Lowland · Peat · Hokkaido, JP

Sarufutsu River

Sarufutsu River venue image
Tomorrow · About as good as it gets
Greenwell's Spider
Forecast · Tomorrow
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
72% projected
Today's fly
Greenwell's Spider
Greenwell's Spider
Conditions on the water · Tomorrow
Estimate
Level
Dry recently
No gauge reading
Water temp14.8°C
ClarityClear
Weather17°C
WindN 13 km/h
Pressure1023 hPa
Rain · recent1.7 mm
Rain · ahead0.7 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for Itou (Sakhalin Taimen)
Warm — slow
15°C est.ideal 6–14°C
0°14°28°
How to fish it · for Itou (Sakhalin Taimen)
When
Late spring and autumn, subject to conservation rules
Where
The Sarufutsu moves slowly through the peat wetlands of Japan's far north, dark and unhurried, and it is first a conservation icon and only second a fishery:…
Why this works
Excellent — water temperature is working for you, but time of day is the limiting factor today.
Hatch timeline · tomorrowPeak at 16h

12h(now) — Daddy Long Legs

Stage: On emergersApproach: Emerger or dryActivity: 84%
Also:Cinnamon Sedge68%Pale Watery49%Heather Fly40%
Weather boostDegree-days at peak11 food groups active

Peak activity at 16h — Blue Winged Olive (Blue Winged Olive, Weather boost)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 4 as a supporter.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Ephemera orientalis (Lowland Mayfly)Hatch
2
3
3
3
2
Cicada (Semi)Hatch
2
2
Stenopsyche CaddisHatch
2
3
3
2
Ugui / Japanese DaceHatch
2
3
3
3
3
3
3
3
3
3
3
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Fly box · Itou (Sakhalin Taimen)
LB
Large baitfish streamerTop
8–10 · Streamer
Strip it for fish chasing fry or in coloured water.
MS
Mouse / surface-wake fly
12–16 · Fly
A dependable searching pattern for these waters.
LS
Leech streamer
8–10 · Streamer
Strip it for fish chasing fry or in coloured water.
Permits & access
Permit required — see local rules.
  • Conservation-first water
  • Verify current local rules, land access and closures; barbless hooks, keep fish wet, guide strongly recommended
  • No catch-rate promises.
What's coming
Plan ahead
5-day outlook
Gallery · 1
  1. Terrain map of the venue
    Terrain map
Conservation note

Sakhalin taimen / Itou (Parahucho perryi) — a conservation-sensitive northern Hokkaido population, taxonomically distinct from European huchen (Hucho hucho) and Siberian taimen (Hucho taimen); do NOT route through the European hucho scoring path. Catch-and-release and habitat protection dominate. Amemasu also present. Prose only.

The full read · show the working · for Itou (Sakhalin Taimen) · confidence 70%
How the 80 is built — score × weight = contribution
Temperature96 × 30%28.8
Flow90 × 25%22.5
Clarity85 × 20%17.0
Feeding Time20 × 15%3.0
Pressure85 × 10%8.5
Conditions total= 80
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Taimen late spring → autumn

    Sakhalin taimen (Itou) — conservation-first, catch-and-release only. Species surfaced in prose; not scored. Legal status: guidance_not_permission.

Related guides
Euro Nymphingsubsurface methods
Booking & contacts