| Year | Nr. Bottom Trawl | Nr. Gillnets | Nr. Other | Nr. Nephrops Trawl | Bottom Trawl (t) | Gillnet (t) | Other (t) | Nephrops Trawl (t) | Total catch |
|---|---|---|---|---|---|---|---|---|---|
| 1995 | 106 | 103 | 102 | 58 | 119 | 41 | 185 | 164 | 509 |
| 1996 | 90 | 125 | 120 | 58 | 248 | 45 | 239 | 259 | 791 |
| 1997 | 88 | 108 | 134 | 56 | 383 | 60 | 178 | 212 | 833 |
| 1998 | 85 | 129 | 122 | 46 | 362 | 69 | 108 | 296 | 835 |
| 1999 | 100 | 133 | 119 | 41 | 520 | 50 | 128 | 293 | 991 |
| 2000 | 94 | 163 | 177 | 34 | 355 | 765 | 190 | 220 | 1530 |
| 2001 | 76 | 239 | 191 | 36 | 279 | 619 | 211 | 251 | 1360 |
| 2002 | 74 | 207 | 182 | 36 | 184 | 249 | 228 | 309 | 970 |
| 2003 | 73 | 187 | 214 | 37 | 184 | 900 | 260 | 341 | 1685 |
| 2004 | 74 | 179 | 213 | 29 | 307 | 1268 | 295 | 353 | 2223 |
| 2005 | 80 | 129 | 243 | 31 | 452 | 1495 | 391 | 514 | 2852 |
| 2006 | 68 | 109 | 257 | 28 | 489 | 1273 | 424 | 405 | 2591 |
| 2007 | 72 | 98 | 256 | 22 | 560 | 1489 | 436 | 310 | 2795 |
| 2008 | 63 | 87 | 240 | 22 | 381 | 1690 | 536 | 341 | 2948 |
| 2009 | 63 | 105 | 226 | 17 | 574 | 2473 | 602 | 419 | 4068 |
| 2010 | 66 | 165 | 217 | 18 | 453 | 1762 | 510 | 556 | 3281 |
| 2011 | 55 | 170 | 202 | 17 | 300 | 1991 | 463 | 475 | 3229 |
| 2012 | 59 | 158 | 186 | 18 | 178 | 1744 | 301 | 444 | 2667 |
| 2013 | 64 | 87 | 170 | 16 | 144 | 859 | 157 | 337 | 1497 |
| 2014 | 57 | 80 | 152 | 16 | 146 | 712 | 93 | 234 | 1185 |
| 2015 | 49 | 55 | 128 | 14 | 145 | 512 | 54 | 223 | 934 |
| 2016 | 54 | 43 | 115 | 12 | 156 | 500 | 38 | 200 | 894 |
| 2017 | 50 | 40 | 97 | 9 | 130 | 89 | 35 | 213 | 467 |
| 2018 | 47 | 35 | 85 | 9 | 248 | 100 | 50 | 244 | 642 |
| 2019 | 49 | 32 | 85 | 8 | 240 | 53 | 34 | 181 | 508 |
| 2020 | 53 | 25 | 69 | 8 | 192 | 30 | 37 | 177 | 436 |
| 2021 | 49 | 31 | 60 | 7 | 147 | 47 | 20 | 196 | 410 |
| 2022 | 51 | 21 | 53 | 3 | 122 | 9 | 25 | 2 | 158 |
| 2023 | 49 | 18 | 53 | 0 | 166 | 12 | 28 | 0 | 206 |
| 2024 | 51 | 15 | 55 | 1 | 158 | 10 | 33 | 2 | 203 |
Key signals
The biomass index from the spring survey has shown a downward trend since 2010, but has increased significantly in the past three years.
Recruitment has been poor since 2010 with the exception of 2025 when recruitment increased substantially.
Length distribution has shown an increase in total length since 2010 due to low recruitment resulting in a population consisting of older and larger individuals, with the exception of 2025.
Total biomass peaked in 2005 in the SMB survey and seems to be increasing again, following a period of low biomass.
Fishing mortality (F) is below FMSY.
GENERAL INFORMATION
Anglerfish (or monkfish) is a benthic "sit and wait" predator that is most abundant south and west of Iceland. It is found at depths from 20-2800 m, though most abundant between 50 and 250 m.
Females grow larger than males and can reach a size of 130 cm while males larger than 80 cm are rare. Similarly, females become sexually mature around 80 cm and males around 61 cm.
The north-western edge of the anglerfish’s habitable area is found in Icelandic waters, which renders it more sensitive to environmental changes than many other species in the area.
