HADDOCK

Key signals

Survey biomass steadily increased from 2011, peaking sharply in 2023–2025 at levels similar to the peak observed in 2003–2006.
High recruitment from 2020–2022 is the primary driver behind the current biomass peak. However, recruitment in 2023 and 2024 has fallen below the decade’s average, while 2025 recruitment estimates are near this average. The earliest signs of 2026 recruitment are high, indicating likely increases in the future.
Length distributions have remained stable over the past decade, reflecting consistent periodic recruitment and a broad range of sizes currently present in the stock.
Despite a sharp decrease in reference biomass from last year, current biomass estimates from the stock assessment are one of the highest recorded since 1979, though these estimates carry considerable uncertainty.
Harvest rates have generally fluctuated around the target harvest rate set over the last decade, with no major deviations.

General information

Haddock (Melanogrammus aeglefinus) is abundant in the coastal waters around Iceland and is mostly limited to the Icelandic continental shelf. Haddock is predominantly distributed around Iceland’s western and southern coasts, typically in depths between 10 and 200 meters. Historically, spawning activity has been restricted to southern waters. Recently, an increasing proportion of the fishable stock has been observed off the northern coast compared to previous decades.

Fishery

Landing trends

Landings of haddock in ICES area 5.a in 2025 totaled 84322 tonnes (Figure 1). This represents a significant decrease from the high levels of approximately 100,000 tonnes recorded between 2005 and 2008, returning to levels somewhat lower than observed between 1975 and the early 2000s. Foreign vessel landings have significantly declined following the expansion of the Icelandic Exclusive Economic Zone (EEZ), with Faroese vessels now accounting for the majority of foreign catches and which in 2025 was 1612 tonnes.

Figure 1: Haddock in 5a. Recorded landings since 1905.

Demersal seine catches have remained stable at about 15%, and contributions from other vessel types are minimal(Figure 2). Main fishing grounds are in the southern, southwestern, and western regions, with recent years showing increased catches from northern and northeastern waters (Figure 4 and Figure 5).

Figure 2: Haddock in 5a. Landings in tons and percent of total by gear and year

Figure 3: Haddock in 5a. Depth distribution of haddock catches from bottom trawls, longlines, trawls and demersal seine from Icelandic logbooks

Figure 4: Haddock in 5a. Changes in spatial distribution of haddock catches as recorded in Icelandic logbooks.

Figure 5: Haddock in 5a. Spatial distribution of catches by all gears for selected years.

The haddock fishery in ICES area 5a has seen minimal structural changes recently, although the number of vessels responsible for 95% of the catch has steadily decreased (Figure 6 and Table 1). Approximately 250 longliners, 60 trawlers, and 40 demersal seine boats report catches annually. Historically, trawlers have dominated the catches, currently accounting for around 60%, while catches from longliners have increased significantly since the mid-1990s (Figure 2).

Figure 6: Haddock in 5a. 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: Haddock in 5a. Number of Icelandic vessels landing haddock, and all landed catch divided by gear type.

