Atlantic cod

The annual stock assessment uses state-of-the-art techniques, is carried out by a working group of leading scientists and provides concise advice to managers; all data and methods, the process and results are transparent and publicly available online, and have been peer reviewed. Last benchmark was undertaken in April 2017, an age-based analytical assessment (State-space Assessment Model, SAM) is currently used. It replaced the previous Extended Survivors’ Analysis model, XSA; the recruitment model was also changed (ICES 2017)​.

Input data includes commercial catches (e.g., international landings, ages and length frequencies from catch sampling); four survey indices performed in different times of the year, and correspondent annual maturity data; natural mortalities from annual stomach sampling. Bycatch is included in the assessment model. Discarding is not included as it is likely negligible (below 5%) and not considered to "change perception on NEA cod stock size"; estimates are besides fragmented and contradictory. Bycatch and discards time series are currently being updated but were not included in this year's assessment (ICES 2018). Assessment includes data from 1946 to present. Estimates of cod cannibalism, that now cover more years (period before 1984 is now included), are included in the natural mortality, changing historical recruitment and total stock biomass estimates. Large uncertainties are encountered in recruitment estimates, SSB as well as "conflicting signals from the different surveys and catch-at-age data". In addition, catch split in sampling of trawl catches of cod in the first half of the year in parts of Division 2.a is not considered adequate; coastal cod and NE Arctic stocks may be misidentified (ICES 2018). 

ICES’ ACOM (Advisory Committee) issues advice for this fishery. Norway’s Institute of Marine Research (IMR) and Russia’s Polar Research Institute of Marine Fisheries and Oceanography (PINRO) provide much of the basis for the scientific advice, through annual cod surveys and cooperation in data collection and research programmes (Lockwood et al., 2010). ICES’ advice for 2019 is as follows for all scenarios (ICES 2018):

Management plan (MP): According to the agreed MP, catches in 2019 should not exceed 674,678 tonnes (F₂₀₁₉=0.46). Under this catch scenario, the Spawning Stock Biomass (SSB) is expected to be at 1005,533 tonnes in 2020.

ICES evaluated the management plan and its later amendment in 2010 – when the Joint Norwegian-Russian Fisheries Commission (JRNFC) decided to use the plan for more 5 years before a next evaluation – and found it to be consistent with the Precautionary Approach (PA) (ICES, 2015a,b). In 2016, JRNFC requested ICES to evaluate ten alternative harvest control rules (one of which is the existing harvest control rule) and all proposals are considered as precautionary (ICES 2016)(ICES 2016).

MSY approach: The MSY approach implies fishing at F_MSY (=0.4), corresponding to catches in 2019 of no more than 605,331 tonnes. Under this scenario, SSB is expected to remain at 1059,787 tonnes in 2020.

Other recommendations: Bycatch of coastal cod and golden redfish Sebastes norvegicus should be kept as low as possible (ICES 2018). Coastal cod's stock size has been well below the biomass rebuilding threshold set in the rebuilding plan and fishing pressure increased in the last three years (ICES 2018). On the other hand, the stock size of golden redfish has been decreasing and is currently at the historical minimum, below both biological reference points; fishing pressure is above the F_MSY. The species is mainly bycaught (direct fishery is conditioned), representing Norway and Russia 87% of total removals in 2017 (of 5,340 tonnes). In 2017 bycatch is preliminary at 64% by trawls (increasing from last years), 18% by gillnets and 15% by longlines (ICES 2018)(ICES 2018).

The stock remains in its full reproductive capacity in 2018 with SSB at 1,485,912 tonnes, above B_pa = MSY B_trigger (460,000 tonnes) and B_lim (220,000 tonnes), as since 2002. It is although following a decreasing trend since 2013, when the maximum peak was attained (2,662,000 tonnes). F has been increasing since 2012 and in 2017 was at 0.4, what equals MSY levels but still below F_lim (0.74). "Abundance of age 3–7 fish in 2017 was increased compared to last year, while the abundance of older age groups was decreased" (ICES 2018). Catches in 2017 were estimated at 868,276 tonnes (ICES 2018)(ICES 2018).

