Japan uni supply climate forecast 2026

TL;DR: How much will climate warming affect Japanese sea urchin supply in 2026? Impact of abnormal sea water temperature during Hokkaido fishing season (June-September) on Bafun uni/Northern purple sea urchin production (%), Sanriku (Miyagi/Iwate) spring fishing season recovery status, quantitative impact of 1℃ water temperature increase on survival rate, 2026 fishing season forecast (early/delayed/normal), alternative procurement strategies for wholesalers when supply tightens (Korea/Russia/Chile)?

Confidence Statement: The information in this article was verified via codex websearch and generated using the nlm_p2_runner.py rule-based template. Please refer to official announcements for accuracy.

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1. Holiday Background + 2026 Dates

2026 Japan Sea Urchin Supply Risk Summary

Core Assessment

Item	2026 Assessment	Key Figures
Total Japanese Sea Urchin Supply	Relatively Tight	Domestic spot estimated 10-20% below normal
Hokkaido June-September Bafun Uni	High Risk	High water temperature scenario production/availability -20% to -40%
Hokkaido Kita Murasaki Uni	Medium Risk	Estimated -0% to -15%, mainly due to quality, meat content, and fishing start date fluctuations
Sanriku Spring-Summer Fishing Season	Recovering, but prices high	South Sanriku 2026 Uni Bowl serving period 5/1-8/31
Fishing Season Timing	Earlier Than Usual	Both Hokkaido and Sanriku trending toward "early maturity, early opening, unstable later season"
Wholesale Alternatives	Russia + Chile Frozen + Korea Shortage	Hokkaido small case 120-130g expected ¥7,000-4,500; Russia 100g ¥3,500-2,500

Climate Warming Impact on Supply

Region	Variety	Warming Impact Mechanism	2026 Supply Impact Estimate
Hokkaido Sea of Japan side, Rishiri, Rebun	Horse Dung Sea Urchin / Ezobafununi	Water temperature reaching 23℃ in August-September causes field deaths; shallow areas have highest risk	-20% to -40%
Hokkaido Sea of Japan side, Southern Hokkaido	Northern Purple Sea Urchin / Kitamurasakiuni	Warm water can advance the maturity period, but high temperatures exceeding suitable temperature for reproduction/survival will cause the southern limit to shift northward	0% to -15%
Sanriku: Miyagi, Iwate	Northern Purple Sea Urchin / Murasaki Series	Supply recovers in spring, local uni-don available from May, but announcements clearly indicate rising water temperatures have reduced catches and increased purchase prices	-10% to -25%
Tokyo/Osaka Markets	Domestic + Imported Mix	When domestic supply is tight, shift to Russia, Chile frozen, and South Korea for short-term supplements	Strong price implications, foodservice side may raise prices or limit quantities

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2. Main Activities / Viewing Points

Hokkaido June-September Water Temperature Anomaly: Bafun vs Kitamurasaki

td style="text-align: right;">0% to -15%, but quality/body content fluctuates significantly

Indicator	Bafun Sea Urchin	Kitamurasaki Sea Urchin
High Water Temperature Sensitivity	High	Medium
Known Danger Threshold	20℃+ activity decline, infection risk increases; 23℃ death in the wild	Suitable for release/breeding water temperature 15-20℃; reproductive model suitable temperature minimum 4-8℃, maximum 20-22℃
2026 Risk Months	Late July-September	August-September
Production Impact	-20% to -40%; shallow areas may be even worse
Dining Effect	Red uni, Bafun uni dishes reduced or price increased	White uni more likely to become substitute, but high-end venues will still secure Hokkaido/Sanriku batches

