WSG-AS 16-05

Trends in Seabird Bycatch in Alaska Longline Fisheries 1993–2015

he following analysis was conducted to eval- ALBATROSS BYCATCH AFTER ADOPTION uate progress toward reducing albatross by- OF STREAMER LINES catch in the Alaska longline fisheries and to Although albatross bycatch rates decreased dramati- T suggest where performance might be im- cally with the adoption of streamer lines, they varied proved. Seabird bycatch rates (birds per million considerably year to year and showed an increasing hooks for all figures) for Alaska longline fisheries trend driven by the sablefish fishery and, to a lesser were derived from data collected by the NOAA extent, the halibut fishery. Extrapolating to the entire Fisheries North Pacific Observer Program. Results fleet, NOAA Fisheries estimated that 594 albatrosses are from observed haul samples and were not ex- were taken in Alaska longline fisheries in 2015. trapolated beyond the sample or to the entire fleet. Mean albatross bycatch rates by target species after streamer PRE- VERSUS POST-STREAMER LINES line adoption. ■ ■ ■ ■ Research with the fishing industry in 1999 and 2000 SABLEFISH HALIBUT PACIFIC COD TURBOT showed that properly used streamer lines could * dramatically reduce the bycatch of seabirds. With * the voluntary adoption of streamer lines by Alaska * fleets in 2002 (required in 2004), seabird bycatch rates decreased dramatically compared with the pre-streamer-line period of 1993–2001. As a result, albatross bycatch rates decreased by 89% while the bycatch rates for non-albatross seabirds (primarily

northern fulmar, gull species and shearwater spe- RATE BYCATCH ALBATROSS cies) decreased by 77%.

Mean albatross and non-albatross seabird bycatch rates, *The NOAA Fisheries North Pacific Observer Program began monitoring 1993–2015. the Pacific halibut fishery and smaller vessels in 2013. Albatross NonAlbatross 10 ◆ ALBATROSS BYCATCH RATE 140 ■ NON-ALBATROSS BYCATCH RATE Sablefish In the sablefish fishery, albatross bycatch 120 8 rates were highest off the Aleutian Islands but rates 100 were similar among the three Gulf of Alaska regions.

6 Laysan albatrosses were caught at higher rates in the 80 western Gulf of Alaska and black-footed albatrosses 60 4 were caught at higher rates in the eastern Gulf of Alas- ka. Also in the sablefish fishery, albatross bycatch rates Albatross bycatch rate 40 Non Albatross bycatch rate were 17 times lower in sets made at night than in those 2

ALBATROSS BYCATCH RATE BYCATCH ALBATROSS 20 made during the day. Of the 178 vessels observed in

NON-ALBATROSS BYCATCH RATE BYCATCH NON-ALBATROSS the sablefish fishery from 2013 to 2015, only 32 had

0 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 0 albatross bycatch. Of those, five vessels accounted for 56% of the 94 albatrosses taken in the observer sample, suggesting that estimates of total fleet alba- tross bycatch are driven by a few vessels. NON-ALBATROSS BYCATCH AFTER Mean non-albatross bycatch rates by target species after ADOPTION OF STREAMER LINES streamer line adoption. ■ ■ ■ ■ The bycatch rates of non-albatross seabirds were SABLEFISH SablefishHALIBUTHalibut PacificPACIFIC Cod CODTurbot TURBOT considerably higher and more variable year-to-year 180 compared with albatrosses (see other side); they 160 were driven by the turbot fishery and show a de- 140 creasing trend in recent years. Extrapolating to the entire fleet, NOAA Fisheries estimated that 4,698 120 non-albatross seabirds were taken in Alaska longline 100 fisheries in 2015. The bycatch rates of non-albatross 80 seabirds were two to three times lower in the eastern bycatch rate per million hooks 60 Gulf of Alaska than in the other management areas. Of albatross the 374 vessels monitored from 2013 to 2015 (all - 40 Non NON-ALBATROSS BYCATCH RATE BYCATCH NON-ALBATROSS target species), 58 vessels had non-albatross seabird 20 bycatch. Of those, five vessels accounted for 42% of 0 the 1,627 non-albatross seabird takes in the observer 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 sample, suggesting that, similar to albatross, estimates of total fleet non-albatross bycatch are driven by a few vessels. Unlike those for albatrosses, mean bycatch PERFORMANCE rates of non-albatross seabirds in the sablefish Alaska longline fisheries represent one of the few case fishery were 1.4 times higher in sets made at night histories where successful bycatch research translated than those made during the day, driven by a four-times into a dramatic bycatch reduction in a commercial higher rate of northern fulmar bycatch at night. fishery. This success is a testament to the value of collaborative research with the fishing industry and ■ ■ Mean albatross bycatch BLACK-FOOTED LAYSAN the commitment of Alaska longline fishermen to rates in the sablefish fishery by management area after seabird conservation. Comparing estimated seabird adopting streamer lines bycatch before and during the 14 years since streamer (2002–2015). lines were adopted, roughly 9,400 albatrosses and 141,000 non-albatross were saved. The increasing trend in albatross bycatch rates in the sablefish fishery suggests that performance could be improved in this fishery by paying more attention to the proper use of seabird bycatch prevention strategies, especially on

ALBATROSS BYCATCH RATE BYCATCH ALBATROSS the few vessels with high bycatch rates.

AI W-GOA C-GOA E-GOA Photo courtesy of Washington Sea Grant.

Mean albatross and non-albatross bycatch rates in the sablefish fishery for day vs. night sets after adopting streamer lines (2002–2015).

■ BLACK-FOOTED ■ FULMAR ■ GULL ■ LAYSAN ■ SHEARWATER ■ OTHER

University of Washington wsg.washington.edu

WSG-AS 16-05 • 1-17 ALBATROSS BYCATCH RATE BYCATCH ALBATROSS Day Night NON-ALBATROSS BYCATCH RATE BYCATCH NON-ALBATROSS Day Night Day and night are defined by civil twilight.