Cod, Atlantic Cod

Gadus morhua

Method of production — Caught at sea
Capture method — Gill or fixed net
Capture area — Baltic Sea (FAO 27)
Stock area — Baltic East
Stock detail — Subdivisions 24-32
Certification — Marine Stewardship Council (MSC)
Picture of Cod, Atlantic Cod

Sustainability rating three info

Sustainability overview

Danish and Swedish fisheries in the Eastern Baltic were certified to the Marine Stewardship Council (MSC) standard as environmentally responsible fisheries in April and June 2011 respectively but are currently suspended. Choose otter trawled fish as there is no incidence of harbour porpoise bycatch associated with this method compared to gillnetting in the Baltic.

Biology

Cod belongs to a family of fish known as gadoids, which also includes species such as haddock, pollack, pouting and ling. It is a cold-temperate (boreal) marine, demersal (bottom-dwelling) species. Also found in brackish water. Their depth range is 0 - 600 m, but they are more usually found between 150 and 200 m. They have a common length of 100 cm. Maximum length 200 cm. Maximum published weight 96 kg and a maximum reported age of 25 years. In the North Sea cod mature at 4-5 years at a length of about 50 cm. They spawn in winter and the beginning of spring from February to April. Fecundity ranges from 2.5 million eggs in a 5 kg female to a record of 9 million eggs in a 34 kg female. Sex ratio is nearly 50%, with slight predominance of females. The fish has a protruding upper jaw, a conspicuous barbel on the lower jaw (used to look for food), and a light lateral line, curved above the pectoral fins. Widely distributed in a variety of habitats, from the shoreline down to the continental shelf. Juveniles prefer shallow (less than 10-30 m depth) sublittoral waters with complex habitats, such as seagrass beds, areas with gravel, rocks, or boulder, which provide protection from predators. Adults are usually found in deeper, colder waters. During the day, cod form schools and swim about 30-80 m above the bottom, dispersing at night to feed.

Stock information

Stock Area

Baltic East

Stock information

Cod is overall the most important species in the commercial fisheries in the Baltic Sea. The abundance and distribution of cod has varied considerably over time due to biological as well as anthropogenic causes. Two populations are present in the area: eastern and western Baltic cod. These cod stocks have different morphometric characters and population genetics. They overlap in the area near Bornholm Island. The eastern cod occurs in the central, eastern and northern part of the Baltic but not in significant numbers north of the Aalands Islands. The western cod inhabits the areas west of Bornholm island including the Danish Straits. The eastern population is the largest (90% eastern:10% western population), but some fluctuations in the relative proportions of the cod stocks occur due to differences and changes in exploitation level and recruitment. The recruitment of this stock is strongly driven by environmental factors. For example spawning takes place in deep basins where oxygen and salinity levels are sufficiently high for eggs to survive. The amount of water with these characteristics depends mainly on the inflow of high salinity water from the North Sea. Removals of cod in recreational fisheries in the Baltic are substantial.<><>In 2013 an aged-based analytical assessment was carried out and the stock benchmarked in 2015. Over the past five years there have been reductions in growth rate, a reduction in the biomass of larger cod (those above 40 cms) and potential changes in the natural mortality rate which it has not been possible to fully quantify in an analytical assessment, so a data limited assessment based on survey trends is carried out. There are no reference points defined for the stock however spawning stock biomass is above the MSY Btrigger proxy value although fishing pressure is too high. ICES advises that when the precautionary approach is applied, catches in 2018 for the eastern Baltic cod stock should be no more than 26 071 tonnes.