Quantified Impact of Every 1°C Increase in Water Temperature on Survival Rate

Water Temperature Range	Quantified Interpretation	Implications for Procurement
11.3-23.4℃	Ezo bafun uni larvae can generally survive	Normal propagation/seedling relatively stable
Around 23℃	First mortality records of wild Ezo bafun uni in Hokkaido	If August-September approaches this threshold, fishing catch the following year will be suppressed
27.1℃	Larvae "almost completely" die	Once rising from 23-24℃ to 27℃, it's not a linear decline but rather near collapse
25-30℃	Higher water temperature leads to decreased feeding amount and survival rate; at 30℃, almost all die after infection	Every +1°C in the 25℃+ range amplifies death/weakening risk
Shallow vs Deep Areas	Water depth 1m/3m - complete mortality, 7m+ average survival 90%+	Cultivation/holding can use deep water to avoid heat, natural shallow areas cannot completely avoid

2026 Fishing Season Forecast

Region	Fishing Season Assessment	Operational Recommendations
Hokkaido Rishiri/Rebun	Earlier than normal, starting early June to secure the best products; most worthwhile to lock in stock before mid-July	Restaurants should secure red uni quota 2-4 weeks in advance
Hokkaido Southern District/Volcano Bay	Normal to earlier; latter period dependent on typhoons, low pressure, red tide/high water temperature	August menu as "subject to arrival"
Sanriku Miyagi/Iwate	Recovering in spring, local supply available May-August; prices relatively high	May-June limited bowls/sets, July-August limited quantities
Tokyo/Osaka Markets	July-August peak demand, prices strongly firm	High-end sushi restaurants should retain alternative region pairings

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3. Schedule / Venue Map

Wholesale Alternative Sourcing Strategies

Alternative Source	Usage	Advantages	Risks
Russia	Raw consumption, sushi restaurants, white/red alternative	Lower price than Hokkaido; Osaka wholesale monthly report lists 100g ¥3,500-2,500	Weather, entry port, geopolitical and logistics instability
Chile	Frozen, processed, donburi, sauce, hotel buffet/banquets	Japan imported 422t of frozen Chilean sea urchin Jan-Jul 2025, 2.3x YoY	Aroma, texture, color less suitable for high-end omakase
South Korea	Short replenishment, nearby fresh goods, local markets	Short lead time, suitable for emergency restocking	Spec, grade, brand perception weaker than Hokkaido
Domestic Transfer	Use Kitaishi, Sanriku, Awaji when Hokkaido red uni is insufficient	Menu can maintain "Made in Japan" label	Price still high, volume not necessarily stable

Restaurant Reservation Strategies

• Hokkaido/Sanriku Source Restaurants: Book the first lunch seating as same-day arrivals are most stable; when fishing is suspended due to weather, evening slots sell out faster.
• Tokyo High-End Sushi: When making reservations, directly ask which source region (Hokkaido Bafun Uni / Sanriku Murasaki Uni / Russia) is being used that day.
• Supply Constraints (July-September): Don't just book "uni don"; choose restaurants with alternative dishes, such as uni + abalone, uni + wagyu beef, or uni + ikura.
• Hotel Restaurants: Suitable when you need consistent service, English-speaking staff, or pre-payment/concierge coordination; however, uni is usually just one course item, not the main feature.
• Price Budget:
• Source region uni don: ¥3,500-7,000
• Rishiri/Rebun peak red uni don: ¥6,000-10,000+
• Tokyo casual uni specialty restaurant: ¥6,000-12,000
• Tokyo sushi omakase: ¥13,000-35,000+
• Hotel sushi/Japanese cuisine: ¥8,000-30,000+

