Lecture 6

Fishery Dynamics and Management

Byeong-Hak Choe

bchoe@geneseo.edu

SUNY Geneseo

October 7, 2026

🐟 A Renewable Resource Stock

• In Lecture 5, extracting a non-renewable resource reduced a fixed stock.
• A fish stock can grow and reproduce, so natural growth changes the problem.
• Harvest today affects both next year’s stock and next year’s catch.
• Our fishing experiment showed the choices. Now we will explain the stock dynamics with graphs.

Core reading: Tietenberg and Lewis, Environmental and Natural Resource Economics, 12th edition (2023), Chapter 17, “Common-Pool Resources: Commercially Valuable Fisheries.” The main diagrams are original ggplot adaptations of Figure 17.2 (printed p. 425), Figure 17.3 (p. 427), Figure 17.4 (p. 428), and Figure 17.5 (p. 429). These are printed page numbers; add 29 for physical PDF pages in the supplied file.

Suggested pacing for 2.5 classes of approximately 50 minutes: slides 2–9, stock and growth (50 minutes, including graph-reading practice); slides 10–21, effort, adjustment, and economic targets (50 minutes); slides 22–30, policy and synthesis (25 minutes). Pause at each graph and have students predict the next reveal. Keep the scallop case and EEZ example brief if time is limited. If the first meeting is a half-class, use slides 2–5, then complete the biological bridge in the next meeting.

Figure 17.6 (p. 432) was covered in Lecture 4. Recall its entry/zero-profit result when comparing targets, without repeating the marginal/average-revenue derivation. The emphasis here is biological stock dynamics and sustainable benchmarks. A full discounted optimal-control solution is outside this short lecture.

All numerical examples and plotted parameters are illustrative classroom values, not estimates of an actual fishery. The low-stock-threshold diagram and the simpler effort model use distinct growth specifications, explicitly identified on the slides.

TL, printed pp. 424–426. Emphasize that renewable means capable of regeneration, not guaranteed to recover after any harvest. Refer briefly to Classwork 3 without repeating the experiment or asserting that its fixed growth increment was a realistic biological function.

📦 Stock, Growth, and Harvest

• \(S_t\): fish stock at the start of year \(t\), measured in metric tons.
• \(G(S_t)\): net biological growth during that year, in tons per year.
  • Reproduction and growth of fish, minus natural deaths, before harvest.
  • The current stock \(S_t\) determines net growth, which can be positive, zero, or negative.
• \(H_t\): harvest during that year, in tons per year.

\[ S_{t+1}=S_t+G(S_t)-H_t. \]

TL, pp. 424–426. Annual periods have length one year, so annual growth and harvest flows contribute that year’s tonnage to the stock accounting. Net growth combines reproduction and individual growth minus natural deaths; migration can also affect stock in a particular managed area. The parentheses in G(S_t) mean that net growth depends on the stock, rather than being a fixed number of fish added every year as in our classroom experiment. A positive value adds biomass, a negative value removes biomass even without fishing, and zero means natural additions and losses balance. Subscript t identifies the year; t+1 is the following year. This is a simplified aggregate-biomass model, abstracting from age structure, seasonal timing, and migration between managed areas.

⚠️ Low-Stock Threshold and Carrying Capacity

• Growth becomes negative below the minimum viable stock.
• A very small population can have difficulty reproducing successfully.
• Even stopping fishing may not be enough for recovery below such a threshold.
• Carrying capacity (\(K\)) is the stock the environment can support without fishing.
• At \(K\), natural additions and losses balance, so net growth is zero. Above \(K\), the stock shrinks.
• A low-stock threshold is a possible risk. Both thresholds and carrying capacity depend on species and conditions.

TL, pp. 425–426. The figure includes a low-stock threshold; do not claim every fish stock has the same positive threshold. Environmental variability and species biology affect recovery. K is the natural equilibrium stock in the absence of harvest: reproduction and individual growth balance natural mortality. At stocks above K, limited food and habitat make natural losses exceed additions, bringing the stock down. Carrying capacity can change with environmental conditions and habitat quality. The next effort diagrams, like the textbook’s Figures 17.3–17.5, will use a simpler baseline without the low-stock threshold. No Allee-effect terminology or cubic-growth equation is required for students.

