Improving area swept estimates from bottom trawl surveys

2011 ◽  
Vol 110 (1) ◽  
pp. 198-206 ◽  
Author(s):  
Stan Kotwicki ◽  
Michael H. Martin ◽  
Edward A. Laman
Keyword(s):  
Bottom Trawl ◽  
Trawl Surveys

Vertical Distribution of Fish Biomass in Lake Superior: Implications for Day Bottom Trawl Surveys

2007 ◽  
Vol 27 (3) ◽  
pp. 735-749 ◽  
Author(s):  
Jason D. Stockwell ◽  
Daniel L. Yule ◽  
Thomas R. Hrabik ◽  
Jean V. Adams ◽  
Owen T. Gorman ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Lake Superior ◽  
Bottom Trawl ◽  
Fish Biomass ◽  
Distribution Of Fish ◽  
Trawl Surveys

scholarly journals Acoustic data collected during and between bottom trawl stations: consistency and common trends

2007 ◽  
Vol 64 (1) ◽  
pp. 166-180 ◽  
Author(s):  
Nicolas Bez ◽  
David Reid ◽  
Suzanna Neville ◽  
Yves Vérin ◽  
Vidar Hjellvik ◽  
...  
Keyword(s):  
Bottom Trawl ◽  
Vertical Profiles ◽  
Spatial Structures ◽  
Acoustic Measurements ◽  
Acoustic Data ◽  
Global Indices ◽  
Abundance Estimates ◽  
Before And After ◽  
Systematic Perturbation ◽  
Trawl Surveys

Acoustic data are often collected during bottom trawl surveys. Their use can potentially improve the precision and accuracy of fish abundance estimates if acoustic data collected between trawl stations are consistent with those collected during trawling operations. This question is addressed here through the analysis of 20 bottom trawl surveys (three survey areas and five different survey series) with coincident acoustic measurements during and between trawl stations. Firstly, on-station and underway acoustic data were compared using statistics computed globally over each survey (average vertical profiles, global indices of collocations, and spatial structures) for various combinations of depth layers. Secondly, we focussed on underway acoustic data recorded in the vicinity of stations, distinguishing between data recorded before and after the tows. On-station and underway acoustic data were highly consistent, and no systematic perturbation of the acoustic sign due to the presence of the gear a few hundred metres behind the vessel was observed.

scholarly journals Some updates to the method for calculation of parameters of bottom trawl system

2016 ◽  
Vol 184 (1) ◽  
pp. 253-263
Author(s):  
Egor A. Zakharov ◽  
Oleg N. Kruchinin
Keyword(s):  
Experimental Data ◽  
Transcendental Equation ◽  
Geometric Parameters ◽  
Bottom Trawl ◽  
Fishing Gear ◽  
Calculation Of Parameters ◽  
Trawl Surveys

The method for calculation of geometric parameters of trawl system proposed by F.I. Baranov is analyzed. The calculation includes evaluation of spacer force and drag for all elements of trawl system and solution of transcendental equation to find a distance between the otter boards of bottom trawl. Special attention is paid to considering and enhancement of common techniques for determining force and geometric parameters of some elements of trawl system, with identifying the most appropriate ways. The calculations and experimental data are compared for a trawl system using the Scanmar equipment for monitoring of fishing gear. The updated model simulates more adequately the forming of bottom trawl geometry, therefore it can be used for assessment of the catch area during trawl surveys conducted by bottom trawls.

scholarly journals FISHERY RESOURCES IN THE WEST COAST OF ACEH AFTER TSUNAMI: RESULTS OF THE BOTTOM TRAWL SURVEYS

2017 ◽  
Vol 13 (2) ◽  
pp. 55
Author(s):  
Wijopriono Wijopriono ◽  
Wedjatmiko Wedjatmiko ◽  
Suprapto Suprapto
Keyword(s):  
West Coast ◽  
The State ◽  
Bottom Trawl ◽  
The West ◽  
Fishery Resources ◽  
Aceh Province ◽  
Trawl Surveys

Investigation on fishery resources in the west coast of Aceh Province was carried out during July until August 2005 and August until September 2006. One of the objectives of the investigation was to determine the state of demersai stock after the area severely hit by tsunami in December 2004.

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