly a 25–30% cut from current take, which removes the ~20% overshoot and adds a safety margin so biomass moves away from the collapse threshold rather than hovering at it. Tie the limit to an independent annual stock reading (catch-per-unit-effort, average fish size, and a recruitment proxy) through a pre-agreed rule: the cap rises automatically as the stock recovers and tightens automatically if indicators worsen. Writing the adjustment rule down in advance, with science rather than negotiation setting the number each year, is the structural fix for a regulator that has historically bent to the industry — it removes the annual discretionary decision that capture exploits.

Divide the total limit into individual harvest shares so each operator holds a defined, enforceable claim to a slice of the catch. This converts the resource from a race into an owned asset: a boat that conserves no longer simply hands its restraint to rivals, and a boat that overshoots its share faces a real, attributable consequence. But unconstrained tradable shares would let a few buyers accumulate the fishery and dispossess the bottom quartile — exactly the outcome that defines failure here. So constrain the shares: allocate the initial split partly on historical landings and partly as an equal per-operator base so the smallest boats get a floor; cap how much any single holder may own; make a subsistence tranche of each operator's share non-transferable; and let leasing or sale of the remainder happen only within the fishery's own community, not to outside capital. This keeps the efficiency of tradable entitlements while protecting the weakest.

Soften the income shock during the cut, because a 25–30% catch reduction otherwise risks breaching the income floor before recovery delivers larger, more valuable fish. Phase the cap down over two to three years rather than imposing it overnight. Fund a transition pool — financed by a modest landings levy, the processing buyers (who need the stock to survive and can offer forward purchase commitments), and any available public conservation money — to support temporary effort reduction, gear improvements, and retraining or alternative income for those who exit. Pay particular attention to the bottom quartile: targeted bridging payments or buyback of shares from those choosing to leave both relieves pressure on the stock and concentrates remaining shares among the operators who stay, raising their per-boat income as the stock rebounds. Because demersal fish grow and command higher prices at larger size, much of the income lost to lower volume returns within a few years as catch composition shifts toward bigger fish — make this visible to operators so the short-term sacrifice is credible.

Make the rules legitimate and self-policing. Stand up a co-management body with elected representatives from all five villages, the regulator, and the buyers, with authority to set local rules within the science-driven cap, resolve disputes, and handle hardship exceptions. Because this is a small, bounded community of repeat players who will meet again, lean on that: published landings, at-sea and landing-site monitoring, and graduated sanctions — a warning, then escalating penalties, then suspension of shares for repeat offenders — applied evenly to everyone including the largest holders. Even-handed enforcement is what makes honest operators keep cooperating rather than defecting once they see others cheat unpunished.

Watch the leading indicators continuously and treat worsening signs as a trigger to tighten, not a topic to debate.

Final operating rule: hold total catch below the level the stock can replace until the independent indicators show recovery, allocate that capped catch as enforceable individual shares that are floored and capped to protect the smallest operators, and adjust the cap each year by the pre-committed science rule under a co-management body that monitors honestly and sanctions everyone alike — letting the stock and the per-boat value recover together.

## Recommendation R2
Treat the stock as a shared asset that is being drawn down faster than it rebuilds, and recognise the central trap: each boat keeps the full value of every extra fish but feels only a fraction of the collective loss, so individually sensible decisions are steering the whole cohort toward a collapse that nobody wants. Moral appeals to "fish less" will fail for exactly this reason — the restraint costs the restrainer everything and saves them almost nothing. The intervention must change the decision environment, protect the weakest operators by design, and act inside the four-to-seven-year window before the collapse threshold makes recovery impossible.

Stand up a co-management council with elected seats from each of the five villages, formally recognised and backstopped by the regulator. Because the agency has historically deferred to industry, its credibility is weak; legitimacy must instead come from the operators themselves plus transparent evidence, with the regulator's role being to recognise the council's rules and enforce against outsiders. Reserve guaranteed seats for smaller-boat operators so the council cannot be captured by the largest players.

Close the de-facto open access. Register the roughly 120 currently active operators as the rights-holding group, freeze new entry during recovery, and exclude transient vessels. This bounds who the resource is being protected for.