🌱 Stock, Natural Growth, and MSY

Adapted from TL Figure 17.2, pp. 425–426. The three reveals use the same axes and growth function. First, read the axes: horizontal is biomass stock, vertical is net annual growth. The hump is not the number of fish over time. At S_0, project up to the curve and across to read G(S_0). S_min is the minimum viable stock, and K is the natural equilibrium/carrying-capacity stock.

Second, show movement with no harvest. The sign of G determines the direction of stock change. At K, births and growth balance natural losses. A small disturbance on either side of K leads back toward K, so it is stable. Movement below S_min leads farther down and movement above it leads away toward K, so S_min is unstable. Explain stability in plain language: does a disturbance make the stock return, or move farther away?

Third, add the growth maximum. Maximum sustainable yield, MSY, is the largest annual harvest that can be maintained by matching net growth at the corresponding stock. S_MSY is the stock supporting that growth. The supplied textbook labels its biological growth maximum S-star; we use S_MSY to avoid confusing MSY with an economically optimal stock. At carrying capacity, the stock is large but net growth is zero. Harvest above current growth draws down the stock. A constant quota equal to estimated MSY leaves little protection against negative growth shocks or stock-assessment error.

🧩 The Simplified Fishery Model

• For the next graphs, use a smooth growth curve without the low-stock threshold.
• The fish price and the cost of one unit of fishing effort are constant.
• At the same effort, a larger stock makes fish easier to catch.
• These assumptions let us connect stock, effort, sustainable catch, and net benefit.

TL, p. 427. Make the textbook’s simplification explicit: Figure 17.2 draws a positive viability threshold, whereas Figure 17.3 draws the ordinary growth hump beginning at the origin. We do not carry the threshold into the numerical effort model. Baseline G(S)=0.4S(1-S/100), H(S,E)=0.02ES, and K=100 model tons. Show the equations only if students request them; they can read the curves without calculating derivatives. Constant fish price treats this fishery as small relative to its market, not as a complete demand-and-supply model. Constant cost per effort unit does not imply constant cost per ton of fish; fewer fish per effort unit makes each ton more expensive when stock declines.

🟢 Fixed Catch: A Stable Stock \(S_{H}\)

Graphical application of TL’s sustainable-yield definition, p. 426. First identify the higher intersection, where growth equals the annual catch of eight tons. Then consider a small disturbance below it: growth exceeds catch, so the stock rises. Finally consider a small disturbance above it: catch exceeds growth, so the stock falls. Both movements return toward the intersection, making it stable under this fixed-catch rule. The return is local: a stock far below the lower intersection will not recover under the same catch rule. These are direction-of-adjustment comparisons, not a claim that stock jumps to equilibrium in one year.

⚠️ Fixed Catch: An Unstable Stock \(S_{L}\)

At the lower intersection, growth also equals catch, but a disturbance pushes the stock away. Below it, catch exceeds growth and the stock falls farther. Above it, growth exceeds catch and the stock rises farther, eventually toward the higher stable intersection. This lower intersection is therefore unstable under the fixed-catch rule. It arises even in this model without a biological minimum viable stock: harvest itself creates the threshold for recovery. A sustainable catch is conditional on the initial stock. Actual harvest cannot exceed available biomass, so managers must reduce or stop the catch before a declining path reaches zero. This is a fixed catch, distinct from fixed effort in the next graphs.

⚓ Fishing Effort

• Effort is an input, such as fishing days, vessel hours, or trips.
• More effort raises catch at a given stock.
• With the same effort, a smaller stock produces a smaller catch.

\[ H(S,E)=qES. \]

• \(q\) measures how effectively effort catches fish. In our example, \(q=0.02\).

TL, p. 427, and harvest technology in the appendix. E is an annual effort index; q is held constant and converts effort times biomass into annual catch. In the illustrative calibration, one effort unit harvests 2% of the initial stock over the annual period. No real fleet or species is implied. Distinguish input E from output H. We use constant q; improving catchability and lowering the cost of an effort unit are different technological changes.

