Nygaard and Christiansen assess wolffish in NAFO subarea 1; increasing spotted wolffish biomass
Assessment of wolffish in NAFO subarea 1
Northwest Atlantic Fisheries Organization
Serial No. N7745
NAFO SCR Doc. 26/025 SCIENTIFIC COUNCIL MEETING – JUNE 2026
An assessment of wolffish in NAFO subarea 1.
Rasmus Nygaard1, Henrik Christiansen1 1Greenland Institute of Natural Resources, Box 570, 3900 Nuuk, Greenland 2026-05-31
NYGAARD, R., & CHRISTIANSEN, H. 2026. An assessment of wolffish in NAFO subarea 1. NAFO Scientific Council Research Document, SCR Doc. 26/025: 1-12.
Abstract
There are three species of wolffish in Greenland waters, Atlantic wolffish (Anarhichas lupus), spotted wolffish (Anarhichas minor) and Northern wolffish (Anarhichas denticulatus), but only the two first are of commercial interest. Although the species are easily distinguishable from one another reporting and catch statistics rarely distinguish catch at a species level but aggregate catch as unspecified wolffish (CAT). In 2025 the vast majority of the logbook reported catches actually distinguish catch at a species level. However, a historical separation of the catch statics on a species level, may prove difficult, although some observations of the species composition have been made through research work and exists in the literature. Commercial fishery targeting wolffish started in the 1928, but significant landings were not seen until after World War II. Initially, wolffish were targeted inshore for production of wolffish skin. In 1951 production of frozen filets started and reported landings increased to a level of 5000-6000 tons. With the failing cod fishery off West Greenland trawlers started targeting Atlantic wolffish on the banks off West Greenland and from 1974-1976 reported landings from trawlers were around 3000 tons per year. During the 1980’s reported catches gradually decreased, and landings were at a very low level during the 1990’s. From 2003 landings gradually increased and stabilized at a level of around 1000 tons, mainly spotted wolffish landed from small vessels and open boats to factories in division 1A B and C and remained at this level until 2014. Since 2015, reported catches have decreased and around 200 tonnes/year but rising in 2025 mainly due to increase longline fishery in division 1A. Two surveys covers the stock of wolffish in NAFO 1A. The surveys have both registered an increasing spotted wolffish biomass in the recent decade. The difference between the survey indices for Atlantic wolffish can largely be explained by differences in survey area where the increase in the Greenland SFW survey is mainly observed north of the EU-Germany survey area. In the Greenland Shrimp and fish survey, the abundance index of both species seem to increase at a steady rate.
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www.nafo.int 2 Introduction
Three species of wolffish occur in Greenland waters, Atlantic wolffish (Anarhichas lupus), spotted wolffish (Anarhichas minor) and Northern wolffish (Anarhichas denticulatus). Only the first two (spotted wolffish and Atlantic wolffish) are of commercial interest. Spotted wolffish has a larger Lmax length than Atlantic wolffish and the individual growth rate for Atlantic wolffish is slower than for Spotted wolffish in subarea 1 (Beese and Känder 1969, Schmidt 1980). Although spotted and Atlantic wolffish are easily distinguishable from one another (spotted wolffish has spots, and Atlantic wolffish has stripes), the fishing industry and catch statistics have rarely distinguished between the two species in landing reports or logbooks. A historical separation of the catch statics on a species level, may prove difficult, although some observations of the species composition have been made through research work. A thorough breakdown of the catches on a species level and inshore offshore areas might improve the knowledge about the distribution of the species (see also Riget F.F. 1985). Research performed by Greenland and Federal Republic of Germany (Beese and Kändler, 1969), revealed an almost complete absence of Atlantic wolffish in landings and research fishery from division 1A and 1B in 1957 and 1960, but a dominance of Atlantic wolffish in division 1C in 1976 (99% by weight, depth 70-90 meters) and 1D in 1980 (58% by weight, depth 300-500 meters) (Schmidt 1980). Therefore, the breakdown of the catches by division gives some indication of species composition as Atlantic wolffish has a more southern distribution and seems more connected to the shallow offshore banks. Spotted wolffish can be found in all divisions offshore and through survey and landing observations, still seems to be the dominant species in the fjords. However, Atlantic wolffish has shifted its distribution further north during the past decade (SCR 26-011) and can be found as far north as the Upernavik district. Atlantic wolffish has also been observed in surveys in the Disko bay (1A inshore) and Sisimiut (1B inshore). Logbook catches in 2025 were actually reported at a species level and the vast majority of the catch was Spotted wolffish. Description of the Fisheries
