The SSB of Northeast Arctic saithe has declined since 2005 and is according to ICES likely to be close to Bpa in 2013, and it may be increased risk of reduced reproductive capacity. The fishing mortality was below Fpa from 1996 to 2009, but started to increase in 2005 and is likely to be close to Fpa in 2013. It may therefore be increased risk of harvesting the stock unsustainably.
Harvest control rule
A Harvest Control Rule (HCR) for Northeast Arctic saithe was evaluated and implemented in 2007.
ICES state that it is not possible to provide advice according to management plan. However, scenarios based on stable SSB and giving catches of 140 kt in 2014 are considered coherent with objectives of the management plan.
The stock assessment for saithe is based on a set of input data that is used the same way over several years. The information that is used in addition to the landings statistics is catch per unit effort (CPUE) from Norwegian trawl and acoustic indices from research surveys. In 2012 it became very clear that these two do not longer show the same trends. CPUE in trawl seems to be quite stable, while the research survey shows a considerable reduction in later years. Therefore IMR recommended Norwegian authorities to apply a stock assessment not including CPUE as a basis for setting TAC for 2013. According to the HCR this would give a TAC for saithe in 2013 of 129 thousand tons. Norwegian authorities set the TAC for 2013 to 140 425 tons, which was a reduction of about 15 % compared to the recommended TAC for 2013.
ICES could not accept any assessment for Northeast Arctic saithe this year. Two exploratory scenarios, one with and one without CPUE data and giving divergent views on stock status and fishing levels, have been evaluated and are considered to capture the main aspects of stock dynamics. ICES therefore recommended to prolong this year’s TAC of 140 000 tons also for 2014. IMR recommends that one should consider a lower TAC to increase the probability for harvesting the stock sustainable and having good reproductive capacity. Since 2005 the recruitment has been about 20% below the long term mean. According to the management plan the TAC should not be changed by more than ± 15% from year to year as long as the SSB is above Bpa. A reduction of 15% compared to this year’s TAC corresponds to 119 000 tons. If SSB already is below Bpa, a TAC according to the management plan is lower.
The limit spawning stock biomass (Blim) = 136 000 tons
Precautionary approach spawning stock biomass (Bpa) = 220 000 tons
The limit fishing mortality (Flim) = 0,58
Precautionary approach fishing mortality (Fpa) = 0,35
Expected fishing mortality in 2013: F = 0,25 – 0,41
Expected spawning stock biomass in 2014: 150 000 – 300 000 tons