Atlantic wolffish

Anarhichas lupus


Technical report
Published by

Marine and Freshwater Research Institute, Iceland

Published

12 June 2026

Key signals

  • Biomass indices have declined across all survey parameters following a peak in 2022–23, and fishing mortality now exceeds Fmsy, Fpa, and Fmgt.

  • Recruitment index (≤40 cm) declined to a historical minimum in 2011, recovered through 2023, and has since declined again toward critically low levels.

  • Spawning stock biomass still remains above Blim, Bpa, and MGT Btrigger, though current exploitation levels are slightly above reference points.

  • Although survey indices are declining, commercial catch data suggest that the wolffish stock remains in balance, which is confirmed by the stock assessment.

  • Continued closure of the Látragrunn spawning area during the spawning and incubation season is recommended.

General information

The Atlantic wolffish is a long-bodied species with a large head, characterized by prominent canine teeth for seizing prey and powerful molars for crushing it. Most individuals caught measure between 50 and 80 cm in length, although the largest specimen recorded in Icelandic waters reached 125 cm. The species is most commonly found on the continental shelf northwest of Iceland. Its feeding grounds are typically located on muddy or sandy bottoms at depths shallower than 100 meters. In contrast, spawning grounds are found on coarser substrates featuring crevices or cavities, generally at depths greater than 100 meters.

Fishery

The primary fishing grounds for Atlantic wolffish are located on the western and northwestern parts of the Icelandic continental shelf. Since 2010, the proportion of the catch taken in the northwest has increased, while it has declined in the west. Catches at the main spawning ground, Látragrunn (west of Iceland), have decreased since 2008 (Figure 1; Figure 2). Notably, part of this area has been closed to trawling during the spawning and incubation period since 2010. Approximately 80% of the Atlantic wolffish catch is taken at depths shallower than 120 m. The proportion of the catch from the 0–60 m depth range increased in 2017 and has remained stable since. In the 61–120 m depth range, the catch proportion has remained relatively stable since 2000. At depths of 121–180 m, which include the main spawning ground at Látragrunn, the catch proportion has been declining over the past decade (Figure 3). Atlantic wolffish are primarily caught by longliners, demersal trawlers, and demersal seiners (Figure 4). The relative contributions of these fleets have changed in recent years, with demersal seiners increasing their share to approximately one-third of the total catch (Figure 4). Since 2001, the number of vessels reporting annual Atlantic wolffish catches of 10 tonnes or more has declined. This reduction is mainly attributable to the longline fleet, where the number of vessels decreased from 195 in 2001 to 29 in 2025, representing the lowest level since 2000. The number of trawlers and demersal seiners has varied over time but without marked long-term trends (Table 1). In 1994 and 1995, more than 500 vessels accounted for 95% of the annual Atlantic wolffish catch in Icelandic waters. This number declined to approximately 200 vessels by 2008, despite higher catch levels. Since 2010, the number of vessels accounting for 95% of the annual catch has remained relatively stable (approximately 150–200 vessels), despite reductions in total catch (Figure 5).

