Table S3.

Summary of chemical and nutrient methods

Assay	Method description	Refs.
Ammonia, µg⋅L⁻¹	Phenate method	Standard methods 4500-NH₃-G (68)
Calcium, mg⋅L⁻¹	Flame atomic absorption spectrophotometry	65
Chlorine (Cl⁻), mg⋅L⁻¹	Dionex membrane-suppression ion chromatography	65, 66
Magnesium, mg⋅L⁻¹	Flame atomic absorption spectrophotometry	65
Nitrate/nitrite, µg⋅L⁻¹	Cadmium reduction	Standard methods 4500-NO₃-E (68)
Pheophytin corrected chlorophyll a, µg⋅L⁻¹	Fluorometry with pheophytin correction following ethanol extraction	Standard methods 10200.H (68)
pH	Hydrolab multisonde	66
Potassium, mg⋅L⁻¹	Flame atomic absorption spectrophotometry (0.5% HNO₃ preservative)	66
Sodium, mg⋅L⁻¹	Flame atomic absorption spectrophotometry (0.5% HNO₃ preservative)	66
Soluble reactive phosphorus, µg⋅L⁻¹	Ascorbic acid method	Standard methods 4500-P.E. (68)
Sulfate (SO₄), µg⋅L⁻¹	Dionex membrane- suppression ion chromatography	66
Total dissolved nitrogen, µg⋅L⁻¹	Second derivative spectroscopy following persulfate digestion	67
Total dissolved phosphorus, µg⋅L⁻¹	Ascorbic acid method following persulfate digestion	Standard methods 4500-P.E and 4500-N.C (68)
Total nitrogen, µg⋅L⁻¹	Second derivative spectroscopy following persulfate digestion	67
Total phosphorus, µg⋅L⁻¹	Ascorbic acid method following persulfate digestion	Standard methods 4500-P.E and 4500-N.C (68)
Total chlorophyll a, µg⋅L⁻¹	Fluorometry following ethanol extraction	Standard methods 10200.H (68)