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Item Identification
Keywords
Physical Location
Data Set Info
Support Roles
Extents
Access Info
Distribution Info
URLs
Data Quality
Data Management
Lineage
Acquisition Info
Catalog Details

Summary

Short Citation
Alaska Fisheries Science Center, 2024: AFSC/RACE/MACE: Results of 2017 acoustic trawl survey Gulf of Alaska DY1706, https://www.fisheries.noaa.gov/inport/item/65612.
Full Citation Examples

Abstract

Scientists from the Midwater Assessment and Conservation Engineering (MACE) Program of the Alaska Fisheries Science Center's (AFSC) Resource Assessment and Conservation Engineering (RACE) Division conducted an acoustic-trawl (AT) survey of the Gulf of Alaska (GOA) shelf to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus) in summer 2017. Previous surveys of the GOA have also been conducted by the MACE program during the summers of 2003, 2005, 2011, 2013, and 2015. The 2017 survey covered the shelf from the Islands of Four Mountains to Yakutat Trough including many bays and troughs. Surface water temperatures across the GOA shelf averaged 11.6° C, overall, approximately 0.6° C cooler than in 2015 (mean 12.2° C) and 1.0° C warmer than in 2013 (mean 10.6° C), which were the only other surveys with comparable coverage. Large aggregations of age-0 pollock were observed throughout the survey but especially in the Shumagin Islands and Shelikof Strait areas. The estimated amounts of age-1+ pollock for the entire surveyed area were 2.64 billion fish weighing 1,341,973 metric tons (t). The majority of the pollock biomass was observed on the continental shelf (84%), Shelikof Strait (5%), near Mitrofania Island (3%), and east of Kodiak Island in Chiniak (2%) and Barnabas Troughs (4%). The majority (86%) of the biomass in the survey area consisted of age-5 fish from the 2012 year class. Compared to previous summer GOA surveys, fish weight at length was similar, but length at age was slightly smaller. Backscatter was attributed to species other than pollock when trawl verification, differentiation based on backscatter frequency response, or other methods allowed. Abundance and biomass estimates were calculated for Pacific ocean perch (Sebastes alutus; 305.9 million fish weighing 172,388 t), and backscatter distribution and abundance relative to previous surveys was estimated for euphausiids (primarily consisting of Thysanoessa inermis, but also including T. spinifera, T. raschii, and Euphausia pacifica).

Distribution Information

Access Constraints:

The data set is still being analyzed and will not be available for distribution until it has been finalized and all QA/QC practices have been performed. Contact the Data Point Of Contact for estimated time of release.

Use Constraints:

User must read and fully comprehend the metadata prior to use. User must acknowledge the Originator when using the data set as a source. User must share data products developed using the source data set with the Originator. Data should not be used beyond the limits of the source scale.

Child Items

No Child Items for this record.

Contact Information

Point of Contact
Darin Jones
darin.jones@noaa.gov

Metadata Contact
Metadata Coordinators MC
AFSC.metadata@noaa.gov

Extents

Geographic Area 1

-170.1399° W, -141.1529° E, 60.127° N, 52.5667° S

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Time Frame 1
2017-06-08 - 2017-08-14

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Item Identification

Title: AFSC/RACE/MACE: Results of 2017 acoustic trawl survey Gulf of Alaska DY1706
Short Name: 2017 Summer Gulf of Alaska EIT Survey
Creation Date: 2017-08-14
Revision Date: 2017-08-14
Abstract:

