Key signals
- The fishable biomass index has been slightly above the reference level since 2016 with the exception of 2016 and 2025 when it was below the reference level.
- Since 2005, shrimp has only been located in the inner part of Arnarfjörður.
- The haddock abundance index was high in 2004-2012 and 2020-2025 but the abundance of haddock was lower in 2026.
General information
Northern shrimp (Pandalus borealis) is the most common shrimp species in Icelandic waters. It is found all around the country but is most common in cold waters at depths of 10-700 m. While it has been found at greater depths, there are only a few records of it below 1000 m. Northern shrimp are common prey for many fish species, and the stocks are vulnerable to predation. In areas with high levels of predation, shrimp stocks remain small, but they can recover relatively quickly if predation pressure decreases.
A distinction is made between shrimp found in shallow coastal waters and those in offshore waters. Separate advice is provided for shrimp in Arnarfjörður.
The fishery
Shrimp fishing started in Arnarfjörður in the 1930‘s. Between 1960 and 2015, the catch in Arnarfjörður fluctuated between 100 and 850 tonnes, except in the quota years 2005/2006 and 2006/2007 (Figure 1) when no fishing was allowed due to low shrimp biomass index in the area. Since 1994, the catch has decreased steadily and was only 116 tonnes in the quota year 2016/2017. No fishing was allowed in 2017/2018 or 2025/2026 due to a low shrimp biomass index. Since 2018, the catch ranged between 100 and 200 tonnes. Catch per unit effort (CPUE) was relatively stable between 1960 and 1985, with a sharp increase in the following decade. Since 2000, CPUE has increased steadily, mainly due to increased density of shrimp within the innermost part of the fjord.
The distribution of the fishery has varied over time (Figure 2). The main fishing area has decreased and since 2009 most of the catch has been taken from a relatively small area within the innermost part of Arnarfjörður.
Survey data
The annual Icelandic shrimp survey has been conducted since 1988 in Arnarfjörður in the autumn. The 2026 survey was conducted on 9-12 September and included 22 fixed stations at depths of 52-102 m. Information on sampling procedure can be found in the manual ‘Handbók um stofnmælingu rækju 2026’ (Jónsdóttir 2026).
In 1988–1996, shrimp was found throughout the whole fjord (Figure 3). In 1997, the distributional area decreased and since 2005 shrimp has only been found within a small area at the innermost part of the fjord. These changes in distribution are thought to be mainly due to increased abundance of cod and haddock in the outer part of the fjord. In 2026, northern shrimp was found deep in Arnarfjorður, both in the northern and southern arms.
Indices
Four indices are used to assess the state of the shrimp stock: total biomass, fishable biomass, female biomass, and juvenile biomass. Juveniles include all individuals equal to and below 13 mm carapace length, while the fishable biomass include all individuals equal to and above 15.5 mm carapace length. The fishable biomass index is used for calculation of the advice. Individuals between 13 and 15.5 mm carapace length are divided between the juvenile and fishable biomass indices. The female biomass includes all females and is defined as the spawning stock biomass.
The total stock and fishable indices were relatively stable until 2005 when they decreased sharply (Figure 4). Since 2006 the indices were again relatively stable but at a lower level compared with before. However, in 2016 the indices decreased, and the fishable index was slightly above the reference level where the state of the stock is considered critical. The fishable index value of 20% of the mean of the three highest indices (Ilim) is used as a proxy for Blim. In 2017 the fishable index was at historically low levels and below the reference level. In 2018-2024, the fishable biomass index was just above the reference level but was below the reference level in 2025. In 2026 it was again above the reference level. The juvenile index was low in 2016-2026 with the exceptions of 2024 and 2026.
Length distribution
Since 2011, the mean length of females has been lower and female maximum length has not reached the same length as before (Figure 5). Since 2016 large females have not been observed in Arnarfjörður. In 2026, a high number of small males were observed (juveniles).
Abundance of Atlantic cod and haddock
The abundance of 0-group juvenile gadoids has fluctuated without a trend throughout the study period. In 2026, the abundance of 0-group cod and haddock was low (Figure 6). The haddock abundance index (1 year and older) increased from 1994 and was relative high during the periods 2004-2012 and 2020-2025 they were high. The index decreased in 2026. The abundance of cod (1 year and older) has fluctuated without a trend.
Temperature
The mean sea surface temperature during the shrimp survey increased from 1998 to 2003 and has remained at 8 - 10°C since 2007, except in 2018 when it was 7°C (Figure 7). In 2026, the mean sea surface temperature was the second highest recorded in the survey.
Bottom temperature increased steadily until 2008 but has fluctuated between 5.1 and 5.7°C in 2020-2025. In 2026, it decreased and was 4.2°C.
Management
The Ministry of Industries is responsible for management of the Icelandic fisheries and implementation of legislation. The fishing season was from early winter (following the annual Icelandic shrimp survey in September/October) until 30 April but in 2017 it was changed to 31 August. TAC and landed catch has roughly followed the advice given by MFRI (Figure 8).
References
Jónsdóttir, I.G. 2026. Handbók um stofnmælingu rækju árið 2026. Kver Hafrannsóknastofnunar, KV2026-04.