To trawl or not to trawl: Questioning core assumptions of trawl placement choice in fisheries acoustics surveys

Thomas, Rebecca E.; Gauthier, Stéphane; Grandin, Chris; Hicks, Allan; Parker-Stetter, Sandy

doi:10.1016/j.fishres.2023.106897

Advanced Search

Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

Advanced Search
Custom Query

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields

Language:

Dates

Publication Date Range:

to

Document Data

Title:

Document Type:

Library

Collection:

Series:

People

Author:

Clear All

Query Builder

Query box

Clear All

For additional assistance using the Custom Query please check out our Help Page

i

To trawl or not to trawl: Questioning core assumptions of trawl placement choice in fisheries acoustics surveys

2024
By Thomas, Rebecca E. ; Gauthier, Stéphane ; Grandin, Chris ; ...
Source: Fisheries Research, 270, 106897

[PDF-2.91 MB]

Details You May Also Like

Details:

Journal Title:

Fisheries Research
Personal Author:

Thomas, Rebecca E. ; Gauthier, Stéphane ; Grandin, Chris ; Hicks, Allan ; Parker-Stetter, Sandy

Thomas, Rebecca E. ; Gauthier, Stéphane ; Grandin, Chris ; Hicks, Allan ; Parker-Stetter, Sandy Less -
NOAA Program & Office:

NMFS (National Marine Fisheries Service) ; AFSC (Alaska Fisheries Science Center) ; NWFSC (Northwest Fisheries Science Center)

NMFS (National Marine Fisheries Service) ; AFSC (Alaska Fisheries Science Center) ; NWFSC (Northwest Fisheries Science Center) Less -
Description:

In acoustic-trawl surveys, acoustic echosign needs to be biologically characterized, and if done correctly, will lead to accurate biomass estimates, robust stock assessments, and ensuing healthy fish stocks. However, methods for validating the core assumption that trawl placement choice yields a representative sample of the associated echosign (given an ideal net) are rarely described. Therefore we detail several such methods, using Pacific hake as a case study, exploiting both historic survey data as well as additional field experimental data. Specific methods focused on validation of (1) trawl effort spatially matching backscatter distributions, (2) trawled-location backscatter amounts matching all-location backscatter amounts, (3) trawled depth matching backscatter depth, and (4) spatial homogeneity of fish length within an aggregation. Application of the methods to the adult Pacific hake survey generally validated the assumption that trawl placement choice yielded a representative sample of the associated echosign, except for two instances. The backscatter from fished aggregations was greater than that from general aggregations in one of the two survey years analyzed. In addition, experimental field data detected a slight but significant trend of longer fish in the offshore portion of an aggregation. Neither of these occurrences are expected to yield a bias in the biomass estimate of Pacific hake.
Keywords:

[+]

Aquatic Science
Source:

Fisheries Research, 270, 106897
DOI:

https://doi.org/10.1016/j.fishres.2023.106897
ISSN:

0165-7836
Format:

PDF
Publisher:

Elsevier BV
Document Type:

Journal Article
License:

https://creativecommons.org/licenses/by/4.0/
Rights Information:

CC BY
Compliance:

Submitted
Main Document Checksum:

[+]

urn:sha256:3ef01292864e6d39dbf02db015a79d2abab642fbae49e4a4ddf24c2503d60655
Download URL:

https://repository.library.noaa.gov/view/noaa/56149/noaa_56149_DS1.pdf
File Type:

No Additional Files

More +

To trawl or not to trawl: Questioning core assumptions of trawl placement choice in fisheries acoustics surveys

Details:

Supporting Files

You May Also Like