Fig 1.
a) Distribution of sampling sites in Livingston (LI) and Deception Islands (DI). b) sampling sites from previous studies from the literature. The yellow rectangle in b) shows the location of LI and DI. Map constructed with QGIS software.
Table 1.
Sample descriptions: Number of samples, replicates and macroalgal hosts.
Fig 2.
Predominant diatoms found on Antarctic macrophytes.
Monoraphid diatoms shown in raphe and raphe-less valve view. Biraphids shown in valvar and pleural view. a) Cocconeis fasciolata, b) Cocconeis californica var. californica, c) Cocconeis dallmannii, d) Cocconeis sp. 1, e) Cocconeis californica var. kerguelensis, f) Cocconeis melchioroides, g) Gomphonemopsis cf. ligowskii, h) Pseudogomphonema kamtschaticum, i) Licmophora gracilis, j) Navicula glaciei, k) Navicula incertata, l) Navicula perminuta, m) Pseudogomphonema sp. 1.
Table 2.
Sampling site characterization of depth and temperature (T) and diatom epiphyte richness (S) and diversity (H’) found on each macroalgal host.
Fig 3.
Ternary plot of predominant epiphytic diatoms shared between Rhodophyta (Rhodo), Phaeophyceaes (Phaeo) and Chlorophyta (Chloro).
Species codes: CCAL = Cocconeis californica, CCKG = Cocconeis californica var. kerguelensis, CDAL = Cocconeis dallmanii, CFAS = Cocconeis fasciolata, CMEO = Cocconeis melchioroides, CSP1 = Cocconeis sp. 1, GLIG = Gomphonemopsis ligowskii, LGRA = Licmophora gracilis, NGLA = Navicula glacialis, NICE = Navicula incertata, NPER = Navicula perminuta, PSKA = Pseudogomphonema kamtschaticum, PSS1 = Pseudogomphonema sp 1, Other = diatom species in under 2% frequency and abundance.
Table 3.
ANOSIM test results performed on communities from Phaeophyceae (Phae) and Rhodophyta (Rhod) hosts.
Fig 4.
nMDS of the diatom communities.
a) complete set and b) predominant diatoms (square root transformed). Bacill = macroscopically visible Bacillariophyceae, Chloro = Chlorophyta, Phaeo = Phaeophyceae, Rhodo = Rhodophyta. Species codes: CCAL = Cocconeis californica, CCKG = Cocconeis californica var. kerguelensis, CDAL = Cocconeis dallmanii, CFAS = Cocconeis fasciolata, CMEO = Cocconeis melchioroides, CSP1 = Cocconeis sp. 1, GLIG = Gomphonemopsis ligowskii, LGRA = Licmophora gracilis, NGLA = Navicula glacialis, NICE = Navicula incertata, NPER = Navicula perminuta, PSKA = Pseudogomphonema kamtschaticum, PSS1 = Pseudogomphonema sp 1, Other = diatom species in under 2% frequency and abundance.
Table 4.
Average abundance and dissimilarity of diatom communities from Rhodophyta (Rhod) and Phaeophyceae (Phae).
Fig 5.
RDA with the first two axes explaining 89.83% of total variance Eigen values of axis 1 = 2.80 and axis 2 = 0.582.
DI = Deception island, LI = Livingston island.
Fig 6.
Depth diagram of diatom distribution in Deception and Livingston Island.
The rest of diatoms found are summarized in the “Other” panel.
Table 5.
ANOSIM test results performed on communities from Deception (DI) and Livingston Island (LI).
Table 6.
Breakdown of average dissimilarity between epiphytic diatoms in Deception and Livingston Island locations (SIMPER).
Fig 7.
Hierarchical clustering calculated with 10,000 permutations with the studies of Davis Station (DS), Terra Nova Bay (TNB1, 2, 3), and South Shetland Islands (Deception [DI], Livingston [LI], and King George Island, divided into Potter Cove [PC] and Admiralty Bay [AB]) with presence-absence data aggregated at the study level (n total = 192).