Norway lobster

Nephrops norvegicus


Technical report
Published by

Marine and Freshwater Research Institute, Iceland

Published

19 March 2026

Key signals

  • Stock has been monitored with UWTV survey to count burrows since 2016.
  • The fishery was closed in 2022 due to recruitment failure.
  • Burrow count index from the UWTV survey increased in 2025.

General information

Fishery of Norway lobster (Nephrops norvegicus) started in the early 1950s and during the first two decades it was mainly conducted by Icelandic, Belgian and French vessels (Figure 1). Since 1974 the fishery has been conducted by Icelandic vessels. In the beginning Nephrops was mainly fished during spring and summer and the fleet was large, up to 200 boats in the 1970s. In recent years, the season was longer, as the fishery started in the middle of March and ended in November/December. There was a gradual decrease in the number of boats participating in the Nephrops fishery; seven boats participated prior to the moratorium which began in 2022. The species is entirely caught in Nephrops trawls, but there have been occasional creel trials (Eiríksson and Jónasson, 2018).

Figure 1: Norway lobster. Catches by geographic area.

The Nephrops fishing grounds in Iceland are the northernmost part of the species distributional range. The high latitude of the species distribution impacts its biology. For example, female Nephrops in more southern stocks (e.g., in Scotland, Ireland, France, and Portugal) reproduce annually, while female Nephrops in Iceland reproduce biennially (Eiríksson, 2014). Further, female Nephrops in Iceland experience slower post-maturity growth than their more southern counterparts. These differences decrease the productivity of the Icelandic stock relative to the more southern stocks and warrants lower exploitation rates.

The fishery

Landings

Peak landings of 6,000 tonnes were reached in 1963 (Figure 1, Eiríksson and Jónasson, 2018). Landings fluctuated over subsequent decades then declined from the mid-2010s onward. In 2019, two key fishing areas—Jökuldjúp (southwest Iceland) and Lónsdjúp (southeast Iceland)—were closed to fishing Nephrops.

From 2019 to 2021, a limited monitoring fishery operated in the remaining open areas to sample and map Nephrops distribution. Landings during this period dropped dramatically to 194 tonnes in 2020 and 107 tonnes in 2021. A complete moratorium has been in effect since 2022.

CPUE

Catch per unit effort (CPUE, measured as kg caught per hour towed during May-August trawling) peaked in 2007-2008 at over 100 kg/hour. However, CPUE declined sharply in the years leading up to the moratorium, falling to just 9.8 kg/hour by 2021 (Table 1). Regional CPUE patterns showed similar declining trends across all areas, though the southeast historically maintained higher catch rates. By the final years of fishing, the southern area had the lowest CPUE (Figure 2, Figure 3).

Effort

Fishing effort generally decreased across all areas from 1970 to 2008 (Figure 4). After 2008, regional patterns diverged: effort in Westman Islands until 2013 then declined, effort in the southwest increased until 2015 then declined, and effort in the southeast remained relatively stable. A small increase in southeastern effort from 2019-2021 reflects the monitoring fishery operations.

