Table S1: Areas Surveyed During CIMAR-Fiordos (CF) Cruises Between 2002 and 2010 in The

Electronicsupplement

Table S1: Areas surveyed during CIMAR-Fiordos (CF) cruises between 2002 and 2010 in the Patagonian Fjord Region. During all cruises the abundance of floating kelp was monitored. In four areas Macrocystis pyrifera samples were taken to examine the associated fauna. Roman numerals indicate the number of sampling sites for faunal examination and parenthesized letters refer to the condition of the sampled algae at these sites. (f) = floating algae, (b) = benthic algae.

Area / Latitude / CIMAR-Fiordos / Year / Examination of fauna
Maullín Area / -38.9244°-
-41.9086° / CF8-11, 14 / 2002-05, 2008 / no
Interior Sea of Chiloé / -41.6511°-
-43.4176° / CF10-11, 14 / 2004-05, 2008 / CF11, 2005; VI (f)
Guafo Passage / -43.5176°-
-43.9092° / CF8-11 / 2002-05 / no
Chonos’ Archipelago / -43.9359°-
-46.2446° / CF8-9, 14 / 2002-03, 2008 / CF8, 2002; VI (f)
Kawésqar Fjords / -47.0209°-
-50.1279° / CF14 / 2008 / CF14, 2008; IV (f)
Magellan Region / -52.6849°-
-55.3809° / CF16 / 2010 / CF16, 2010; II (b), V (f)

Table S2: Sites in the Magellan Region where Macrocystis pyrifera in floating and benthic condition were sampled for the examination of the associated fauna. Sampling was conducted in the framework of the CIMAR-Fiordos 16 reasearch program in austral spring (November) of 2010.

Sampling Site / Latitude / Longitude / Acronym / Condition / Replicates
Western Magellan Strait / -53.1785° / -73.3486° / WMS / Benthic / 4
Carlos III / -53.5692° / -72.3229° / CIII / Floating / 1
Central Magellan Strait / -53.9037° / -71.5642° / CMS / Floating / 4
Whiteside Channel / -53.9259° / -70.2596° / WC / Floating / 4
Cockburn Channel / -54.3452° / -71.6266° / CC / Floating / 4
Ballenero Channel / -54.9246° / -70.7160° / BaC / Benthic / 4
Beagle Channel / -55.0231° / -69.3843° / BeaC / Floating / 4

Table S3: Taxonomic categories, equations and pooling used for the calculation of the total abundances A (ind. kgˉ1), occurrence Oi(%), relative abundance Ari (%) of all major taxa and of taxonomic groups within the molluksArmi (%). * = taxonomicgroupwasindividuallyconsidered. Ni= total number of individuals in a sample, Ww = algal wet weight (g), Noi = number of samples in which the considered taxonomic group occurred at one site, n= total number of samples at one site, Ai = total abundance of the considered taxonomic group, Armi= relative abundance of the considered taxonomic group in a sample, Arm = relative abundance of all molluscs in a sample.

Taxonomiccategory / Total abundance
A = (Ni / Ww) * 1000 / Occurrence
Oi= Noi / n / Relative abundance
Ari = Ai / A / Relative abundance
Mollusca
Armi = Armi / Arm
Mollusca / Bivalvia / No distinction of the different taxa / * / Pooled / *
ShelledGastropods / * / *
Nudibranchia / * / *
Polyplacophora / * / *
Peracarida / Gammaridea / Pooled / Pooled / Notincluded
Hyperiidea
Isopoda
Tanaidacea
Caprellidea
Cumacea
Other / Cnidaria / * / Pooled
ETD of Decapoda / *
Decapoda / *
Echinodermata / *
Pycnogonida / *
Annelida / * / *
Platyhelminthes / * / *
Nemertinea / * / *
NN / * / *

Table S4: Percentage of occurrence and number of associated isopod and amphipod species with benthic and floating Macrocystis pyrifera at the different sampling sites and in the Magellan Region (MR). Benthic sampling sites are highlighted in grey. n = number of replica per sampling site, + = presence of species (for sampling site with n=1), - = absence species. Species that were most frequent at benthic and floating sampling sites (> 71% occurrence in MR) are highlighted in bold. WMS = Western Magellan Strait, BaC = Ballenero Channel, CIII = Carlos III, CMS = Central Magellan Strait, WC = Whiteside Channel, CC = Cockburn Channel, BeaC = Beagle Channel.