Year	Nr. Bottom Trawl	Nr. Other	Nr. Danish Seine	Nr. Long Line	Bottom Trawl	Other	Danish Seine	Long Line	Total catch
2000	164	504	117	479	23 300	1 740	3 101	13 089	41 230
2001	146	631	91	447	22 034	2 050	3 036	11 982	39 102
2002	144	548	91	417	30 377	1 990	3 596	13 638	49 601
2003	136	550	96	435	36 239	1 664	4 804	17 284	59 991
2004	131	656	95	449	50 722	1 787	8 095	23 198	83 802
2005	126	488	90	449	53 046	1 573	10 493	30 767	95 879
2006	116	416	93	436	45 968	1 217	12 709	36 237	96 131
2007	109	345	94	407	57 033	1 080	12 869	37 199	108 181
2008	102	311	91	362	51 228	944	16 457	33 051	101 680
2009	98	448	81	335	39 078	608	15 182	26 571	81 439
2010	94	623	67	279	29 341	475	10 138	23 916	63 870
2011	95	630	54	278	20 718	473	6 866	21 175	49 232
2012	98	699	56	289	20 469	473	6 048	18 722	45 712
2013	95	702	65	282	18 829	398	4 955	19 197	43 379
2014	84	654	47	283	13 438	329	3 776	15 598	33 141
2015	83	607	50	257	17 337	360	4 327	16 432	38 456
2016	82	580	53	237	17 045	321	4 456	14 927	36 749
2017	80	531	53	210	16 456	343	4 539	14 447	35 785
2018	71	494	58	194	26 639	336	5 585	15 190	47 750
2019	69	493	43	183	35 947	302	6 237	14 650	57 136
2020	73	536	42	149	32 005	278	5 079	16 189	53 551
2021	82	532	46	142	35 961	264	5 338	14 541	56 104
2022	73	513	57	115	39 003	243	3 929	13 830	57 005
2023	76	607	60	97	44 869	304	6 599	17 589	69 361
2024	78	594	37	89	57 706	265	8 757	16 819	83 547
2025	71	594	40	92	53 556	274	12 018	16 640	82 488

Catch per unit of effort from commercial fisheries

Catch-per-unit-effort (CPUE) from hauls where haddock comprise more than 50% of the catch show a steady increase in CPUE since 1990 across the main gear types (Figure 7). CPUE levels from bottom trawls and demersal seine are among the highest recorded in the time series, whereas those from longlines remain relatively low. This trend aligns with fishers’ perception that haddock are easy to catch. However, this pattern differs from that observed in surveys and stock assessments, which show less of an increase after 2000 and a more pronounced decline in recent years.

It is important to note that these differences may partly reflect changes in the size composition of the stock. The biomass of haddock ≥60 cm is currently at the highest observed level in the time series, while total biomass is near its long-term average. This suggests that CPUE trends may be more reflective of the abundance of larger individuals rather than overall stock size.

Regional differences in CPUE are also evident. In the area north of Iceland, CPUE has shown a continuous increase, whereas in southern regions it more closely mirrors the biomass trends observed in the spring survey. Bycatch is minimal, as haddock are typically targeted in species-specific catch compositions.

CPUE could not be estimated for 2022 due to the unavailability of effort data at the time of assessment.

Figure 7: Haddock in 5a. Catch per unit of effort in the most important gear types. The dashed lines are based on locations where more than 50% of the catch is haddock and solid lines on all records where haddock is caught. A change occurred in the longline fleet starting September 1999. Earlier only vessels larger than 10 BRT were required to return logbooks but later all vessels were required to return logbooks. Effort data is not available for 2022.

Landings and discards

Historical landings data come from various databases.

Historical landings data are sourced from various databases such as ICES STATLAN database, Directorate of Fisheries and the Icelandic Coast Guard.

Icelandic law prohibits discarding, and discard rates since 2001 have been low, generally below 3% of the total annual landings, both in weight and numbers (Figure 8, also see MRI (2016) for further details). Fisheries management regulations effectively discourage discarding through quota flexibility and quota conversion measures. In addition to prevent high grading and quota mismatch the fisheries are allowed to land fish that will not be accounted for in the allotted quota, provided that the proceedings when the landed catch is sold will go to the Fisheries Project Fund (Verkefnasjóður sjávarútvegsins).

Figure 8: Haddock in 5a. Estimates of annual discards by gear (point estimate and 95% confidence interval). No estimates are available since 2018.

Data and sampling

Commercial data

Sampling from commercial catches is generally comprehensive, covering the main gears (demersal seines, longlines, and trawls) and adequately representing the spatial and seasonal distribution of catches (Figure 9 and Figure 10). An overview of the sampled otoliths is provided in Table 3.

Figure 9: Haddock in 5a. 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 10: Haddock in 5a. Fishing grounds last year as reported in logbooks (contours) and positions of samples taken from landings (crosses) by main gear types.