Set a cohort-wide total allowable catch on a glide-path rather than a one-time shock. Cutting the full twenty percent immediately would breach the income floor and trigger evasion; instead start around ten percent below current harvest and tighten on a schedule keyed to the annual stock survey, aiming to return biomass to its productive range within the decade. Crucially, allocate the catch so each operator receives a protected baseline share plus a proportional share above it — a flat percentage cut would push the bottom quartile under subsistence, which is itself a defined failure. The baseline floor, a hardship top-up, and a stabilization transfer funded during the steepest cut years keep the weakest boats viable while the stock rebuilds.

Make use and condition visible cheaply. Require catch to be reported at the point of sale through the processing buyers — this is hard to evade and turns the downstream chain into the monitoring backbone — and run a yearly fishery-independent biomass-and-size survey. Both feed a public council dashboard so that limits track the resource's actual condition rather than arbitrary numbers, which is what makes the limits defensible and obeyed.

Attach graduated, proportional consequences: a warning, then a temporary share reduction, then a seasonal suspension for repeated or large violations. Proportionality matters more than severity in a community that must keep cooperating year after year; disproportionate punishment would corrode the legitimacy the whole arrangement depends on.

Accelerate the biological rebound by closing rotating no-take micro-reserves over known spawning grounds. With reduced overall pressure, this is the main lever that lets the stock replenish itself within the window, substituting for any costly restocking.

Fund the system from within: a small per-landing levy plus a buyer co-contribution pays for monitoring, the survey, and the stabilization transfers. Operators owe accurate reporting and participation in survey days in return for their secured access — obligations are reciprocal and understandable, which is what sustains contribution. Maintain an appeals path for share and sanction disputes and a documented hardship process so adjustments are rule-based, not dependent on who advocates loudest.

Build in adaptation. Each year, the survey result either tightens or relaxes the glide-path; if biomass recovers faster than expected, catch can rise, and if it stalls, the cap tightens further. Keep a transparent public ledger of catches, biomass trend, sanctions, and fund disbursements to guard against both capture by powerful operators and overreach in monitoring.

Final operating rule: hold the cohort catch to the highest level the annual survey shows is consistent with biomass climbing back toward its productive range within ten years; distribute every cut through protected baseline shares and a stabilization fund so the bottom quartile never falls below subsistence; and let observed stock condition — not industry pressure or a fixed number — move the limit up or down each year.

## Recommendation R3
Treat the four-to-seven-year collapse window as the binding fact: every year of deferral is a loss that cannot be bought back later, so the first move is to act now rather than wait for consensus, while making the early steps small enough to be survivable and adjustable.

Replace open access with a single, science-anchored total catch limit that is explicitly tied to the measured condition of the stock, not negotiated against landings pressure. Set this year's limit to remove the overshoot on a glide path: cut total catch toward the sustainable yield over the first three years (roughly a third of the needed reduction per year), then hold and let measured biomass dictate further moves. The limit must be published as a formula keyed to the biologist's assessment, so that when the stock recovers the limit rises automatically — this turns restraint into a visible promise of future reward rather than an open-ended sacrifice, and it removes the incentive to lobby the number down each season.

Allocate the limit as individual, non-transferable (or only locally transferable) shares, distributed progressively rather than uniformly. Give every registered operator a guaranteed floor share sized to subsistence, then distribute the remainder in proportion to recent track record. A flat percentage cut is regressive and would push the smallest boats under; a floor-plus-proportional split protects the bottom quartile while still concentrating most of the reduction on the largest harvesters, who can absorb it. Because the success test is cohort-averaged income, pair the share system with two cushions: a transition fund (financed by a small levy on landings and on downstream processor margin) that pays stewardship and gear-conversion stipends to the smallest operators during the drawdown, and seasonal or area closures that let effort be redeployed (off-season maintenance work, restoration, monitoring) rather than simply lost.