The Fishery
In 2017-2021, anglerfish was caught in the southeast, southwest and, to a small extent west of Iceland as reported in logbooks (Figure 1 and Figure 2). From 1995-2000 captures were mostly in the southeast and southwest after which it was captured more frequently in the west and in 2010-2016 also northwest and north of Iceland (Figure 1, Figure 2). Geographic distribution has changed mostly in the form of more aggregated patches because of a large reduction in caches in the southeast, south, southwest, and west areas apart from a large increase in the northwest from 2010-2016. During the past four years, spatial distribution has gradually decreased towards its previous state, before 2000 (Figure 1).
On Icelandic fishing grounds, anglerfish is mostly caught at depths between 50 and 250 m (Figure 3). In 2000-2016 it was captured to a large extent in anglerfish gillnets. Otherwise, bottom trawls and Nephrops trawls were most common until last year when the Nephrops fisheries stopped (Figure 4, Table 1). The number of boats reporting anglerfish catches peaked in 2007, with a total of 472 boats, but annual catch peaked in 2005 at 1631 t. Since then, catches have declined annually amounting to 171 t in 2024. A large reduction in catches between 2016 and 2017 can be explained by a reduction in the anglerfish gillnet fishery which accounted for 54% of the anglerfish fisheries in 2016, 14% in 2017, and 5% in 2022 (Table 1). A reduction from 411 to 159 vessels from 2021-2022, and a significant reduction in total catch, can be explained by a Nephrops fishing ban.
Length distributions from commercial catches
Length measurements from monkfish catches in 2001-2016 and 2019 reveal a change towards dominantly larger individuals after 2012, resulting in larger mean length (Figure 6). Data are however scarce after 2012 due to lower catches resulting in fewer length measurements as they are proportional to the catches.
Survey Data
The annual Iceland spring groundfish survey (hereafter spring survey) has been conducted in March since 1985 and covers the whole Icelandic anglerfish distribution area. An additional autumn groundfish survey (hereafter autumn survey) has been conducted annually from 1996 but does not represent the anglerfish distribution and abundance as well as the spring survey. The autumn survey was not conducted in 2011.
In the surveys, harvestable biomass index is calculated as total biomass of individuals 40 cm and larger. From 1998 to 2005 the harvestable biomass index increased rapidly and remained high until 2011, followed by a sharp decline in the next five years. 2016-2019, the harvestable biomass index was relatively stable but decreased rapidly but with a small increase this year (Figure 7). The recruitment index estimated as abundance ≤ 40 cm, shows a dramatic increase, starting in 1997-1998, but a reduction in recruitment from 2008. Recruitment has since 2010 remained low (Figure 7). These changes resulted in a change in relative length distribution towards smaller mean length in 1995-2010 and larger individuals after that due to a lack of recruitment (Figure 10).
Anglerfish is caught in the spring survey mainly to the southeast, southwest, and west of Iceland (Figure 9). The cold waters northeast and east of Iceland are almost completely void of anglerfish. Anglerfish in the northeast are usually caught in the southernmost part. Until 1999, anglerfish was caught almost exclusively south of Iceland after which it was captured in greater numbers in the west and northwest. Since 2016-2017, the relative abundance has decreased in the northwest and west (Figure 9).
In the autumn survey anglerfish is mainly caught south of Iceland (Figure 8). Relative abundance in the NW area was usually high in 2005-2017, in accordance with the spring survey (Figure 9).
Stock assessment
Application of the rfb-rule
- r is calculated as the average of last two years values, divided by average of three preceding years values which results in r=1.682
- \(f\) is the length-ratio component or fishing pressure proxy calculated as the mean length from catches last year divided by the target reference length (Lc * 0.75 + L∞ * 0.25) (Figure 12).
b is the biomass safeguard and is used to reduce catch advice when index falls below trigger. Ilim for anglerfish is based on the average of the biomass indices in the years 1985-1999. Itrigger is Ilim *1.4. The biomass index this year is above Itrigger and hence, b is 1 (Figure 13).
m is the tuning parameter and for slow growing species (with von Bertalanffy K<0.2), m equals to 0.95 (Figure 15).
Management
The Ministry of Industries and Innovation is responsible for management of the Icelandic fisheries and implementation of legislation. Anglerfish has been subject to TAC limitations from the 2001/2002 quota year. From the quota year 2003/2004 to 2012/2013, TAC limitations were set higher than recommended by the Marine Research Institute and, additionally, catches were sometimes higher than the TAC. Since 2015/2016 however, catches were 5-9% lower than the set TAC until 2017/2018 when they were 23% lower (Table 3). In the last fishing year, less than 50% of the set TAC was caught (Table 3).
Figure 16 shows the net transfer of quota to and from anglerfish in the Icelandic ITQ system. During years with high catches, quota from other species was transferred to anglerfish. Since the population started declining, anglerfish quota has been transferred to other species, which amounted up to 13% in the quota years 2010/2011 to 2020/2021. However, in the last fishing year (2023/2024) approximately 30% was transferred to anglerfish. Transfer of anglerfish quota to the next fishing year has usually been under 13% but exceeded 30% in 2021/2022 (Figure 16).
