Fig 1.
Sampling locations around Isla de los Estados and Mitre Peninsula.
Red–locations sampled in 1973 and 2018; green– 2018 sampling only. Circles represent exposed locations; triangles represent sheltered locations. Data from GEBCO Compilation Group (2019) GEBCO 2019 Grid (doi:10.5285/836f016a-33be-6ddc-e053-6c86abc0788e) and Natural Earth, free vector and raster map data @ naturalearthdata.com.
Fig 2.
Kelp canopy density from Landsat imagery.
a) Mean proportional kelp canopy density at the trimester time scale for both site (black) and regional (blue) scales. b) Mean proportional kelp canopy density with a 2-year running mean at both the site (black) and regional (blue) scales along with the 2-year running mean of the NOAA Multivariate ENSO Index (MEI), lagged by one year. c) Relationship between the site scale mean proportional kelp canopy density and MEI shown in b. Red line shows the linear fit between the variables. d) Relationship between the regional scale mean proportional kelp canopy density and MEI shown in b. Red line shows the linear fit between the variables.
Fig 3.
Lessonia vadosa at Isla de los Estados, 1973 and 2018.
Table 1.
Benthic community characteristics based on 25 x 2 m transects (50 m2).
IE–Isla de los Estados, MP–Mitre Peninsula. Values are means with standard deviations in parentheses from surveys in 2018.
Table 2.
Top ten invertebrate taxa based on Index of Relative Dominance (IRD).
IRD = % numerical abundance (number of individuals.m-2) x % frequency of occurrence (freq.). Feed. = feeding groups: 1 = passive suspension feeders, 2 –active suspension feeders, 3 = herbivorous browsers, 4 = carnivores, 5 = omnivores, 6 = deposit feeders.
Fig 4.
The bivalve mollusk Gaimardia trapesina growing on the fronds of Macrocystis pyrifera.
Table 3.
Top ten taxa observed on single M. pyrifera plant.
Fronds and stipes = 49.1 kg; holdfast = 3.5 kg. Percentages based on total number of non-colonial individuals (N = 18,770).
Fig 5.
Principle coordinates analysis of benthic invertebrate community composition based on density (number of individuals.m-2) by location and exposure.
Data were ln(x+1)-transformed prior to analyses. Vectors are the relative contribution and direction of influence of benthic components to the observed variation among sites (Pearson Product movement ≥ 0.5).
Table 4.
Comparison of benthic community composition based on density (number of individuals.m-2) between locations and exposures based on permutation-based multivariate analysis of variance (PERMANOVA).
Table 5.
Species of fishes observed during expedition at Isla de los Estados (IE) and Mitre Peninsula (MP).
Pisc = piscivore; Inv = invertivore. Values are mean number of individuals.m-2, with one standard deviation of the mean in parentheses.–means the taxa was not observed. Family names in bold.
Table 6.
Comparison of fish assemblage composition based on density (number of individuals.m-2) between locations and exposures based on permutation-based multivariate analysis of variance (PERMANOVA).
Fig 6.
Principle coordinates analysis of fish assemblage composition based on density (number of individuals.m-2) by location.
Data were ln(x+1)-transformed prior to analyses. Vectors are the relative contribution and direction of influence of fish assemblage components to the observed variation among sites (Pearson Product movement ≥ 0.5). P. = Patagonotothen spp.