Rate this item
(7 votes)

Collapse of Newfoundland cod fisheries, Northwest Atlantic

Main Contributors:

Roweena Patel, Kate Williman, Viveca Mellegard, Philipp Siegel

Other Contributors:

Reinette (Oonsie) Biggs, Juan Carlos Rocha


The Newfoundland cod fishery is a social-ecological system that is centered upon Arctic cod, Gadus morhua populations in the waters off Newfoundland and Labrador in the Northwest Atlantic. High fishing pressure, along with regional climatic variability that delivered colder water to the Northwest Atlantic ocean, disturbed the cod spawning grounds and led to a dramatic cod fishery collapse. Recovery in the fishery has been minimal and very slow, partly because cod population growth will take time to replenish the amount of stock that was lost. This regime shift has impacted ecosystem services by reducing the food source both at the local and the global scale. There has also been a loss of income from cod fishing at the local scale that affects human wellbeing among Newfoundland fishers and the communities relying directly and indirectly on the fishing industry. Actions taken to restore the cod regime shift includes banning of the commercial fisheries in the Northwest Atlantic, tighter regulations and dock-side monitoring programs.

Type of regime shift

Ecosystem type

  • Marine & coastal

Land uses

  • Fisheries

Spatial scale of the case study

  • Sub-continental/regional (e.g. southern Africa, Amazon basin)

Continent or Ocean

  • North America
  • Atlantic Ocean


  • Northern North Atlantic


  • Canada

Locate with Google Map


Key direct drivers

  • Harvest and resource consumption
  • Adoption of new technology
  • Environmental shocks (eg floods)

Land use

  • Fisheries


Ecosystem type

  • Marine & coastal

Key Ecosystem Processes

  • Primary production


  • Biodiversity

Provisioning services

  • Fisheries

Cultural services

  • Recreation
  • Knowledge and educational values

Human Well-being

  • Food and nutrition
  • Livelihoods and economic activity
  • Cultural, aesthetic and recreational values
  • Cultural identity

Key Attributes

Spatial scale of RS

  • National (country)
  • Sub-continental/regional

Time scale of RS

  • Years
  • Decades


  • Hysteretic


  • Models
  • Contemporary observations

Confidence: Existence of RS

  • Well established – Wide agreement in the literature that the RS exists

Confidence: Mechanism underlying RS

  • Contested – Multiple proposed mechanisms, reasonable evidence both for and against different mechanisms

Alternate regimes

Regime 1: Viable cod fishery (1500 - 1960)

This regime covers the Newfoundland fishery from its beginning in the 16th century to approximately 1960, when significant fishing intensification began (Haedrich & Hamilton 2010). Over these five centuries, cod abundance remained high enough to support a coastal fishing industry (Rose et al. 2004). The food web includes large cod stocks that control prey populations of capelin and the copepod Calanus finmarchicus through predation.


Regime 2: Collapsed cod fishery (1990 - present day)

This regime covers the Newfoundland fishery from approximately 1990, when the cod population collapsed, up until present day. Cod abundance is thought to have remained at less than 10% of what it was in the 1960s since this time (Haedrich & Hamilton 2000). Meanwhile, crustacean abundance (including crabs and shrimps) has increased, possibly due to a reduction in predation by cod, and supports viable industries (Rose et al. 2000). Both coastal and offshore fishing industries are present, albeit at greatly reduced catch rates.

Drivers and causes of the regime shift

The Drivers that can cause a regime shift in the North Atlantic cod abundance from a viable cod fishery to a collapsed cod fishery are an interplay of high fishing pressure and regional climatic variability (Lilly et al. 2013). Overfishing leads to a depletion of fish stocks below the sustainable population size (Myers & Worm 2005). In the Northwest Atlantic, cod fisheries collapsed within one fishing season in the early 1990s and overfishing was the main driver.  At that period in time, cod stocks in the Northwest Atlantic were overestimated both scientifically and from fishing industry. Furthermore fishing quotas were inadequate and disregarded because of a “tragedy of the commons” problem (Milich 1999) and because of foreign fishing fleets not respecting Canadian and NAFO regulations (Lilly et al. 2013).


A climatic seesaw pattern, the North Atlantic Oscillation (NAO), played its part in the downfall of Canadian cod fisheries alongside overfishing. If NAO values become positive, westerly winds in the North Atlantic increase in strength leading to milder conditions in the Northeast Atlantic and to cooler conditions in the northwestern part of the ocean (Cohen & Barlow 2005). These conditions act as a negative driver impacting cod stocks on a biogeographical as well as a physiological level. Migrations into warmer waters and higher mortalities among cod populations are the cause of strong positive NAO values (Rose et al. 2000).