Make the limit credible by co-setting it. The decision body that sets each year's number must include elected representatives from all five villages and the processors, the independent biologist, and the regulator, with a written charter that fixes its scope, bars anyone with a direct financial stake from the final vote, and publishes the reasons for each decision. This is the deliberate counter to a regulator that has historically deferred to the industry: legitimacy and a conflict-of-interest firewall, not just authority, are what keep the cap from being hollowed out. Voice for the affected operators buys the compliance that pure enforcement cannot.

Make use and stock condition visible. Require simple catch reporting at landing sites, cross-checked against processor purchase records (the processors become an enforcement asset, since their buying is already metered), and publish a plain dashboard of stock indicators and remaining quota. Enforce with graduated sanctions: a warning and overage-deduction for first violations, escalating fines, and suspension of shares only for repeated or large abuse. Graduated, proportional, locally legitimate sanctions sustain cooperation in a tight community far better than rare harsh punishment, which breeds evasion.

Run the whole arrangement on a fixed annual review cadence. Each year the body compares measured biomass against the recovery glide path and adjusts the next limit by rule: if the stock is tracking or beating recovery, ease the limit and grow incomes; if it is lagging, tighten. Build in an emergency brake — if any indicator signals the stock is approaching the collapse threshold faster than modeled, the limit drops to a precautionary floor immediately, because that boundary cannot be re-crossed.

Final operating rule: **Each year, set a single published total catch limit equal to the biologist-assessed sustainable yield for the current biomass (capped on a three-year glide down from today's overshoot), divide it into individual non-transferable shares with a protected subsistence floor for every operator and the rest proportional to track record, fund a transition cushion for the smallest boats from a landings-and-processor levy, verify catch against processor records with graduated sanctions, set the number through a village-and-regulator body that publishes its reasons and excludes conflicted voters, and re-tune the limit annually by formula against measured stock recovery — loosening as biomass returns and slamming to a precautionary floor the moment the collapse threshold is in reach.**

## Recommendation R4
The stock is being drawn down faster than it can renew because every operator captures the full value of each extra catch while sharing only a fraction of the cost of decline, and the body that could set limits has leaned on the people it should be restraining. With collapse four to seven years out and recovery from collapse far harder than prevention, the design must do three things at once: bind total catch below the renewal rate quickly, do so through an arrangement the fishers themselves accept and help run, and protect the weakest operators so the cure does not destroy the livelihoods it is meant to save.

Begin by closing the open door. Freeze the eligible fleet at the operators currently active and admit no new boats during recovery; this stops a race to grab catch before limits bite. Set a total allowable catch below the latest stock assessment's sustainable level. Because the stock is near a tipping point, front-load the restraint: an immediate cut of roughly a quarter to a third from current effort, deeper than steady-state harvesting would require, to pull the trajectory clearly away from the threshold. Crucially, do not lift this emergency cut simply because one season looks better. Define a separate, harder recovery test: catch-per-effort and average fish size must rise for several consecutive years before the limit is relaxed, and relaxation happens in graduated steps with monitoring for backsliding. Entering the danger zone is easy; leaving it safely takes sustained proof.

Allocate the catch not as individually tradable permits but as village-level shares, with a guaranteed minimum landing for every active boat. Tradable individual quotas would, in a poor heterogeneous fleet, consolidate into the hands of those with capital and push the smallest operators out — exactly the failure to be avoided. Village shares let each community manage its own allocation against local knowledge, and the per-boat floor keeps the bottom quartile above subsistence. Pair the catch limit with gear rules — minimum mesh size and a closed season over the spawning period — so the fleet stops removing juveniles; the shrinking average size is the signal that the stock's future breeders are being taken, and fixing that is as important as the headline tonnage.

Make compliance self-financing and self-policing. Levy a small charge on landings at the processor weigh-points, where fish already pass through a chokepoint, and use that revenue for two purposes: to fund monitoring at those existing points (no need for intrusive per-boat surveillance) and to capitalize a transition fund. Direct the fund at the operators with the least cushion — short-term income support, gear conversion grants, and seasonal alternative work — phased down only as catch rates and incomes recover. This is what keeps aggregate income within the twenty-percent band while restraint is heaviest, and it is targeted so the cohort average does not hide ruin in the bottom quartile.