Table 1: Norway lobster. Landings (in tonnes) and standardized CPUE (kg/hour trawled) by region (southwest, sw; south, s; and southeast, se) and for the entire fishery.
Year SW-Landings SW - CPUE S - Landings S - CPUE SE - Landings SE - CPUE Landings CPUE
1962 1991 585 240 2816
1963 4754 543 764 6062
1964 2546 261 1265 4073
1965 2421 397 1297 4116
1966 1398 450 2162 4011
1967 1348 594 997 2939
1968 1520 531 594 2646
1969 1665 747 1289 3701
1970 1518 35,9 910 34,7 1716 51,1 4145 40,2
1971 1410 46,9 1455 43 1947 55,5 4812 48,4
1972 1439 36,8 1400 35,9 1742 40,8 4581 37,7
1973 1273 30,9 487 31,7 1036 31,9 2796 31,3
1974 400 32 495 32,2 1093 48,5 1983 39,4
1975 500 33,6 689 35,6 1167 43,9 2357 38,5
1976 675 32,4 609 31,5 1495 42,1 2780 36,2
1977 572 27,5 667 32,8 1483 42,5 2723 35,7
1978 396 31,2 284 28,6 1378 47,9 2059 40
1979 700 33,9 445 32,8 295 34,2 1440 33,6
1980 734 43,8 540 34,4 1124 55,5 2398 45,5
1981 398 44 627 44,1 1495 58,8 2520 51,8
1982 640 44 509 42,8 1454 60,2 2603 51,5
1983 572 42,5 710 45,8 1390 51,6 2672 47,8
1984 422 36,1 722 47,9 1315 48,5 2459 45,6
1985 522 46,9 583 57,1 1280 60,8 2385 56,4
1986 495 49 454 56,2 1615 68,2 2564 61,3
1987 615 43,5 599 57,4 1498 55,6 2712 52,6
1988 625 39,3 965 42,7 650 36,8 2240 39,9
1989 394 32,8 645 35,7 827 38 1866 36
1990 217 29,3 304 29 1171 48,1 1692 40
1991 374 35 361 29 1422 51 2157 42,1
1992 400 40,8 414 40 1417 60,5 2230 51,3
1993 446 42,1 435 38,3 1500 61,6 2381 51,4
1994 539 30,8 493 35,4 1205 43,8 2238 38
1995 510 26 325 28 192 26 1027 27
1996 514 30 721 37,8 398 39,2 1633 35,2
1997 371 25,2 533 30,5 324 46,2 1228 31,3
1998 145 22,2 746 39,1 520 49 1411 38,9
1999 131 25,5 669 38,2 576 47,9 1376 39,7
2000 107 25,8 454 38,2 678 64,3 1239 46,6
2001 258 26,6 296 29,2 866 73,5 1420 44,9
2002 288 25,6 265 29,9 995 64,8 1548 43,7
2003 133 30,5 357 32,9 1176 69,9 1666 52
2004 126 16,8 341 25,9 970 58,4 1437 38,5
2005 218 30,6 953 48,2 860 46,9 2030 44,9
2006 316 47,6 490 46,4 1069 93,7 1875 65,5
2007 1200 93 53 59,1 753 111,5 2006 97,6
2008 599 87,5 477 102,8 994 144,5 2070 112,7
2009 1130 70 472 99 862 87 2464 80
2010 1173 76,8 652 71,6 715 82,1 2540 75,8
2011 846 65,7 474 65,9 920 89,1 2240 71
2012 791 62,9 439 57,2 684 75,7 1914 63
2013 647 59,7 341 46,3 736 73,5 1724 60,5
2014 1093 74,8 234 43,6 638 68,1 1965 67,4
2015 956 52,6 83 25,6 415 51,2 1454 48,3
2016 812 44,9 57 23,6 529 51,7 1398 44,5
2017 711 47,8 10 15,4 472 40,8 1194 44,4
2018 402 28,5 10 19 316 28,9 727 28,3
2019 160 23 7 20,9 93 25,5 259 23,4
2020 83 13,9 3 17,5 109 16,3 194 14,8
2021 25 9,8 2 8,0 81 9,8 107 9,8
Figure 2: Norway lobster. Catch distribution 2004-2021.
Figure 3: Norway lobster. Standardized CPUE in 1970–2021 in the southwest (SW grounds), Westman Islands and southeast (SE grounds) areas.
Figure 4: Norway lobster. Standardized effort in 1970–2021 in the southwest (SW grounds), Westman Islands and southeast (SE grounds) areas.

Survey Data

Underwater TV survey

The first underwater TV (UWTV) survey in Icelandic water was conducted in April and June 2016. In total, 86 UWTV-stations on a roughly 4.5 nautical mile grid were completed on all known Nephrops grounds. The size of the Nephrops area was estimated from VMS data. A minimum of 6 pings from Nephrops vessels at fishing speed on 800 x 800 meter resolution grid was used as a threshold, which includes approximately 99% of the pings. Adjoining grids were combined and fishing grounds smaller than 4 km2 were excluded. The total size of the fishing grounds was estimated to be 5989 km2 based on data from 2007–2016, but there was a gradual shift to fishing on new or connected grounds in 2017 and 2018, especially in the SW area. The estimated size of Nephrops grounds in 2018 was 6588 km2 (Table 2, Figure 5). In total there were nine distinct areas ranging from 247 km2 to 1400 km2. The largest ground (Vestmannaeyjar) is in the southern part (Háfadjúp to Selvogsbanki) and the smallest one is Lónsdjúp in the east. Three grounds were split up into 2–3 patches: Vestmannaeyjar, Hornafjarðardjúp and Selvogsgrunn.