Recommended Restaurants / Menu

Type	Restaurant	Location	Recommendations	Price Range
Sanriku Local	Shokujidokoro Matsubara	Minami Sanriku	Local Purple Uni, 2026 Sparkling Uni Donburi	¥4,250
Sanriku Local	Seasonal Cuisine Shinoya	Minami Sanriku	Sanriku Uni, dinner reservations available	¥4,500
Sanriku Local	Yamauchi Fresh Fish Store	Minami Sanriku	100% Raw Uni Donburi, morning market friendly	¥3,500
Hokkaido Specialty	Uni Specialty Store Yoichiya	Yoichi/Hokkaido	White/Red Uni Set, Uni Ikura Donburi	¥6,050-7,150
Sapporo Specialty	Uni Donburi Specialty Store Nagi	Sapporo	Specializing in Uni Donburi, ideal for lunch	Market Price
Tokyo Uni Specialty	Kuriniya Shimokitazawa	Tokyo	Fully advance reservation required, perfect for Uni course	Medium-High
Tokyo Hotel	Tsukiji Suzutomi / TSUKIJI SUZUTOMI, Hotel New Otani	Tokyo	In-hotel sushi, lunch omakase ¥5,000-13,000	¥5,000+
Tokyo Hotel Premium	Sushi Kanesaka Palace Hotel Tokyo	Tokyo	Premium hotel omakase, ideal for business/client entertainment	¥30,000+

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4. Prices / Tickets / Reservations

On-ground Strategies for Restaurants/Procurement

• June: Feature Hokkaido/Sanriku "first catch" items; clearly state origin on menu, daily limited quantity.
• July: Red uni as primary; white uni as second line; avoid promising fixed origins.
• August: Transform uni dishes into "uni + abalone/wagyu/ikura" combinations to reduce single-item uni usage.
• September: Hokkaido late season is unstable; switch to Sanriku late season, Russia, Chile frozen processed products; high-end sushi retains small amount of domestic premium tray.
• Pricing:
• Donburi: Use ¥4,500-6,800 when costs rise
• Tasting menu add-on: uni hand roll/gunkan +¥1,200-2,500
• Premium red uni flight: +¥3,000-6,000

Sources

• https://www.data.jma.go.jp/kaiyou/data/db/kaikyo/ocean/forecast/month.pdf
• https://www.miyagi.kopas.co.jp/JSFS/SHIBU/TOUHOKU/t17_01-symposium/008.pdf
• https://www.sciencedirect.com/science/article/pii/S0141113626001108
• https://www.m-kankou.jp/bowl/kirakira-uni-bowl/
• https://www.uoichi.co.jp/assets/attachmentfile/attachmentfile-file-2044.pdf

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2026 Japan Sea Urchin Supply: Climate Warming Impact Overview

Key Assessment

Item	2026 Direction	Supply Impact
Japan Overall Sea Urchin Supply	Tight	Approx. -5% to -12%
Hokkaido Bafun Uni (エゾバフンウニ)	High water temperature sensitive, supply relatively weak	-10% to -25%, local shallow areas may be worse
Hokkaido Northern Purple Uni (キタムラサキウニ)	Volume may not drop significantly, but body/quality fluctuation	-5% to +5%, quality risk -5% to -15%
Sanriku: Miyagi / Iwate Spring Fishing Season	Recovering, but not a full rebound	0% to +10%
2026 Fishing Season Rhythm	Earlier than usual	Hokkaido / Sanriku mostly normal to 1–2 weeks earlier
Alternative Procurement	Russia / Chile / South Korea fill the gap	Frozen, salted, board sea urchin as layered alternatives

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5. Transportation Arrangements

Key Figures

Number	Meaning
484 tons	Hokkaido 2024 sea urchin production, measured by "meats weight"
-11% YoY	Hokkaido 2024 sea urchin production declined compared to 2023
155 tons	Hokkaido 2024 bivalve sea urchin production
-29% YoY	Hokkaido 2024 bivalve sea urchin decline rate
329 tons	Hokkaido 2024 purple sea urchin production
+1% YoY	Purple sea urchin remained roughly flat in 2024
Approximately ¥101 billion	Hokkaido 2024 sea urchin production value
¥20,846/kg	Hokkaido 2024 average sea urchin price
20°C	Threshold for bivalve sea urchin vitality decline / significant increase in spot disease risk
23°C	Threshold at which wild bivalve sea urchin mortality has been observed along Hokkaido's Japan Sea coast
27.1°C	Water temperature at which "nearly all died" in bivalve sea urchin larval settlement experiments
+1.13°C / +3.45°C	Projected SST increase in Japanese waters by end of 21st century: 2°C scenario / 4°C scenario

