SBC LTER: Reef: Kelp Forest Community Dynamics: Kelp Forest Data to support "Estimating biomass of benthic kelp forest invertebrates from body size and percent cover"

These data describe quantitative relationships between wet mass and length or wet mass and percent cover, and conversion factors to transform wet mass into dry mass, shell-free and decalcified dry mass, and ash-free dry mass for 84 species of benthic macroinvertebrates common to giant kelp forests in southern California. Data are based on organisms collected from sites in the Santa Barbara Channel between April 2010 and May 2014. These measurements are intended to facilitate the conversion of invertebrate abundance into common metrics of biomass, for quantitative studies of community dynamics, trophic interactions, energy flow and biodiversity. Converting numerical abundance (i.e., organism density) to biomass requires information on the relationship between individual size and biomass. For colonial and small aggregating taxa that are numerous and indistinct, measures of abundance are usually proportional (e.g., percent cover). Hence, converstions are taxa-specific, based on either size or cover, and a variety of metrics of species biomass are included, e.g., wet mass, shell-free wet mass, ash-free dry mass. Data are published in Reed, D. C, J. C. Nelson, S. L. Harrer, and R. J. Miller, Estimating biomass of benthic kelp forest invertebrates from body size and percent cover data. Marine Biology. DOI: 10.1007/s00227-016-2879-x. From the paper abstract: The inability to compare different measures of species abundance (such as density and percent cover) or different metrics of species biomass (such as wet mass and ash-free dry mass) hampers quantitative studies of community dynamics, trophic interactions, energy flow and biodiversity. This has been especially problematic for the dynamic and highly productive communities inhabiting shallow reefs in temperate seas where varied metrics are commonly used to characterize the abundance and biomass of different suites of species. Regressions for all 84 species were highly significant and regression fits were very good for most species. Interspecific differences between regression slopes and between ratios used to convert one metric of mass into another indicate that caution should be used when attempting to estimate biomass using generic relationships or ratios that were developed for other species, even if those species are closely related.