Washington Pink Shrimp Fishery Shrimp Trawl Operations and Bycatch of Eulachon Smelt, Rockfish, and Flatfish: Technical Report No. FPT 16-13

The ocean pink shrimp (Pandalus jordani) trawl fishery is a vital component of Washington's coastal commercial fisheries. Beginning in the late 1950's the fishery expanded through the 1980's with landings peaking at 18 million pounds and then contracted in the following decade with annual landings less than five million pounds. Since the late 1990's, landings have generally increased, and the direct value of the fishery has trended continuously upward while fleet size has continued to decline. During this same period, annual shrimp landings into Washington averaged about 20% of the coastwide total for California, Oregon, and Washington combined. The fishery is state managed, although it is also subject to federal restrictions for groundfish catch and essential fish habitat through the Pacific Fishery Management Council Groundfish Fishery Management Plan (PFMC 2014). Management is accomplished through a state limited entry program with regulations for a fixed seven-month season, shrimp size restrictions, mandatory use of biological reduction devices, and logbooks.

In March 2010, the National Marine Fisheries Service listed the southern Distinct Population Segment of Thaleichthyus pacificus, also known as eulachon, as threatened under the Endangered Species Act (75 FR13012). The Eulachon Biological Review Team ranked bycatch second among the severity of threats impacting recovery of eulachon stocks (Gustafson et al. 2010). At that time, bycatch data was lacking for the Washington ocean shrimp trawl fishery which encounters eulachon on the fishing grounds. In this study, we evaluate various factors influencing the catch of eulachon, rockfish, and flatfish species. Observers were deployed aboard Washington shrimp trawl vessels in 2011 and 2012 to collect catch composition data at the tow level. In 2011, 24% of trips were observed. In 2012, following reduced funding, 16% of trips were observed. During these two comparatively strong years for pink shrimp production, with landings at 9.6 and 9.3 million pounds respectively, eulachon bycatch was estimated at 7.8 metric tons (17,100 pounds) for 2011 and 171 metric tons (378,011 pounds) for 2012. The increase in eulachon bycatch occurred at the same time fishery regulations reduced the allowable bar-spacing for fin fish excluders from 2 inches (51 millimeters) to 0.75 inches (19 millimeters) in 2012. Flatfish species bycatch was estimated at 27 metric tons (60,000 pounds) and 54 metric tons (119,000 pounds), and rockfish species bycatch at 3.2 metric tons (7,000 pounds) and 1.8 metric tons (4,700 pounds), in 2011 and 2012, respectively. Bycatch data were analyzed for gear, temporal, and spatial effects. Results indicate a reduction in bycatch volume by excluders with narrower (1 inch and less) bar-spacing in the panel, compared to wider (more than 1 inch) barspacing, but not a significant difference among the excluders with sub 1 inch bar spacing. Other effects, including fishing month, depth, latitude, and tow duration were found in some instances to be statistically significant, but not biologically meaningful.