Multi-agency Bottomfish Research Underway in Northern Mariana Islands

June 19, 2014

Scientists aboard the NOAA R/V Oscar Elton Sette are engaged in a 30-day research project in the waters of the northern islands of the Commonwealth of the Northern Mariana Islands (CNMI). The primary mission is to learn more about the biology and environment of bottomfish resources in the CNMI which support important local fisheries. Data gathered in the mission will be used to improve assessments of bottomfish and reef fish stocks, and provide a foundation for scientific advice to resource managers. The research project continues the partnership between NOAA's Pacific Islands Fisheries Science Center (PIFSC) and marine resource agencies in the CNMI and is designed to support the research initiatives of the participating CNMI agencies. The expedition is one of two bottomfish research projects to be conducted this summer by PIFSC on the Sette.

During this expedition, identified as project SE 14-04, PIFSC biologist Robert Humphreys will serve as Chief Scientist to lead a diverse research team that includes other scientists from PIFSC and CNMI agency scientists from the Division of Fish and Wildlife (DFW; part of the Department of Land and Natural Resources) and the Bureau of Environmental and Coastal Quality (BECQ). Other members of the research team include instructors and students from Northern Marianas College, local fishermen, and two archeologists.

On the 1st leg of the research project (June 19–July 3, 2014), scientific operations will be conducted in the nearshore and coastal waters around Uracas, Maug, and Asuncion within the Mariana Trench Marine National Monument. During the 2nd leg of the expedition (July 7–21, 2014), studies will be focused on waters of the Northern Mariana Islands of Pagan, Guguan, Sarigan, and Anatahan. During the initial Leg 1 transit to the study area, the two archeologists will be transported to the island of Alamagan along with their field camp equipment and supplies. The team will conduct archeological field studies on the island while scientists on the Sette are conducting their biological work at other locations and will be retrieved prior to the Sette's return to port in Saipan at the end of the mission.

Daylight sampling activities will be conducted from the Sette and her three small boats. The DFW scientific team and local fishermen will use two small boats to collect samples of select reef fish and deep-slope bottomfish species in support of agency projects to determine age and growth, reproductive maturity, and trophic relations of these commercially valuable fish. The life history sampling will also directly benefit researchers at the University of Guam, as these sampling operations will provide needed tissue samples for future DNA-based investigations to evaluate the genetic connectivity of fishes within the Mariana Archipelago.

As bottomfish are being retrieved during sampling operations on the Sette, underwater video cameras will be lowered over the side of the ship to record any predatory interactions of sharks with the captured bottomfish near the sea surface. The video will also provide a means to better identify the species of sharks involved. BECQ scientists will conduct daylight small boat snorkel surveys of the intertidal habitat around each of the islands to document the benthic community and collect water samples for environmental monitoring.

Small boats launched from the Sette will be used to collect fish samples from the Northern Mariana Islands for life history 
        studies.
Small boats launched from the Sette will be used to collect fish samples from the Northern Mariana Islands for life history studies.

Night activities of the Sette will include plankton sampling using an Isaacs-Kidd midwater trawl towed from a depth of 100 meters to the surface and surface night-light collections; samples of larvae and juvenile fishes collected in these operations will support the genetic connectivity study. Researchers will also collect oceanographic data. Data on the speed and direction of ocean currents at various depths will be collected using an onboard instrument called an Acoustic Doppler Current Profiler (ADCP). Other oceanographic measurements of the water column will be gathered using a conductivity-temperature-depth (CTD) instrument that is lowered and retrieved from the ship. The CTD provides a depth profile of temperature, salinity, and oxygen concentrations. Additionally, water-sampling bottles attached to the CTD will collect specimens of water at pre-determined depths that will be filtered and processed onboard the ship to determine water chemistry and chlorophyll content. These ocean measurements will help to characterize the physical environment adjacent to each of the islands.

In addition to the collection of data valuable for CNMI bottomfish research and stock assessment, the various day and night scientific operations will provide a rare opportunity for Northern Marianas College students and instructors to learn and experience at-sea marine research in the remote Northern Mariana Islands.

Many of the scientific collection activities during the SE 14-04 research project will be conducted onboard the NOAA Ship 
        Oscar Elton Sette.  Hydraulic reels will be used to retrieve handline gear deployed to catch study specimens of deep-slope 
        bottomfish living at depths of 100-400 meters in northern waters of the CNMI.
Many of the scientific collection activities during the SE 14-04 research project will be conducted onboard the NOAA Ship Oscar Elton Sette. Hydraulic reels will be used to retrieve handline gear deployed to catch study specimens of deep-slope bottomfish living at depths of 100-400 meters in northern waters of the CNMI.

 

The expedition's operating area (highlighted in red) extends from Uracas island (also known as Farallón de Pájaros) to Anatahan island in the Northern Mariana Island chain.