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First-Ever Northern Marianas Bottomfish Project Brings Fishers and Scientists Together

September 02, 2025

A first-of-its-kind collaboration brings new understanding of deep-water fish populations in the Commonwealth of the Northern Mariana Islands.

Three people sitting on a boat smiling at the camera while they travel through the open ocean. CNMI fisher Lino Tenorio, CNMI stock assessment lead Erin Bohaboy, and survey lead Ben Richards, head out for another day of surveying. Credit: NOAA Fisheries/Erin Bohaboy (NOAA Fisheries permits: #10509-25)

A team of local fishers and NOAA scientists worked together to develop the first-ever standardized, fishery-independent bottomfish survey in the Commonwealth of the Northern Mariana Islands. U.S. fisheries are among the largest and most sustainable fisheries in the world. This mission aimed to better understand the region’s culturally and economically important deep-water fish species (called bottomfish). This information will help us create more sustainable fish stocks. 

“You know what really hit me first … is that I related it as an opportunity comparable to being asked to get on a rocket to fly to the moon. CNMI is my world so I am very grateful for this opportunity,” —Lino Tenorio, partnering CNMI fisherman

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Map of the Mariana Archipelago with arrows showing the order of islands visited during pilot project.
Map of the route Oscar Elton Sette took during the pilot project, stopping at survey sites across CNMI. Credit: NOAA Fisheries

This groundbreaking project brought local fishers aboard NOAA ship Oscar Elton Sette, where they traveled 1,900 nautical miles to collect this under-researched data. Imagine starting a road trip in California and driving all the way to Nebraska, that’s about how far they traveled! They traversed this vast distance in 15 days, stopping at 91 sampling stations across nine islands.

Scientists and fishers agree that a major success of this project is how it brought people together.

Through this collaboration, fishers contributed their decades of experience and generational knowledge in catching fish. Scientists brought experimental designs and techniques for aging fish and better understanding fish reproduction. Both groups gained valuable insights into the fishery, fish behavior, and biology. With this combined knowledge, we learned that bottomfish populations vary between the northern and southern islands. 

“I'm going to walk off as a scientist, as a fisher scientist, and I'm going to be able to bring everything that I've learned with me to share with everybody,” —Audrey Toves, partnering Guam fisherwoman 

The local fishers collected and analyzed 609 bottomfish specimens representing multiple species. They noticed that fish sizes appeared to be larger, and their depth ranges and distribution appeared noticeably different in the northern islands compared to the southern islands. This helped shape the initial findings from this project. Preliminary analyses suggest that these fish may have expanded depth ranges. They also suggest that fish seen more rarely in the south are more abundant in the north. These findings will help strengthen our population assessments, which is crucial to understanding the health of the local bottomfish stock. 

“We each hold pieces to the puzzle,” Eva Schemmel, fish biologist with NOAA Fisheries, explained. “Fishers understand the fishery, including fish movements, spawning patterns, seasonality, and fluctuations—knowledge that scientists must have to complete the overall picture. As scientists, we interpret signals from fish tissue (gonads) and bones (otoliths), which can be more readily understood with context and input from fishers.”

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Two men in an on-ship laboratory watching the third man prepare standardized survey gear.
Local CNMI fishers Lino Tenorio and James Roberto work with Jamie Barlow to develop standardized survey gear (hook configuration, leader length, lights, etc). Credit: NOAA Fisheries/Eva Schemmel

Local Fishers Help Lead the Work 

Local fishers not only helped conduct the fieldwork, they also helped design the project. Their deep-rooted understanding of the local waters, fish behavior, and effective fishing methods helped structure the project. Researchers and fishers created a model for how science and local fishing expertise can collaborate to effectively manage ocean resources across the Pacific, becoming more than the sum of their individual parts. The design of this project will help inform our future population assessments, making our work more accurate and relevant to these communities.

“I feel like I am a part of the team, and it's more so like a family from day one up until this day. Just before I disembarked the ship, it's like I honestly felt like crying,” Tenorio said. “I feel so emotional and so touched by everybody's professionalism, togetherness.” 

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A man and a woman hold up a poster depicting the size of various bottomfish while a third man stands behind them. All three are smiling at the camera while posing their hands in casual, friendly gestures.
Local CNMI fishers Lino Tenorio and James Roberto, and Guam fisherwoman Audrey Toves, show off a poster they co-designed with NOAA Fisheries for a community event on Saipan on July 20, 2025. The poster shows the median sizes of bottomfish in the Northern Mariana Islands compared to median sizes around Saipan. Credit: NOAA Fisheries/Eva Schemmel

Long-Term Goals

This project is the first of its kind in CNMI, and it marks the beginning of an important, long-term research initiative. Much like how James Roberto finally got to travel through the whole Mariana Archipelago, our goal is to also create a more comprehensive understanding of this unique ecosystem. The data collected from this ongoing effort will significantly enhance our understanding of deep-water fish populations and their ecosystems. Over time, these observations will:

  • Improve stock assessments: Providing more accurate and robust evaluations of fish populations, which are essential for effective management
  • Guide sustainable fishing practices: Informing science-based fishing limits and strategies to ensure the long-term health and productivity of these vital resources
  • Enhance understanding of fish life cycles: Offering deeper insights into the growth patterns, reproductive cycles, and habitat needs of these culturally and economically important species in CNMI

“My favorite memory is honestly finally reaching Uracas. That's the only island I never got to go to. So reaching Uracas, now I completed the whole CNMI archipelago. I am happy about that.” —James Roberto, partnering CNMI fisherman 

Why Bottomfish Matter 

Bottomfish are significant in CNMI’s commercial, recreational, and subsistence fishing. To ensure responsible management of these vital species, scientists require accurate data on their populations, habitats, growth patterns, and reproductive cycles.

This is NOAA Fisheries’ first project that provides important observations, helping scientists track:

  • Abundance of these important species around CNMI
  • Spatial patterns of abundance
  • Changes in abundance over time
  • How long they live, at what age they start reproducing, and how many offspring they produce
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Nine gindai are lined up on a mat to show the differences in fish size of the same species.
Gindai (Pristipomoides zonatus) are photographed on measuring mats to record fish length and document the catch. Credit: NOAA Fisheries/Eva Schemmel

Last updated by Pacific Islands Fisheries Science Center on September 05, 2025