Dogtooth Tuna fishing in Hachijo-jima

May, June, July and August are the prime months. No permit is required for recreational sea fishing.

When

J
F
M
A
M
J
J
A
S
O
N
D

Season grading is our editorial judgement, not a sourced figure. It says when the fish is catchable, not when the water is legally open — for that, read the closed seasons below.

Do you need a permit?

No permit is required for recreational sea fishing.

Water
Saltwater
Prefecture
Tokyo
Region
Kanto
Getting there
55 min flight from Haneda, or 10 h overnight ferry

How far our answer goes here

  • ✓National lawApplies everywhere. Foreign-national gear limits, protected species, bluefin controls.
  • ✓PrefectureMinimum sizes, closed seasons and legal gear. This is a floor — local rules add to it, never subtract.
  • ✓Sea-area / inland committeeTokyo Sea-area Fisheries Adjustment Commission. Trolling is by approval only; chumming was permitted by a 2020s amendment.
  • —Cooperative permitSea fishing needs no cooperative permit. A Common Fishery Right still covers the shore — see the rule above.

Rules stack. Everything above the line we hold; everything below it you still need to confirm on the ground. That gap is exactly what a local guide is for.

Legal gear in Tokyo

●Hand line & rod fishing○Trolling●Landing net●Scoop net●△Cast net●Fishing spear (excluding harpoons)●Rake / clam tool●Hand gathering

Sea areas only, as of 2026-03-31. Anything not listed — diving apparatus, spearguns — may not be used at all. Full table & footnotes

Size limits and closed seasons

Tokyo VERIFIED

Set by the Tokyo Fisheries Adjustment Rules and the Inland Water Fisheries Adjustment Rules.

Applies to: Inland. This table covers rivers and lakes. Sea fishing in this prefecture is governed separately.

Closed seasons

Ayu over 10 cm — inland1 Jan – 31 May
Yamame over 12 cm — inland1 Oct – end of Feb
Iwana char over 12 cm — inland1 Oct – end of Feb
Sculpin — inland1 Jan – 30 Apr
Corbicula — Tama River estuary1 May 2026 – 30 Apr 2027A standing committee instruction, renewed annually. Check the Tokyo Metropolitan Gazette for the current term.

May not be taken at or under this size

Ayu (sweetfish) — inland10 cm total length or under
Yamame — inland12 cm total length or under
Iwana char — inland12 cm total length or under
Rainbow trout — inland12 cm total length or under
Common carp — inland18 cm total length or under
Japanese eel — inland26 cm total length or under
Corbicula — inland1.5 cm shell length or under

Prohibited methods

  • Inland — Weir traps (yana)
  • Inland — Trammel nets
  • Inland — Bindo traps and anything similar
  • Inland — Underwater guns and any spring- or elastic-powered spear
  • Inland — Any gear or method using light
  • Inland — Passing an electric current through the water
  • Inland — Set nets, sweep nets, dewatering and draining a stretch to strand fish
  • Inland — Taking the eggs of yamame, iwana, rainbow trout or sculpin

Tokyo's inland limits are the tightest we hold on eel — 26 cm, against 20–21 cm in most prefectures and 30 cm in Wakayama. Note also that the size limits and the closed seasons work as a pair: ayu of 10 cm or under may never be taken, and the larger ones are additionally closed from January to May. Most of the Tama and Edo rivers are covered by a fishery right, so a cooperative permit is needed on top of these rules.

Local committee instructions

  • Trolling is now permitted, but only by approval. It used to be banned outright for anglers; the Tokyo Sea-area Fisheries Adjustment Commission may now approve it for tournaments and similar events. Casual trolling is still out.
  • Chumming at sea is now allowed. The prohibition in art. 40(1)(i) of the Tokyo Fisheries Adjustment Rules was removed, so anglers may chum in Tokyo's marine waters.
  • Corbicula in the Tama River estuary is under an annual committee instruction restricting both recreational taking and the exercise of the common fishery right.
  • Bluefin tuna is under the national controls described above — relevant for Hachijo-jima.
Source: Tokyo Metropolitan Government, Bureau of Industrial and Labour Affairs — Inland Water Fisheries Adjustment Rules arts. 34, 35, 36 (revised 2 Dec 2025), plus the marine recreation page. The pages moved in 2026; earlier paths now 404. https://www.sangyo-rodo.metro.tokyo.lg.jp/nourin/suisan/yuugyorec/✓ checked 2026-08-28

About Dogtooth Tuna

Reef-associated and famously hard to stop. Southern islands only.

Japanese
· isomaguro
Scientific name
Gymnosarda unicolor
Typical size
80–160 cm (31–63 in)

How it is fished here

Jigging, Shore & popper casting

Elsewhere

Dogtooth Tuna is also listed at Yakushima, Tokara Islands, Okinawa main island, Ishigaki & the Yaeyamas. Everything caught in Hachijo-jima.