The management agreement for the NE Arctic cod of the Joint Norwegian-Russian Fishery Commission (JNRFC), regularly evaluated, has been considered to be in accordance with the Precautionary Approach (ICES, 2011b), like in 2016 (ICES 2017). It includes an harvest control rule (HCR) aimed at maintaining the target fishing mortality at F_pa= 0.40 unless SSB falls below B_pa, in which case F should be linearly reduced to F=0 at SSB=0 (ICES, 2013b). In October 2016, JNRFC amended the agreed management plan (together with the haddock fishery within the same area; first implemented in 2004 and amended in 2009), being now the TAC "calculated as the average catch predicted for the coming 3 years using the target level of exploitation (F_tr)" (more details here). ICES evaluated the plan and concluded that it is consistent with the PA and “not in contradiction to the MSY approach” (ICES, 2015a). As requested by JRNFC, ICES concluded that all 10 alternative HCR presented are "precautionary in accordance with the ICES standard that the annual probability of SSB falling below Blim should be no more than 5%" (ICES 2016)(ICES 2016)​.

Fisheries authorities in Norway and Russia formally stipulate the TACs through the JNRFC and usually based it on ICES scientific recommendations. The total quota for cod is then divided between Norway, Russia and other fishing countries (JNRFC, undated). The TAC, usually released in October, was defined at 775,000 tonnes for 2018: Norway at 350,159 thousand tonnes (21,000 tonnes to coastal cod and 7,000 tonnes for research purposes), and the remaining for Russia and other countries (Government of Norway 2017). Although this represented a 13% reduction comparing to 2017, the TAC was 11% above the scientifically advised (ICES 2018). Since 2013 the TAC has been following a decreasing trend and since 2016 the TAC is set above the scientific recommendation. The Arctic Fisheries Working Group (AFWG) report considers the existence of quota swaps between years and countries as a possible reason to explain the TAC set over the scientific recommendation; for 2018 a sum of around 1,000 tonnes were transferred. It is highlighted as well that the 2018 TAC by JNRFC was not established according to the HCR in place (ICES 2018).

Technical regulations are since 2011 harmonized within Norwegian and Russian Economic Exclusive Zones (EEZ): minimum landing size of 44 cm, maximum of 15% of allowable catch of fish below the minimum size (combined for cod, haddock and saithe in the Norwegian EEZ and cod and haddock in the Russian EEZ). A discarding ban started in 1987 only for cod and haddock and in 2009, a list identifies all species, dead or dying, that are obliged to be landed (with some exemptions) (Gullestad et al., 2015). Other regulations consist on mesh size limitations, a real-time closure system for juveniles (fishing is prohibited in areas where the proportion by number of undersized cod, haddock, and saithe combined has been observed by inspectors to exceed 15%) and other seasonal and spatial restrictions. Sorting grids are mandatory for trawl fisheries since 1997, and the minimum mesh size for bottom trawls is 130 mm for the entire Barents Sea (ICES, 2014a,b).

llegal, unregulated, and unreported (IUU) fishing used to be a problem in the past, reaching 20-25% of total catches (Stokke 2010), but is considered as negligible nowadays, mainly since 2009 (ICES 2018). It is believed as a result of a greater cooperation between Russian and Norwegian authorities, as well as EU requirements for catch certification (MFCA, 2010). Port-state measures under the NEAFC contributed as well to solve the problem (Stokke 2010). Monitoring and enforcement of regulations is conducted through Vessel Monitoring System (VMS) satellite tracking for some fleets, radio checks, inspections at sea and catches' control points while entering and leaving the EEZ (MEP, 2012; ICES, 2014a). An onboard detailed logbook is mandatory for most vessels and the majority of the fleet reports to the authorities on a daily basis (ICES, 2016b).

Landings have been generally following the set TAC from 2012 onwards and total catches are “very close to officially reported landings” according to Norwegian-Russian analysis group (ICES, 2015b) (ICES 2018). In 2017, catch estimates at 868,000 tonnes were slightly below the set TAC at 890,000 tonnes. Discarding is forbidden in Russia and Norway; data is scarce, fragmented and may be contradictory but overall discards are likely negligible, below 5% (ICES 2017)(ICES 2018)(ICES 2018). Observer coverage is still low, but no compliance issues have been reported (Pfiffer and Sieben, 2014).

