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Data Collected by Observers

Objective: This system is designed to provide visitors a tool to better understand where fish and invertebrates are caught in the Bering Sea/Aleutian Islands (BSAI) and Gulf of Alaska (GOA) groundfish fisheries by examining data collected by observers.


Description: The underlying information for these maps comes from a database of observer samples maintained by the Fisheries Monitoring and Analysis (FMA) Division of the Alaska Fisheries Science Center. Information collected by observers, together with catch and production reports submitted by the fishing industry, provide the basis for estimating overall catches from the GOA and BSAI. The portion of the catch sampled by observers varies by region, vessel-type, gear-type, and target fishery. Since 2001, vessels with observers in the BSAI have accounted for approximately 90% of the groundfish tonnage caught and observers have sampled the catch from about three-fourths of the hauls/sets. Vessels with observers in the GOA have accounted for approximately 40% of the groundfish tonnage caught and observers have sampled the catch from about two-thirds of the hauls/sets.

Appropriate Usage: Since all fishing operations are not observed, neither the maps nor the data can be used to characterize the fisheries completely. Furthermore, estimates of the composition of observed catches or sets are generally determined by expanding sample catch compositions recorded by observers. These maps present aggregate catch composition only from observed hauls and sets and expanded as described above and will not always provide an accurate portrayal of catches of target and non-target species by the whole fleet. Inaccuracies will be greatest for rarely-occurring species and when sample sizes are relatively small. We caution users about making simple expansions from these data because of the complexity of the groundfish fisheries and the fleets which harvest them.

Confidentiality: Cells representing less than 3 vessels of a particular gear type and calendar year are not shown due to confidentiality issues. For more information on the amount of information available to the public see the Data Availability Page.



Links to Observer Data:

These data are from years 1993-2007. Updated June 2008.

Interactive Maps

 Download Data from Maps

Download Shape File of Maps

Rockfish Map

Rockfish Data

Rockfish Shape File

Other Fish A-K Map

Other Fish A-K Data

Other Fish A-K Shape File

Other Fish L-P Map

Other Fish L-P Data

Other Fish L-P Shape File

Other Fish R-Z Map

Other Fish R-Z Data

Other Fish R-Z Shape File

Invertebrate Map

Invertebrate Data

Invertebrate Shape File

Description of Maps

Format of Data Files

Metadata for Shape Files

Download the Map Grid Shapefiles

For information regarding data presented on this web page contact Ren Narita


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