Species → North Atlantic right whale

North Atlantic right whale

Eubalaena glacialis

384 individuals
Extinction risk Critically Endangered
Nutrient cyclingMarine environmentCarbonMegafauna
North Atlantic right whale (Eubalaena glacialis)
Photo: NOAA Fisheries / Peter Duley, Wikimedia Commons (Public domain)

What if it disappeared?

Impact Moderate
A few months to a year

Without great whales to bring nutrients drawn from depth back up to the surface while feeding, phytoplankton production would lose an input measured directly in the areas where they are still present today.

Documented
Detail

Roman, J. et McCarthy, J.J. (2010). The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal Basin. PLoS ONE, 5(10), e13255.

Whales feed at depth, then surface to breathe and defecate near the surface, where their nitrogen- and iron-rich waste stimulates phytoplankton growth — the base of the entire marine food chain. The authors quantify this input for the Gulf of Maine and estimate that it once far exceeded river inputs, before commercial whaling reduced whale populations.

Over decades

Rebuilding great whale populations would export roughly 160,000 tonnes of carbon per year to the ocean floor — compared with 9.1 million fewer tonnes currently stored since the start of commercial whaling.

Documented
Detail

Pershing, A.J., Christensen, L.B., Record, N.R., Sherwood, G.D. et Stetson, P.B. (2010). The Impact of Whaling on the Ocean Carbon Cycle: Why Bigger Was Better. PLoS ONE, 5(8), e12444.

A whale sinks to the ocean floor when it dies, durably exporting the carbon in its body. Great whales are more efficient at this than the smaller species that would occupy the same niche: removing a 92-tonne blue whale frees up enough food for seven minke whales, but their combined biomass amounts to only half that of the whale it replaced.

Very long term

This volume of carbon remains modest compared with total human emissions — a real, documented supplement, not a climate lever on its own.

Extrapolated
Detail

Extrapolation à partir de Pershing et al. (2010) : le raisonnement du modèle appliqué à la trajectoire de rétablissement réelle de la population, pas un résultat publié pour cet horizon précis.

Even a full recovery of great whale populations would represent only a tiny fraction of human-caused carbon emissions. This is a real, measured ecological service, but one the authors themselves present as a supplement, never as a stand-alone climate solution.

What's missing to confirm it: More recent work notes that the recovery of great whales' carbon benefits is itself threatened by climate change, which is altering the availability of their food — the actual trajectory over this horizon remains uncertain.

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