ME70 Water Column Sonar Data Collected During DY1706
Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska (DY1706, ME70). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries, Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment survey along the Gulf of Alaska (GOA) shelf and associated bays during the late spring and summer of 2017 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted 9 June-16 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The primary instrument for the survey was a Simrad EK60 split-beam echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). A Simrad ME70 multibeam echosounder system was used during nighttime operations to evaluate the topography of the seafloor in various habitats for select (typically untrawable) areas. The vessel departed Kodiak, Alaska on 9 June and conducted the survey in three legs with all port calls in Kodiak; the project was completed with the arrival of the vessel in Kodiak on 16 August. Leg 1 of the project was conducted 9-28 June along the Gulf of Alaska (GOA) shelf from the Islands of Four Mountains to Outer Shumagin Trough (12-18, 20-21, 22, and 26-27 June). Leg 1 survey areas included Sanak Trough (19 June), Morzhovoi Bay (19-20 June), Pavlof Bay (21 June), Shumagin Islands area (23-25 and 26 June), and Mitrofania area (25 June); the vessel transited to Kodiak 27-28 June. The vessel departed Kodiak on 3 July to start leg 2 (3-28 July) and conducted survey work in Shelikof Strait (3-8 and 10 July), Nakchamik area (9 July), Alitak Bay (12-13 July), initial survey of Barnabas Trough (14-15 July), and GOA shelf (9-10, 10-12, and July). The vessel returned to Kodiak on 15 July, ending leg 2, due to mechanical issues and departed Kodak on 28 July to start leg 3. Leg 3 work included surveys of Chiniak Trough (28-29 July), Barnabas Trough (31 July-1 August), Marmot Bay (3-4 August), and completion of GOA shelf work (3 July; 2 and 4-14 August). The vessel transited to Kodiak Island (14-15 August) and ended the project in Kodiak on 16 August. Sphere calibrations of the EK60 and ME70 echosounder systems were conducted in Kalsin Bay, Kodiak Island, Alaska on 9 June with an additional EK60 calibration conducted at the end of the project on 16 August. Small surveys were conducted on select untrawlable habitat areas throughout the project using a Simrad ME70 multibeam echosounder system.
Dataset Citation
- Cite as: Alaska Fisheries Science Center. 2017. 'ME70 Water Column Sonar Data Collected During DY1706'. NOAA National Centers for Environmental Information. doi:10.7289/V5C827J3 [access date]
Dataset Identifiers
- DY1706_ME70
- doi:10.7289/V5C827J3
- NCEI Metadata ID:gov.noaa.ngdc.mgg.wcd:DY1706_ME70
ISO 19115-2 Metadata
gov.noaa.ngdc.mgg.wcd:DY1706_ME70
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Ordering Instructions | Contact the NCEI Water Column Sonar Data Manager to order data. |
Distributor |
NOAA National Centers for Environmental Information ncei.info@noaa.gov |
Dataset Point of Contact |
NOAA National Centers for Environmental Information ncei.info@noaa.gov |
Dataset Point of Contact | Water Column Sonar Data Manager NOAA National Centers for Environmental Information (303) 497-4742 wcd.info@noaa.gov |
Time Period | 2017-06-09T11:39:37 to 2017-08-12T13:13:57 |
Spatial Reference System | urn:ogc:def:crs:EPSG::4326Vertical Datum: Unknown |
Spatial Bounding Box Coordinates |
West: -169.45381
East: -144.36042
South: 52.60697
North: 60.17117
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Dataset Progress Status | Complete - production of the data has been completed |
Data Update Frequency | Not planned |
Purpose | Acoustic-trawl (AT) survey of walleye pollock (Gadus chalcogrammus) along the Gulf of Alaska shelf and associated bays from the Islands of Four Mountains to Yakutat Bay, 9 June-16 August, 2017. |
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International Hydrographic Organization (IHO) Sea Area ("Limits of Oceans and Seas" publication S-23)
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Lineage Statement | The EK60 transducers installed on NOAA Ship Oscar Dyson are mounted on a deployable centerboard. The transducer draft settings in the EK60 software are nominally correct when the centerboard is fully extended (draft correction setting is 9.15 meters below the surface). When the centerboard is in the retracted position (transducers approximately even with the vessel's keel), the transducers are nominally 6.1 meters below the surface. The ME70 multibeam echosounder system transducer is mounted on the ship's hull about 10 meters forward of the centerboard and about 1.5 meters to the port side of the vessel centerline. ME70 transmit pulses are synchronized with the EK60, with the EK60 providing its timing to the ME70. The EK60 and ME70 echosounder systems were calibrated at the start of the cruise in Kalsin Bay, Kodiak Island, Alaska 9 June 2017; the EK60 was again calibrated at the end of the cruise, 15 August 2017 also in Kalsin Bay. |
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Last Modified: 2020-06-03
For questions about the information on this page, please email: ncei.info@noaa.gov
For questions about the information on this page, please email: ncei.info@noaa.gov