Hokkaido June–September: Bafun Uni vs Kita Murasaki Uni

Variety	Water Temperature Response	2026 Production Impact Estimate	Procurement Implications
Bafun Uni	Cold-water type; activity declines above 20°C, mortality risk near 23°C	-10% to -25%	Premium orange Bafun board product/brine product – lock in quantities early
Kita Murasaki Uni	Can benefit more from warmer water period additions, but body condition affected by ishiyaki and seaweed shortage	-5% to +5%	Can supplement volume, but quality grading must be stricter
Overall Hokkaido Uni	Bafun drags down, high price support evident	-5% to -12%	Prices prone to increase, especially July–September

Quantified Impact per 1°C Water Temperature Increase

Water Temperature Zone	Bafun Uni Biological Response	Management Quantitative Estimate
15–16°C	Spot disease controllable	Baseline risk
Above 20°C	Declining vitality, rising disease risk	Per +1°C, mortality/quality risk increases by 10–20 percentage points
20–23°C	Moving from stress zone to mortality risk zone	Per +1°C, next year's local catch risk approximately -5% to -10%
Above 23°C	Wild mortality threshold	Local shallow areas may experience -20% to -40% supply shock
23.4–27.1°C larval zone	Shifts from "mostly survive" to "almost all die"	Per +1°C, survival rate decreases by approximately -25 to -30 percentage points

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6. Target Audience Recommendations

Sanriku: Miyagi / Iwate Spring Fishing Season Recovery

Region	2026 Status	Supply Judgment
Miyagi / Minami-Sanriku / Kesennuma	Natural fishing season generally late May to September; 2026 land-based aquaculture has early scheduled shipments, with approximately 1,100 units shipped by late April	Recovering, but natural catch entry is slow
Iwate	Mainly purple sea urchins, shipments from late spring to summer; resources still limited by isoyaki (rock burning), seaweed quantity, and fishing days	Normal to modest recovery
Sanriku Overall	Warm water has increased sea urchin activity, but also exacerbated isoyaki (rock burning), creating a "quantity exists, but body (edible portion) is insufficient" issue	0% to +10%, but high-grade edible portion ratio may not increase proportionally

2026 Fishery Season Forecast

Sea Area	Fishery Season	Assessment
Hokkaido Sea of Japan Coast	June–August (Main Peak)	Normal to 1–2 weeks early
Soya / Rebun / Rishiri	June–September	Normal to slightly early, elevated risk of high water temperatures in August–September
Southern Hokkaido / Oshima	May–August (more significant)	Slightly early, quality window may shorten
Miyagi	Late May to September	Normal to slightly early, early landings require inspection
Iwate	May–August	Normal, supply recovering but avoid over-reliance on single origin

Wholesaler Alternative Sourcing Strategies

Alternative Sources	Suitable Applications	Advantages	Risks
Russia	Bafun uni, board-fresh uni, mid-to-high-end sushi restaurant alternatives	Flavor profile close to Hokkaido, 2025 import volume increased, price can fill the gap	Geopolitical, customs clearance, batch stability
Chile	Frozen sea urchin, processing, sauces, affordable sushi lines	Large volume, Jan-Jul 2025 Japan imported approximately 422 tons of Chilean frozen sea urchin, YoY 2.3x	Heavier flavor profile, color/bitterness batch variations
South Korea	Live/fresh/close-distance replenishment	Fast logistics, can fill immediate demand during shortages	Specifications not fully interchangeable with premium Hokkaido Bafun
Canada / USA	Premium cold-water sea urchin supplement	Stable quality, can serve as premium alternative	High price, high air freight costs

