But we will not realize it until 2073. This 21 are species that went extinct between 1960's and 1980's. My money would be into the molluscs lost as collateral

But we will not realize it until 2073. This 21 are species that went extinct between 1960's and 1980's. My money would be into the molluscs lost as collateral damages by the effects of the Saint Lawrence Seaway, and the birds by a combination of touristic development plus Mikonia tree invasion starting on 60's and 70's.