Surveys were conducted at John Brown’s Beach (57.05 N, 135.37 W), near Sitka, Alaska, USA. Specific site information is included in the file "Tide_Pool_Characteristics.csv" under Supplemental Files.

Sampling and analytical procedures:
We selected 36 tide pools to study and surveyed each using a flexible quadrat with 10cm x 10cm mesh openings. At the beginning of the survey, the perimeter of each tide pool was delineated using a piece of cord, then the pool was drained using a bilge pump and a bucket. The surveyors then laid down the mesh quadrat and used it to measure the total bottom surface area of the tide pool. The surveyor then identified all non-mobile species (sessile invertebrates and algae) present, measured the surface area occupied by each, and, when finished, refilled the tide pool with the previously removed water. This dataset includes only the sessile organism abundance data from the study. See "Related Datasets" section for mobile species data percent cover data.

Known Issues:
There are multiple small gaps in the data. Dead mussels and dead barnacles were not assessed in the first set of surveys. The time of the pools being drained and refilled was not recorded during the surveys between January and May 2019. There were also a pair of tide pools (22 and 23) that were connected, preventing accurate volume measurements from being taken.

WoRMS Taxa Match:

BCO-DMO checked the provided taxonomic names using the World Register of Marine Species Taxa Match tool (WoRMS). All names matched a known name exactly, though two matched an unaccepted synonym. The following are details on the results of the Taxa Match:

in dataset: Petrocelis; accepted name: Mastocarpus. The Petrocelis form of Mastocarpus represents a distinct life-history stage. It remains as a separate classification in the data.
in dataset: Pterosiphonia bipinnata; accepted name: Savoiea bipinnata. This name was changed in the data.

surveys_cover.csv