Management

The fishery is managed through TAC, effort, seasonal fisheries restrictions, and technical measures. The cod fisheries in the eastern Baltic are also regulated by a seasonal closure from 1 July to 31 August. A closure of a central part of the main spawning area in the Bornholm Deep has been implemented since the mid-1990s for all fisheries. A year-round area closure for all fisheries in specific areas of the Bornholm Deep, the Gotland Basin, and the Gdansk Deep was introduced in 2005, aimed at reducing fishing mortality. Since 2006, area closures have been implemented from 1 May to 31 October. The plan was designed to protect the spawning aggregation. Highgrading has been prohibited since 1 January 2010 in all Baltic Sea fisheries. Data from observer schemes indicate that highgrading is a minor problem. To decrease discards, a "Bacoma" codend with a 120 mm mesh was introduced by the International Baltic Sea Fisheries Commission (IBSFC) in 2001 in parallel with an increase in diamond mesh size to 130 mm in traditional codends. The expected effect of introducing the "Bacoma" 120 mm exit window was nullified by compensatory measures in the industry. This was to some extent explained by the mismatch between the selectivity of the 120 m "Bacoma" trawl and the minimum landing size. In October 2003, the regulation was changed to a 110 mm "Bacoma" window. This was expected to enhance the compliance and to be in better accordance with the minimum landing size, which was changed from 35 to 38 cm in the same year. On 1 March 2010 the "Bacoma" 120 mm was re-introduced, along with an extended "Bacoma" window (5.5 m) to further decrease discarding, and the minimum landing size was kept at 38 cm. The management plan agreed in 2007 aims to reduce Fishing Mortality (F) by 10% each year until the target F is reached. Although the plan is evaluated by ICES as being in accordance with the precautionary principle, it should be noted that F in the management plan is much larger than the current estimate of FMSY. Although the catches for most years since 2008 have been below the level advised by ICES the fishing mortality has not declined as anticipated. Due to this effect it is considered that following the relative F reductions (10%) stipulated in the plan will not reduce F. The TACs and catches in 2015-2016 and the TAC for 2017 have been considerably higher than the advised catch. The full TAC has not been taken since 2007. Danish and Swedish fisheries in the Eastern Baltic were certified to the Marine Stewardship Council (MSC) standard as environmentally responsible fisheries in April and June 2011 respectively but are currently suspended.

Capture Information

Gillnets in the Baltic are associated with bycatch of endangered harbour porpoises. Gillnets can be very size selective for the target fish but can be unselective at the species level for both non-target fish and for mammals, birds and turtles. Harbour porpoise are highly prone to bycatch in bottom-set gillnets used to catch demersal species such as cod, turbot, hake, saithe, sole, skate and dogfish and tangle net fisheries used to capture flat fish and crustaceans, due largely to their feeding habits on or near the seabed. Porpoises are generally taken as single animals. EU Regulation 812/2004 requires all community fishing vessels, greater than or equal to 12 metres, using drift, gill and tangle nets to use pingers - acoustic devices to deter marine mammal entanglement in nets. It also requires Member States to introduce observer schemes to monitor cetacean bycatch in certain fisheries, most notably in pelagic trawls, and the phase out of driftnet fisheries in the Baltic Sea. Because of their durability, nets are made of nylon, if lost the net can continue to fish, a phenomenon known as 'ghost fishing'. The minimum landing size for cod in EU waters is 35 cm and 38 cm in the Baltic. The approximate size at which 50% of females first spawn however is 60 to 70 cm. Fisheries for cod in the eastern Baltic has very little bycatch of other species and a limited discarding of juvenile cod.

Alternatives

Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.

Basa, Tra, Catfish or Vietnamese River Cobbler
Bass, seabass (Farmed)
Bream, Gilthead (Farmed)
Cod, Atlantic Cod
Coley, Saithe
Haddock
Hake, Cape
Hake, European
Japanese amberjack, Yellowtail or Seriola
Pollack or Lythe
Pollock, Alaska, Walleye
Pouting or Bib
Sturgeon (Farmed)
Tilapia
Whiting

References

ICES Advice 2017, Book 8 http://ices.dk/sites/pub/Publication%20Reports/Advice/2017/2017/cod.27.24-32.pdf