Length compositions

Commercial catches primarily consist of haddock ranging from 40 to 70 cm, a range that has remained stable in recent years (Figure 11). Gillnet fisheries tend to target slightly larger individuals, and the modes of the length distributions vary more markedly depending on the presence of larger haddock.

Most length measurements are derived from the three main fleet segments: trawl, longline, and demersal seine fisheries (Table 2). The number of length samples collected by gear type has fluctuated in recent years, reflecting shifts in fleet composition.

Figure 11: Haddock in 5a. Commercial length distributions by gear and year

Table 2: Haddock in 5a. Number of samples and length measurements from landed catch.

Year	Bottom Trawl		Danish Seine		Long Line
Year	Number of samples	Number of lengths	Number of samples	Number of lengths	Number of samples	Number of lengths
2000	344	66 143	21	3 114	88	14 393
2001	359	71 914	26	4 098	168	30 110
2002	467	85 869	47	7 644	212	32 425
2003	422	71 509	47	7 066	210	31 239
2004	503	82 474	75	10 416	252	35 405
2005	514	94 529	102	14 880	375	53 472
2006	500	74 627	227	29 848	648	75 293
2007	837	102 155	507	34 914	499	87 705
2008	813	83 284	380	29 468	571	88 919
2009	630	56 466	328	35 155	406	63 817
2010	470	59 477	192	19 653	344	56 681
2011	357	53 462	92	8 382	237	43 200
2012	349	41 424	112	10 190	302	60 838
2013	265	34 355	50	2 555	237	43 132
2014	155	13 731	22	3 128	217	37 035
2015	187	26 101	18	2 742	221	41 593
2016	163	21 500	17	2 425	202	37 492
2017	200	23 387	39	6 305	232	42 360
2018	134	21 780	28	5 545	231	35 621
2019	295	50 698	30	3 254	187	25 692
2020	109	17 640	14	1 551	64	8 929
2021	139	22 264	20	2 112	38	4 669
2022	124	18 937	16	1 942	34	3 941
2023	129	23 242	22	1 933	28	3 382
2024	255	51 257	30	4 050	52	6 510
2025	274	48 712	43	5 263	38	5 090

Age compositions

The catch in numbers-at-age is illustrated in Figure 23. In 2025, the catch was primarily composed of the 2014 to 2017 year classes. In recent years, the number of year classes contributing to the catch has increased, reflecting a period of low fishing mortality. Notably, the oldest year class contributing more than 1% to the total catch was 11 years old (Figure 12).

Figure 12: Haddock in 5a. Catch at age from the commercial fishery in Iceland waters. Biomass caught by year and age, bars are colored by cohort.

Table 3: Haddock in 5a. Number of samples and otoliths collected from landed catch.

Year	Bottom Trawl		Danish Seine		Long Line
Year	Number of samples	Number of otoliths	Number of samples	Number of otoliths	Number of samples	Number of otoliths
2000	344	6 773	21	800	88	2 848
2001	359	5 208	26	359	168	2 755
2002	467	6 510	47	750	212	2 848
2003	422	7 237	47	850	210	3 499
2004	503	6 786	75	698	252	2 855
2005	514	6 478	102	823	375	3 520
2006	500	6 446	227	1 205	648	4 707
2007	837	6 601	507	1 961	499	4 419
2008	813	7 637	380	2 153	571	4 463
2009	630	5 448	328	1 800	406	2 800
2010	470	5 456	192	1 399	344	3 199
2011	357	3 512	92	1 028	237	2 675
2012	349	4 446	112	1 356	302	3 200
2013	265	3 036	50	707	237	2 751
2014	155	1 421	22	300	217	1 550
2015	187	1 924	18	250	221	1 150
2016	163	1 769	17	325	202	975
2017	200	1 363	39	225	232	945
2018	134	1 385	28	225	231	845
2019	295	1 740	30	350	187	925
2020	109	1 322	14	275	64	625
2021	139	1 820	20	300	38	775
2022	124	1 100	16	120	34	265
2023	129	1 424	22	220	28	440
2024	255	2 178	30	300	52	700
2025	274	2 523	43	420	38	500

Weight at age in the catch

Mean weight-at-age in the catch is shown in Figure 13. The weights of older year classes have increased in recent years, following a period of low values when the stock was large between 2005 and 2009. The increase in mean weight is particularly evident for younger haddock from the small 2008–2013 cohorts, contributing to an above-average mean weight among older fish. Although the mean weight of younger year classes in the catch has declined somewhat, it remains above the long-term average.