🚤 Harvest Lines and Fishing Effort

Adapted from TL Figure 17.3, p. 427. First show E_1=4: equilibrium S_1=80 and H(E_1)=H(S_1,E_1)=6.4. Then add E_2=8: equilibrium S_2=60 and H(E_2)=H(S_2,E_2)=9.6. Here H(E_i) labels catch at the sustainable stock associated with that effort, not catch at any arbitrary stock. A larger E rotates the harvest ray upward because H=qES. For fixed E, the intersection identifies a positive stock at which growth equals harvest. The positive equilibrium is stable in this smooth baseline: below it, growth exceeds harvest; above it, harvest exceeds growth. Do not transfer the unstable lower intersection of the fixed-quota graph to this fixed-effort graph. Ask students which variable is on the horizontal axis before reading the movement to the left.

🔁 Catch Now, Stock Later

• Initially, \(S=80\) and \(E=4\): growth and harvest are both 6.4 tons.
• Double effort to \(E=8\). Catch immediately rises to 12.8 tons, while growth is still 6.4 tons.

\[ S_{t+1}=80+6.4-12.8=73.6. \]

• As stock falls, catch per effort unit falls. The new steady stock is 60 tons, with catch of 9.6 tons per year.

Numerical illustration of TL Figure 17.3, p. 427. Use H=0.02ES; no growth calculation is required because growth at S=80 is supplied. The immediate catch response is larger than the eventual sustainable-catch increase. Once effort changes, stock cannot jump instantly to the new equilibrium. The biological adjustment lowers subsequent catch at the same effort. This annual stock accounting is illustrative, not a calibrated transition for a real fishery.

📉 Stock Adjusts Over Time

Original simulation of the stock accounting rule using the illustrative baseline. At year 0, effort rises from 4 to 8 and remains there. Each step uses S_next=S+G(S)-H(S,8), rather than placing the stock immediately at its sustainable equilibrium. Explain that this is a time path, whereas Figures 17.3–17.5 compare maintained steady states. A falling stock need not imply extinction: here it approaches a lower positive equilibrium. Starting stock, the biological function, and the harvest rule determine the path.

🪞 Changing the Horizontal Axis

Annual effort \(E\)	Steady stock \(S\)	Sustainable catch \(Y(E)\)
4	80 tons	6.4 tons per year
8	60 tons	9.6 tons per year

• In the stock graph, more effort moves the equilibrium left toward a smaller stock.
• In the next graph, the horizontal axis is effort, so more effort moves us right.

TL, p. 427. The table transfers the same equilibrium points from Figure 17.3 to Figure 17.4. Y(E) means annual sustainable catch after the stock settles at the equilibrium associated with E. It is not a new growth curve and is not catch during every year of the transition. The algebraic bridge, optional for the whiteboard, is S(E)=100-5E and Y(E)=2E-0.1E^2 for 0<=E<=20. No derivation is required in this graphical lecture.

🎣 Sustainable Catch and Effort

Adapted from TL Figure 17.4, p. 428. First transfer E_1,H_1 and E_2,H_2. Then show MSY at E_m=10, stock 50, catch 10. At E_OA=14, stock is only 30 and sustainable catch is 8.4. The subscript OA identifies the open-access, break-even outcome. The revenue-and-cost graphs below will explain why unrestricted entry leads to that effort: R=C=8400, with zero economic profit. The falling branch means that higher maintained effort reduces sustainable production because it reduces the stock supporting growth. It does not mean adding a fishing day instantly reduces the day’s catch at an unchanged stock. Each point is a different long-run stock/effort combination, not a year along a single trajectory.

🧠 Immediate Catch and Sustainable Catch

• Immediate catch: what boats catch at the stock available today.
• Sustainable catch: what can be caught each year after growth and harvest balance.
• More effort can raise catch now but leave a stock that supports less catch later.
• Check: What happens to the stock if catch stays above net growth?