Table 2: Norway lobster. Survey station name, ID, area of the fishing grounds, number of burrows, and mean (M) burrow density.
Area ID Area (km²) Millions burrows M. burrow density
(N/m²)
Skeiðarárdjúp 9 859 317 0.37
Breiðamerkurdjúp 6 638 299 0.47
Vestmannaeyjasvæði 1, 10 1 400 172 0.12
Grindavik 7 1 307 159 0.12
Lónsdjúp 4, 13 247 128 0.52
Hornafjarðardjúp 2 259 120 0.46
Eldey 5 845 115 0.14
Jökuldjúp 3 737 114 0.16
Selvogur 8, 11, 12 296 33 0.11
Total NA 6 588 1 457 0.22
Figure 5: Norway lobster. Polygons of fishing grounds based on VMS data. Vestmannaeyjasvæði (1), Hornafjarðardjúp (2), Jökuldjúp (3), Lónsdjúp (4), Eldey (5), Breiðamerkurdjúp (6), Grindavík (7), Selvogur (8), Skeiðarárdjúp (9), Vestmannaeyjasvæði (10), Selvogur (11), Selvogur (12), Lónsdjúp (13).

The total number of Nephrops in the survey conducted in 2025 was estimated to be 1457 million animals, compared to 813 million animals in 2023 (Figure 6). The increase in abundance was largely driven by increases in Breiðamerkurdjúp, Hornarfjarðardjúp, Lónsdjúp, and Skeiðarárdjúp (Figure 7). Average density in 2025 was 0.22 burrows/m2 up from the 2023 average density of 0.12 burrows/m2 (Table 2, Figure 8). The highest burrow density was in Lónsdjúp (0.52), Breiðamerkurdjúp (0.47), and Hornarfjarðardjúp (0.46) burrows/m2 (Figure 9). The areas with the lowest densities (0.11-0.12 burrows/m2) were Selvogur, Vestmannaeyjar, and Grindavik. Results from 2016–2021, 2023, 2025 are shown for comparison (Figure 10).

Figure 6: Norway lobster. Estimated abundance (millions of burrows) from UWTV surveys 2016–2021, 2023, 2025, based on kriging interpolation. Error bars show 95% confidence intervals.
Figure 7: Norway lobster. Estimated abundance (millions of burrows) per fishing area from UWTV surveys 2016–2021, 2023, 2025, based on kriging interpolation. Error bars show 95% confidence intervals.
Figure 8: Norway lobster. Violin and boxplots of adjusted burrow density distributions by year 2016–2021, 2023, 2025. The blue line indicates the mean density over time. The horizontal black lines represent the median, white boxes are the inter quartile ranges, the black vertical lines show the range, and the black dots are outliers.
Figure 9: Norway lobster. Observed density of burrows (N/m2) at station locations from the UWTV surveys conducted in 2025 (top) and kriged prediction variance of fishing ground (bottom). Stations are marked.
Figure 10: Norway lobster. Observed density of burrows (N/m2) at station locations from the UWTV surveys conducted in 2016–2021, 2023, and 2025.

Larvae survey

Starting in 2018, bongo net (500 µm mesh size) sampling was conducted after roughly every fourth UWTV station. The objective is to sample pelagic Nephrops larvae in order to estimate recruitment. The bongo net was towed in a V–shaped manner down to 40 m and up to the surface. Between 23 and 29 stations are taken each survey. Nephrops larvae were found on 10 stations in 2018, 19 stations in 2019, 15 stations in 2020, 16 stations in 2021, 10 stations in 2023, 22 stations in 2024, and 10 stations in 2025 (Figure 11). The average density was 15.1 larvae/1000 m3 in 2018, 24 larvae in 2019, 8.1 larvae in 2020, 11.0 larvae in 2021, 7.6 larvae in 2023, 27.1 larvae in 2024, and 5.68 larvae in 2025. The occurrence of Nephrops larvae was wider in the 2019–2021 surveys, compared to the 2018, 2023, and 2025 surveys, but the highest in 2024 with 96% of stations containing Nephrops larvae. The information from this sampling might be indicative of future recruitment.

