The decline of global whale biomass

Shown are estimates of global whale biomass in pre-whaling periods versus the year 2001. This is measured in tonnes of carbon.

Source: Pershing, A. J., Christensen, L. B., Record, N. R., Sherwood, G. D., & Stetson, P. B. (2010). The impact of whaling on the ocean carbon cycle: why bigger was better.