Harbour porpoise (Phocoena phocoena) is mainly found in the South of the polar front, in coastal waters. Even if considered as Least concern under the IUCN red list (IUCN 2008), it is under the OSPAR List of threatened and/or declining species and habitats (OSPAR Commission 2009) and the CITES (Appendix II). It is particularly sensitive to the interaction with static gears due to their characteristics (Bjørge et al. 2010). Capture by two Norwegian coastal fisheries, namely by the gillnet cod (and monkfish) fishery, is a current concern but the impact is not yet fully determined due to unreliable data (Bjørge et al. 2013)(NAMMCO 2014)(Nichols et al. 2015)(ICES 2018). 

Other concern regards the interaction of the fishery with golden redfish (Sebastes norvegicus) which is considered to be in "reduced reproductive capacity" and with fishing pressure above the Maximum Sustainable Yield. The species is mainly bycaught (direct fishery is conditioned), representing Norway and Russia 87% of total removals in 2017 (of 5,340 tonnes) when ICES recommended to keep bycatch as low as possible. In 2017 bycatch is preliminary at 64% by trawls (increasing from last years), 18% by gillnets and 15% by longlines (ICES 2018)(ICES 2018). S. norvegicus is currently classified as an Endangered species on the Norwegian Redlist according to the International Union for Conservation of Nature (IUCN) criteria (ICES, 2016b). Even if bycaught in low proportions by each of the MSC certified fleets (Hønneland et al. 2014)(Nichols et al. 2015)(Knapman et al. 2018)(Kiseleva and Nichols 2018)(Gaudian et al. 2018) there is no reliable information of the cumulative impacts of all operating fisheries with this ETP species.

Seabirds and marine mammals have been recorded feeding both within trawl nets and apparently on fish escaping through meshes but only few bycatch of seabirds or marine mammals in otter trawls have been recorded widely. Basking shark Cetorhinus maximus (vulnerable in IUCN red list; (IUCN 2005)), porbeagle Lamna nasus (vulnerable in IUCN red list; (IUCN 2006)) and picked dogfish (spurdog) Squalus acanthias (vulnerable; (IUCN 2016)) can be caught but have to be landed or released if alive. There is also some bycatch of rays, which are generally released alive, but records are not detailed to the species level; Starry ray Amblyraja radiata (Least Concern in the region) is likely the most captured species (Hønneland et al. 2014). These and other skates/rays are occasionally caught, particularly by gillnets, but within national and international requirements (Nichols et al. 2015). Sometimes, trawl fisheries caught harp seals Pagophilus groenlandicus but the impact of this gear is considered with a low risk for bycatch of marine mammals (Gaudian et al. 2016).

There is a strategy in place to manage and minimize the impacts of the fishery in place, both by the managing countries and ICES. All commercial fish, seabird and marine mammal populations are monitored. Real-time appropriate conservation actions can be implemented if needed. There are besides several generic measures under the Russian–Norwegian Fisheries Convention and the Norwegian management plans for the Barents Sea and Norwegian Sea to manage retained species, supported both by IMR and PINRO monitoring. With the introduction of the electronic logbook it is now obligatory to record the presence or absence of marine mammals and seabirds in the catch. There are real-time closure rules if any species exceeds threshold levels in individual catches; and regulations to safeguard aggregations of both juveniles of most species and aggregations of depleted species such as redfish, Greenland and Atlantic halibut. Where such species are taken as bycatch, there are also stringent bycatch regulations in place to minimise the risk of cryptic targeting of the species. There are also haul limits for redfish and halibut in both Russian and Norwegian EEZs. Escape grids in front of the cod end and cod end mesh sizes will affect all species. Discarding of commercial fish species is prohibited; detailed records and regular (daily) reporting of all fishing activity and catches must be maintained, and compliance with technical measures checked (Nichols et al. 2015)(Kiseleva et al. 2017). There are current efforts in place to determine the interaction and develop specific measures to mitigate the impact of the fishery with harbour porpoise (Nichols et al. 2015) and the use of pingers is already being tested (Lassen and Chaudhury 2017).

