Dataset: Composition of experimental marine invertebrate communities across latitude

Methodology:

Marine invertebrate communities developed on PVC settlement panels (14 x 14 cm) hung on floating docks one meter below the water surface at local marinas at three coastal sites in each region (Panama, Mexico, California, Alaska). Communities developed for three or 12 months under the following treatments: caged (i.e. reduced predation), partial cage (i.e. procedural cage control; ambient predation) and (c) open (i.e. ambient predation). Caging material had a mesh size of 0.635 cm. These treatments were fully crossed with biomass removals of 0%, approximately 20% (actual 18%, 36cm2) or approximately 60% (actual 54%, 107cm2) panel surface scrapes. On panels assigned a removal treatment, a total of three parallel scrapes or one scrape positioned randomly on the surface of the panel to reach the 60% or 20% surface opening was performed, respectively. Communities that assembled for three months received two removal rounds (1 and 2 months after deployment) while those that assembled for 12 months received five rounds (1, 2, 6, 10, and 11 months after deployment) before the richness of each community was assessed. Experiments were initiated in Alaska in June 2015, California in May 2016, Mexico in June 2017 and Panama in December 2015.

Sampling and analytical procedures:

Following the assigned developmental period and approximately one month after the last biomass removal, communities were retrieved and brought back to a laboratory for assessment.

Sessile marine invertebrates from each community were identified to the lowest taxonomic level possible on a 50-point grid using a stereoscope to generate a measure of percent cover by taxa.