Stock of northeast arctic cod (Gadus morhua)
The spawning stock of northeast arctic cod is at a high level. The northeast arctic cod is the largest cod stock in the world.
What is being monitored?
Cite these dataInstitute of Marine Research (2019). Stock of northeast arctic cod in the Barents Sea. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL: http://www.mosj.no/en/fauna/marine/northeast-arctic-cod.html
|Recruits||106||Institute of Marine Research||1415||620||412||580||879||2462||2317||2574||849||388||746||1421||1028||1323||1477||1526||1250||843||486||908||1898||1262||186||111||214||390||995||1859||641||599||609||373||630||211||130||160||174||156||414||556||1118||327||298||189||155||395||732||925||731||499||408||669||952||542||671||550||408||692||246||630||539||1411||1239||706||287||473||554||614||719||399||245||688||691|
|Total stock||106 kg||Institute of Marine Research||4197||3640||3524||3005||2832||3651||4048||4124||4259||3564||3333||2820||2416||2763||2422||2397||2164||1961||1500||1474||2281||2781||3223||2740||2077||1629||1622||2274||2207||2115||2014||1975||1597||1110||838||960||734||707||811||986||1344||1204||1004||1000||1018||1527||1872||2304||2104||1813||1680||1495||1267||1149||1181||1459||1615||1716||1625||1559||1566||1956||2698||3438||3814||4021||4154||4360||3926||3624||3125||3037||2624|
|Spawning stock||106 kg||Institute of Marine Research||991||1022||837||625||562||511||499||396||410||331||284||207||204||443||403||406||320||214||192||107||122||134||229||151||231||319||365||324||160||131||168||352||235||165||103||152||311||281||228||188||162||111||180||235||332||707||910||777||592||524||547||545||379||284||240||364||507||596||711||617||605||657||694||1107||1407||2024||2350||2662||2523||2085||1713||1809||1486|
The XSA (eXtended Survivors Analysis) method (Darby & Flatman 1994), a standard method used by ICES, is used to calculate the size of the cod stock. In addition to the catch statistics (the number of fish caught in the various age groups), the calculations include 4 series of abundance indices (relative measurements) from research cruises and 1 series of catches per unit of catching effort from Russian commercial trawling. The cruise indices constitute the bottom trawl index from the Norwegian-Russian cruise in the Barents Sea in February, and a combination of the acoustic index from this cruise and the acoustic index from spawning stock investigations in the Lofoten area in March-April. The bottom trawl index from the Russian cruise in the Barents Sea in November–December is also included. Cannibalism (the number of cod eaten by cod) is also included in the calculations.
The Institute of Marine Research is developing a new stock calculation model – Fleksibest (see Frøysa et al. 2002). Early versions of this model have been used on a trial basis when ICES has performed its stock evaluations in the past 3 years, and the model may eventually become a principal tool for stock evaluation for Norwegian-Arctic cod.
The model is relatively rigid and does not offer opportunities to take in information on uncertainties in cruise and catch data. It assumes, for example, that the number of fish caught and divided among age groups is exact, which is not the case (both the reporting of the total catch in tonnes and the age distribution may suffer from uncertainty and/or bias).
The extent of the stock of northeast arctic cod expanded in the warm period after 2004. Basis for the data both from research cruises and the fisheries is influenced by this. This has probablu contributed to an increased uncertainty in stock estimations the last years.
Reference level and action level
The reference level is the precautionary limit for the spawning stock. The action limit is when the estimated spawning stock is below the precautionary limit for the spawning stock.
Precautionary limit for the spawning stock: 460 000 tonnes.
Status and trend
Both the total stock and the spawning stock have grown since 2006, and peaked in 2013. Since then there has been a decline, but both the total stock and the spawning stock is still well above the long term average for 1946-2017. The spawning stock in 2018 was estimated to be 1.5 million tonnes. This is far above the action limit set by fisheries management. The spawning stock is important to ensure good recruitment.
The distribution area of northeast arctic cod has expanded during the warm period after 2004. Data obtained from research cruises and the fisheries are influenced by this. It has probably contributed to increasing uncertainty in the stock estimates in recent years.
The size of the cod stock is influenced by natural conditions, like the sea temperature and the occurrence of predators, in addition to human impacts, where fishing is most important.
The agreed quota for 2019 is 725,000 tonnes. This is higher than the advice from the International Council for the Exploration of the Sea (ICES), which is based on the revised catch rule for 2016. For 2018, the quota agreed upon was 775,000 tonnes, which was 63,000 tonnes higher than the advice from ICES.
The total international catch in 2017 was 868,000 tonnes. The Norwegian catch was 357,000 tonnes. The fishery in 2017 is considered sustainable.
Other cod fishing nations are ranked as follows:
- The Faeroes
- Great Britain
About 70% of the annual catch is taken by bottom trawls, the rest with nets, lines, seine nets and jigging.
In its recommendation concerning the quota for 2017, ICES classified the stock as having good reproductive capacity and being harvested sustainably. The size of the spawning stock has been above the precautionary level since 2002. Fishing mortality has been substantially reduced from well above the critical level in 1999 to below the precautionary level as of 2008. The last years it has increased again and reached the precautionary level in 2017.
Low fishing pressure has helped to keep the stock at a high level, and additionally, good access of food and comparatively high temperatures have contributed to several years of good stocks of cod and haddock in the Barents Sea at present. The rise in temperature has given the fish a larger habitat and increased access to food.
About the monitoring
The indicator aims at presenting the size of the spawning stock of northeast arctic cod in the Barents Sea over time. The stock is monitored by Norwegian (www.imr.no) and Russian (www.pinro.ru) institutes of marine research. The estimations of spawning stock size is conducted once every year, and is based on historical catch data and data from research cruises.
Norwegian and Russian institutes of marine research contributes through the International Council for the Exploration of the Sea (ICES), giving advices to the Norwegian-Russian Fishery Commission on management of the stock of northeast arctic cod in the Barents Sea.
Places and areas
Relations to other monitoring
- Monitoring programme
- International environmental agreements
- Voluntary international cooperation
- Related monitoring