How the regime shift worked

In the late 1980s and 90s overfishing became a main problem in the Canadian cod fishery. A lack of regulating fishing policies lead to overexploitation of stocks through Canadian and international fishing fleets (Lilly et al. 2013). In combination with new technological advances in the fisheries sector and a misunderstanding of the prevailing size of cod stocks the viable cod fishery regime was driven towards turning into a collapsed cod fishery state (Myers et al. 1997). Climatic regional cooling in the Northwest Atlantic due to a positive North Atlantic Oscillation (NAO) contributed its share. Low water temperatures caused cod populations to migrate further south into warmer waters and caused decreases in metabolic rate, personal fitness and larval recruitment and increased cod mortality (Myers et al. 1997; Rose et al. 2000; Fromentin & Planque 1996). As a result of overfishing and climatic change, cod fisheries collapsed in the fishing season 1991/92 in Canada.



Impacts on ecosystem services and human well-being


Cod provided provisioning services in the form of food and cultural services in the form of employment in the fishing industry as well as cultural identity for communities that grew up around the fisheries for over 500 years. As the cod industry collapsed, a strong global market for shellfish encouraged the replacement of cod with northern shrimp and snow crab. In this way, the regime shift in marine ecology caused a shift in provisioning ecosystem services from cod to crustaceans. However, the knowledge, skills and experience of cod fishers became redundant and coastal areas experienced changes in culture, traditions and community dynamics (McCay and Finlayson 1996).


Cod fisheries directly or indirectly supported half of Newfoundland’s 600,000 population (Milich, 1999). 40,000 people lost their jobs when the government announced the moratorium in 1992 (Haedrich & Hamilton 2000).  The growing shellfish industry absorbed some of this workforce and government subsidies and retraining programmes supported some fishers. However, shellfish processing plants are mainly inland and many of the coastal communities experienced high levels of outmigration by young adults in search of alternate sources of income and employment (McCay and Finlayson 1996).  Many of the cultural traditions unique to Newfoundland, such as folklore and music,  have been weakened as a consequence and it is possible that sense of place and identity becomes diluted in younger generations who move away and adapt to other places and ways of life.  This impacts human wellbeing by separating families and breaking social bonds. Demographic shifts have been observed, particularly among rural populations, where there is a lower birth rate and ageing populations (Schrank 2005).

Management options


Actions to prevent an alternate regime occurred within 1970s in Northwest Atlantic. In 1973-1975 the Northwest Atlantic (NWA) region around Newfoundland removed any non Canadian shipping fleets to reduce the number of vessels fishing cod. In 1977 a 200 nautical mile exclusive economic zone (EEZ) was implemented. Ongoing fast implementation of quotas and regulations occurred in response to perceived declines of cod stock in the collapse in the northeast Atlantic. However there was no such response in the NWA until a complete collapse in the early 1990s (Lilly et al. 2013).



Actions to restore the cod regime include the ban of commercial fisheries in the Northwest Atlantic after the collapse in the 1990s. The input control limited the number of licences for recreational fishing and the output controls limited the total allowable catch and decreased the quotas. These quotas were continuously assessed via the harvest control rule, where predictions and current stock levels influenced the quota for the following year. In 1997 the provincial act of professionalisation of the harvesting sector was implemented to limit access and to provide other types of training to fish harvesters. Several task forces focused on the restructuring and adjustment programs were established in response to the collapse of cod fisheries, such as the federal -provincial Cod Recovery Action Teams. The mandate of these  teams is to develop stock rebuilding and long term management strategies. This is a joint initiative between the federal (government) and provincial (fishing communities) where there is an extensive consultation of a variety of stakeholder with regular exchange of information. However restructuring initiatives and adjustment programs were terminated in 2005 due to several reasons, including high cost and failure to meet the social needs of stakeholders. (Khan & Chuenpagdee, 2013; DFO, 2010). The Northwest Atlantic Fishery Organisation (NAFO) now regulates the seas outside of the Canadian EEZ after the Portuguese-crewed vessel fishing 45km outside of the EEZ harvested juvenile cod for the Portuguese market (Milich 1999). The NAFO regulate quotas for all of the northwest, currently the total allowable catch for 2013 is 14,000 metric tons ( 2013). Table 1 summarizes the changes in policy pre and post collapse of the cod fishery. There were many changes that occurred in fisheries from pre collapse to post collapse. For example before the collapse the management regime was top down and used a single species approach, whereas post collapse the management was integrated and moved towards an ecosystem approach alongside stakeholder involvement. Biologically and ecologically sensitive habitats were identified and protected post collapse -  previously there was no such regulation.  Pre collapse, there were no regulations regarding gear type - restrictions in gear type and usage were implemented post collapse. Dock-side monitoring programs in addition to log books and vessel monitoring prevent incidences of misreportings, high grading, illegal and unreported catches which were prevalent pre collapse (Khan & Chuenpagdee 2013).