Figure 11: Norway lobster. Number of larvae caught in bongo net per 1000 m3 from surveys conducted in 2018–2021, 2023, and 2024.

Trawl Survey

A Nephrops trawl survey was conducted from 1973 to 2015. In the survey, 55 standardized two-hour tows were conducted on all Nephrops grounds. The stock abundance index declined from the peak in 2009 and reached the lowest value in 2015. Nephrops catchability is related to water clarity (higher catches in murkier waters) and groundfish density (lower catches when groundfish density is high). This is reflected in the biology and the burrowing behavior of Nephrops as the strong temporal patterns in catch rates make the traditional trawl surveys unfeasible to estimate abundance. CPUE in the survey varied from year to year, and peaked between 2000 and 2010 for most areas (Figure 12). This led to the adoption of UWTV survey in 2016 to monitor stock status and provide a stock indicator for developing management advice (Campbell, et al., 2009).

Figure 12: Norway lobster. Catch per unit effort (CPUE) in Nephrops surveys conducted since 1987.

Length Distribution

In 2024 and 2025, 44 and 11 trawl stations were sampled during surveys, respectively. The most frequent sizes (carapace length, CL) of males in the samples in 2024 and 2025 were between 42 and 65 mm (Figure 13, Table 3). After many years of increasing median size of both male and females, it seems that the median size has started to decrease. Further, after many years of few Nephrops smaller than 40 mm CL, the proportion of small Nephrops has also increased. These changes indicate increased recruitment.

Figure 13: Norway lobster. Size distribution by sex, 1970–2025. Each ridge shows the proportion of males (blue) and females (red) at different carapace lengths for a given year. Vertical lines indicate the 25th, 50th (median), and 75th percentiles. Data are from both landings sampling and Nephrops surveys.
Table 3: Norway lobster. The year, number of samples, number of males and females measured since 2000 in Nephrops surveys and sampling.
Year Samples Males measured Females measured
2000 126 26 117 3 222
2001 121 26 881 3 045
2002 279 51 721 6 687
2003 190 35 624 4 650
2004 187 38 212 5 658
2005 142 28 747 2 790
2006 158 31 059 1 557
2007 142 25 735 1 844
2008 160 30 889 3 627
2009 203 36 631 5 744
2010 202 35 251 5 282
2011 178 29 948 5 082
2012 174 26 463 5 963
2013 159 28 558 3 160
2014 155 25 880 2 614
2015 132 20 378 1 722
2016 82 10 748 606
2017 86 11 630 1 320
2018 73 10 322 1 410
2019 79 10 439 1 593
2020 53 6 430 1 009
2021 27 3 396 256
2022 40 4 606 373
2023 17 627 23
2024 44 2 497 249
2025 11 599 71

Bottom Trawling on Nephrops Grounds

Trawling Intensity

In addition to trawling with Nephrops trawl, a considerable amount of bottom trawling for groundfish occurs on some Nephrops grounds. There were around 6600 towed hours annually (2014–2018) on Nephrops grounds (Table 4). Most of the activity was on the Vestmannaeyjar Nephrops ground or almost 4000 towed hours (2.4 hours annually/km2). Slightly higher trawling activity was in Breiðamerkurdjúp or 2.5 h/km2 and high trawling activity was also in Hornafjarðardjúp (0.9 h/km2) and Lónsdjúp (0.7 h/km2). On average, the CPUE of cod (Gadus morhua), the most important demersal fish species, south of 65°N was 0.5 tonnes per hour (t/h) towed. The CPUE of cod was high within Vestmannaeyjar grounds (1.2 t/h), but lower than average in the eastern Nephrops areas, i.e., Breiðamerkurdjúp, Hornafjarðardjúp and Lónsdjúp, or around 0.3 t/h in all regions. CPUE of haddock (Melanogrammus aeglefinus) and ling (Molva molva) were also higher within the Vestmannaeyjar region compared to other areas south of 65°N. Because of poor state of the Nephrops stock, the core Nephrops areas southeast of Iceland were closed from additional disturbance of groundfish bottom trawling in 2022. Those areas had relatively high trawling activity but are of less importance for groundfish than the Vestmannaeyjar grounds.