Scientists from the Midwater Assessment and Conservation Engineering (MACE) Program of the Alaska Fisheries Science Center's (AFSC) Resource Assessment and Conservation Engineering (RACE) Division conducted an acoustic-trawl (AT) survey of the Gulf of Alaska (GOA) shelf to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus) in summer 2017. Previous surveys of the GOA have also been conducted by the MACE program during the summers of 2003, 2005, 2011, 2013, and 2015. The 2017 survey covered the shelf from the Islands of Four Mountains to Yakutat Trough including many bays and troughs. Surface water temperatures across the GOA shelf averaged 11.6° C, overall, approximately 0.6° C cooler than in 2015 (mean 12.2° C) and 1.0° C warmer than in 2013 (mean 10.6° C), which were the only other surveys with comparable coverage. Large aggregations of age-0 pollock were observed throughout the survey but especially in the Shumagin Islands and Shelikof Strait areas. The estimated amounts of age-1+ pollock for the entire surveyed area were 2.64 billion fish weighing 1,341,973 metric tons (t). The majority of the pollock biomass was observed on the continental shelf (84%), Shelikof Strait (5%), near Mitrofania Island (3%), and east of Kodiak Island in Chiniak (2%) and Barnabas Troughs (4%). The majority (86%) of the biomass in the survey area consisted of age-5 fish from the 2012 year class. Compared to previous summer GOA surveys, fish weight at length was similar, but length at age was slightly smaller. Backscatter was attributed to species other than pollock when trawl verification, differentiation based on backscatter frequency response, or other methods allowed. Abundance and biomass estimates were calculated for Pacific ocean perch (Sebastes alutus; 305.9 million fish weighing 172,388 t), and backscatter distribution and abundance relative to previous surveys was estimated for euphausiids (primarily consisting of Thysanoessa inermis, but also including T. spinifera, T. raschii, and Euphausia pacifica).

Purpose:

Pollock Stock assessment

Notes:

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Other Citation Details:

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Supplemental Information:

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Keywords

Theme Keywords

Thesaurus Keyword
UNCONTROLLED
Enter the thesaurus that the keyword belongs to. Do not provide this node if no thesaurus exists. Pollock, Alaska, Acoustics

Physical Location

Organization: Alaska Fisheries Science Center
City: Seattle
State/Province: WA
Country: USA

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Files
Maintenance Frequency: None Planned
Data Presentation Form: Document (digital)
Entity Attribute Overview:

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Entity Attribute Detail Citation:

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Distribution Liability:

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Data Set Credit: Enter credits to external persons or organizations contributing to the data set.

Support Roles

Data Steward

CC ID: 1090975
Date Effective From: 2015
Date Effective To:
Contact (Person): Towler, Rick
Email Address: rick.towler@noaa.gov

Distributor

CC ID: 1090976
Date Effective From: 2015
Date Effective To:
Contact (Person): Anderson, Charles
Address: 325 Broadway, E/GC3
Boulder, CO 33149
Email Address: charles.anderson@noaa.gov
Phone: 303-497-4742

Metadata Contact

CC ID: 1090977
Date Effective From: 2014-07-31
Date Effective To:
Contact (Person): MC, Metadata Coordinators
Email Address: AFSC.metadata@noaa.gov

Originator

CC ID: 1090978
Date Effective From: 2014-07-31
Date Effective To:
Contact (Person): McCarthy, Abigail
Email Address: abigail.mccarthy@noaa.gov

Point of Contact

CC ID: 1090979
Date Effective From: 2015
Date Effective To:
Contact (Person): Jones, Darin
Email Address: darin.jones@noaa.gov

Extents

Extent Group 1

Extent Description:

Enter a general description of the extent, if any.

Extent Group 1 / Geographic Area 1

CC ID: 1090982
W° Bound: -170.1399
E° Bound: -141.1529
N° Bound: 60.127
S° Bound: 52.5667
Description

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Extent Group 1 / Time Frame 1

CC ID: 1090981
Time Frame Type: Range
Start: 2017-06-08
End: 2017-08-14
Description:

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Access Information

Security Class: Unclassified
Data Access Procedure:

Go to https://www.ngdc.noaa.gov/mgg/wcd/ or email Anderson, Charles (charles.anderson@noaa.gov)

Data Access Constraints:

The data set is still being analyzed and will not be available for distribution until it has been finalized and all QA/QC practices have been performed. Contact the Data Point Of Contact for estimated time of release.

