The science behind the Greenpeace "There's probably no cod" ad campaign

Page - August 12, 2009
Greenpeace launched its “There’s probably no cod” ad campaign to sound the alarm bells that the consequences of overfishing are severe, often irreversible, and happening in Canada.

The devastation of the cod off the east coast is an example of the ecological and social impacts that occur when overexploitation meets mismanagement of our marine species.

Recent studies have confirmed that even with fishing bans and attempts at conservation, certain populations of cod are facing inevitable local extinction (extirpation), while others are struggling to recover.

The most alarming verdict of the Department of Fisheries and Oceans (DFO) 2009 stock assessment reports for cod was for the southern Gulf of St. Lawrence Atlantic cod. A further analysis of these findings was published in a study in the Canadian Journal of Fisheries and Aquatic Sciences in October of 2008. The study revealed an inevitable disappearance due to high natural mortality, low recruitment, and the lowest spawning stock biomass in 60 years, which is expected to decrease even further even with zero catch. The authors predict extirpation within 40 years with zero catch and 20 years with fishery removals at the allowed catch level for 2008-2009.

Why can't the cod recover?

The answer to this question has become complex, differing for each population and ecosystem, but the reason they have reached the levels they are today is simple: overexploitation. Even with stocks at dangerously low levels and most in a collapsed state in Atlantic Canada, DFO allows fishing in various forms.

For example, for the southern gulf cod, a decreased Total Allowable Catch (TAC) of 300 tonnes (TAC) was set to cover by-catch (catch of non-target species) provisions for fisheries targeting other species, Aboriginal and recreational fisheries, and scientific surveys. While down from 2,000 tonnes with no directed fishery (commercial fishery that targets cod), a TAC is still being set, and this stock is known to be going extinct even with no fishing pressure.

The general trends found in all the 2009 stock assessments for Atlantic cod managed by Canada are that fishing mortality or exploitation remains above recommended levels for stock reconstruction and health. The assessments recommend that fishing mortality must be kept at the lowest possible level, usually meaning no directed fishery. They also recommend that measures be in place to reduce the bycatch of cod in other fisheries.

Is there hope?

The results of the northern cod stock assessment offer some hope for recovery. The northern cod, which consists of the populations found off southern Labrador and eastern Newfoundland, suffered the worst collapse of all cod populations, and one of the worst in fisheries history, reducing them to less than 1 per cent of their previous level.

Before finding itself a place on Canada's endangered species list, the northern cod directed fishery was closed by the Canadian government in July 1992. However, despite a ban, little recovery has taken place. Although the recent stock assessment indicates that the number of northern cod is increasing, they remain at only about 8 per cent of their 1980s level, which is about 1/3 of what they were in the 1960s.

Despite a ban on commercial fishing, the fisheries have re-opened and closed over the years. Since 2006 a directed 'stewardship' fishery has been permitted, as well as recreational fisheries. Perhaps most critically, bycatch is allowed in fisheries such as winter flounder. Given that the northern cod assessment states that "there are no management goals against which current status and trends may be compared; there is no target for rebuilding, nor is there a target rebuilding rate," there is no assurance that signs and hope of recovery will turn to long term sustainability of the population.

Caution: no cod ahead!

We should remain hopeful that the cod will recover, but continuing a trend of seeking out cod which show any sign of recovery, shows no foresight. While the situation may be slowly improving for certain cod stocks, things must be kept in perspective and past mistakes must not be repeated. We still have a very long way to go before we are working with sustainable stocks that can be fished without putting into question the future health of our cod populations.

Operating as if there's probably no cod is the most precautionary approach to recovery. When it comes to our cod, a 'stewardship' fishery is a contradiction in terms, we should not be 'playing' with our ailing stocks and lost livelihoods through recreational fisheries, and any directed fishery is one further step towards an inevitable fate: a future without Atlantic Canadian cod.

2009 Atlantic cod stock assessment reports:

DFO. 2009. Stock Assessment of Northern (2J3KL) cod in 2009. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2009/009

DFO. 2009. Cod on the Southern Scotian Shelf and in the Bay of Fundy (Div. 4X/5Y). DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2009/015.

DFO. 2009. Assessment of cod stock in the northern Gulf of St. Lawrence (3Pn,4RS) in 2008.

DFO Can. Sci. Advis. Sec., Sci. Advis. Rep. 2009/010.

DFO. 2009. Stock Assessment of Subdivision 3Ps cod. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2009/008.

DFO. 2009. Assessment of Cod in the Southern Gulf of St. Lawrence. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2009/007.

Swain, Douglas P. and Ghislain A. Chouinard. Predicted extirpation of the dominant demersal fish in a large marine ecosystem: Altantic cod (Gadus morhua) in the southern Gulf of St. Lawrence. Can. J. Fish. Aquat. Sci. 65: 2315-2319 (2008)

Recent studies:

Hutchings, J.A. 2005. Life history consequences of overexploitation to population recovery in Northwest Atlantic cod (Gadus morhua). Can. J. Fish. Aquat. Sci. 62: 824-832.

Baum, Julia K. and Boris Worm. 2009. Cascading top-down effects of changing oceanic predator abundances. Journal of Animal Ecolog.

Myers, R.A., Hutchings, J.A., and Barrowman, N.J. 1996. Hypotheses for the decline of cod in the North Atlantic. Mar. Ecol. Prog. Ser. 138: 293-308.

Savenkoff, C., Swain, D.P., Hanson, J.M., Castonguay, M., Hammill, M.O., Bourdages, H., Morissette, L., and Chabot, D. 2007. Effects of fishing and predation in a heavily exploited ecosystem: comparing periods before and after the collapse of groundfish in the southern Gulf of St. Lawrence (Canada). Ecol. Model. 204: 115-128.

Shelton, P.A., Sinclair, A.F., Chouinard, G.A., Mohn, R., and Duplisea, D.E. 2006. Fishing under low productivity conditions is further delaying recovery of Northwest Atlantic cod (Gadus morhua). Can. J. Fish. Aquat. Sci. 63: 235-238.

Sinclair, A.F. 2001. Natural mortality of cod (Gadus morhua) in the southern Gulf of St. Lawrence. ICES J. Mar. Sci. 58: 1-10.

Sinclair, A.F., Swain, D.P., and Hanson, J.M. 2002. Disentangling the effects of size-selective mortality, density, and temperature on length-at-age. Can. J. Fish. Aquat. Sci. 59:372-382.

Swain, D.P., and Sinclair, A.F. 2000. Pelagic fishes and the cod recruitment dilemma in the Northwest Atlantic. Can. J. Fish. Aquat. Sci. 57: 1321-1325.

Swain, D.P., Sinclair, A.F., and Hanson, J.M. 2007. Evolutionary response to size-selective mortality in an exploited fish population. Proc. R. Soc. Lond. B Biol. Sci. 274: 1015-1022.

Trzcinski, M.K., Mohn, R., and Bowen, W.D. 2006. Continued decline of an Atlantic cod population: how important is gray seal predation? Ecol. Appl. 16: 2276-2292

DFO, 2007. Accounting for Changes in Natural Mortality in Gulf of St Lawrence Cod Stocks. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2007/002.

Le Bris A., Fréchet A., Brêthes J.-C. 2009. Estimation of the exploitation rate of thenorthern Gulf of St. Lawrence (3Pn,4RS) Atlantic Cod (Gadus morhua) stock, basedon tagging data. DFO Can. Sci. Advis. Sec. Res. Doc. 2009/012. v + 35p.