Table 1.

Preferable environmental conditions (Optimum) and niche limits (Niche) of the individual parameters of dominant bloom-forming dinoflagellate species in the Baltic coastal waters, calculated using the Gaussian-model approach. T – temperature above pycnocline, °C; Sal – salinity above pycnocline; TP and TN – total phosphorus and total nitrogen, μmol L⁻¹; n_tot – total number of the species' occurrences in the database; n – number of the species’ occurrences within the realized niche limits of the measured parameter. Optimum values of the parameters are highlighted in bold.

Speciesa	Features	T (°C)	Sal	TP	TN	TN/TPb
Amphidinium crassum ntot = 115	Optimum	15.06	8.0	8.99	146.90	16.34
	Niche	10.82–19.30	0.93–15.07	2.63–15.36	91.12–202.69
	n	62	88	27	12
Ceratium furca ntot = 36	Optimum	14.74	16.14	1.08	21.13	19.56
	Niche	9.34–20.14	13.42–18.87	0.65–1.51	0–47.77
	n	27	31	19	36
Ceratium fusus ntot = 253	Optimum	12.76	16.41	1.09	29.19	26.78
	Niche	9.22–16.30	10.0–22.82	0–2.24	16.92–41.47
	n	110	239	246	122
Ceratium lineatum ntot = 108	Optimum	9.45	25.45	1.30	19.22	14.78
	Niche	5.07–13.83	18.44–32.46	0.38–2.21	0.87–37.57
	n	73	29	88	86
Ceratium tripos ntot = 282	Optimum	10.01	13.19	1.63	32.04	19.66
	Niche	3.26–16.77	8.41–17.97	0.28–2.97	8.69–55.38
	n	206	231	205	216
Dinophysis acuminata ntot = 197	Optimum	12.17	17.08	2.36	31.38	13.30
	Niche	3.97–20.37	9.92–24.24	0–4.87	12.07–50.68
	n	169	185	197	159
Dinophysis norvegica ntot = 232	Optimum	8.33	19.69	1.16	30.65	26.42
	Niche	1.08–15.57	14.92–24.45	0.53–1.80	12.37–48.92
	n	174	139	108	190
Gyrodinium spirale ntot = 80	Optimum	9.30	16.90	0.52	23.30	44.81
	Niche	5.07–13.53	13.26–20.53	0–1.45	11.53–35.08
	n	48	50	75	61
Prorocentrum cordatum ntot = 457	Optimum	21.79	10.67	2.76	32.66	11.83
	Niche	12.58–31.00	5.56–15.78	0.04–5.48	9.74–55.59
	n	278	386	234	222
Prorocentrum micans ntot = 242	Optimum	18.2	12.07	0.88	31.38	35.66
	Niche	12.4–24.0	2.70–21.44	0–2.32	21.95–40.82
	n	139	222	234	70
Proterythropsis vigilans ntot = 84	Optimum	11.50	15.91	0.62	30.67	49.47
	Niche	3.81–19.18	11.16–20.67	0–1.26	14.38–46.96
	n	70	73	80	72
Protoperidinium bipes ntot = 105	Optimum	11.03	18.04	0.86	19.19	22.31
	Niche	4.50–17.57	13.40–22.68	0.05–1.67	6.53–31.85
	n	81	75	85	76
Protoperidinium brevipes ntot = 86	Optimum	11.04	18.82	0.76	31.63	41.62
	Niche	6.48–15.61	11.77–25.87	0.07–1.46	24.55–38.70
	n	57	78	73	16
Protoperidinium conicum ntot = 57	Optimum	12.40	23.38	1.29	24.34	18.87
	Niche	7.77–17.04	19.33–27.44	0.82–1.75	11.73–36.95
	n	35	17	16	45
Protoperidinium pellucidum ntot = 165	Optimum	11.37	17.86	0.56	18.52	33.07
	Niche	5.86–16.88	11.57–24.14	0.20–0.93	14.48–22.55
	n	165	152	97	86
Protoperidinium steinii ntot = 107	Optimum	11.83	15.7	1.10	19.5	17.73
	Niche	7.28–16.38	12.27–19.13	0.49–1.71	15.31–23.0
	n	84	84	63	53

^aData for Kryptoperidinium triquetrum were not included in the table due to ambiguity of the results on temperature and PO₄³⁻ niches that require additional analysis, which will be considered in a separate study.

^bThe TN/TP ratio was calculated as the relation of TN optimum to TP optimum of each species.