< Back to Northeast Dashboard

Has quality of fishery data changed with changes in observer coverage?

Indicators: Observer Coverage

Key Findings

Implementation of the Sector Program coincided with a large decrease in the number of fishing days-at-sea (DAS) and an increase in observer coverage compared to the baseline period. However, the exact increase in coverage is difficult to determine, in part as a result of the heterogeneity of the fisheries and observer allocation among trips, as well as differences in data recording. We assessed changes via two methods. The first was NOAA-estimated observer coverage levels, and the second was from NOAA-reported DAS and observed DAS for fisheries more specific to the Sector Program. Both methods indicate that the observer coverage increased sharply to 39 percent in 2010, the first year of the Sector Program. Available data from the NOAA-estimated combined “groundfish trawl and sink gillnet” fisheries shows a nearly four-fold increase in observer coverage from 2009 to 2011. Both methods indicate observer coverage during the Sector Program was higher than 25 percent, compared to baseline levels that ranged from less than 2 percent to 16 percent, depending on estimation method or year.

Interactive Charts


This indicator measures the proportion of fishing activity that is observed by third-party individuals on fishing vessels.


Baseline: Before Catch Share Program (2002-2010)

At-sea observers are placed on vessels participating in the Northeast multispecies fishery through the Northeast Fishery Observer Program (NEFOP) to collect data needed for managing the fishery. The multispecies fishery is one of several fisheries observed under this program. The number of observed sea days depends on available funding (Cost of Fishery Management: Public). The number of observed sea days for bottom otter trawls increased from 2002-2005, with a decrease in 2006 and subsequent increase through 2009. Days-at-sea (DAS) estimates for the large mesh multispecies groundfish fishery decreased from 2003-2004 and then remained relatively constant for the remainder of the baseline period. The resulting estimates of proportion of observer coverage mirrored the trend in the number of observed sea days over the baseline period (initial increases, followed by decreased coverage in 2006 and subsequent increases). In estimates of total observer coverage in the combined groundfish trawl and sink gillnet fisheries, similar trends were observed. While the inter-annual trends are similar, the precise levels of observer coverage in the baseline period differ between estimation methods.

During Catch Share Program

With implementation of the Sector Program in 2010, NMFS also implemented the At-Sea Monitoring (ASM) Program to provide additional observer coverage for sector vessels. The ASM program aims for 30 percent observer coverage on multispecies vessels enrolled in sectors, meaning that observer coverage after 2009 increased significantly within the Sector Program. The number of observed sea days following implementation of the Sector Program increased, with a decrease in large mesh multispecies DAS, resulting in a twofold increase to 39 percent in the observer coverage estimate. It is worth noting that while sector vessels are exempt from DAS requirements, monitoring DAS continues to be used to determine the directed nature of the fishing trip for placing observers. Observer coverage for the combined groundfish trawl and sink gillnet fisheries increased to over six times from the 2005-2009 average. Coverage levels for the combined fisheries remained the same from 2010-2011 and decreased to 25 percent in 2012. For more information on Northeast observer coverage, see Cost of Fishery Management: Private.

Data Gaps and Limitations

The quality of data available for managing the fishery depends on many factors, including catch-accounting, speed at which data become available, and the degree of detail of data. Here we assessed a relatively simple, but important, metric of data quality: the fraction of days-at-sea that had on-board observers to monitor the catch.

Data needed to independently estimate coverage levels (fractional DAS observer coverage) were not available for all time periods. The chief limitation was the lack of matching between how publications and reports summarize total fleet DAS and observed DAS. Total fleet DAS are listed for the large-mesh groundfish fishery, while the observed days-at-sea is the entire groundfish trawl fishery. Observed DAS were not available for the entirety of the 2012 FY and were therefore omitted from analysis. NOAA-generated estimates of observer coverage aggregate fleets together, so the best match is the aggregated groundfish-sink gillnet fisheries. The latter is likely a decent proxy for trends in the degree of observer coverage, as groundfish days at sea outnumber sink gillnet days at sea. Fishing effort for the sink anchor drift gillnet fishery appears to be approximately one-quarter to one-third that for all otter trawls, making the combined fleet percentages a decent proxy for observer coverage in the multispecies groundfish fishery.

Information Sources

Murphy T, Kitts A, Records D, Demarest C, McPherson M, Walden J, Caless D, Bing-Sawyer E, Steinback S, Olson J. 2012. 2011 Final Report on the Performance of the Northeast Multispecies (Groundfish) Fishery ( 2011-April 2012). Available online: http://www.nefsc.noaa.gov/publications/crd/crd1230/

National Observer Program annual reports (2005-2012). Data included percent observer coverage for the New England groundfish trawl and sink gillnet fisheries. Available online: http://www.st.nmfs.noaa.gov/observer-home/reports/nopannualreports/index

Northeast Fisheries Observer Program Incidental Take reports (2002-2012). Data included observed sea days for all bottom trawls. Available online: http://www.nefsc.noaa.gov/fsb/take_reports/nefop.html

Greater Atlantic Regional Fisheries Office Allocation Management System database (2002-2009). Data included days-at-sea. Available online: http://www.nero.noaa.gov/ro/fso/das.htm

Updated: February 2014

© 2017 MRAG Americas, Inc. All Rights Reserved.