Fishing year | Recommended TAC | National TAC | Total catch |
|---|---|---|---|
2010/2011 | 2 500 | 3 000 | 3 376 |
2011/2012 | 2 500 | 2 850 | 3 006 |
2012/2013 | 1 500 | 1 800 | 1 906 |
2013/2014 | 1 500 | 1 500 | 1 403 |
2014/2015 | 1 000 | 1 000 | 1 080 |
2015/2016 | 1 000 | 1 000 | 913 |
2016/2017 | 711 | 711 | 677 |
2017/2018 | 853 | 853 | 653 |
2018/2019 | 722 | 722 | 565 |
2019/2020 | 441 | 441 | 428 |
2020/2021 | 503 | 503 | 437 |
2021/2022 | 402 | 402 | 199 |
2022/2023 | 258 | 258 | 188 |
2023/2024 | 188 | 188 | 236 |
2024/2025 | 188 | 188 | |
2025/2026 | 226 | 226 | |
2026/2027 | 226 | 226 |
References
ICES. 2025. ICES Guidelines - Advice rules for stocks in category 2 and 3. Version 3. ICES Guidelines and Policies - Advice Technical Guidelines. 31 pp. https://doi.org/10.17895/ices.pub.28506179
Comments on the assessment and advice
The assessment is based on ICES \(\text{rfb}\)-rule for data limited stocks for the first time in 2022, where life history traits, exploitation characteristics and other relevant parameters for data-limited stocks are considered (ICES 2025). The \(\text{rfb}\)-rule has the following form:
\[A_{y + 1} = A_{y - 1}\text{\:r\:f\:b\:m}\]
where \(A_{y + 1}\) is the advised catch, \(A_{y - 1}\) is last year’s advice, \(r\) corresponds to the trend in biomass index (as in the current ICES “2 over 3” rule), \(f\) is a proxy for the exploitation (mean catch length divided by an MSY reference length) and \(b\) a biomass safeguard (reducing the catch when biomass index drops below a trigger value).
\(r\) is the ratio of the mean of the last two survey indices and the mean of the three preceding values or:
\[\begin{matrix} r = \frac{\sum_{i = y - 2}^{y - 1}I_{1}/2}{\sum_{i = y - 3}^{y - 5}I_{1}/3} \\ \end{matrix}\]
\(f\) is the length-ratio component where:
\[f = \frac{{\overline{L}}_{y - 1}}{L_{F = M}}\]
where \(\overline{L}\) is is the mean catch length above \(L_{F = M}\).
\(L_{F = M}\) is calculated as:
\[L_{F = M} = 0.75L_{c} + 0.25L_{\infty}\]
where \(L_{c}\) is the length where frequency is half that of the modal value (Figure 12), and L∞ is von Bertalanffy L∞.
\(b\) is the biomass safeguard and is used to reduce catch advice when index falls below trigger,
\[b = \min\left( 1,I_{y} - 1/I_{\text{trigger}} \right)\]
where \(I_{\text{trigger}}\) = \(i_{\text{lossω}}\)
\(m\) is a multiplier based on stock growth. \(K\) for anglerfish is <0.2 and therefore \(m\) is 0.95.
Analysis on the assessment and advice
The assessment is based on the rfb-rule for ICES category 3 data-limited stocks and has been applied for anglerfish since 2023, for which the advice is valid for two years at a time. The Icelandic spring trawl survey (IS-SMB) was used as the index for the stock development. The advice is calculated using the equation Ay+1 = Ay-1 r f b m which result in a more than 20% increase and is hence capped at 20% using the uncertainty cap (1).
Ay: Catch advice for 2024/2025
188
Stock biomass trend
Index A (2024-2025)
1 232
Index B (2021-2023)
719
r: Stock biomass trend (index ratio A/B)
1.714
Fishing pressure proxy
Mean catch length (Lmean = L2024)
90
MSY proxy length (LF=M)
78
f: Fishing pressure proxy (Lmean/LF=M)
1.165
Fishing pressure proxy relative to MSY proxy (LF=M/Lmean)
0.859
Biomass safeguard
Last index value (I2025)
1 178
Index trigger value (Itrigger=Iloss*1.4)
437
b: Index relative to trigger value, min{I2025/Itrigger, 1}
1
Precautionary multiplier to maintain biomass above Blim with 95% probability
m: Multiplier (generic multiplier based on life history)
0.95
Advice calculation1)
356
Stability clause (+20% / -30% compared to Ay, only applied if b>1)2)
1
Catch advice for 2025/2026 and 2026/2027
226
% advice change3)
20
1) Ay × r × f × b × m
2) min{max(0.7Ay, Ay+1), 1.2Ay}
3) The figures in the table are rounded. Calculations were done with unrounded inputs, and compared values may not match exactly when calculated using the rounded figures in the table.