Address the captured regulator structurally rather than by exhortation. Replace open discretion with a rule: the regulator retains formal authority to set the total catch but is bound to a published assessment and a pre-agreed harvest-control formula, so each year's limit follows transparently from the stock's measured state rather than from negotiation with the industry. Stand up a co-management board with seats for the five villages, the processors, the regulator, and an independent scientist, charged with allocation, dispute resolution, and graduated sanctions for violations — a warning, then a catch deduction, then suspension. Publish the assessment, the catch limit, landings, and board minutes. Visibility and a science-triggered rule are what make capture costly and the limits legitimate enough that fishers will accept enforcement, including enforcement of each other.

Tie everything to the resource's own condition. Re-survey the stock annually; let the harvest-control rule raise the catch as biomass recovers and tighten it automatically if recovery stalls or any year shows renewed decline, with the transition fund as the shock absorber during tight years.

The operating rule: each year, set the total catch from the current stock assessment via the published harvest-control formula; never relax the emergency cut until catch-per-effort and fish size have risen for several consecutive years; allocate by village share with a guaranteed per-boat floor; fund monitoring and a bottom-quartile-targeted transition fund from a landings levy; and keep the limit, the data, and the board's decisions public so neither the stock's decline nor the regulator's choices can again be hidden. Hold restraint until the stock is verifiably back in its productive range, then ease — slowly, and only on the evidence.

## Recommendation R5
Treat this as a shared stock that is being drawn down faster than it renews because each boat keeps the full value of its own catch while the cost of depletion is spread across everyone — so no appeal to restraint will hold unless the rules of access themselves change. The design has four interlocking parts: a science-anchored catch limit, a fair way to divide it, a transition cushion for the people the cut would otherwise sink, and a governance arrangement that the regulator cannot quietly hand back to the industry.

First, set a total allowable catch that is deliberately below the best estimate of maximum sustainable yield for the rebuild period — roughly a 25–30% reduction from current landings in year one — rather than merely trimming to the MSY point estimate. The stock estimate is uncertain and the collapse threshold is irreversible, so the limit must carry a buffer: underestimating renewal costs a little forgone catch, while overestimating it costs the whole fishery. Tie the limit to a written harvest-control rule: each year the limit is reset from the biologist's survey of catch-per-unit-effort and average fish size, and it tightens automatically — sharply — if the stock drifts toward the danger zone, loosening only as biomass climbs back into the productive range. This makes the limit a transparent function of stock condition, not an annual negotiation the strongest operators can win.

Second, divide the limit into per-boat shares rather than leaving a single pooled quota that triggers a race to fish it first. Freeze access to the current registered operators for the rebuild — no new entrants — so the burden of recovery is not used to displace the existing cohort. Allocate shares progressively: give every boat an equal baseline share sufficient for a viable trip, then distribute the remainder in proportion to recent catch history. This protects the smallest operators, because a flat percentage cut applied to everyone falls hardest on boats that were already near subsistence. Permit short-term leasing of unused share within the cohort so a fisher having a bad season can still earn, but prohibit permanent sale of shares to outside capital — unrestricted trading reliably consolidates the fishery into a few hands and pushes the bottom quartile out, which is precisely the outcome to avoid.

Third, build an explicit income floor and bridge. Fund it with a small levy on landings plus, where available, time-limited public or buyer-backed transition money, and use it three ways: a guaranteed minimum payment that tops up the bottom-quartile boats whenever their share-constrained income falls below a subsistence line; paid stewardship work during the low-catch years (survey assistance, gear retrieval, habitat and spawning-area protection) that keeps crews employed and the stock recovering at the same time; and modest buy-forward or storage arrangements with processors so the downstream buyers, who also depend on the stock, help finance the recovery rather than pressing for higher catches. The target is that aggregate cohort income stays within 20% of today even as total catch falls, because the cut is concentrated where it can be absorbed and the floor catches the rest.

