Benthic infauna and epifauna assemblages as efh component



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Essential Fish Habitat project status report 

 

Reporting date: 10/31/08 



 

Project number: 2008-08 

 

Title: Characterization of Benthic Infauna Community for Modeling Essential Fish 



Habitat in the Eastern Bering Sea 

 

PIs: Cynthia Yeung, Mei-Sun Yang, Robert McConnaughey 



 

Funding year: 2008 

 

Funding amount: 66,500 



 

Status: 


 Complete 

 Incomplete, on schedule   

 Incomplete, behind schedule 

 

Planned completion date if incomplete: 



 

Stomach collection was completed in August 2008.  Processing of stomach samples is in 

progress and on schedule. 

 

Infauna and sediment grab sampling is incomplete and behind schedule.  The NOAA ship 



Fairweather on which sampling was scheduled during July 21-August 9, 2008 was 

unable to sail for lack of an engineer.  Eventually, only two of the original 19 scheduled 

sea days were salvaged, one of which was required for round-trip transit to the study area.  

One of three passes on one of six planned acoustic transects and three of 31 planned grab 

stations were sampled in the remaining time (Fig. 1). 

 

A new proposal has been submitted to EFH FY09 for funds to complete the project.  



Additional ship days are proposed on a chartered vessel for the 2009 RACE EBS trawl 

survey to collect grab samples.  Contingent on supplemental EFH funding, the project 

will be completed one year behind schedule: 

     August 2009 – infauna and sediment grab sampling; stomach collection completed. 

     February 2010 - sample processing completed. 

     June 2010 - data analysis and reporting completed. 

 

Reporting: Have the project results been reported? If yes, where were the results 



reported? 

 

No. 



 

Results: What is the most important result of the study? 

 

Sediment properties and benthic infauna community are defining habitat characteristics 



for certain fish species.  Infauna compose a significant portion of the diets of these 

 




species, and sediment properties are the main structuring force of infauna communities.  

The strength of this relationship is examined by investigating the spatial correspondence 

between fish diet and infauna distribution, and the predictability of infauna community by 

sediment properties. 

 

We requested the collection of 15 stomachs per fish species (6) per station at 27 of the 31 



planned infauna and sediment grab stations (Fig. 1) on the 2008 EBS bottom trawl survey 

(total stomachs requested=1620).  We requested that, if possible, the 15 stomachs for 

each species be obtained from three length classes (<20 cm, 20-40 cm, >40 cm) in equal 

numbers (5).  Collection was not requested at all 31 stations because effort was a concern.  

Actual numbers obtained were: 229 Alaska plaice (AKP); 260 yellowfin sole (YFS); 286 

northern rock sole; 215 flathead sole (FHS); 70 long head dab (LHD); 10 spinyhead 

sculpin (SHS); (total stomachs collected=1,070).  The number of stomachs collected from 

target groundfish species at each grab station is given in Table 1.  Length class 

distribution of these stomachs by species is being determined.  Stomach content analysis 

is in progress. 

 

Results showed the feasibility, effort-wise, to collect stomachs on the trawl survey even 



at all planned grab stations (31), since the actual number of stomachs attained will still 

likely be far less than the targeted number.  Hence, ship time and man power 

requirements would still be manageable. 

 

Due to loss of ship time, only three of 31 infauna and sediment grab stations were 



sampled in 2008 (Fig. 1).  Infauna analysis is in progress.  Granulometric analysis of 

sediment samples has been completed (Table 1).  Geochemical analysis of the 2008 

sediment samples will be run together with the additional sediment samples to be 

collected in 2009 with supplementary EFH FY09 funding.  This would be the most cost-

efficient way to proceed.  However, if funding is not available, analysis will proceed on 

the 2008 samples only.  

 

 

Table 1.  Classification of sediments collected in July-August 2008 with van Veen grab 



on the NOAA ship Fairweather, and the corresponding numbers and species of stomach 

samples collected in the same period during the bottom trawl survey on FV Arcturus and 



Aldebaran.   

Sediment Stomachs 

station  lat 

lon  type %gravel %sand %mud station LHD AKP NRS YFS FHS SHS

A02 55.00 

166.95 


SM  0.0  48.8 51.2  A02

0

0



0  0 15

11

X10* 56.44 164.44 MS  0.0 



62.5  37.5 

E06


0

2

15  10  0



0

F07 56.67 

164.00 

MS 0.0  59.8 40.2  F07



0

15

15 15  0



0

 

 



 

 

 



 

 

 



 

 

 



 

 

 



 

 

 



*~17 km (~9 nmi) NE of E06 in same trawl cell; see Fig. 1  

 

 



 

 

 



 

 

 



type – SM=sandy mud; MS=muddy sand   

 

 



 

 

 



 

 

 



 

 

 



 




 

Benthic sampling data from the 2008 project will be added to the dataset of 26 such 



samples taken in the EBS in 2006 (Fig. 1), with the eventual goal of building a shelf-scale 

analysis of infauna-sediment associations. 

 

A new EFH proposal under the same title has been submitted for FY09 to complete grab 



sampling for this 2008 EFH project.  The research plans to fulfill 2008 EFH project goals, 

continue building databases of benthic infauna communities and sediment characteristics 

in the EBS, and generate inputs to advance habitat modeling.  Sampling is proposed to be 

conducted on a chartered EBS trawl survey vessel.  Stomach collection will be requested 

again as a 2009 EBS trawl survey special project to (1) compare concomitantly-collected 

data on infauna prey field and fish diet, (2) augment sample sizes for certain 

species/length sizes, and, if sample sizes are adequate, (3) compare interannual variability 

of diet. 



 


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