Carbon dioxide exchange and productivity in Lake Erie and Lake Ontario

Summary

1.	Comparisons between measured and calculated components of the dissolved inorganic carbon system have shown that the Lyman apparent dissociation constants are applicable to Lake Ontario.
2.	Calculations show that Lake Erie acts as a net source of carbon dioxide over the period of a year. Only in the summer does it take up CO2. The net flux out of the lake is around 460 gC/m2/year, which is within a factor of two of the productivity of the lake.
3.	Measurements of pCO2 and Pco2 have been used to find the net change in total dissolved inorganic carbon in two “limnocorrals” and the Bay of Quinte and the flux between these and the atmosphere. The community metabolism and the gross productivity have been calculated from these measurements. The gross productivity measurements are in reasonable agreement with values obtained using to oxygen light and dark bottle technique.