TL, pp. 426–428. Answer: it declines. Refer to the E=14 point versus the E=10 point. A current record catch is not sufficient evidence of a healthy stock or a sustainable harvest. Biomass, growth, and effort must also be observed. Avoid introducing unverified current fisheries statistics; this is a model-based inference.

💵 Revenue and Fishing Costs

• Let \(Y(E)\) be sustainable annual catch. Fish sell for $1,000 per ton.
• Fishing costs $600 per effort unit. Subtract cost from revenue to find annual net benefit.

\(R(E)\) \(=\) \(1{,}000\,Y(E)\)

\(C(E)\) \(=\) \(600E\)

\(\text{Annual net benefit}\) \(=\) \(R(E)-C(E)\)

TL, pp. 427–429. These prices and costs are illustrative model dollars, not observed market estimates. Constant price makes total revenue have the same shape as sustainable yield. A constant cost per effort unit creates a straight total-cost line. With price-taking fishers and no additional external harms in this simplified model, the fishery’s revenue less real harvesting cost is the annual net-benefit measure used for the static sustainable comparison. It is not a full consumer-surplus calculation for the entire fish market.

📊 Revenue, Costs, and Net Benefit

Adapted from TL Figure 17.5, p. 429, and explanation on p. 428. Revenue equals price times sustainable catch; cost equals cost per effort unit times effort. Reveal the curves, then the largest gap, then the MSY and break-even markers. Efficient effort maximizes R-C, not R alone. The tangent at E_e is parallel to the cost line: for a very small change in effort, the extra revenue matches the extra cost. Explain local slopes in words; no derivatives. In the illustrative model, R=2000E-100E^2 and C=600E, so E_e=7, R=9100, C=4200, and net benefit=4900. E_m=10 maximizes catch and revenue. At E_OA=14, R=C=8400 and net benefit is zero. Figure 17.6 adds the entry logic behind this positive zero-profit outcome; that logic was already covered in Lecture 4.

🟢 The Static Efficient Target

• Choose the sustainable effort with the largest annual revenue-minus-cost gap.
• In our example: \(E_e=7\), maintained stock is 65 tons, and annual catch is 9.1 tons.
• Annual net benefit is $4,900.
• Static means comparing steady annual outcomes before choosing a discounted harvest path over time.

TL, pp. 426–430. E_e is the static efficient sustainable effort, not automatically the dynamically optimal effort for a given initial stock and discount rate. Maintaining that stock requires growth to equal catch. The book calls the static criterion a zero-discount benchmark. At a nonsteady initial stock, the transition itself has benefits and costs; maximizing a steady-state annual gap alone does not solve that transition.

🔍 Biological and Economic Targets

Target	Effort	Stock	Annual catch	Annual net benefit
Static efficient	7	65	9.1	$4,900
Maximum sustainable yield	10	50	10.0	$4,000
Open access	14	30	8.4	$0

• The largest sustainable catch need not give the largest net benefit.
• Unrestricted entry can use up the fishery’s economic surplus.

TL Figures 17.5–17.6, pp. 428–433. Stock/catch units are tons and tons per year. The table summarizes the same illustrative model. Do not reteach MR/AR from Figure 17.6. Entry continues when entrants can earn an economic profit, and the positive open-access steady state has R=C. Zero economic profit does not mean zero sales, unpaid fishers, or physical extinction; opportunity costs of labor and capital are included. The ordering of catch between the efficient and open-access outcomes is specific to this calibration; the robust lesson is excessive effort and dissipated rent. With positive effort cost, the static efficient effort lies below MSY effort in this benchmark.

🛠️ Cheaper Fishing Effort

Suppose the cost of an effort unit falls, while fish price and catchability stay unchanged.

• Which curve changes in the revenue and cost graph?
• Would the static efficient effort increase or decrease?
• What would happen to the maintained fish stock?

TL, pp. 428–429. Allow a short pair discussion or draw on the whiteboard. The cost line becomes flatter. With positive costs and the stated benchmark, static efficient effort increases toward MSY effort; maintained stock falls. This is a change in the cost per effort unit, holding q constant, not an increase in catchability that changes the effort-to-catch mapping. For example, reducing c from600 to400 raises E_e from7 to8, lowers stock from65 to60, and raises annual sustainable catch from9.1 to9.6. The textbook’s broader technology example makes the same comparative-static point.