Figure 1: Atlantic wolffish. Geographical distribution of the Icelandic fishery over the past 9 years, based on reported logbook catch data.
Figure 2: Atlantic wolffish. Spatial distribution of the Icelandic fishery by fishing area since 2000 according to logbooks. All gears combined.
Figure 3: Atlantic wolffish. Depth distribution of demersal trawl, longline and demersal seine catches according to logbooks.
Figure 4: Atlantic wolffish. Total catch (landings) by fishing gear since 1994, according to statistics from the Directorate of Fisheries.
Figure 5: Atlantic wolffish. Number of vessels (all gear types) accounting for 95% of the total catch annually since 1994. Left: Plotted against year. Right: Plotted against total catch. Data from the Directorate of Fisheries.
Table 1: Atlantic wolffish. Number of Icelandic boats and catches by fleet segment participating in the Atlantic wolffish fishery from logbooks.
Year nr. longlines nr. trawlers nr. demersal seiners nr. other Longline Demersal trawl Demersal seine Total catch
2000 161 53 16 0 8 687 3 380 528 12 595
2001 195 59 14 1 11 267 3 391 513 15 182
2002 140 44 13 0 7 773 3 735 601 12 110
2003 138 45 19 0 7 785 5 463 1 066 14 313
2004 103 34 29 0 4 670 4 773 1 609 11 052
2005 91 47 24 1 5 445 6 893 1 140 13 508
2006 120 48 25 0 6 626 6 286 1 149 14 061
2007 105 60 24 0 5 259 7 566 1 338 14 163
2008 87 60 22 3 4 663 6 960 1 427 13 093
2009 114 55 28 1 6 708 5 468 1 205 13 391
2010 74 46 20 3 5 916 4 436 842 11 286
2011 64 37 18 0 5 344 3 565 1 010 9 918
2012 66 24 22 1 5 328 2 827 895 9 091
2013 73 30 18 2 4 652 2 341 647 7 662
2014 70 23 13 1 3 681 1 637 891 6 220
2015 56 34 17 2 3 989 1 905 926 6 848
2016 61 37 18 2 4 848 1 662 1 127 7 661
2017 59 28 18 2 3 829 1 102 1 095 6 049
2018 60 37 27 6 4 923 1 587 2 186 8 770
2019 64 34 21 1 4 595 1 630 2 168 8 404
2020 46 38 24 1 2 491 2 046 2 040 6 588
2021 45 48 22 0 3 343 3 021 2 086 8 451
2022 40 48 23 0 2 506 2 981 2 223 7 710
2023 34 49 20 0 2 899 2 755 2 346 8 000
2024 37 45 24 0 2 405 2 914 2 826 8 145
2025 29 46 24 0 2 096 3 460 3 056 8 612

Catch per unit of effort from commercial fisheries

CPUE estimates of Atlantic wolffish in Icelandic waters are not considered representative of stock abundance, as changes in fleet composition, technological improvements and differences in gear setup, among other factors, have not been accounted for in the estimation of CPUE. Non-standardized estimates of CPUE for longline (kg/1000 hooks), demersal trawl (kg/hour) and demersal seine (kg/set) are calculated as the total catch weight from sets or tows in which Atlantic wolffish constituted more than 10% of the catch, according to logbook records.

CPUE for longline vessels was relatively stable prior to 2018, fluctuating around 75 kg/1000 hooks; however, it doubled between 2020 and 2025 and has remained high since. CPUE of demersal trawl was highest in 2005 and 2015, at approximately 270-300 kg/hour. Between these years, it dropped below 200 kg/hour and has remained around that level since. CPUE of demersal seine increased from just under 400 kg/set to around 650 kg/set during 2020-2023 and is currently at its highest level (Figure 6).

In summary, there is a contrast in recent trends among gear types: over the past five years, CPUE for bottom trawl has remained stable, while CPUE for demersal seine and longline has increased.

CPUE data are not used in the stock assessment, as they do not reliably reflect trends in stock abundance.

Figure 6: Atlantic wolffish. Non-standardized estimates of CPUE for demersal trawl (left, kg/h), demersal seine (middle, kg/sets) and longline (right, kg/1000 hooks).

Landings and discards

Landings by Icelandic vessels are obtained from the Icelandic Directorate of Fisheries. Landings of Norwegian and Faroese vessels are given by the Icelandic Coast Guard. Discarding is banned by law in the Icelandic demersal fishery. Measures in the Icelandic management system such as converting quota from one species to another are used by the Icelandic fleet to a large extent, and is thought to discourage discards in mixed fisheries.

Data and sampling

Commercial data

The commercial catch samples taken should be representative of the landings with most number of samples taken in areas of high catch intensity. In general, sampling from commercial catches is considered acceptable from the main gears (demersal seines and trawls). The sampling seems to follow the spatial and seasonal distribution of catches (Figure 8 and Figure 7).