Both Norwegian and Russian jurisdictions require catches of species from a set list to be landed, being discarding of commercial species forbidden. The fishery is generically considered as relatively “clean” with low levels of bycatch (Southall et al. 2010) apart the mentioned interaction with ETP species.

Bycatch data oscillates with season and fishing area. Non-target species are identified and quantified. Besides cod and haddock, the main retained species by volume is saithe (~1%). Other retained species include redfish (beaked redfish Sebastes mentella and golden redfish Sebastes norvegicus), three species of wolffish (Anarhichas spp.), American plaice (Hippoglossoides platessoides), Greenland halibut (Reinhardtius hippoglossoides), and small quantities of ling. Uncertainties can be found in skates, rays and other species that may be discarded in low quantities (Hønneland et al. 2014)(Nichols et al. 2015)​(Hønneland et al. 2016)(Gaudian et al. 2016)(Knapman et al. 2018).

Management measures such as a discard ban (both by Norwegian and Russian jurisdictions), area closures, minimum sizes, use of a larger mesh size, bycatch limits and sorting grids for trawls are in place to reduce impacts on retained bycatch species. Real-time closures along the Norwegian coast, in order to reduce the percentage of juvenile fish in catches, are implemented since 1984 (ICES 2018).

The Barents Sea and N-Norway regional scale of vulnerable marine habitats mapping are captured and available in cartography from sources such as the EU Red List of Marine Habitats, the project MAREANO, and the OSPAR 2010 database (Smith and Ríos 2018).

Sensitive species and habitats’ composition have been determined spatially. More than 3050 benthic species are identified. Qualitative effects on the total impact of trawling on the ecosystem have been studied to some degree and the most serious effects have been demonstrated for hard bottom habitats dominated by large sessile fauna, where erected organisms such as sponges, anthozoans and corals have been shown to decrease considerably in abundance in the pass of the ground gear (Freese et al, 1999; Althaus et al., 2009). Studies by Denisenko (2001, 2005, 2007) in the Barents Sea revealed that in areas of intensive bottom fisheries there was a degradation in the overall benthic habitats, with a shift towards more opportunistic, short-lived detritus eating organisms, and considerable decrease in the benthos biomass (Southall et al. 2010). According to Denisenko (2007) the gross biomass (75-80%) of the benthic community in the Barents Sea Sea is composed by 15-20 species (Southall et al. 2010). Investigations by Fossa et al., (2002) concluded that the damage to coral reefs in Norway amounts to between 30% and 50% of the total coral area. Most obvious impact of trawling on Lophelia pertusa is the mechanical damage caused by the gear itself. The impact of trawled gear will kill the coral polyps and break up the reef structure. Impacts of trawling on soft (e.g., sandy, clay-silt) bottoms have been less studied. According to available research in sandy bottoms of high seas fishing grounds, trawling disturbances have not produced large changes in the benthic assemblages, suggesting these habitats may be resistant to trawling due to natural disturbances and large natural variability (ICES, 2014b). However, more research is needed to fully evaluate possible impacts on this type of habitats. More recently, the impacts of bottom trawling on megabenthos were examined in the Barents sea and megabenthos density and diversity (namely the sponges Craniella zetlandica and Phakellia / Axinella,  Flabellum macandrewi (Scleractinia), Ditrupa arietina (Polychaeta), Funiculina quadrangularis (Pennatulacea), and Spatangus purpureus (Echinoidea)) showed a negative relation  with fishing intensity. However, some asteroids, lamp shells, and small sponges showed a positive trend (Buhl-Mortensen et al. 2016). 

Longlines, gillnets and hooks and lines are not expected to cause irreversible harm to the seabed habitat, in temporal and spatial terms, given the characteristics of the gears. Therefore these fishing gears are not a concern (Nichols et al. 2015) (Knapman et al. 2018).