Survey data

Information on haddock abundance and biological parameters in Division 5.a is available from two surveys: the Icelandic spring groundfish survey and the Icelandic autumn groundfish survey. The spring survey has been conducted annually since 1985 and covers the core distribution area of the haddock fishery. The autumn survey, initiated in 1996 and expanded in 2000 to include deeper water stations, provides supplementary insight into stock development. Both surveys were originally designed to monitor the Icelandic cod stock but have proven effective in tracking the haddock stock, including juvenile abundance and fishable biomass. A full autumn survey could not be carried out in 2011. Detailed survey methodologies are described in the Stock Annex.

Figure 14 presents a recruitment index (abundance <25 cm) alongside biomass indices for total biomass, biomass >45 cm, and biomass >60 cm. Spatial shifts in biomass distribution observed in the spring survey are shown in Figure 15, indicating an increasing proportion of biomass in the northern regions (NW and NE). Length distributions from the surveys are displayed in Figure 17, and spatial distribution of survey stations is shown in Figure 16.

Both surveys show a substantial increase in total biomass between 2002 and 2005, followed by a marked decline from 2007 to 2010. Overall agreement between the two surveys is good, although the autumn survey tends to show less contrast between periods of high and low biomass. A discrepancy was observed during 2013–2015, when the autumn survey estimated substantially higher biomass for fish >60 cm compared to the spring survey. Differences between the surveys are more pronounced in the >60 cm biomass index, which has reached its highest recorded level in recent years according to both surveys. A sharp increase in total survey biomass was observed in autumn 2022 and spring 2023.

Age-disaggregated indices from the spring survey are shown in Figure 18. Consistent with the increase in >60 cm biomass, the index for age 11+ is now higher than previously recorded. This is likely due to reduced fishing mortality following the implementation of the management plan for haddock in 5.a. Despite a recent period of low recruitment, the biomass for other age groups is currently near the geometric mean in both surveys.

Figure 14: Haddock in 5a. Indices (total biomass, biomass> 45 cm, biomass> 60 cm and abundance <25 cm) in the Spring Survey (March) 1985 and onwards (line shaded area) and the autumn survey (point ranges).

Figure 15: Haddock in 5a. Changes in geographical distribution of the survey biomass.

Figure 16: Haddock in 5a. Location of haddock in the most recent March (SMB) and the Autumn (SMH) surveys, bubble sizes are relative to catch sizes, and crosses indicate stations where no haddock was observed.

Figure 17: Haddock in 5a. Length disaggregated abundance indices from the March survey 1985 and onwards.

Figure 18: Haddock in 5a. Age disaggregated indices in the Spring Survey (left) and the autumn survey (rights). Bars indicated the deviation from the log mean index, fill colors indicate cohorts. Note different scales on y-axes.

Stock weight at age

Mean weight-at-age in the catch is shown in Figure 13. Stock weights are derived from the spring groundfish survey and are also used as mean weight-at-age in the estimation of spawning stock biomass. Both stock and catch weights for the older year classes have increased in recent years, following a period of notably low values when the stock was large between 2005 and 2009.

The increase in mean weight-at-age is particularly evident among younger haddock from the small 2008–2013 cohorts, contributing to above-average mean weights in the older age groups. Although the mean weight of the younger year classes has declined somewhat in recent years, it remains above the long-term average.

Figure 19: Haddock in 5a. Stock weights from the March survey in Icelandic waters. Bars are coloured by cohort.

