Year | Nr. Long Line | Nr. Bottom Trawl | Nr. Danish Seine | Nr. Other | Long Line | Bottom Trawl | Danish Seine | Other | Total catch |
---|---|---|---|---|---|---|---|---|---|
2000 | 349 | 137 | 79 | 275 | 171 | 203 | 85 | 36 | 495 |
2001 | 348 | 136 | 85 | 343 | 255 | 216 | 95 | 61 | 627 |
2002 | 309 | 129 | 82 | 317 | 272 | 246 | 116 | 46 | 680 |
2003 | 320 | 126 | 88 | 303 | 202 | 220 | 141 | 68 | 631 |
2004 | 331 | 118 | 84 | 284 | 218 | 217 | 94 | 40 | 569 |
2005 | 327 | 119 | 79 | 204 | 205 | 225 | 54 | 37 | 521 |
2006 | 319 | 107 | 73 | 157 | 228 | 178 | 38 | 20 | 464 |
2007 | 295 | 107 | 70 | 113 | 187 | 182 | 39 | 21 | 429 |
2008 | 252 | 97 | 63 | 96 | 242 | 191 | 46 | 19 | 498 |
2009 | 235 | 92 | 61 | 120 | 298 | 165 | 47 | 19 | 529 |
2010 | 207 | 84 | 50 | 149 | 386 | 127 | 34 | 13 | 560 |
2011 | 195 | 79 | 47 | 172 | 423 | 89 | 24 | 12 | 548 |
2012 | 33 | 54 | 0 | 23 | 1 | 33 | 0 | 1 | 35 |
2013 | 46 | 67 | 21 | 25 | 2 | 35 | 1 | 3 | 41 |
2014 | 61 | 60 | 17 | 30 | 6 | 33 | 4 | 2 | 45 |
2015 | 0 | 63 | 18 | 17 | 0 | 72 | 9 | 2 | 83 |
2016 | 0 | 70 | 17 | 23 | 0 | 113 | 4 | 2 | 119 |
2017 | 0 | 67 | 25 | 19 | 0 | 85 | 16 | 1 | 102 |
2018 | 0 | 64 | 29 | 28 | 0 | 115 | 16 | 3 | 134 |
2019 | 0 | 59 | 30 | 23 | 0 | 103 | 22 | 2 | 127 |
2020 | 11 | 64 | 29 | 22 | 1 | 120 | 17 | 3 | 141 |
2021 | 0 | 63 | 30 | 31 | 0 | 134 | 16 | 3 | 153 |
2022 | 14 | 62 | 27 | 29 | 23 | 152 | 17 | 3 | 195 |
2023 | 12 | 55 | 25 | 36 | 19 | 137 | 17 | 4 | 177 |
General information
Atlantic halibut is the largest flatfish species in the world’s oceans and the largest bony fish in Icelandic waters. The largest recorded measurement in Iceland is from the year 1935, when a 365 cm long halibut was caught off the north coast, weighing 266 kg. It matures slowly; at the length of 80 cm about half of the males have reached maturity, whereas females reach that level at 103 cm.
Atlantic halibut is found all around Iceland but is most common off the west and south coasts. It is a demersal species on muddy, sandy or gravel substrate, and sometimes even on hard bottoms at 20-2000 m depths. The juvenile halibut occupy relatively shallow waters, up to the age of 3-5 years, after which they migrate to deeper waters of the continental shelf and slope.
Atlantic halibut is known for occasional long-distance migrations. Individuals tagged in Icelandic waters have been recaptured off Faroe Islands, East- and West-Greenland, and in the waters off Newfoundland. Recaptures from Iceland include fish tagged in Faroe Islands and Canada.
Fishery
The geographical distribution of the Atlantic halibut fishery has changed since 2011 following a ban on targeted fishing as well as mandatory release of all viable fish (Figure 1).
In 2000-2011, the main fishing grounds for Atlantic halibut were in the western part of the Icelandic shelf (Figure 2 and Figure 1) according to logbook entries. After the ban on targeted fishing, most of the landed catch has been taken on demersal trawl fishing grounds in the west and northwest areas (Figure 2).
Targeted fishing was mainly conducted in deep waters, over 300 m depth (Figure 3). The ban on targeted fishing particularly affected the amount of Atlantic halibut taken in these deeper waters.
Atlantic halibut on Icelandic fishing grounds was mainly caught on longline and in demersal trawl, or approximately 85% of landings in 2006-2011 (Table 1). After the ban in 2011, most of the landed catch comes from demersal trawlers (Table 1 and Figure 4). Close to no catch is landed from longliners after the ban and this fleet segment reports most of the releases of live halibut (Table 2). The reported number of released halibut increased since 2018 and so has the number of vessels that have reported released fish (Table 2). In 2021 the number of longliners reporting releases of live halibut increased significantly and the number of viable halibut released. Data on released halibut in 2023 were not accessible when this report was published. No biological samples were taken from landed catch since 2020.
