The following supplement accompanies the article Depth-induced adjustment of fatty acid and pigment composition suggests high biochemical plasticity in the tropical seagrass Halophila stipulacea Pedro Beca-Carretero*, Freddy Guihéneuf, Gidon Winters, Dagmar B. Stengel *Corresponding author: [email protected] Marine Ecology Progress Series 608: 105–117 (2019) Fig. S1. Map of study area in the Gulf of Aqaba (GoA), Red Sea, Israel, with the two transects (T-1, T-2) extending ~ 25 m from shallow (6 and 9 m) to intermediate (15 m) and deep areas (21 m). Blue cross represents the position (29.493 N, 34.909 E) of environmental data collection in adjacent waters. Fig. S2. Water temperature and irradiance (PAR) changes across a depth gradient (0 – 50 m) of July 2016 in adjacent waters (29.493 N, 34.909 E) from Israel’s National Monitoring of the Gulf of Eilat modified from Winters (2016). Table S1. Data for fatty acid composition compiled from the literature and unpublished data (Beca et al., unpubl) used to assess similarities between seagrass populations worldwide. ID References Species Family Location Latitude Mean Temp PUFA (% TFA) PUFA/SFA 1 Beca-Carretereo et al unpubl Zostera marina Zosteraceae Ireland, Kilkieran Bay 53.2 11.8 70.2 3.3 2 Beca-Carretereo et al unpubl Zostera noltii Zosteraceae Ireland, Kilkieran Bay 53.3 12 70.1 3.1 3 This study Halophila stipulacea Zosteraceae Israel, Red Sea 29.5 24 66.6 2.8 4 Sousa et al (2017) Zostera noltii Zosteraceae Portugal, Ria Aveiro 40.4 16.1 62.1 2.1 5 Beca-Carretero et al (2018) Posidonia oceanica Posidoniaceae Spain, Cala Montgo 40.7 19.1 65.7 2.9 6 Beca-Carretero et al (2018) Posidonia oceanica Posidoniaceae Spain, Delta del Ebro 42.1 17.2 66 2.9 7 Beca-Carretero et al (2018) Cymodocea nodosa Cymodoceaceae Spain, Cala Montgo 40.7 19.1 67.6 3 8 Beca-Carretero et al (2018) Cymodocea nodosa Cymodoceaceae Spain, Delta del Ebro 42.1 17.2 66.5 3 9 Sanina et al (2004) Zostera marina Zosteraceae Russia, Sea of Japan 43.9 8.2 74.3 4.1 10 Vaskovsy et al (1996) Zostera marina Zosteraceae China, Yellow Sea 35 15.2 72.2 3.8 11 Vaskovsy et al (1996) Phyllospadix iwatensis Zosteraceae China, Yellow Sea 35 15.2 72.2 3.9 12 Coelho et al (2011) Zostera noltii Zosteraceae Portugal, Ria Aveiro 40.6 16.1 64.8 2.1 13 Nicholst et al (1985) Thallassia hemprichii Hydrocharitaceae USA, Lizard Island -16.9 26.1 40.5 1.2 14 Kharlamenko et al (2001) Zostera marina Zosteraceae Russia, Sea of Japan 42.5 9.3 66.4 2.6 15 Hanson et al (2010) Halophila ovalis Hydrocharitaceae Australia, Bay Marine Park -30.5 21.5 48.1 1.2 16 Hanson et al (2010) Posidonia sinuosa Posidoniaceae Australia, Bay Marine Park -30.5 21.5 50.2 1.4 17 Richoux et al (2008) Zostera capensis Zosteraceae South Africa, Kariega Estuary -33.7 20.4 60 1.7 18 Jeffries et al (1972) Ruppia maritima Ruppiaceae USA, Rodhe Island 41.5 12.6 58.5 2.9 19 Viso. et al (1993) Posidonia oceanica Posidoniaceae Grecce, Athens 37.9 20.2 51.4 1.3 20 Viso. et al (1993) Posidonia oceanica Posidoniaceae France, Villefrnache-sur-mer 43.7 18.5 70 3.1 3 .