LIHUE — Hooks are in the water for the 2019 Hawaii bottomfish survey, an annual count of abundance done by researchers from the Pacific Islands Fisheries Science Center since 2016.
Those hooks are part of the second half of the annual survey, and the first portion of the survey went off without a hitch according to Benjamin Richards, National Oceanic and Atmospheric Administration researcher aboard the NOAA ship Oscar Elton Sette.
The NOAA ship returned to Honolulu Sept. 29 after using deep-water cameras to measure, count and watch Deep-7 bottomfish at 176 locations around the Main Hawaiian Islands.
Target species for these surveys are the “Deep-7” fish — opakapaka, onaga, ‘ehu, gindai, kalekale, lehi, and hapu‘upu‘u.
“The fall 2019 bottomfish survey went very well. With a very professional crew and science party, we had smooth sailing,” Richards said, pointing out newly established collaborations between NOAA Fisheries and the National Weather Service offices. “For the first time, we had National Weather Service Forecasters onboard the NOAA Ship Sette for the duration of the survey. This allowed us to choose ideal operating areas, with light winds and calm seas, maximizing the amount of work the team was able to accomplish.”
The main Hawaiian islands bottomfish survey is a multi-gear survey, using both deep-water cameras as well as cooperative research fishers deploying typical hook-and-line gear used for bottomfish.
Using two gears allows NOAA scientists to compensate for biases in each of the gear types, according to NOAA.
The camera portion of the survey is valuable because it allows NOAA scientists to count individuals at specific survey locations, identify the fish to species, and measure each fish observed in the cameras, Richards said.
And with cameras, all that can be done without harming the fish.
“As any fisherman knows, there are times when fish are present in a location but are not interested in biting a hook,” Richards said. “The cameras also allow us to collect information about the fish community regardless of whether they are biting.”
Now that researchers are done cruising the seas around the Main Hawaiian Islands the second phase of the survey has begun — the part where they’re partnering with local commercial fishers to actually catch some fish.
Commercial fishers involved worked with NOAA scientists to develop a standardized hook-and-line survey method that best matches local commercial fishing methods used across the Main Hawaiian Islands.
Each vessel fishes two lines, each containing four standard size hooks, for thirty minutes at locations determined by NOAA scientists. All of the fish captured during this portion of the survey are provided to the Pacific Islands Fisheries Science Center Life History Program.
“Using these fish, NOAA scientists are able to get information about the age of fishes in the population and when they are beginning to produce offspring. All of this information is valuable to continually improve the stock assessment,” Richards said.
While commercial fisher partners are putting their hooks out, researchers are pouring over the video data collected by all of the deep-water cameras, and Richards says it is going to take several months to analyze all the data.
“The results of the survey and a report should be available in early 2020,” Richards said. “The most time intensive step is looking through all of the video data collected by the cameras to count, identify, and measure all of the fish that were seen.”
Jessica Else, environment reporter, can be reached at 245-0452 or at firstname.lastname@example.org