Table 4: Norway lobster. Summary of the average (2014-2018) annual conventional bottom trawl effort on Nephrops grounds and all areas south of 65°N (inclusive of the Nephrops grounds). Effort is in hours, effort density is hours/km2 (h/km2), catch for cod, haddock and ling is the average catch in tonnes/year (t/yr), and CPUE is the tonnes per hour for each species (cod, C; haddock, H; ling, L). Areas 10, 11, 12, and 13 are not included as they are small (Figure 6).
Area ID Effort h/km² Cod (t/yr) C CPUE Haddock (t/yr) H CPUE Ling (t/yr) L CPUE
South of 65°N   NA  47371  NA 23784  0.50  7068  0.15  772  0.02 
Jökuldjúp  3  53  0.07  18  0.35  3  0.06  1  0.02 
Eldey  5  317  0.38  239  0.75  44  0.14  10  0.03 
Grindav.-/Skerjadjúp  7  468  0.36  106  0.22  17  0.04  13  0.03 
Selvogur  8  13  0.04  7  0.51  1  0.07  0  0.01 
Vestmannaeyjasvæði  1  3387  2.42  3970  1.17  821  0.24  408  0.12 
Skeiðarárdjúp  9  360  0.42  44  0.12  66  0.18  18  0.05 
Breiðamerkurdjúp  6  1619  2.54  488  0.30  67  0.04  57  0.04 
Hornafjarðardjúp  2  237  0.91  72  0.31  14  0.06  3  0.01 
Lónsdjúp  4  172  0.70  60  0.35  15  0.09  2  0.01 

Current boundaries of closures for all bottom trawling on Nephrops grounds:

Breiðamerkurdjúp

  1. 63°52ˈ50ˈˈN - 16°16ˈ00ˈˈV
  2. 63°35ˈ00ˈˈN - 15°46ˈ00ˈˈV
  3. 63°37ˈ00ˈˈN - 15°41ˈ00ˈˈV
  4. 63°57ˈ50ˈˈN - 16°02ˈ00ˈˈV
  5. 63°52ˈ50ˈˈN - 16°16ˈ00ˈˈV

Hornafjarðardjúp

  1. 64°00ˈ00ˈˈN - 15°18ˈ00ˈˈV
  2. 63°43ˈ00ˈˈN - 14°52ˈ00ˈˈV
  3. 63°46ˈ00ˈˈN - 14°47ˈ00ˈˈV
  4. 64°00ˈ00ˈˈN - 15°10ˈ00ˈˈV
  5. 64°00ˈ00ˈˈN - 15°18ˈ00ˈˈV

Lónsdjúp

  1. 64°10ˈ00ˈˈN - 14°42ˈ00ˈˈV
  2. 63°56ˈ00ˈˈN - 14°12ˈ00ˈˈV
  3. 63°56ˈ00ˈˈN - 14°05ˈ00ˈˈV
  4. 64°10ˈ00ˈˈN - 14°30ˈ00ˈˈV
  5. 64°10ˈ00ˈˈN - 14°42ˈ00ˈˈV

Management

The Ministry of Industries is responsible for the management of Icelandic fisheries and the implementation of legislation. Throughout 1995/96–2003/04, the total allowable catch (TAC) and advice were relatively stable at approximately 1200–1600 tonnes. The recommended TAC then began to increase, reaching a peak of 2200 tonnes in 2008/09 and in 2009/10 when the catch peaked at 2456 tonnes. Following this, CPUE began to decline and subsequent reductions in TAC followed. In 2019, due to the poor state of the Nephrops stock, MFRI advised a limited monitoring fishery TAC of 235 tonnes, closure of Jökuldjúp and Lónsdjúp to Nephrops fishing, and closure of Breiðamerkurdjúp, Hornafjarðardjúp and Lónsdjúp to bottom trawling. In 2020, MFRI advised a TAC of 214 tonnes for sampling and distribution mapping, with the same spatial management measures as previously recommended. In 2021, the monitoring fishery TAC was reduced to 143 tonnes under the same spatial management regime. Since 2022 a moratorium has been in place and the MFRI has continued to recommend the closure of Breiðamerkurdjúp, Hornafjarðardjúp, and Lónsdjúp to bottom trawling.

