Fig 1.
The Southern Ocean continental shelf around South Georgia, with study sites and major habitat categories of Barnes et al. (2016b).
The habitats are old, outer sediments (blue), young basin sediments (green), fjord and canyons (yellow) and moraines (red).
Table 1.
Functional group categorization of benthos on South Georgia’s shelf.
Fig 2.
Measures of benthic colonization, seabed carbon stocks and functional group partitioning at South Georgia, Southern Ocean.
The plots are benthos density and richness (A) at sample sites, in which the size of point increases with density and the darkness of point increases with richness. Functional group diversity (B) in which size increases with number of functional groups and colour represents which functional group is numerically dominant. Carbon accumulation in benthos (C) in which size increases with C magnitude and the colours represent habitat category of Fig 1. Carbon immobilization and estimate of sequestration (D) in which symbol size increases with magnitude of C immobilization (circles) and sequestration estimate (stars). All data are given in supplementary materials S1 Table.
Fig 3.
Benthic carbon, functional groups and substratum relationships at South Georgia.
Increase in carbon accumulation and immobilization with number of benthos functional groups (A and B respectively). Carbon immobilization with the proportion of substratum which is hard (boulder and cobble rubble) (C). Number of benthos part burial observations with the proportion of substratum which is mixed (boulder and cobbles with mud) (D). The associated ANOVA statistics are F = 84.6, 85.8, 69.6 and 153.1 for Fig 3A-D respectively, all p<0.001.
Table 2.
Carbonaccumulation across macrobenthic functional groups at South Georgia.
The values are GLM ANOVA output, with most significant factor shown in bold. P values are shown (*P< 0.05 and **P< 0.01).
Table 3.
Carbonimmobilisation across macrobenthic functional groups at South Georgia.
The values are GLM ANOVA output, with most significant factor shown in bold. P values are shown (*P< 0.05 and **P< 0.01).
Table 4.
Carbonsequestration across macrobenthic functional groups at South Georgia.
The values are GLM ANOVA output, with most significant factor shown in bold. P values are shown (*P< 0.05 and **P< 0.01).
Table 5.
Carbonburial across macrobenthic functional groups at South Georgia.
The values are GLM ANOVA output, with most significant factor shown in bold. P values are shown (*P< 0.05 and **P< 0.01).
Fig 4.
Non-metric multidimensional scaling (nMDS) ordination of benthos using different habitat and benthos categories.
Each point represents a site from Fig 1. Benthos ordinated by functional groups and displayed in Barnes et al. (2016b) habitat categories (colours in Fig 1)(A). Benthos ordinated by functional groups and displayed in Hogg et al. (2016) habitat categories (B). Benthos ordinated by morphospecies in habitat categories from Barnes et al. (2016q) (C). Benthos ordinated by functional groups, carbon storage and biodiversity characteristics and displayed in Barnes et al. (2016q) habitat categories (D).
Fig 5.
Schematic estimating different carbon storage zones across South Georgia’s continental shelf.
The shades are from lightest grey (low benthos carbon), mid grey (moderate benthos carbon), dark grey (high carbon immobilization but low conversion to sequestration) and black (moderate carbon immobilization but high conversion to sequestration). The black box outlines indicate areas that were not sampled with respect to benthos Carbon characteristics.