locations & seawater temperatures / experimental period / Irradiance at noon / Daily dose
IQUIQUE
(20º14’S, 70º08’W)
16.8 ± 0.9 °C / UVB
(W m-2) / UVA
(W m-2) / PAR
(µmol m-2 s-1) / UVB
(kJ m-2) / UVA
(kJ m-2) / PAR
(kJ m-2)
28 Feb
29 Feb
01 Mar
02 Mar
03 Mar
04 Mar
05 Mar
06 Mar
07 Mar
08 Mar / 1.96
1.91
1.80
1.89
1.80
1.91
1.83
1.91
1.79
1.84 / 69.14
67.21
64.44
66.36
64.86
69.80
67.25
68.92
64.44
68.17 / 2051.8 ± 4.4
2020.0 ± 3.9
1975.6 ± 6.7
1997.9 ± 7.5
1938.7 ± 3.6
2004.4 ± 9.6
1973.5 ± 5.4
1994.4 ± 1.4
1914.3 ± 5.7
1964.1 ± 3.8 / 55.4
54.3
53.1
53.5
54.3
54.7
54.0
54.3
52.8
52.2 / 1881.0
1837.0
1832.0
1782.0
1840.5
1846.1
1820.5
1820.3
1752.5
1724.7 / 12122.4
11937.1
11681.0
11678.5
11891.2
11814.0
11710.1
11719.9
11421.6
11099.1
COQUIMBO
(29º58’S, 71º21’W)
18.2 ± 1.0 °C / 05 Jan
06 Jan
07 Jan
08 Jan
10 Jan
11 Jan
14 Jan
15 Jan
16 Jan
18 Jan / 0.66
0.99
1.60
1.63
1.74
1.79
1.62
1.05
0.36
1.60 / 22.24
34.34
60.61
58.42
62.58
61.48
61.40
36.67
10.79
60.88 / *1098.0 ± 6.4
1748.1 ± 73.6
2060.3 ± 7.3
2010.5 ± 7.7
2107.0 ± 16.7
2113.0 ± 3.8
2095.3 ± 7.9
1590.8 ± 32.7
*377.7 ± 1.3
2093.5 ± 20.1 / 20.6
48.0
42.2
43.6
43.8
46.4
45.2
40.2
29.7
41.5 / 653.0
1733.5
1600.9
1572.1
1544.1
1645.8
1659.2
1405.5
1011.0
1495.7 / 8466.2
16268.1
13101.1
12848.9
11618.1
13451.5
12603.1
11278.0
8431.6
11748.3
CALFUCO
(39º45’S, 73º23’W)
15.4 ± 1.3 °C / 01 Feb
03 Feb
06 Feb
07 Feb
08 Feb
09 Feb
10 Feb
11 Feb
12 Feb
13 Feb / 0.60
1.56
1.58
1.44
1.45
1.60
1.53
1.54
1.10
1.12 / 17.61
55.48
55.46
51.40
52.86
58.29
52.58
51.34
36.70
38.59 / *574.3 ± 2.1
1772.0 ± 6.4
1772.4 ± 6.1
1805.4 ± 2.4
1783.6 ± 3.3
1457.5 ± 669.3
1814.1 ± 3.9
1764.5 ± 3.1
1122.4 ± 19.5
819.5 ± 167.8 / 33.0
45.4
43.0
42.5
43.7
36.9
44.5
45.0
34.9
34.5 / 1186.3
1591.9
1560.1
1545.2
1586.0
1288.4
1593.3
1568.7
1211.0
1203.5 / 9130.8
10714.6
10957.4
11167.6
11169.2
8642.4
11205.6
10922.5
8137.7
7761.2

Table S1: Levels of solar radiation and water temperature measured during austral summer 2008, at three different sites (Iquique, Coquimbo, Calfuco) along the Chilean Pacific coast.

*Sky completely cloudy in the morning

Table S2: Results from the statistical analysis of Macrocystis pyrifera pigment contents (Chl a, Chl c and carotenoids) after 15 days of floating, using a 3-factorial ANOVA, with the fixed factors Filter (=PAR, PAR+UV) and Control (=C) and Grazing (=G) and the random factor Site (Iquique, Coquimbo, Calfuco). NATSR (the treatment without filters, used to test for filter artifacts) was not included in the analyses because initial tests confirmed that there were no filter effects for any of the examined variables.

Chl a / Chl c / carotenoids
df / F / *P-value / df / F / *P-value / df / F / P-value
Filter / 1 / 0.900 / 0.443 / 1 / 0.432 / 0.579 / 1 / 0.574 / 0.528
CG / 1 / 0.215 / 0.688 / 1 / 0.101 / 0.781 / 1 / 0.403 / 0.591
Site / 2 / 5.816 / 0.147 / 2 / 1.850 / 0.468 / 2 / 2.737 / 0.387
Filter×CG / 1 / 0.948 / 0.433 / 1 / 0.026 / 0.887 / 1 / 0.551 / 0.535
Filter×Site / 2 / 2.237 / 0.309 / 2 / 0.652 / 0.605 / 2 / 1.072 / 0.483
CG×Site / 2 / 1.791 / 0.358 / 2 / 1.910 / 0.344 / 2 / 1.366 / 0.423
Filter×CG×Site / 2 / 1.668 / 0.203 / 2 / 2.968 / 0.064 / 2 / 2.169 / 0.129
Error / 36 / 36 / 36

* significant differences at level 0.01

Table S3: Results from the statistical analysis of electron transport rate variables (ETRmax, α and Ek) and non-photochemical quenching values (NPQ) of Macrocystis pyrifera after 15 days of floating, using a 3-factorial ANOVA, with the fixed factors Filter (=PAR, PAR+UV) and Control (=C) and Grazing (=G) and the random factor Site (Iquique, Coquimbo, Calfuco). NATSR (the treatment without filters, used to test for filter artifacts) was not included in the analyses because initial tests confirmed that there were no filter effects for any of the examined variables. P-values in bold highlight significant differences at p < 0.05.

ETRmax / Ek / alpha / NPQ
df / F / P-value / df / F / P-value / df / F / P-value / df / F / P-value
Filter / 1 / 0.362 / 0.609 / 1 / 0.608 / 0.517 / 1 / 0.936 / 0.435 / 1 / 1.379 / 0.361
CG / 1 / 0.057 / 0.833 / 1 / 14.386 / 0.063 / 1 / 1.771 / 0.315 / 1 / 2.452 / 0.258
Site / 2 / 45.156 / 0.001 / 2 / 13.056 / 0.203 / 2 / 23.769 / 0.601 / 2 / 29.197 / 0.510
Filter×CG / 1 / 1.306 / 0.371 / 1 / 1.389 / 0.360 / 1 / 1.330 / 0.368 / 1 / 0.699 / 0.491
Filter×Site / 2 / 0.483 / 0.674 / 2 / 3.497 / 0.222 / 2 / 1.037 / 0.491 / 2 / 1.656 / 0.376
CG×Site / 2 / 0.082 / 0.924 / 2 / 0.016 / 0.985 / 2 / 0.417 / 0.706 / 2 / 0.022 / 0.978
Filter×CG×Site / 2 / 1.550 / 0.226 / 2 / 0.864 / 0.430 / 2 / 0.630 / 0.538 / 2 / 1.632 / 0.210
Error / 36 / 36 / 36 / 36

Figure S1. Map of Chile with experimental sites.