Oregon Fishery-Independent and -Dependent Data
The commercial non-whiting groundfish fishing industry and corresponding research activity have a long concurrent history on the Oregon continental shelf. Although federal fisheries-independent surveys have been conducted across most of the groundfish fishery’s depth range, data is limited by years and seasons surveyed as well as absence of data in the shallowest waters (< 55 m). Fishery-dependent data (logbooks) covers those shallow waters and a broader temporal range, but it is self-reported. Limitations in data coverage combined with a historical focus on continental slope-dwelling groundfishes has led to a gap in understanding of dynamics within the nearshore fishery. In this chapter I analyzed spatial and temporal changes in catch, as well as gaps in fishery and scientific survey data, for six flatfishes in the Oregon nearshore non-whiting groundfish trawl fishery. Visualization of both fishery-independent (NOAA survey) and -dependent (logbook and landings) data allowed for a qualitative comparison of data coverage as well as an assessment of differences in species distribution when mapping data in each dataset. These analyses illuminate where knowledge gaps lie in both data types and how they complement one another, providing more context for future management of nearshore groundfishes. I found that the earliest years of the NOAA surveys (1980 – 1998) have the most information gaps and had the highest potential to benefit from complementary use of fishery-dependent data for spatial and temporal analyses. This was largely due to (1) triennial rather than annual sampling and a transect-based design in the NOAA surveys, and (2) the larger spatial and temporal coverage of logbook data (inshore and latitudinal) during that period. Commonly caught species, like Dover sole and petrale sole, had better spatial sampling coverage of their populations compared to species that live in shallow water and are less frequently targeted, such as starry flounder and sand sole. Overlap between datasets was variable but often highest near the two largest ports: Astoria and Newport, OR. There is limited previous work that uses logbook data for visual analyses, and it primarily assesses rockfishes. Only one previous comparison has been made between the two data sources. This work provides a new perspective by comparing four decades of NOAA survey data and logbooks to illustrate the potential utility of fishery-dependent data for future analyses of Oregon flatfishes.