A sentinel fishery is advised for 2026 to determine whether commercial CPUE trends can corroborate the steep increase in Nephrops stocks indicated by the UWTV survey index and augment the low sample sizes of biological data obtained in by the Nephrops trawl survey. It is expected that, if the sentinel fishery indicates a current low commercial CPUE as observed in the last year of fishing before the closure (2021, ~10 kg hr⁻¹, Table 1), then roughly 6.7 tonnes will result from 40 days of fishing. This calculation is estimated from a maximum of 6-hour tows, a maximum of 4 tows per day, and a 30% reduction in kg due to a size composition dominated by smaller recruiting Nephrops (Figure 13, Table 3):

\[ \underbrace{40}_{\text{days}} \times \underbrace{4}_{\text{tows/day}} \times \underbrace{6\,\text{h}}_{\text{tow}^{-1}} \times \underbrace{10\,\text{kg}\,\text{h}^{-1}}_{\text{catch rate}} \times \underbrace{0.7}_{\text{efficiency}} \div 1{,}000\,\text{kg}\,\text{tonne}^{-1} = 6.7\,\text{tonnes} \]

If instead the CPUE is closer to 50 kg hr⁻¹, which was more commonly observed historically, then the calculation suggests a higher catch level:

\[ \underbrace{40}_{\text{days}} \times \underbrace{4}_{\text{tows/day}} \times \underbrace{6\,\text{h}}_{\text{tow}^{-1}} \times \underbrace{50\,\text{kg}\,\text{h}^{-1}}_{\text{catch rate}} \times \underbrace{0.7}_{\text{efficiency}} \div 1{,}000\,\text{kg}\,\text{tonne}^{-1} = 33.6\,\text{tonnes} \]

The 6.7 tonne estimation is similar to a sentinel fishery of 2-5 tonnes that was previously advised by ICES on a smaller Nephrops stock with 0 catch advice—Nephrops Functional Unit 25 in Division 8.c (ICES, 2018; ICES, 2025a). The 33.6 tonne estimate is similar to a level of fishing currently advised by ICES in the adjacent Nephrops Functional Unit 31, also within Division 8.c (ICES, 2025b).

References

Campbell, N., Dobby., H., Bailey, N. 2009. Investigating and mitigating uncertainties in the assessment of Scottish Nephrops norvegicus populations using simulated underwater television data. ICES J Mar Sci 2009; 66 (4): 646-655

Eiríksson, H. 2014. Reproductive Biology of Female Norway Lobster, Nephrops norvegicus (Linnaeus, 1758) Leach, in Icelandic Waters During the Period 1960–2010: Comparative Overview of Distribution Areas in the Northeast Atlantic and the Mediterranean. Advances in Marine Biology, vol. 68, pp. 65-210.

Eiríksson, H. and Jónasson, J.P. 2018. The fishery and stock assessment of Norway lobster (Nephrops norvegicus) in Icelandic waters during 1950‐2016. Haf‐ og vatnarannsóknir. HV2018‐25.

ICES (2018). EU request for advice on a sentinel fishery for Norway lobster (Nephrops) in functional unit 25, Division 8.c. ICES Advice: Special Requests. Report. https://doi.org/10.17895/ices.pub.3967

ICES (2025a). Norway lobster (Nephrops norvegicus) in Division 8.c, Functional Unit 25 (southern Bay of Biscay and northern Galicia). ICES Advice: Recurrent Advice. Report. https://doi.org/10.17895/ices.advice.27202740.v1

ICES (2025b). Norway lobster (Nephrops norvegicus) in Division 8.c, Functional Unit 31 (southern Bay of Biscay and Cantabrian Sea). ICES Advice: Recurrent Advice. Report. https://doi.org/10.17895/ices.advice.27202752.v1