Key References

  1. Arnason, R., Sandal, L. K., Steinshamn, S. I., & Vestergaard, N. (2004). Optimal Feedback Controls: Comparative Evaluation of the Cod Fisheries in Denmark, Iceland, and Norway. American Journal of Agricultural Economics, 86(2): 531-542.
  2. Bavington, D. (2010). From hunting fish to managing populations: fisheries science and the destruction of Newfoundland cod fisheries. Science as Culture, 19(4), 509-528.
  3. Berec, L., Angulo, E., & Courchamp, F. (2007). Multiple Allee effects and population management. Trends in Ecology and Evolution, 22(4): 185-191.
  4. Caddy, J.F., and Agnew, D.J., (2005). An overview of recent global experiences with recovery plans for depleted marine resources and suggested guidelines for recovery planning. Reviews in Fish Biology and Fisheries 14: 43–112.
  5. Canada-Newfoundland and Labrador. (2003). A strategy for the recovery and management of cod stocks in Newfoundland and Labrador. Action Team for Cod Recovery Report, Department of Fisheries and Oceans, Department of Fisheries and Aquaculture, St. John’s, NL, Canada.
  6. Canada-Quebec. (2005). Towards a recovery strategy for Gulf of St. Lawrence cod stocks. Canada-Quebec Cod Action Team Cod Rebuilding Strategy. Department of Fisheries and Oceans, Moncton, Quebec, Canada.
  7. Clark, R.A., Fox, C. J.,Viner, D., Livermore, M. (2003). North Sea cod and climate change – modelling the effects of temperature on population dynamics. Global Change Biology, 9(11): 1669–1680.
  8. Cohen, J., & Barlow, M. (2005). The NAO, the AO, and Global Warming: How Closely Related?. Journal of Climate, 18: 4498-4513.
  9. Colbourne, E., Craig, J., Fitzpatrick, C., Senciall, D., Stead, P., Bailey, W., & Department of Fisheries and Oceans, Ottawa, ON(Canada); Canadian Science Advisory Secretariat, Ottawa, ON(Canada). (2011). An assessment of the physical oceanographic environment on the Newfoundland and Labrador Shelf during 2010 (No. 2011/089). DFO, Ottawa, ON(Canada).
  10. Cox, K. (1994). Why the cold killed the cod. [ Toronto] Globe and Mail, 31 January.
  11. DFO. (2010). Economic overview of the groundfish industry. Economic analysis and statistics, policy sector. Presentation at the Fisheries Resource Conservation Council Meeting. Feb 17–20, 2010, Montreal, Quebec, Canada.
  12. Drinkwater, K. F. (2002). A review of the role of climate variability in the decline of northern cod. Fisheries in a Changing Climate, 113-130.
  13. Drinkwater, K. F. (2005). The response of Atlantic cod (Gadus morhua) to future climate change. ICES Journal of Marine Science: Journal du Conseil, 62(7), 1327-1337.
  14. Drinkwater, K. F. (2006). The regime shift of the 1920s and 1930s in the North Atlantic. Progress in Oceanography, 68(2), 134-151.
  15. Dutil, J.-D., & Brander, K. (2003). Comparing productivity of North Atlantic cod (Gadus morhua) stocks and limits to growth production. Fisheries Oceanography, 12(4/5): 502–512.
  16. Eide, A., Heen, K., Armstrong, C., Flaaten, O., & Vasiliev, A. (2013). Challenges and Successes in the Management of a Shared Fish Stock–The Case of the Russian–Norwegian Barents Sea Cod Fishery. Acta Borealia,30(1), 1-20.
  17. Fromentin,J.-M., & Planque, B. (1996). Calanus and environment in the eastern North Atlantic. II. Influence of the North Atlantic Oscillation on C. finmarchicus and C. helgolandicus. Marine Ecology Progress Series, 134: 111-118.
  18. Greene, C. H., & Pershing, A. J (2000). The response of Calanus finmarchicus populations to climate variability in the Northwest Atlantic: basin-scale forcing associated with the North Atlantic Oscillation. Journal of Marine Science, 57: 1536–1544.
  19. Greene, C. H., Pershing, A. J., Cronin, T. M., & Ceci, N. (2008). Arctic climate change and its impacts on the ecology of the North Atlantic. Ecology, 89(11): 24-38.
  20. Haedrich, R. L., & Hamilton, L. C. (2000). The fall and future of Newfoundland's cod fishery. Society & Natural Resources, 13(4), 359-372.
  21. Hamilton, L. (2010). Footprints: Demographic effects of outmigration. Migration in the Circumpolar North: Issues and Contexts. L. Husky and C. Southcott (Eds). Edmonton, Alberta: Canadian Circumpolar Institute, 1-14.