It is wider accepted that fishing activity has been having an effect in the Barents Sea benthic habitat but there is no evidence that these changes have led to wider changes in the ecosystem functioning, losses of productivity or ecosystem services (Hønneland et al. 2016). A comprehensive review of the biotic and abiotic drivers influencing early life history dynamics of the Barents Sea cod is presented in (Ottersen et al. 2014). Experimental studies also suggest possible ocean acidification effects on cod larval survival and recruitment (Stiasny et al. 2016).

There is a good understanding of the trophic chain, importance of key species and predator-prey relationships as well as "factors affecting the negative change in other ecosystem elements" in the Barents Sea ecoregion.  "Several ecosystem modelling studies have been undertaken for the Barents Sea, which have explored for example the trophic relations between fish species, and links between capelin, cod, seabirds, and marine mammals (e.g. ecopath type studies, EcoCod, Gadget, Biofrost, MULTSPEC, STOCOBAR, ECOSIM) as well as broader ecosystem models such as NORWECOM.E2E and hydrodynamic models (e.g. (Pfeiffer et al. 2013); Hønneland et al., 2016). An integrated ecosystem survey is carried out yearly since 2004 by IMR/PINRO (Pfeiffer et al. 2013) seeking to "provide scientific-based advice in order to allow the authorities to make management decisions regarding the long-term utilization of the resources in the Barents Sea area" (Cappell et al. 2015). Both Arctic Fisheries (AFWG) and Integrated Assessments of the Barents Sea (WGIBAR) Working Groups provide annual assessments. "The length of time series for some of this information is impressive and amongst the highest in the world" (Hønneland et al. 2016). 

"ECOSIM modelling of indirect effects suggests that there are no major trophic consequences (notably on cetaceans) of changing harvest rates of cod within the boundaries of established sustainable limits. There is no evidence of declines in marine mammal populations based on current monitoring information. Sufficient evidence is therefore available on the consequences of current levels of removal of target species to suggest no unacceptable impacts of the fishery on the Barents Sea ecosystem" (Pfeiffer et al. 2013)(Hønneland et al. 2014). Cod and capelin have close interactions and these are considered in the multispecies approach used for the cod stock assessment; interactions between stocks and fisheries are evaluated; GADGET modelling has also been used to understand the importance of all pieces in the whole trophic chain. All target species (cod, haddock and saithe) are biologically healthy, all resources are regularly assessed and under a management strategy; discarding is banned and seems to be negligible. Climate-change impacts appear to have more consequences in the Barents Sea ecosystem than the operating fisheries (Gascoigne et al. 2017). The required "assessments of threatened species and habitats and the development of an ecologically coherent network of marine protected areas, and assessment of human activities that may adversely affect ecosystems" under the "relevant conventions and agreements, such as the UN Convention on Biological Diversity" and OSPAR, along with the integrated management plan for the Barents Sea-Lofoten, are important tools to properly understand and manage the ecosystem in the region (Cappell et al. 2015). 

"The integrated Barents Sea-Lofoten ecosystem-based management plan (adopted by the Norwegian government in 2006 and reviewed and updated in 2011) evaluates the status of the ecosystem, the main activities, the cumulative impact of these activities on different components of the ecosystem and sets goals for different parts of the ecosystem, as well as measures and monitoring indicators designed to achieve those goals." A gap analysis identifies, among others, new activities to be conducted in terms of determining the impacts of the fishery in the seabed habitat. The document is considered as a real-time resource to monitor the ecosystem and explicitly determines new or adapted measures to achive the goals. There is an overarching plan for the Norwegian Barents Sea and Lofoten Area but the Russian zone lacks this type of initiative; there are also limitations on the knowledge about the specific and cumulative impacts of the fishing gears on benthic communities functioning and structure. Other gaps are identified in regard to certain areas (Svalbard Fisheries Protection Zone) and to specific VMEs (sponges and coral gardens). A partial strategy is considered to exist, there are current efforts to extend some of the existing Norwegian measures, monitoring, planning and analysis to the Russian territory. Several other measures are in place: TAC for most of the retained species, gears' specifications to increase selectivity, move-on rules to protect juveniles as well as corals and sponges, spawning areas, marine protected areas (Hønneland et al. 2014)(Gaudian et al. 2016)(Gascoigne et al. 2017)​(Knapman et al. 2018).