Stock size
Stock size
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Biomass indices for cod from spring (SMB) and autumn (SMH) groundfish survey, shaded areas and vertical lines show one standard deviation in the estimates Source: The Marine Research Institute |
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Spawning and fishable (ages 4+) stock biomass (thous. t) at spawning time and average fishing mortality (ages 5-10) for cod Source: The Marine Research Institute |
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Total nominal landings of Atlantic cod (Gadus morhua) in 2010 were 169 000 t, compared to 181 000 t in 2009. Based on domestic advice, the national TAC for cod in the quota year 2010/2011 was set, prior to the fishing season, at 160 000 t.
Mean weight at age in landings in 2010 was higher than predicted. Mean weight at age in the survey in 2011 was higher than in recent years and similar to the average from 1985–2010. Those data are used to predict mean weight at age in the landings and spawning stock 2011 –2012.
Biomass indices in the spring survey have increased during the last 4 years, mostly due to increased abundance of large cod. Indices of fish below minimum landing size have not increased. The autumn survey indices show more increase than the spring survey.
In 2011, the reference biomass is estimated as 970 000 t and the spawning stock 362 000 t compared to Blim=125 and Btrigger=220 000 t. The stock has been increasing in recent years and the reference biomass is the largest since 1989 and the spawning stock since 1964. During the last decade, the harvest rate has declined from 34–40% to around 22% in the last three years, and the fishing mortality from 0.76 in 2000 to 0.33 in 2010.
Recruitment during the last decade has been around 68% of the long-term average. The exploitation rate has been declining in recent years and is now similar to what would be expected from the management plan adopted by the Icelandic authorities last year. Decreased harvest rate is the main reason for the recent increase in stock size.
Based on the present assessment, the TAC in 2011/2012 should be set at 177 000 t according to the management plan. Following the HCR will most likely lead to increasing SSB and TAC in the next 4–5 years. The TAC is predicted to increase to 200– 250 000 t but recruitment would need to return to pre-1985 levels for the TAC to increase more.
The Marine Research Institute emphasizes the importance of managers subtracting all other expected catches prior to allocating the ITQ catches to the fishing fleet. Furthermore, it is recommended that regulations on mesh size of gillnets and area closures on spawning grounds remain in effect.
This text is from an annual Stock Status Report from the Marine Research Institute. The report is in Icelandic but with an English abstract and table and figure texts.