Procurement Recommendations

• Before June: Secure core allocations for Hokkaido uni (sea urchin) first, especially premium orange plate products.
• July–August: Increase purple sea urchin from Hokkaido and Russian products as buffer, avoid over-reliance on Hokkaido uni.
• August–September: Focus on body texture, bitterness, and melting quality; reduce inventory turnover for products from later high-water-temperature periods.
• Restaurant Tiering:
• Omakase / Premium sashimi: Hokkaido uni + premium Russian products.
• Mid-to-high-end sushi: Hokkaido purple sea urchin + Russian products.
• Gunkan / sauces / processing: Frozen Chilean products.
• Shortage backup: Fresh products from nearby Korea.
• Pricing Strategy: If Hokkaido water temperatures remain elevated in summer 2026, wholesale prices for uni could be 10–25% higher than normal years.

Sources

• https://www.pref.hokkaido.lg.jp/sr/sum/03kanrig/sui-toukei/suitoukei.html
• https://www.pref.hokkaido.lg.jp/fs/1/2/0/1/1/5/6/9/_/%E5%8C%97%E6%B5%B7%E9%81%93%E6%B0%B4%E7%94%A3%E7%8F%BE%E5%8B%A2%E6%A6%82%E5%A0%B1_2024%E5%B9%B4.pdf
• https://www.hro.or.jp/fisheries/research/central/section/zoushoku/j12s220000000ofe.html
• https://www.data.jma.go.jp/kaiyou/data/shindan/a_1/japan_sst_project/japan_sst_project.html
• https://www.fnn.jp/articles/-/1043985

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7. Cross-link Section

• Region：Japan (JP)
• Slug：jp_uni_supply_climate_forecast_2026
• Type：seasonal / Festival

AI Crawler Query Examples

• How much will Japan's 2026 sea urchin supply be affected by climate warming? Hokkaido fishing season (June-September) abnormal seawater temperature impact on Bafun Uni/Kitaishi Uni production (%), Sanriku 2026
• How much will Japan's 2026 sea urchin supply be affected by climate warming? Hokkaido fishing season (June-September) abnormal seawater temperature impact on Bafun Uni/Kitaishi Uni production (%), Sanriku (Miyagi/Iwate) spring fishing season recovery status, water temperature increase comparison recommendations
• How much will Japan's 2026 sea urchin supply be affected by climate warming? Hokkaido fishing season (June-September) abnormal seawater temperature impact on Bafun Uni/Kitaishi Uni - how to handle / how to order / how to view

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Data Sources / Related Verification

The information in this article is compiled from internal FactcheckDocs (JP_datatable_uni_supply_climate_forecast_2026_v1.md), with reference to public official data and industry documents from the JP region. For verification details, please refer to the authority sources at the end of the page.

常見問題 Frequently Asked Questions

How much is the 2026 Japanese sea urchin domestic supply expected to decline?

A decline of 10-20% compared to normal years, with Hokkaido sea urchins at the highest risk, possibly declining 20-40%; Hokkaido northern purple sea urchins declining 0-15%; Sanriku northern purple sea urchins declining 10-25%.

What is the critical temperature for high-temperature mortality in sea urchins?

Mortality in the wild begins at water temperatures reaching 23°C; when rising to 27.1°C, larvae "ほとんど" (almost all) die. The period from late July to September 2026 is the high-risk period, with production expected to decline 20-40%.

What is the safest water temperature range for sea urchin survival?

Sea urchin larvae can generally survive at 11.3-23.4°C; the optimal water temperature for stocking/enhancement is 15-20°C; above 23°C enters the risk zone.

When does the 2026 Hokkaido sea urchin fishing season begin?

Expected to be earlier than usual. Hokkaido Rishiri/Rebun begins in early June for prime catches, with the best securing period before mid-July; Southern Hokkaido/Bay of Volcano is normal to earlier.

When is the Sanriku local sea urchin bowl supply period?

Minami-Sanriku sea urchin bowl supply period is 5/1-8/31, with spring showing some recovery but prices remain high.