⏳ The Value of Leaving Fish

• Fish left today can grow and reproduce, adding to future harvest opportunities.
• A larger stock can make future fish less costly to catch.
• Harvesting today earns income now. Discounting helps compare that income with future benefits.
• Our graphs compare steady annual outcomes. Choosing the best path over time is an additional problem.

TL, pp. 429–431. Link to Lecture 5 without presenting the classic non-renewable Hotelling rent-growth rule as the rule for fisheries. Biological growth and stock-dependent catch costs modify the trade-off. Higher discounting can encourage more current harvest in the textbook’s simple model, but the optimal steady stock and transition depend on biological growth, costs, initial stock, and the objective. The textbook discusses possible extinction under additional assumptions, and pp.430–431 explain that efficiency and sustainability need not always coincide. Do not claim that positive discounting automatically implies extinction, or that all economically optimal fisheries lie below MSY stock. Full dynamic optimization is optional material outside the 2.5-class core.

🐟 A Catch Limit That Rebuilds Stock

Application of TL’s stock accounting, pp.424–426, and adaptive quota discussion p.442. At S=20, baseline growth is6.4. Catch8 leads to next stock18.4; catch4 leads to22.4. A positive net stock addition requires H<G(S), not simply a quota below the global growth maximum. A fixed catch can be sustainable at one stock but unsafe at another. Rebuilding requires stock assessments, catch rules suited to the depleted state, and time for growth. The graph does not assert a universal optimal catch of4 or a precise rebuilding schedule.

📋 A Catch Limit and the Race to Fish

• A total allowable catch (TAC) limits the whole fishery’s catch during a specified period.
• In a different, larger fishery, suppose the season closes when the fleet catches 100 tons.
• Each fisher still wants to catch fish before the others do.
• The stock may receive protection, while a crowded season and extra capacity make harvesting costly.

TL, pp.435–436,438–439, and Self-Test2 p.455. This is a hypothetical aggregate-cap example, not a current fisheries regulation. A well-set and enforced cap can protect biomass while leaving the scramble for its allocation unresolved. Link to the shared-bay experiment and Lecture4 without repeating property-rights terminology at length. Do not infer that all seasonal or gear rules waste resources: some protect spawning, juveniles, habitat, or bycatch species, harms that the single-stock catch cap does not capture.

🧾 Catch Shares

• A catch share gives a fisher or group a portion of the permitted total catch.
• A 10% share allows 10 tons when the TAC is 100 tons, but 6 tons when it is 60 tons.
• Securing a share can reduce the need to race. Transferable shares can move catch toward lower-cost fishers.
• The total cap still matters, and the initial allocation determines who receives the valuable shares.

TL, pp.438–442. Catch shares divide an aggregate cap; they do not make an excessive cap sustainable. An individual transferable quota (ITQ) is a catch entitlement that can be transferred among fishers. Trading can lower harvesting costs while keeping the permitted total fixed. Initial allocation and concentration affect access, equity, and who receives rents. Students need the distinction between a percentage share and fixed tonnage, not a quota-price calculation.

Optional historical example, TL p.442: stock estimates for New Zealand orange roughy proved too high, making issued catch entitlements unsafe. Replacing fixed-tonnage entitlements with percentage shares allowed managers to adjust the annual TAC as stock information changed. This is the textbook’s historical account, not an assessment of current orange roughy stocks. Neither shares nor private ownership automatically resolves biological uncertainty or every ecosystem externality.

🧾 Quota and Territorial Programs

• IFQ (Individual Fishing Quota): an individual’s allocation of the allowed catch.
• ITQ (Individual Transferable Quota): an IFQ that can be sold or leased.
• IVQ (Individual Vessel Quota): catch allocated to a particular boat. Transfer rules vary.
• TURF (Territorial Use Rights in Fisheries): exclusive fishing access to a defined area.
• Examples: ITQs in New Zealand, Iceland, and Canada; in the U.S., Alaska halibut and sablefish IFQs and Gulf of Mexico red snapper IFQs.

