Logbook summary reports for the 2019 calendar year.
About The Species
U.S. wild-caught opah is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.
The stock has never been assessed. The population level is unknown but presumed stable.
At recommended level.
Fishing gear used to catch opah rarely contacts the ocean floor so habitat impacts are minimal.
There is no directed fishery. Regulations are in place to minimize bycatch in the tuna and swordfish fisheries, which incidentally catch opah.
- Opah has never been assessed, but there is no evidence that populations are in decline or that fishing rates are too high.
- Despite the opah's value to commercial and recreational fishermen, little research on the basic biology and ecology of opah has been conducted.
- To begin to fill some of the data gaps, NOAA's Southwest Fisheries Science Center began collecting biological samples from opah in 2009 and initiated an electronic tagging program in 2011.
- Scientists hope to continue tagging opah to learn about their movements and range. This research will provide the basic life history information necessary for future population assessments and management.
- Opah are an unusual looking fish—they have a round, flat body that’s silvery gray in color.
- Toward the belly, the silver shades to a rose red, dotted with white spots.
- Their fins and mouth are red, and their large eyes are encircled with gold.
- Because opah are not a major commercial seafood species and they live in the deep ocean, scientists know very little about their biology and ecology.
- Scientists assume opah share general characteristics with other Pacific Ocean pelagic fish.
- Scientists estimate that opah grow quickly.
- Although they’re not sure of opah’s exact life span, scientists age opah by their fin rays, assuming fin ray marks are formed annually.
- Most opah caught in longline fisheries are estimated to be between 1 and 6 years old.
- They average about 100 pounds with a diameter of 3 feet.
- Opah spawn in warm surface waters throughout the year in the tropics and more seasonally in cooler waters.
- Opah seem to be very productive, potentially spawning many times throughout the spawning season.
- Opah are capable of traveling long distances, often in response to changing oceanic conditions such as temperature.
Where They Live
- Opah are found in tropical and temperate waters around the world.
- NOAA Fisheries and the Western Pacific Fishery Management Council manage this fishery in the Pacific Islands.
- Managed under the Fishery Ecosystem Plan for the Pelagic Fisheries of the Western Pacific:
- No management measures specifically apply to opah. However, general management measures apply to the fisheries that harvest opah.
- Fishermen are required to have permits and record their catch.
- Gear restrictions and operational requirements to minimize bycatch and potential gear conflicts among different fisheries.
- A limit on the number of permits for Hawaii and American Samoa longline fisheries controls participation in the fishery.
- Longline fishing is prohibited in some areas to protect endangered Hawaiian monk seals, reduce conflicts between fishermen, and prevent localized stock depletion (when a large quantity of fish are removed from an area).
- These zones are enforced through the NOAA Fisheries vessel monitoring system program (longline boats must be equipped with a satellite transponder that provides real-time position updates and tracks vessel movements).
- Hawaii- and American Samoa–based longline vessels must carry onboard observers when requested by NOAA Fisheries, in part to record interactions with sea turtles, seabirds, and marine mammals.
- Annual training in safe handling and release techniques for protected species is required, and all vessels must carry and use specific equipment for handling and releasing these animals.
Recreational Fishing Regulations
Commercial Fishing Regulations
Subsistence Fishing Regulations
Opah Research in the Eastern Pacific Ocean
Opah are a mid-water pelagic fish that occur seasonally in the Southern California Bight. While they are not targeted, they are taken incidentally in both local recreational fisheries for tuna and the California drift gillnet fishery targeting swordfish.
In recent years, there appears to have been an upsurge in opah catch and the rich meat has become increasingly popular in seafood markets. Despite their value to commercial and recreational fishermen, little research on the basic biology and ecology of opah has been conducted, especially in the Southern California Bight. For example, there are limited data on foraging ecology, size composition in fisheries, essential habitat, and stock structure. To begin to fill some of the data gaps, the Southwest Fisheries Science Center began collecting biological samples from opah in 2009 and initiated an electronic tagging program in 2011.
Analyses of the biological samples and the data provided by the tagging program have revealed a plethora of information. Genetic analysis has determined that there are multiple different species of opah, those caught off California being a different species than those caught off Hawaii. Opah also appear to have a unique gill arch structure which has never been seen before. The unique structure might help scientists understand their ability to forage deep in the water column, from generally 50 meters at night down to 200 meters during the day. The vertical movements are likely due to opah following prey with similar migrations. Opah primarily forage on squid and deep water fishes such as barracudinas, a small elongated fish of up to 50 centimeters. Barracudinas are notable mid-water predators and they are an important food for large fishes such as tunas, swordfish, bigeye thresher shark and, evidently, opah.
Our scientists continue to conduct biological sampling and genetic analysis of opah to further explore intraspecific differences. This includes stomach processing to identify the important prey for opah and whether the diet changes with environmental conditions, and dissections of the gills and whole fish to learn about the anatomy of opah and their swimming mechanics.
Scientists also hope to continue tagging opah to learn about their movements and range. This research will provide the basic life history information necessary for future population assessments and management. Historical catch data may also show correlations between opah catch and abundance with changes in sea surface conditions such as El Niño and La Niña.
Data & Maps
Logbook summary reports for the 2018 calendar year.
Logbook summary reports for the 2018 calendar year.
The Life History Program researches the reproductive biology, growth, foraging ecology, and distribution of highly migratory and coastal pelagic species in the northeast Pacific Ocean. Through biological sampling, soft and hard tissue analysis,…