Stock maturity at age

Maturity-at-age data, shown in Figure 20, are derived from the spring survey. In recent years, the maturity-at-age of the youngest age groups has declined, likely reflecting a northward shift in distribution. Maturity-at-size has also decreased, which is most plausibly explained by a larger proportion of these age groups occurring north of Iceland – an area where the proportion of mature individuals has historically been low.

Figure 20: Haddock in division 5a. Maturity at age in the survey. Bars are coloured by cohort. The values are used to calculate the spawning stock.

Stock assessment

Model and data inputs

This stock was last benchmarked in 2025 as part of a harvest control rule evaluation (ICES (2025)). The assessment framework was updated to a state-space statistical catch-at-age model (SAM; Nielsen and Berg (2014)). The model spans from 1979 onward and tracks ages 1 to 12, with age 12 defined as a plus group. Natural mortality is assumed to be 0.2 for all age groups, and selectivity-at-age is allowed to vary over time.

Given that haddock are known to spawn between April and the end of May, the ratio of fishing and natural mortality before spawning was set at 0.4 and 0.3, respectively.

No information is available on natural mortality. For assessment and advisory purpose, natural mortality is assumed to be 0.2 for all age groups.

The assessment is based on four primary data sources, as described above: the Icelandic spring and autumn groundfish surveys, commercial sampling, and landings data. Commercial data are used to construct catch-at-age matrices, which enter the model likelihood alongside survey-at-age data from both surveys. Stock and catch weights-at-age are derived from the spring survey and commercial catches, respectively. Maturity-at-age data are also obtained from the spring survey.

For years prior to 1985 — before the initiation of the spring survey — stock weights and maturity-at-age were assumed to be constant at their 1985 values. A detailed description of the data preparation for model tuning and input is provided in the Stock Annex (ICES (2019a)).

Diagnostics and fit

Model fit diagnostics are shown in Figure 21 and Figure 22, illustrating residuals for observation and process error, respectively. No concerning patterns are evident in either set of residuals. The overall model fit is further evaluated in Figure 24, which compares observed and predicted survey biomass.

Historically, biomass estimates from the autumn survey have aligned more closely with model predictions than those from the spring survey. The spring survey tends to show a greater contrast in observed biomass than is reflected in the model output. When comparing biomass levels before and after the mid-2000s peak, the autumn survey suggests higher post-peak biomass, whereas the spring survey indicates similar levels. The assessment model appears to represent a compromise between the two survey indices.

Figure 21: Haddock in division 5a. Residualsfrom the model fit to survey and catch data based on the both the surveys (observation error). Red circles indicate negative residuals (observed < modelled), while blue postive. Residuals are proportional to the area of the circles.

Figure 22: Haddock in division 5a. Residuals from the model fit to survey and catch data based on the both the surveys (process error). Red circles indicate negative residuals (observed < modelled), while blue postive. Residuals are proportional to the area of the circles.

Figure 23: Haddock in 5a. Catch at age from the commercial fishery in Iceland waters. Bar size is indicative of the catch in numbers and bars are colored by cohort. Note different scales on y-axis

Figure 24: Haddock in division 5a. Aggregated model fit to the total biomass indices. Note that residual correlation is estimated (see text for further details).

Results

The assessment results indicate that the stock declined between 2008 and 2011, as large year classes were replaced by smaller ones (Figure 25). From 2011 to 2017, the stock stabilized due to reduced fishing mortality, and since 2017, stock biomass has increased rapidly, driven by the recruitment of strong year classes into the fishery. The harvest rate is currently estimated to be above the target set by the implemented harvest control rule (HCR), although it remains low by historical standards. The baseline assessment suggests that the stock is at a high level and is expected to remain so in the near future. However, a gradual decline is anticipated as the strong 2019 cohort—currently dominating the catch—is progressively fished down.

The stock–recruitment relationship (Figure 26) indicates episodic high recruitment events that can elevate stock levels, as seen at present. Apart from these peaks, recruitment appears steady, with no evidence of impairment.

