State and federal fishery officials have struggled for decades to determine how many deep-sea bottomfish like onaga and opakapaka are in Hawaiian waters, basing stock assessments on the amount of groupers and snappers caught by commercial fishermen.

The method has made it difficult to assess the health of the fishery and what limits to set on the amount of bottomfish that can be reeled in each year, which affects whether these popular fish appear on the menu and how much they cost if they do.

But scientists with the National Oceanic and Atmospheric Administration say a five-year joint effort with state officials, fishermen and others to improve their stock-assessment methods is about to pay off thanks in large part to a newly developed underwater camera system.

Twelve researchers are set to embark on a 15-day mission to take photos of bottomfish using the 70-pound rigs at 66 locations around the main Hawaiian Islands. Scientists will then spend weeks or possibly months counting the fish in the photos, determining their length and identifying the species, which are found at depths ranging from 300 to 900 feet.

That information will be combined with data that six commercial fishermen are currently collecting through a standardized survey method that involves them fishing at certain areas for a set period of time using the same bait.

The initial data analysis is expected in January, said Benjamin Richards, NOAA fishery biologist and the survey’s lead scientist. A final analysis is expected a few months after that. It will ultimately end up being used in the 2018 stock assessment, he said, the first major update in four years and most comprehensive to date.

All that science then goes to the Western Pacific Regional Fishery Management Council, commonly known as Wespac, a 16-member body tasked with advising NOAA’s National Marine Fisheries Service on how to minimize bycatch, protect habitat and prevent overfishing in nearly 1.5 million square miles of ocean.

Scientists have determined, based on the 2014 stock assessment that uses only catch data reported by commercial fishermen, that the seven main bottomfish species, known as the Deep 7, are not being overfished, Richards said. Recreational fishermen do not have to report their catch.

The catch limit for the 2017 season, which started Sept. 1, is 318,000 pounds. Last year, fishermen reported catching 259,963 pounds of their 326,000-pound limit. 

While some have long suspected commercial fishermen of grossly underreporting their catch, scientists don’t know what their new survey will show. It could lead to higher or lower catch limits, for instance, or affect other management decisions, such as restricted areas.

“We never know what to expect,” Richards said of the upcoming survey.

Rick Gaffney, a former Wespac member and commercial fisherman, said the bottomfish fishery needed to be better managed 30-plus years ago, as opposed to now when there are far fewer fishermen going after groupers and snapper.

“The heyday of bottomfishing in Hawaii was the early 1970s when fresh fish restaurants made their name based on the quality of the bottomfish they plated up for their patrons and scores, perhaps hundreds of small boat fishermen either made a living or substantially supplemented their incomes from other jobs, by delivering fresh bottomfish to local restaurants,” Gaffney said.

“Tourism was on the rise then and the demand for bottomfish may have started to outstrip the supply at that time,” he said.

Today, Gaffney said, there are far fewer bottomfish fishers, and consumers see less of these fish species on the menu.

Michael Seki, NOAA’s Pacific Islands Fisheries Science Center director, told Wespac members at their March meeting that the Hawaii bottomfish community has long struggled with the robustness of the commercial fishery data for scientific and management purposes.

He said many of the issues have been revisited repeatedly for many years.

The center’s 2014 Deep 7 bottomfish stock assessment was subject to peer review, and Seki reported in March that “it did not pass muster,” according the meeting’s minutes. The review panel deemed the data inadequate for some of the conclusions that were made and the assessment was rejected.