  22. Hamilton, L. C., & Butler, M. J. (2001). Outport adaptations: Social indicators through Newfoundland's cod crisis. Human Ecology Review, 8(2), 1-11.
  23. Hátún, H. , Payne, M.R., Beaugrand, G., Reid, P.C., Sandø, A.B., Drange, H., Hansen, B., Jacobsen, J.A, & Bloch, D. (2009). Large bio-geographical shifts in the north-eastern Atlantic Ocean: From the subpolar gyre, via plankton, to blue whiting and pilot whales. Progress in Oceanography, 80: 149–162.
  24. Howard, M. (2003). When fishing grounds are closed: Developing alternative livelihoods for fishing communities. Secretariat for the Pacific Community Women in Fisheries Information Bulletin, 13, 19-22.
  25. Khan, A., & Chuenpagdee, R. (2013). An Interactive Governance and Fish Chain Approach to Fisheries Rebuilding: A Case Study of the Northern Gulf Cod in Eastern Canada. Ambio, 1-14.
  26. Krohn, M., Reidy, S., & Kerr, S. (1997). Bioenergetic analysis of the effects of temperature and prey availability on growth and condition of northern cod (Gadus morhua). Canadian Journal of Fisheries and Aquatic Sciences, 54(1): 113-121.
  27. Lilly, G. R., Nakken, O., & Brattey, J. (2013). A review of the contributions of fisheries and climate variability to contrasting dynamics in two Arcto-boreal Atlantic cod (Gadus morhua) stocks: persistent high productivity in the Barents Sea and collapse on the Newfoundland and Labrador Shelf. Progress in Oceanography.
  28. Mason, F. (2002). The Newfoundland Cod Stock Collapse: A Review and Analysis of Social Factors. Electronic Green Journal, 1(17), Article 2.
  29. McCay, B. J., & Finlayson, A. C., (1995). The political ecology of crisis and institutional change: the case of the northern cod. Annual Meeting of the American Anthropological Association, Washington, DC.
  30. Milich, L. (1999). Resource mismanagement versus sustainable livelihoods: The collapse of the Newfoundland cod fishery. Society & Natural Resources,12(7), 625-642.
  31. Morgan, M. J., DeBlois, E. M., & Rose, G. A. (1997). An observation on the reaction of Atlantic cod (Gadus morhua) in a spawning shoal to bottom trawling. Canadian Journal of Fisheries and Aquatic Sciences, 54(S1), 217-223.
  32. Myers, R. A., Hutchings, J. A., & Barrowman, N. J. (1996). Hypothesis for the decline of cod in the North Atlantic. Marine Ecology Progress Series, 138: 293-308.
  33. Myers, R. A., Hutchings, J. A., & Barrowman, N. J. (1997). Why do Fish Stocks Collapse? The Example of Cod in Atlantic Canada. Ecological Applications, 7(1): 91-106.
  34. (2013). NAFO Fishery. [online] Available at: [Accessed: 1 Dec 2013].
  35. Rose, G. A. (2004). Reconciling overfishing and climate change with stock dynamics of Atlantic cod (Gadus morhua) over 500 years. Canadian Journal of Fisheries and Aquatic Sciences, 61, 1553–1557.
  36. Rose, G. A., DeYoung, B., Kulka, D. W., Goddard, S. V., & Fletcher, G. L. (2000). Distribution shifts and overfishing the northern cod (Gadus morhua): a view from the ocean. Canadian Journal of Fisheries and Aquatic Sciences,57(3), 644-663.
  37. Rose,G.A., deYoung, B., Kulka, D.W., Goddard, S.V., & Fletcher G.L. (2000). Distribution shifts and overfishing the northern cod (Gadus morhua): a view from the ocean. Canadian Journal of Fisheries and Aquatic Sciences, 57: 644–663.
  38. Schrank, William E. (2005). The Newfoundland fishery: ten years after the moratorium. Marine Policy 29.5: 407-420.
  39. Song, A.M., Chuenpagdee, R., and Jentoft, S. (2013). Values, images, and principles: What they represent and how they may improve fisheries governance. Marine Policy 40: 167–175.
  40. Sundby, S. (2000). Recruitment of Atlantic cod stocks in relation to temperature and advection of copepod populations. Sarsia, 85: 277-298.
  41. Vilhjalmsson, H. (1983). Biology, abundance estimates and managements of the Icelandic stock of capelin. Rit. Fiskideild. 3: 153-181.
  42. Worm, B., & Myers, R. A. (2003). Meta-analysis of cod-shrimp interactions reveals top-down control in oceanic food webs. Ecology, 84(1), 162-173.


Roweena Patel, Kate Williman, Viveca Mellegard, Philipp Siegel, Reinette (Oonsie) Biggs, Juan Carlos Rocha. Collapse of Newfoundland cod fisheries, Northwest Atlantic. In: Regime Shifts Database, Last revised 2017-02-07 12:18:06 GMT.
Read 24092 times
Login to post comments