Species / WMS
n=4 / BaC
n=4 / CIII
n=1 / CMS
n=4 / WC
n=4 / CC
n=4 / BeaC
n=4 / Occurrence
in MR
Isopoda / Ischyromenemenziesi / 100 / 50 / + / 50 / 25 / - / 75 / 86
Plakarthriumsp. A / 100 / 100 / + / 25 / - / - / 25 / 71
Limnoriachilensis / 75 / 75 / + / 25 / - / - / 75 / 71
SimiarCassidinopsisemarginata / 50 / - / + / 25 / - / - / - / 43
Uromunna nana / 25 / 75 / - / 25 / - / - / - / 43
Neastacillamagellanica / 75 / 75 / - / - / - / - / - / 29
Exosphaeroma gigas / 50 / 25 / - / - / - / - / - / 29
Neojaerasp. A / 25 / 25 / - / - / - / - / - / 29
Ianiropsisvarians / 50 / - / - / - / - / - / - / 14
Ianiropsischilensis / 25 / - / - / - / - / - / - / 14
Paramunnamenziesi / - / 50 / - / - / - / - / - / 14
Paramunnaspp. / - / 50 / - / - / - / - / - / 14
Janthopsislaevis / - / 25 / - / - / - / - / - / 14
Munnachilensis / - / 25 / - / - / - / - / - / 14
Munnasp. A / - / 25 / - / - / - / - / - / 14
Neojaeraantarctica / - / 25 / - / - / - / - / - / 14
Amphipoda / Peramphithoefemorata / 100 / 100 / + / 75 / 50 / 75 / 75 / 100
Gondogeneiasp. A / 75 / 50 / + / 50 / 75 / 50 / 75 / 100
Jassathurstoni / 100 / 100 / + / 50 / 50 / - / 100 / 86
Paradexaminesp. A / 100 / 75 / + / 25 / 25 / - / - / 71
Bircennacf. macayai / 75 / 75 / + / 50 / 25 / - / - / 71
Paramoerafissicauda / 100 / 100 / - / 25 / - / - / 25 / 57
Gammaropsisspp. / 75 / 100 / - / - / - / 25 / 50 / 57
Paramoerasp.A / 50 / 25 / + / - / 25 / - / - / 57
Gondogeneiasp. B / 50 / 75 / - / 50 / - / - / - / 43
Similar Austroregiaregis / 25 / 25 / - / 25 / - / - / - / 43
Similar Austroregiahuxleyana / 75 / - / - / - / 25 / - / - / 29
Stenothoesp. A / - / 50 / - / - / - / - / 50 / 29
Similar Aorasp. A / 25 / - / - / - / - / - / - / 14
Tryphositessp. A / - / 75 / - / - / - / - / - / 14
Corophium cf. acherusicum / - / 50 / - / - / - / - / - / 14
Liljeborgiamacrodon / - / 25 / - / - / - / - / - / 14
Lysianassidaesp. A / - / 25 / - / - / - / - / - / 14
Lysianassidaesp. B / - / 25 / - / - / - / - / - / 14
Similar Bircennabircenna / - / 25 / - / - / - / - / - / 14
Similar Paradexamine nana / - / 25 / - / - / - / - / - / 14
Stenothoesp. B / - / 25 / - / - / - / - / - / 14
Hyperiidaesp.A / - / - / - / - / 50 / - / - / 14
Haplocheirasp. A / - / - / - / 25 / - / - / - / 14
AmphipodaNN / 25 / - / - / 25 / 25 / - / - / 43
Number of associatedspecies / 23 / 32 / 10 / 15 / 10 / 3 / 9

Table S5: Relative abundances ± SD of associated taxonomic groups with benthic and floating Macrocystis pyrifera within the molluscs in the Magellan Region. Benthic sampling sites are highlighted in grey. WMS = Western Magellan Strait, BaC = Ballenero Channel, CIII = Carlos III, CMS = Central Magellan Strait, WC = Whiteside Channel, CC = Cockburn Channel, BeaC = Beagle Channel.

Taxonomicgroup / WMS / BaC / CIII / CMS / WC / CC / BeaC
Mollusca / Bivalvia / 56±16 / 46±21 / 96 / 97±6 / 51±46 / 99±1 / 86±16
Shelled Gastropoda / 43±17 / 49±25 / 0 / 3±6 / 6±6 / 0±0 / 2±3
Nudibranchia / 0±1 / 5±5 / 4 / 0±0 / 43±46 / 1±1 / 12±16
Polyplacophora / 0±1 / 0±0 / 0 / 0±0 / 0±0 / 0±0 / 0±0

Table S6: Results of the pairwise test of the analysis of similarities (ANOSIM) on the composition of associated fauna with benthic and floating Macrocystis pyrifera from the different sampling areas in the Magellan Region. The ANOSIM was conducted with abundance data of A) all taxonomic categories and B) amphipod and isopod species. Benthic sampling sites are highlighted in grey. Pairs with significant compositional differences (P < 0.05) are marked in bold. WMS = Western Magellan Strait, BaC = Ballenero Channel, CIII = Carlos III, CMS = Central Magellan Strait, WC = Whiteside Channel, CC = Cockburn Channel, BeaC = Beagle Channel.

A. / B.
Comparedsites / R / P / Comparedsites / R / P
WMS / BaC / 0.927 / 0.029 / CIII / CMS / -0.5 / 1
CMS / WC / 0.625 / 0.029 / BeaC / CC / 0.339 / 0.029
WC / CC / 0.542 / 0.029 / WMS / BaC / 0.365 / 0.057
BeaC / CC / 0.5 / 0.029 / CIII / WC / -0.333 / 0.8
WC / BeaC / 0.417 / 0.029 / WC / BeaC / 0.292 / 0.029
CIII / CMS / -0.417 / 1 / CIII / CC / 0.125 / 0.4
CMS / BeaC / 0.333 / 0.057 / CMS / CC / 0.104 / 0.2
CIII / CC / 0.333 / 0.6 / CMS / WC / 0.083 / 0.257
CIII / WC / -0.333 / 1 / CIII / BeaC / -0.083 / 0.6
CMS / CC / 0.208 / 0.114 / CMS / BeaC / 0.036 / 0.429
CIII / BeaC / -0.083 / 0.6 / WC / CC / 0.031 / 0.371