Data Use Constraints:

User must read and fully comprehend the metadata prior to use. User must acknowledge the Originator when using the data set as a source. User must share data products developed using the source data set with the Originator. Data should not be used beyond the limits of the source scale.

Distribution Information

Distribution 1

CC ID: 1090984
Download URL: https://www.ngdc.noaa.gov/mgg/wcd/
Distributor:

URLs

URL 1

CC ID: 1090974
URL: https://www.ngdc.noaa.gov/mgg/wcd/
Name: Enter the name of the URL. Required for Browse Graphic URLs.
File Resource Format: Enter the file resource format
Description:

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Data Quality

Quality Control Procedures Employed:

These data were collected in accordance NOAA protocols for fisheries acoustics surveys and related sampling (Alaska Fisheries Science Center), 23 p. Prepared by Midwater Assessment and Conservation Engineering Program, Alaska Fish. Sci. Center, Natl. Mar. Fish. Serv., NOAA. Available online: http://www.afsc.noaa.gov/RACE/midwater/AFSC%20AT%20Survey%20Protocols_Feb%202013.pdf

Data Management

Have Resources for Management of these Data Been Identified?: No
Approximate Percentage of Budget for these Data Devoted to Data Management: Unknown.
Do these Data Comply with the Data Access Directive?: Yes
Is Access to the Data Limited Based on an Approved Waiver?: No
Approximate Delay Between Data Collection and Dissemination: 180
If Delay is Longer than Latency of Automated Processing, Indicate Under What Authority Data Access is Delayed:

If the delay between data collection and dissemination is longer than the latency of automated processing, explain under what authority data access is delayed. This field should only be included if the delay is longer than the latency of automated processing.

Actual or Planned Long-Term Data Archive Location: NCEI-CO
Approximate Delay Between Data Collection and Archiving: 180
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?:

IT Security and Contingency Plan for the system establishes procedures and applies to the functions, operations, and resources necessary to recover and restore data as hosted in the Western Regional Support Center in Seattle, Washington, following a disruption.

Lineage

Lineage Statement:

Acoustic data were recorded at the five split-beam frequencies using ER60 software and, as a backup, acoustic telegram data were logged with Myriax EchoLog 500 software. Acoustic measurements were collected from 16 m below the sea surface to within 0.5 m of the sounder-detected bottom or a maximum of 1,000 m in deep water. Data were analyzed using Myriax Echoview post-processing software. See National Marine Fisheries Service (NMFS) 2013. NOAA protocols for fisheries acoustics surveys and related sampling (Alaska Fisheries Science Center), 23 p. Prepared by Midwater Assessment and Conservation Engineering Program, Alaska Fish. Sci. Center, Natl. Mar. Fish. Serv., NOAA. Available online: http://www.afsc.noaa.gov/RACE/midwater/AFSC%20AT%20Survey%20Protocols_Feb%202013.pdf

Acquisition Information

Instruments

Instrument 1

CC ID: 1090972
Identifier: Simrad EK60
Docucomp UUID: b7ae3f00-701c-11e0-a1f0-0800200c9a66
Instrument / Gear: Instrument
Instrument Type: Singlebeam Echosounder
Description:

The Simrad EK60 Scientific Sounder system is a new generation fishery researchtool, based on experience from the EK500. The new electronic hardware is combined with up to date PC processing and Windows operation. The EK60 provides facilities for accurate echo sounding, data storage, data analysis and reporting results. The system communication is through Ethernet, which gives flexibility in the location of the EK60 system units and allows easy access to data from other instruments or stations on a vessel network. A post processing software, BI60, is also included in the EK60 system.

Catalog Details

Catalog Item ID: 65612
GUID: gov.noaa.nmfs.inport:65612
Metadata Record Created By: Darin Jones
Metadata Record Created: 2021-10-15 13:59+0000
Metadata Record Last Modified By: Abigail McCarthy
Metadata Record Last Modified: 2023-02-28 19:17+0000
Metadata Record Published: 2023-02-28
Owner Org: AFSC
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2023-02-28
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2024-02-28