TL, pp.438–441 and 444–445. An IFQ is the broader individual allocation category; the label alone does not say whether transfers are allowed. An ITQ is a transferable IFQ. An IVQ assigns the entitlement to a vessel and may or may not permit transfers. A TURF assigns access to a geographic area rather than a share of the catch across the entire fishery. These are harvesting/access entitlements, not ownership of all fish or the ocean itself. Territory-based approaches work more easily for resources that do not migrate far.

The examples are selected from Table 17.1 (p.439) and Table 17.2 (p.441), not an exhaustive or current count of programs. Table 17.1 lists New Zealand, Iceland, and Canada among countries using ITQs. Table 17.2 lists Alaska halibut and sablefish IFQs (1995) and Gulf of Mexico red snapper IFQs (2007). Do not infer that all IFQs have unrestricted transferability. Japan’s local fishing cooperatives and Chile’s nearshore management areas are the textbook’s TURF examples on pp.444–445.

🐚 Atlantic Sea Scallops: Canada and the U.S.

• A historical comparison studied Canadian transferable quotas and U.S. size, effort, and area restrictions.
• Canada: higher stock abundance, fewer undersized scallops harvested, and a sevenfold increase in catch per sea-day.
• United States: stock abundance declined, and revenue per sea-day fell.
• Crew, captains, and owners shared revenues, so those remaining in the Canadian fishery shared the higher returns.
• Connection to our model: a larger stock can raise catch per unit of effort and lower harvesting costs.

TL Example 17.2, pp.443–444, summarizes Repetto, R. (2001), “A natural experiment in fisheries management,” Marine Policy, 25, 252–264 (as cited in the textbook). This is a historical study, not a statement about today’s U.S. scallop management; the preceding program examples include a later U.S. sea scallop IFQ in the textbook’s table.

Scallops are relatively immobile and the two fisheries used similar technologies, making the comparison informative about institutions. The Canadian fishery maintained greater abundance and deterred harvest of undersized scallops. Its catch per sea-day increased sevenfold over the study period, contributing to higher revenue per sea-day. This is an increase within the Canadian fishery, not a claim that its catch rate was seven times the U.S. rate. The U.S. fishery experienced lower stock abundance and revenue per sea-day, with undersized scallop harvest contributing to the problem.

Canadian quota holders decreased from nine to seven over 14 years, but 65% of quota remained with original holders. The study did not find the expected disadvantage for smaller holders in this particular case. Under the “lay” system, revenues after specified operating costs were split among crew, captain, and owner, allowing remaining participants to share gains. This case supports the incentive mechanism, but does not establish that quotas automatically improve every fishery or compensate everyone who leaves.

🔎 Monitoring All Fish Removed

• Bycatch: animals caught while fishers target another species.
• Dead discards: captured animals thrown back that do not survive.
• Selling 10 tons and discarding 5 tons dead of the same species removes 15 tons from its stock.
• Effective rules need credible monitoring of harvest and other fishing-related deaths.

TL, p.442 and pp.449–451. Biological removal includes fishing mortality beyond marketed catch; sales records alone can miss it. The numerical example uses a common biomass unit and is purely illustrative. Monitoring may use observers, records, dock checks, or electronic tools, depending on the fishery. Use selective gear, spatial rules, and habitat protection as complements when an aggregate single-species cap misses other harms. Connect to the experiment’s monitoring setup, but avoid claiming every release causes death.

🤝 Communities and Protected Areas

• Fishers and public authorities can share management and monitoring responsibilities.
• A marine protected area (MPA) has lasting legal protection. Some MPAs still allow fishing under restrictions.
• A marine reserve is a no-take MPA where harvesting is prohibited.
• Protection can safeguard spawning grounds and habitat. Fish may later spill into nearby fishing grounds.
• Recovery can impose costs today. Policy design must consider who bears them.

