pacific herring
Clupea pallasii · Clupeidae · forage fish
Herring of northern Pacific schools, which enter estuaries to spawn and have high commercial value. It is used as bait and also interests sport fishing.
Also called: arenque-do-pacífico, arenque del pacífico, pacific herring
- maximum
- 46 cm
- depth
- 0–475 m
the right time
to be on the water
Choose the place and the species. The index, from 0 to 100, combines weather, sun, moon and tide with each fish's habits. Up to 28 days, with each day's confidence.
Reading the weather across 3 global models and 31 simulations…
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hour by hour
slide your finger or mouse over the chart to see each hoursee hour-by-hour table
why this index at —?
choose the day
Each card shows the day's index (0 to 100) and, below it, a strip with the index for each hour, from 0h to 23h. from poor to excellent.
the fishing month at a glance
what's the best window for the crew?
Choose how many fishing days. We compare each stretch by its average index, discount days with a warning or closed season, and show the 3 best.
trend for the coming weeks
Line: the middle value of 31 simulations of the American GEFS model. Band: where 8 out of 10 fall. Narrow, firm trend; wide, high uncertainty.
everything about the pacific herring
who is the pacific herring
Fish of the family Clupeidae, with an elongated, compressed body, reaching 46 cm, with a common size of 25 cm. It lives in coastal and neritic schools, from 0 to 475 m, and mature adults enter estuaries to spawn. The female lays eggs on the bottom, and males release milt over them, leaving the spawning area white. Juveniles eat mostly crustaceans, and adults eat large crustaceans and small fish. It occurs from the Arctic to the northern Pacific, down to northern Baja California, Mexico. It has high commercial value, is eaten in many ways, and is used as bait.
Essential profile. Identification, where it occurs and rules, with data from FishBase and the cited regulations. Season, time of day, technique and bait are added once we have a good source for the pacific herring; in the meantime, see the similar species.
fun facts
- In Japan, the eggs that females lay on seaweed are salted and considered a delicacy: kazunoko-kombu.
identification
Elongated, compressed body, dark blue to olive on the back and silvery below. The belly has no pronounced keel, the gill cover has no bony striae, and there is no notch in the middle of the upper jaw. It has no clear dark spots on the body or fins, which helps set it apart from the Pacific sardine (Sardinops sagax), which has dark spots along the flank.
where found
In Latin America, only in Mexico, at the northern tip of Baja California, in coastal waters; the species occurs from the Arctic to the northern Pacific.
Habitat: Coastal and neritic waters, in schools, from 0 to 475 m; juveniles form schools in shallow bays and channels near the surface.
rules for the pacific herring
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
We found no species-specific rule beyond the region's general rules.
catch and release
catch and release Releasing the fish alive, quickly and with a wet hand. During a closed season it isn't always allowed: what the regulation says applies.
No dangers recorded for anglers. Small schooling fish: handle with care and return it to the water if you are not using it as bait.
in the kitchen
It can be eaten fresh, dried, salted, smoked, canned or frozen, grilled, fried or baked.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00603, b = 3.13; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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sources and references
Essential profile: size, length-weight, depth, countries and conservation come from FishBase and the cited regulations, and the texts were written from those sources. Season, time of day, sensitivities, technique and baits and lures are not included yet, because we did not find a good source for this species.
- scientific FishBase: Clupea pallasii (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Clupea pallasiiNames by country and language.
similar species
where each number comes from
The weather comes from three independent global models, cross-checked hour by hour: when they agree, confidence goes up; when they diverge, the band between them shows on the chart. Beyond 16 days, we use the GEFS ensemble of 31 simulations: if 20 of the 31 predict rain, the chance of rain is 65%. Sun and moon are calculated astronomically, with no uncertainty.
The index adds up, weighted for each species: time of day (species curve anchored to real sunrise and sunset), moon (transits, rise and set, phase), pressure (3 h trend and 24 h swing), water temperature (in rivers, estimated from air temperature; at sea, estimated by an ocean model), wind, rain, clouds, tide and the month in the species' cycle.
sources for this lookup
how accurate the forecast is
Accuracy measured in the reference project (4 regions, 93 days, forecast vs. observed): maximum temperature is off by 0.6 °C on average the next day and 1.7 °C at 7 days; rain of 5 mm or more is detected 76% of the time the next day and 57% at 7 days. Detection isn't everything: the false alarm rate isn't published here yet, and 93 days in 4 regions is still a small sample. We now also measure every day, at the app's destinations: