Main Hawaiian Islands Deep 7 Bottomfish
The Deep 7 are the most culturally important and highly valued of the deep-water bottomfish species in Hawaiʻi. The Deep 7 bottomfish complex is composed of six snapper species and one grouper species:
- Ehu (squirrelfish snapper), Etelis carbunculus
- Gindai (Brigham's snapper), Pristipomoides zonatu
- Hapuʻupuʻu (Seale's grouper, Hawaiian grouper), Hyporthodus quernus
- Kalekale (Von Siebold's snapper), Pristipomoides sieboldii
- Lehi (silverjaw snapper), Aphareus rutilans
- Onaga (longtail snapper), Etelis coruscan
- 'Ōpakapaka (pink snapper), Pristipomoides filamentosus
Of the complex, ‘ōpakapaka and onaga are the most abundantly harvested by fishermen and highly prized by chefs for their premium texture and mild flavor.
Where They Live
These fish typically live at depths of 75 to 400 meters around the main Hawaiian Islands. They are often associated with hard, rocky seafloor habitats with lots of nooks and crannies. Some limited information suggests that juveniles of some of these species may be found in shallower soft sand and mud environments. Some of these species are not only found in the main Hawaiian Islands, but also exist in the Northwestern Hawaiian Islands, Johnston Atoll, American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands.
This bottomfish complex remains abundant in Hawaiian waters and can continue to be sustainably harvested, according to a 2018 stock assessment. The assessment shows a positive outlook for the stock; they are not currently overfished and are not experiencing overfishing.
Where They Live
Recreational Fishing Regulations
Commercial Fishing Regulations
Subsistence Fishing Regulations
NOAA Fisheries shares management of the Deep 7 bottomfish complex with the State of Hawaiʻi, Department of Land and Natural Resources. To provide for a sustainable harvest, the Western Pacific Regional Fishery Management Council recommended federal regulations for Deep 7 bottomfish, including an annual catch limit and non-commercial bag limits, vessel marking requirements, a federal non-commercial bottomfish permit, and reporting requirements. This management philosophy is described in the Hawaii Archipelago Ecosystem Management Plan. The implemented regulations affect everyone who fishes non-commercially (recreational and subsistence) or commercially for Deep 7 bottomfish fishing in federal waters (3 to 200 nautical miles from shore) of the main Hawaiian Islands.
The Council recommends, and NOAA Fisheries approves, an annual catch limit for the Deep 7 bottomfish each year. This limit reflects the status of the bottomfish stock, based on scientific information collected by the state of Hawaiʻi and NOAA Fisheries, including commercial and non-commercial fishing data and other information, and considers the associated risk of overfishing.
The fishing year for the Deep 7 bottomfish starts on September 1 and runs through August 31 of the following year, unless the annual catch limit is reached before August 31. When the limit is reached, all fishing (commercial and non-commercial) for Deep 7 species is prohibited in state waters (shoreline to 3 nautical miles offshore) and federal waters around the main Hawaiian Islands for the remainder of the fishing year. Seafood dealers, markets, restaurants, and anyone else are prohibited from possessing or selling Deep 7 bottomfish during a fishery closure.
State and federal regulations complement each other, and fishermen should check with the Department of Land and Natural Resources for bottomfish fishery regulations that apply in state waters.
- Fisheries in the Western Pacific; Bottomfish and Seamount Groundfish Fisheries; Management Measures in the Main Hawaiian Islands (73 FR 18450)
- Fisheries in the Western Pacific; Bottomfish and Seamount Groundfish; Permit and Reporting Requirements in the Main Hawaiian Islands (73 FR 41296)
- Fisheries in the Western Pacific; Mechanism for Specifying Annual Catch Limits and Accountability Measures (76 FR 37285)
Much of the biology of the Deep 7 bottomfish is either not known or was only recently investigated. Age, growth, longevity, and maturity are important biological parameters for understanding the life history of these species.
‘Ōpakapaka—one of the snappers of this group—has set the stage for studies currently underway for the other Deep 7 members. The ‘ōpakapaka was once thought to be a short-lived species that didn’t live longer than 20 years. But several age estimation and validation techniques have revealed that the species can live more than 40 years. This biological information, when combined with an assessment of the fish’s reproduction, make the life history of ‘ōpakapaka the most well understood of the Deep 7 bottomfish.
Scientists have investigated the other Deep 7 snappers to a more limited extent. These fish may grow in a similar manner to ‘ōpakapaka, but there is evidence to support faster growth for ehu, gindai, and lehi. In contrast to the Deep 7 snappers, Hawaiian grouper was recently shown to have quite complex biological characteristics. This species changes sex (female to male) at bigger sizes and older ages and can live longer than 50 years.
NOAA's Pacific Islands Fisheries Science Center is responsible for conducting assessments of the Deep 7 bottomfish stock, used by managers such as the Western Pacific Regional Fishery Management Council to develop annual commercial fishery catch limits. The stock assessment process requires reliable sources of data on catch, fishing effort, biology, and abundance.
Research, Surveys, and Data
NOAA researchers monitor the seven species of bottomfish in Hawai‘i by working with local fishermen and deploying underwater camera technology as part of the Bottomfish Fishery-Independent Survey in Hawaiʻi (BFISH). These annual surveys assess the numbers and sizes of bottomfish around the main Hawaiian Islands.
We collect data at various scientifically selected sites around all eight of the islands by working with local fishermen through the Pacific Islands Fisheries Group. At sea, our researchers also collect video footage of bottomfish in their deepwater habitat using an underwater camera system called MOUSS (modular optical underwater survey system). We are committed to cooperative research with local fishermen to build relationships with the community and continually improve the collection of scientific information. Data collected on BFISH surveys guides sustainable fisheries and resource management for the Deep 7 species in Hawai‘i and the overall ecosystem.
The more details we know about a fish species, the more the Council can accurately manage it. We estimate deep 7 bottomfish biological and life history information using biological samples of fish collected during research cruises, as well as samples purchased from and donated by local fishermen. After we identify the species and measure and weigh all the fish, we extract fish gonads to reveal information on sex and reproductive status. We also extract otoliths (ear bones), which display annual rings similar to tree rings and are used to estimate age by counting these rings. Bomb radiocarbon dating of otoliths validates the age estimates from counting otolith rings. After we estimate the fish’s individual age and reproductive status, the next step is to examine growth rates and mortality rates.
NOAA scientists combine data from the annual BFISH surveys and biological information, along with data reported by bottomfish fishers on catch and effort, into an analysis called a stock assessment. The stock assessment estimates the total number of Deep 7 bottomfish around Hawaiʻi and how many can be sustainably harvested into the future, and the assessment forms the basis for federal management regulations recommended by the Council.
Recent Science Blogs
Stock Assessment for the Main Hawaiian Islands Deep 7 Bottomfish Complex in 2018, with Catch Projections Through 2022
Seven popular species of bottomfish remain abundant in Hawaiian waters and can continue to be…