Year | Nr. lonline | Longline nr. fish | Nr. bottom trawl | Bottom trawl nr. fish | Nr. demersal seine | Demersal seine nr. fish | Nr. gilnetters | Gilnets nr. fish |
---|---|---|---|---|---|---|---|---|
2017 | 7 | 472 | 1 | 1 | 0 | 0 | 0 | 0 |
2018 | 13 | 2044 | 0 | 0 | 0 | 0 | 3 | 7 |
2019 | 12 | 2214 | 1 | 3 | 1 | 95 | 0 | 0 |
2020 | 5 | 2480 | 1 | 2 | 1 | 33 | 1 | 1 |
2021 | 14 | 7723 | 1 | 10 | 2 | 66 | 0 | 0 |
2022 | 8 | 2536 | 1 | 1 | 1 | 5 | 2 | 8 |
Sampling overview
Year | Bottom Trawl - nr. samples | Bottom Trawl - nr. lengths | Demersal Seine - nr. samples | Demersal Seine - nr. lengths | Longline - nr. samples | Longline - nr. lengths |
---|---|---|---|---|---|---|
1981 | 1 | 157 | 0 | 0 | 0 | 0 |
1982 | 5 | 1336 | 0 | 0 | 1 | 108 |
1984 | 0 | 0 | 2 | 199 | 0 | 0 |
1985 | 0 | 0 | 1 | 189 | 0 | 0 |
1986 | 0 | 0 | 0 | 0 | 1 | 135 |
1989 | 0 | 0 | 0 | 0 | 1 | 19 |
1991 | 0 | 0 | 1 | 11 | 0 | 0 |
1994 | 0 | 0 | 1 | 122 | 0 | 0 |
1995 | 0 | 0 | 0 | 0 | 2 | 63 |
1996 | 1 | 27 | 2 | 249 | 0 | 0 |
1997 | 1 | 2 | 1 | 57 | 1 | 1 |
1998 | 51 | 215 | 2 | 199 | 8 | 104 |
1999 | 63 | 309 | 1 | 83 | 1 | 26 |
2000 | 24 | 86 | 2 | 168 | 2 | 31 |
2001 | 2 | 30 | 1 | 76 | 0 | 0 |
2002 | 1 | 17 | 0 | 0 | 0 | 0 |
2003 | 1 | 5 | 1 | 4 | 0 | 0 |
2004 | 0 | 0 | 1 | 27 | 0 | 0 |
2007 | 3 | 63 | 0 | 0 | 1 | 1 |
2008 | 0 | 0 | 0 | 0 | 1 | 65 |
2009 | 0 | 0 | 0 | 0 | 2 | 16 |
2011 | 1 | 3 | 0 | 0 | 0 | 0 |
2012 | 5 | 9 | 0 | 0 | 0 | 0 |
2013 | 3 | 21 | 0 | 0 | 0 | 0 |
2017 | 0 | 0 | 0 | 0 | 2 | 5 |
2019 | 11 | 60 | 2 | 3 | 0 | 0 |
2020 | 6 | 26 | 0 | 0 | 0 | 0 |
Icelandic survey data
The Icelandic spring groundfish survey (hereafter spring survey or SMB), which has been conducted annually in March since 1985, covers the most important area of the Atlantic halibut fishery on the continental shelf. It does, however, not cover the habitats of mature fish in deeper waters further offshore. In addition, the Icelandic autumn groundfish survey (hereafter autumn survey or SMH) was commenced in 1996. The autumn survey was not conducted in 2011. The spring survey is considered to measure changes in abundance/biomass of immature halibut better than the autumn survey, but both surveys are inadequate at estimating spawning stock biomass.
Figure 5 shows trends in various biomass indices and a recruitment index based on abundance of Atlantic halibut 30 cm and smaller. Survey length disaggregated abundance indices are shown in Figure 8, and abundance and changes in spatial distribution in Figure 7.
Biomass indices are at similar levels as in the 1990s and early 2000s, except for recruitment index which has remained at lowest levels since 2000.
Figure 6 shows the relative index, indicating no clear difference between the surveys in terms of the total biomass and total abundance of the Atlantic halibut.
Atlantic halibut is mainly caught in the NW and W areas in the spring survey (Figure 7 and Figure 8), although a considerable proportion of the biomass index in 2002-2010 comes from the SE area (Figure 7). Catches of Atlantic halibut in the autumn survey are rather sporadic events with no clear pattern in distribution (Figure 7 and Figure 8). However, most halibut are usually caught in the W and NW areas. Small Atlantic halibut (30-60 cm) are most common in the spring survey, while the length distribution in the autumn survey is more distributed without any noticeable peaks (Figure 9).
Management
The Ministry of Food, Agriculture and Fisheries is responsible for management of the Icelandic fisheries and implementation of legislation. In 2012, a regulation was issued to ban all targeted fishing for Atlantic halibut and stipulating that all viable halibut must be released in other fisheries (regulation no. 470/2012).
TAC is not issued for this stock.