Estimated selectivity-at-age, shown in Figure 27, displays substantial temporal variation. This is consistent with density-dependent growth observed in Icelandic haddock, which affects selectivity patterns over time.

The retrospective analysis (Figure 28) shows an upward revision in recent years, attributed to strong incoming recruitment into the fishable biomass, and the assessment is considered stable as a result.

Some differences have been observed in recent years between model runs depending on which tuning series — spring and/or autumn surveys — are included. However, these differences are currently mostly within the bounds of model uncertainty (Figure 29).

Figure 25: Haddock in division 5a. Summary from assessment. Dashed vertical line indicates the assessment year and yellow shaded region the uncertainty as estimated by the model. Dashed horizontal lines indicate the target harvest rate and MGT Btrigger within the harvest control rule. The black horizontal line indicates Blim.

Figure 26: Haddock in 5a. Spawning stock size and recruitment.

Figure 27: Haddock in 5a. Estimated selection at age.

Figure 28: Haddock in division 5a. Analytical retrospective analysis of the assessment of haddock with a 5 year peel.

Figure 29: Haddock in 5a. Comparision of assessment results where either the spring survey or the autumn survey is omitted from the estimation.

Short term projections

Following the revision of the harvest control rule (HCR) in 2025 (see Management section), short-term projections of stock weights are no longer required for generating catch advice. This is because the harvest rate is now applied to the assessment-year estimate of the reference biomass (2026), defined as haddock ≥45 cm, rather than to the projected biomass for the advisory year (2027).

Nevertheless, short-term projections remain valuable for monitoring the expected development of spawning stock biomass (SSB) over the advisory year and into the subsequent year under the applied HCR. These projections are conducted by applying the HCR for both the advisory year and the following year, using stock and catch weights averaged over the past five years, and recruitment fixed at the mean over the past ten years. A detailed technical description of this procedure is provided in the Stock Annex (ICES (2019a)).

Reference points and advice basis

History

The Icelandic Ministry of Industries is responsible for the management and legislative implementation of Icelandic fisheries. Each fishing year (1 September–31 August), the Ministry issues regulations governing commercial fishing, including the allocation of total allowable catch (TAC) for stocks subject to catch limits. Haddock in Division 5.a has been managed by TAC since 1987. Landings have generally aligned with the advice provided by the Marine and Freshwater Research Institute (MFRI) and the TAC set by the Ministry (Figure 30).

However, since the 2001/2002 fishing year, landings have exceeded the set TAC by more than 5% in twelve fishing years. The most substantial overshoot occurred in 2020/2021, when haddock landings exceeded the advice by 33%. These implementation errors are primarily attributed to features of the management system that allow for inter-annual quota transfers and species transformations — i.e., the conversion of TAC between species.

The Icelandic TAC system does not account for catches taken by Norway and the Faroe Islands under bilateral agreements. While the levels of these foreign catches are known in advance, they have only recently been considered by the Ministry when allocating TAC to Icelandic vessels. There is no minimum landing size for haddock in 5.a. Under current agreements, Faroese vessels may fish up to 5,600 tonnes of demersal species annually in Icelandic waters, including a maximum of 1,200 tonnes of cod and 40 tonnes of Atlantic halibut.

The impact of species transformations and quota transfers is illustrated in Figure 31. During the period of high haddock biomass (2002–2007), there was a notable increase in net transfers of quota from other species to haddock. This may partly reflect changes in haddock distribution, as shown in Figure 5 — particularly in northern areas where fisheries held lower initial haddock quotas. Over the longer term, however, net quota transfers to or from haddock have averaged close to zero.

The introduction of a management plan in 2013 has significantly reduced inter-annual quota transfers. Concurrently, transfers from other species to haddock have increased — likely due to high CPUE in recent years, the ease of catching haddock, and its potential to act as a limiting factor in some mixed fisheries. Additionally, possible underestimation of haddock biomass in recent years may have contributed to increased quota transfers into the haddock fishery. These dynamics were accounted for in the management plan evaluation.