From 1928, small catches of wolffish from Greenland waters were landed by British fishing vessels. However, the commercial fishery for wolffish in West Greenland started around 1938 and was originally based on the production of wolffish skins (mostly spotted wolffish) while the meat was used locally. Production of skins stopped during WWII but resumed in 1945 and peaked in 1948 with a production of more than 100.000 wolffish skins equivalent of about 800 tons (table 1, fig 1). In 1951, a production of frozen fillets started and developed to an important production in the Maniitsoq area (div. 1C) and the fishery gradually spread to the northern inshore areas (Divisions 1A-1B). The fishery was carried out by longliners as a directed fishery targeting mainly spotted wolffish. Annual landings reached a level of more than 5000 tons by 1957 and stayed at this level of 4000 to 6000 until 1970. With the failing cod fishery off West Greenland trawlers started targeting Atlantic wolffish on the banks off West Greenland and from 1974-1976 reported landings from trawlers were around 3000 tons per year (Schmidt 1980). The highest Statlant 21A reported catches occurred in 1977-1979, but in these years non-Greenlandic vessels were excluded from the valuable cod fishery on the banks off West Greenland and massive misreporting were documented (cod reported as American plaice, wolffish or other species). The corrected landings in these years are much lower than official landing statistics (Horsted 1980). After 1980 the cod fishery gradually decreased from West Greenland and catches of wolffish also decreased in this period. The Gradual shift from cod to shrimp fishery may however have caused a substantial amount of discarded wolffish taken and discarded in the shrimp fishery. A study of by-catch in the shrimp fishery conducted in 1994 indicated a low by-catch of spotted wolffish in all divisions and than by-catch of Atlantic wolffish where low and mainly occurred in the southernmost divisions (Engelstoft 1996). However, survey indices of wolffish were at a low level during the 1990’s. To minimize by-catch in the shrimp fishery, offshore shrimp trawlers has been equipped with grid separators since 2002 (G.H. 2001) and the grid separators have been mandatory for inshore operating vessels since 2011 (G.S. 2011). After the implementation of the sorting grids, studies of by-catch in the shrimp fishery indicated very low bycatches of wolffish in the shrimp fishery
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www.nafo.int 3 when using the grid separators (Sünksen 2007). The study does not provide length distributions, but the estimated amounts were converted to total estimates of wolffish to be around 15 tons of Atlantic wolffish (~0,01%), 1,5 tons of spotted wolffish (~0,001%) and less than 0,2 tons of northern wolffish (~0,0001%) in 2007. From 2003 catches gradually increased and stabilized at a level of around 1000 tons, mainly spotted wolffish landed from small vessels and open boats to factories in division 1A-C and remained at this level until 2014. In 2015, reported catch decreased and have remained at a level around 200 tonnes annually since then. In 2025, Catches increased to 338 tonnes, and the increase was mainly due to longliners targeting cod in division 1D. Commercial fishery data
Data on length distribution in catches are rarely available from wolffish. Discrepancy between the species is not always done in logbooks or factory landings data and wolffish are often reported as wolffish sp. (“CAT”). Factory landing data and logbook data for both species combined was available (table 1 and fig 1). Research Survey data
There are two surveys partly covering the stocks of Atlantic wolffish and spotted wolffish in subarea 1. The EU- Germany (EU-G) survey (SCR 20-052) and Greenland Shrimp Fish (SFW) survey in West Greenland (SCR 26- 011). Survey biomass and abundance indices are summarized in table 2 for both surveys. The EU-G survey started in 1982 and covers the shelf at East Greenland (ICES14) continuing to the southern part of West Greenland (1C-F, depth 0-400m). The EU-G survey has had limited coverage of the Greenland West coast in recent years in the recent decade. The Greenland Shrimp and Fish Survey (Greenland SFW) was fully implemented in 1992 and covers the Shelf at Westgreenland from 72N to the south tip of Greenland Cape farewell (NAFO 1A-1F, depth 0-600m. The Gear was changed in the Greenland SFW survey from an older commercial type shrimp trawl (skjaervoy) to a more modern and slightly larger commercial shrimp trawl with rockhopper gear (Cosmos 2600) thereby breaking the timeseries and restarting the index in 2005. Due to vessel decommission of the R/V Paamiut, chartered commercial vessels completed the survey in 2018 (Sjodürberg) and 2019-2020 (Helga Maria). Since 2022 the new research vessel R/V Tarajoq has completed the survey. All chartered vessels used the gear from the previously used research vessel (RV Pâmiut) and the Tarajoq continues the survey time series with the Cosmos trawl. Examinations of gear parameters found that the effects of these vessel changes had a minimal effect on trawl performance (Nogueira and Treble 2020 and Nogueira and Christiansen, 2023). Both surveys are appropriate in regards to main depth distribution of Atlantic and spotted wolffish, but the Greenland Shrimp and Fish Survey, has a larger and better geographical coverage in relation to wolffish.
Northwest Atlantic Fisheries Organization
www.nafo.int 4 Results (Atlantic wolffish)
The EU-G Abundance index of Atlantic wolffish was stable from 1982 to 2005 and then gradually decreased (figure 2). The Biomass index decreased substantially from 1982 to 1984 and the decreased continued until the late 1990’s. The Greenland SFW survey biomass index has slowly increased both prior to and after the gear change in 2005 and the abundance index has gradually increased throughout the time series (disregard the two extreme outlier years 2005 and 2015) although decreasing slightly in 2024 and 2025 (figure 2). The indices both before and after the gear change and with chartered vessels and Tarajoq seems well connected without calibration factors (figure 2).
The differing trends observed in the EU-Germany survey and the Greenland shrimp and fish survey can largely be explained with the difference in survey area. The increase in the indices observed in Greenland shrimp and fish survey are mainly observed in divisions 1A-B and therefore outside the EU-Germany survey area (figure 4). Therefore, the stagnant indices observed in the EU-Germany survey could be due to either reduced survey coverage or a shift in