Figure 7: Ratio of samples by month (bars) compared with proportion landings by month (solid black line) split by year and main gear types. Numbers of above the bars indicate number of samples by year, month and gear.
Figure 8: Atlantic wolffish. Spatial distribution of length samples (crosses) from commercial catches in Icelandic waters.

In 1969-1997, on average 500 otoliths were sampled annually, except in 1970, 1973, and 1974 when no otoliths were sampled. In 1999, the effort of sampling Atlantic wolffish from commercial catch was increased. The number of length and age samples from landed Atlantic wolffish was reduced in 2014 (Table 2 and Table 3). In the years 1999-2014 annual sampling of aged fish was 1600-3000 or on average 2200, but since 2015 this average has been around 1200 fish. In 2025, a total of 4, 29 and 32 samples were collected from longline, bottom trawl and demersal seine catches, respectively (Table 3, Figure 8).

Table 2: Atlantic wolfish. Number of samples and length measured fish from landed catch of Atlantic wolffish.
Year
Bottom Trawl
Demersal Seine
Long Line
Num. samples Num. lengths Num. samples Num. lengths Num. samples Num. lengths
2000 22 2 852 4 468 29 3 698
2001 13 1 806 3 376 33 4 147
2002 37 4 912 2 281 44 5 151
2003 36 4 270 7 1 251 42 6 433
2004 33 3 932 12 1 505 23 3 241
2005 57 7 732 16 1 684 33 5 089
2006 43 5 829 7 754 44 5 882
2007 44 5 935 17 1 839 33 3 963
2008 64 9 903 13 1 355 24 3 351
2009 52 8 470 14 1 674 33 4 464
2010 54 9 640 13 1 666 30 3 911
2011 20 3 015 12 1 391 17 2 524
2012 41 9 684 12 1 206 26 3 574
2013 20 3 175 5 671 26 3 711
2014 31 4 296 31 3 623 30 3 748
2015 20 2 358 20 1 984 26 3 168
2016 13 1 596 10 970 26 2 806
2017 9 956 6 633 24 2 973
2018 9 817 17 1 687 22 2 654
2019 12 1 128 23 2 349 23 2 677
2020 18 1 833 17 1 652 9 1 007
2021 25 2 987 15 1 070 14 1 277
2022 23 2 420 17 1 235 3 269
2023 22 2 365 25 2 203 12 1 039
2024 33 3 646 26 2 075 11 1 174
2025 40 4 725 32 2 972 4 354
Table 3: Atlantic wolffish. Number of samples and aged fish from landed catch of Atlantic wolffish.
Year
Longline
Bottom trawl
Demersal seine
num. samples num. otoliths. num. samples num. otoliths. num. samples num. otoliths.
2000 29 1 395 18 752 4 200
2001 27 1 343 11 509 3 150
2002 25 1 240 16 645 2 100
2003 31 1 525 20 899 6 300
2004 19 950 23 1 060 8 400
2005 15 746 25 1 202 6 292
2006 23 1 110 21 1 029 5 250
2007 18 900 25 1 250 10 451
2008 19 950 25 1 248 4 200
2009 16 800 20 999 4 200
2010 29 1 669 19 1 090 5 285
2011 14 750 15 778 9 550
2012 26 1 300 14 700 7 350
2013 25 1 249 14 691 4 200
2014 30 800 26 675 28 700
2015 25 625 19 479 19 474
2016 25 625 13 325 9 225
2017 23 575 9 220 6 150
2018 22 550 9 225 17 425
2019 22 550 11 276 20 500
2020 9 225 14 350 16 400
2021 14 350 25 625 15 375
2022 3 60 23 465 17 338
2023 12 240 21 420 25 499
2024 11 220 29 580 26 508
2025 4 80 29 580 32 632

Length compositions

The length distribution of landed Atlantic wolffish has been relatively stable since 2005 in all gears (Figure 9).