Figure 30 shows the differences between the national TAC and actual landings for haddock in 5.a. In most cases, deviations can be explained by species transformations. Notably, in the 1999/2000 and 2020/2021 fishing years, the Icelandic government adjusted the TAC mid-season. In 2020/2021, the TAC was increased by 8,000 tonnes and reduced by the same amount in the following fishing year.

Figure 30: Haddock in 5a. Comparison of the realised catches and the set TAC for the fishing operations in Icelandic waters. Note that in the 1999/2000 fishing year the government of Iceland increased TAC mid-season

Figure 31: Haddock in 5a. An overview of the net transfers of quota between years and species transformations in the fishery in 5a.

Harvest control rule

At WKICEMSE 2019, the harvest rate applied under the 2013–2018 harvest control rule (HCR) was deemed no longer precautionary. A harvest rate of 0.35 was found to be consistent with both the precautionary approach and the ICES MSY framework (ICES (2019b)). This rate was retained during the 2025 revision of the HCR conducted at WKICEGAD (ICES (2025)), but is now applied to the reference biomass estimated in the assessment year rather than the advisory year.

The current management plan for haddock in Icelandic waters was reviewed by ICES in 2025 (ICES (2025)). Information regarding management strategies and harvest control rules can be found on the Government of Iceland webpage here.

Beginning with the 2025/2026 fishing year, the harvest control rule was revised as follows:

If \(SSB_{y}\geq B_{trigger}\) then: \[ TAC_{y+1} = 0.35 B_{45cm^+,y} \]

If \(SSB_{y}< B_{trigger}\) then: \[ TAC_{y+1} = 0.35 B_{45cm^+,y} SSB_{y}/B_{trigger}\]

The revised harvest control rule adopted in 2025 retained the same harvest rate and reference biomass definition as the previous HCR. However, the key change was that the harvest rate is now applied to the reference biomass estimated for the assessment year, rather than a projected biomass for the advisory year, as was done previously. As a result, short-term projections of stock weights are no longer required for generating catch advice.

Management considerations

All available indicators from commercial catch data and scientific surveys suggest that haddock in Division 5.a is currently in good condition, a conclusion supported by the stock assessment. In 2025, the stock was estimated to have increased substantially. However, it has begun to decline in the coming years as the above-average year classes that have supported the recent increase move through and out of the fishable biomass. The analytical retrospective analysis revealed a slight negative bias in the estimated spawning stock biomass (SSB). This bias is expected to diminish in future assessments, as the low survey indices from 2020 and 2021 are removed from the retrospective peel and the stock begins its anticipated decline.

Ecosystem considerations

Haddock exhibit density-dependent growth, with low body weights at high densities. Haddock also show slight changes in distribution over time, with an expansion in the northeast areas.

References

ICES. 2019a. “Stock Annex: Haddock (Melanogrammus aeglefinus ) in Division 5.a (Iceland grounds).” International Council for the Exploration of the Seas; ICES publishing.

———. 2019b. “Workshop on the Benchmark Assessment and Management Plan Evaluation for Icelandic Haddock and Saithe (WKICEMSE),” January. https://doi.org/10.17895/ices.pub.5091.

———. 2025. “Workshop on the benchmark assessment and management plan evaluation for Icelandic haddock and saithe (WKICEGAD). ICES Scientific Reports [in press].”

MRI. 2016. “Mælingar á brottkasti þorsks og ýsu (e. Measurments of discards of Cod and Haddock), 2014–2016, Reykjavik, Iceland.” Vol. 3. Marine; Freshwater Research Institute, Iceland; Marine Research Institute, Iceland. https://www.hafogvatn.is/static/research/files/fjolrit-183pdf.

Nielsen, Anders, and Casper W. Berg. 2014. “Estimation of Time-Varying Selectivity in Stock Assessments Using State-Space Models.” Fisheries Research 158: 96–101. https://doi.org/10.1016/j.fishres.2014.01.014.