Methodology:

Data was collected from the shoreline surrounding Rothera Point from depths of from 6, 12 and 20m from rocky substrata and 20m on the soft substrata.

Suction samplers were used on both the rocky and soft substrata.

The data are the biomass data for each species (with its functional group) for each square meter for each of the samples. Please find below some specific precisions for each type of substrata.

**Rocky shore mass data**

4 CSV files for winter and summer ash mass (skeletal mass) and biomass (AFDM). g m-2.

- Rocky_shore_winter_organic_mass.csv Rocky shore winter organic mass (m-2) from Cheshire Island, 6,12 and 20m depth.

- Rocky_shore_summer_organic_mass.csv Rocky shore summer organic mass (m-2) from Cheshire Island, 6,12 and 20m depth.

- Rocky_shore_winter_skeletal_mass.csv Rocky shore winter skeletal mass (m-2) from Cheshire Island, 6,12 and 20m depth.

- Rocky_shore_summer_skeletal_mass.csv Rocky shore summer skeletal mass (m-2) from Cheshire Island, 6,12 and 20m depth

Here are the functional groups for each species

Code, Functional Group

SP, Pioneer sessile suspension

SC, Climax sessile suspension

SS, sedentary suspension

SM, mobile suspension

DC, deposit feeding crawlers

DV, deposit feeding sedentary (soft)

DS, deposit feeding sedentary (hard / shelled)

GC, grazer

PS, scavenger/ predator - sessile soft

PC, scavenger/ predator - sessile hard / shelled

PM, scavenger/ predator - mobile soft

PL, scavenger/ predator - mobile hard / shelled

PA, scavenger/ predator - arthropod

Auto, autotrophic

Parasite, parasites

Flexible, Flexible

The name of each row is given following this nomenclature:

T161 = transect 1, 6m depth, 1st replicate

For rocky samples, data was collected from the shoreline surrounding Rothera Point from depths of from 6, 12 and 20m

**C mass 20m soft hard substrata **

2 files of soft substratum C mass data.

- 20m_soft_substrata_organic_carbon.csv is the soft substratum organic carbon mass (m-2) from both South Cove and Hangar Cove at 20m

- 20m_soft_substrata_skeletal_carbon.csv is the soft substratum skeletal carbon mass (m-2) from both South Cove and Hangar Cove at 20m

Biomass and skeletal g C m-2 for the same functional groupings. Both South Cove, Hangar Cove, winter and summer.

The naming convention for the samples is T1201W is T1=transect 1 (or 2 or 3); 6, 12 or 20 =depth; 1,2 or 3 = replicate number; S,W = summer or winter. Those descriptors appear in the last columns, transect, depth, replicate, season and then 'Site' is the name repeated from the first column.