Algal responses to dissolved organic carbon loss and pH decline during whole-lake acidification: evidence from paleolimnology

Paleolimnology has provided evidence related to algal responses to pH decline and dissolved organic carbon loss in whole-lake acidification. Fossil pigment analyses and 19 year-long historical records were used for quantification of the response to optical and chemical changes after experimental acidification with three different acids. Pigments from green algae went up by a factor of 2 during acidification with sulfuric acid. Those from cryptophytes were not affected and diatoxanthin from diatoms went down. Complex interactions of pH, dissolved organic carbon (DOC) and light may help to explain the high variability found in the responses to acidification.