Fourth — and this is what makes the rest credible — restructure who decides. The regulator has historically deferred to the industry, so do not rely on it writing stricter rules it will then enforce loosely. Place rule-making in a co-management board with elected seats from each of the five villages and the processors, but bound that board inside a scientific envelope it cannot vote away: the independent stock survey sets the outer limit on catch, and the board allocates and adapts within it. Keep the survey funded independently of the operators it constrains, publish a plain public dashboard of stock condition and every boat's catch against its share, and give competing voices — crew, the smallest operators, an outside scientific reviewer — standing to contest decisions before they take effect. Enforce with graduated, proportional sanctions: a first overage draws a warning and a deduction from next year's share; repeated or deliberate violation draws suspension. Add simple monitoring the community trusts — dockside landing records cross-checked against the survey — because limits that are not visibly observed will be ignored.

The operating rule, in one line: hold the catch below a conservatively buffered, survey-set limit and tighten it automatically as the stock nears danger; divide that limit progressively among the current boats with a guaranteed floor and stewardship pay for the weakest, allowing leasing but not sale of shares within the fleet; and vest the rules in a village-and-buyer board that may adjust allocation but never the science-set ceiling, under a public dashboard and graduated sanctions. Recover first by buffering against irreversibility, keep the fleet intact by spreading the cut progressively and cushioning the bottom, and protect both by making the ceiling something no single interest can quietly raise.

## Recommendation R6
The fishery is being drawn down because everyone fishing it captures the full value of their own catch while the cost of decline is shared across all 120 boats and the seasons to come. With recruitment now four to seven years from a collapse it may not recover from, the goal is to turn an open-access race into a bounded, monitored, legitimately governed shared resource — and to carry the smallest operators through the recovery so the cure does not starve them.

Begin by defining the governed unit precisely: this stock, its grounds, the 120 currently active boats, and the downstream processors who depend on them. Freeze the operator roster at those 120 for the duration of the recovery. No new entrants — an open door reopens the race and undoes everything else.

Set a total allowable catch roughly a quarter below the current harvest, which puts landings below the sustainable-yield level and lets biomass rebuild. The catch limit must be anchored to an annual stock assessment produced by an independent scientist or panel funded outside the industry — not negotiated downward with the fleet. This is the single most important defense against the regulator's habit of deferring to the people it is meant to constrain: the number comes from the fish, publicly, every year, and the regulator's job is to apply it, not bargain it.

Make the recovery durable by tying the limit to what is actually observed. Each season's allocation rises or falls with the assessment; if early-warning signs appear — recovery stalling, sizes still shrinking, recruitment proxies weak — the cap tightens automatically rather than waiting for a debate. Add spawning-ground and seasonal closures so the stock has protected windows to reproduce.

Allocate the reduced catch by recent fishing history, but with a hard subsistence floor underneath every boat and a deliberately larger share routed to the smallest operators. The bottom quartile must never be allocated less than a defined subsistence catch. Because the total is smaller in the early years, fund a time-limited income bridge — paid from a small levy on landings plus a recovery grant or loan — to cover the two-to-three-year trough before biomass and catch-per-trip climb back. Offer a voluntary gear-buyback or alternative-livelihood option from the same fund for anyone who would rather exit than wait. The aggregate-income target is met not by fishing harder but by the stock's rebound: as biomass recovers, each boat catches more per trip for less effort, so cohort income returns even under a lower total catch — the bridge simply spans the gap until it does.

Govern it as a standing institution, not a one-off rule. A council of village delegates co-sets the seasonal details with the regulator, which gives the rules local legitimacy and draws on fishers' knowledge of the grounds. Enforcement is graduated and proportional: a first overage draws a warning, then a deduction from next season's allocation, then suspension, then removal — severe enough to deter, fair enough that the community accepts it. A standing appeals panel, chaired independently, handles quota disputes, hardship cases, and sanction challenges. Publish everything that matters: the assessment, the basis for the catch limit, each boat's allocation, the levy's use, and the sanction record. Transparency is what makes any future deference by the regulator visible and costly.

Review the whole arrangement every three years, or immediately if a threshold warning fires, and revise as stock, demand, or membership change.

Operating rule: hold landings below the independently assessed sustainable level every season, tighten automatically whenever the stock nears its collapse threshold, and never let the smallest operators fall below subsistence — bridging them with the shared fund until the recovering stock restores their income.