TL Example17.1 p.434, territorial use rights pp.444–446, and marine protected areas pp.449–450. Co-management means sharing responsibilities, not automatically leaving a resource open to everyone. Community success depends on cooperation, legitimate enforcement, and complementary conservation measures. A local territory cannot fully control a highly mobile stock without wider coordination.

MPA is the broad category, with protections ranging from restrictions on specific uses to full protection. A marine reserve is the fully protected/no-take version in the textbook: harvest is prohibited, and protections address other threats as well. Safeguarding spawning habitat, reducing gear damage, and protecting species interactions complement catch limits. Larger populations may support catches outside the protected boundary through spillover, but this is not guaranteed in every setting. Protection can displace fishing effort and needs monitoring. Do not guarantee that future aggregate gains compensate every current fisher. Taxes, harmful input subsidies, buybacks, and aquaculture are optional further topics if time permits.

🌊 EEZs and Russia’s “Peanut Hole”

• An exclusive economic zone (EEZ) extends up to 200 nautical miles from a coastal baseline. The coastal country manages its fishery resources.
• Short video: The Peanut Hole is a high-seas pocket in the Sea of Okhotsk, surrounded by Russia’s EEZ.
• International fleets targeted pollock there. Fish crossing the boundary complicated conservation.
• In 2014, a UN commission supported Russia’s claim to the seabed and subsoil, without extending its EEZ over the waters above.
• Lesson: fish that cross jurisdictional boundaries still need coordinated management.

TL, p.449, introduces EEZs as the international jurisdictional dimension of fishery management. Use “exclusive economic zone,” not “economic exclusion zone.” The legal maximum is 200 nautical miles from coastal baselines, not 200 ordinary miles. Coastal states have sovereign resource rights and relevant jurisdiction in the EEZ, rather than full territorial sovereignty over every activity there.

The supplied YouTube Short is an optional geographic illustration, not the authority for the legal claim. The Peanut Hole water column lies beyond Russia’s 200-nautical-mile EEZ in the central Sea of Okhotsk. NOAA’s historical account describes international pollock fishing beginning there in 1991 and Russian concerns about another stock collapse. High seas does not mean an absence of all law: flag-state obligations and international cooperation still apply.

The Commission on the Limits of the Continental Shelf adopted its Okhotsk recommendations on 11 March 2014. The process concerns the continental shelf beyond 200 nautical miles. Russia deposited the relevant chart in 2016. UNCLOS Article 78 explicitly preserves the legal status of the waters above the shelf, so do not say the Peanut Hole was integrated into Russia’s EEZ in 2014. Shelf rights cover seabed/subsoil resources and specified sedentary species, not a general entitlement over swimming pollock in the high-seas water column.

Primary sources: UNCLOS Articles 56–57, Articles 77–78, UN Okhotsk recommendations record, UN maritime-zone notification, 2 June 2016, and NOAA historical distant-water-fleet report.

🧭 Management Decision and Exit Check

A fish stock is declining. Boats compete to catch fish quickly, and some catch goes unreported.

Management decision

• What must change about harvest relative to growth for the stock to recover?
• Would a total catch limit by itself end the race to fish?
• What must managers and fishers monitor and enforce?

Exit check

• At a stock of 20 tons, growth is 6.4 tons and harvest is 8 tons. Will next year’s stock rise or fall?
• Why can more effort eventually mean less sustainable catch?
• Why might the best annual economic outcome use less effort than MSY?

Allow three to five minutes of pair discussion. Management answers: removals must be lower than net growth during rebuilding; an aggregate cap alone need not end the race; secure individual/community shares can address allocation incentives, but a biologically sound cap and reliable accounting of all removals remain essential. Monitor catch, discards, other fishing mortality, stock condition, and compliance. There is no uniquely best institution for all fisheries; conditions and implementation matter.

Exit answers: stock falls by1.6 to18.4 tons. Extra effort initially raises catch at a given stock but reduces the maintained stock; beyond MSY effort, the lower stock supports less growth and hence less sustainable catch. MSY maximizes catch, whereas static economic efficiency maximizes revenue minus real effort cost. More effort near the yield peak adds little revenue but still adds cost. Ask students to explain each answer using the corresponding graph rather than memorizing a target number.