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Download the protocol documents, field- and laboratory sheets, and data entry spreadsheets from figshare:

Protocol Link
Ulva Assay https://doi.org/10.25573/serc.14717808


Herbivory – consumption of plant or algal tissue – is the first step in (bottom-up) transfer of primary production up the food chain, and often has important (top-down) effects on the biomass and species composition of benthic communities. This protocol provides a simple, standard method to quantify the relative intensity and selectivity of feeding by herbivores in a manner comparable across sites and conditions. Because the plant baits are suspended above the substratum, the method is most useful in tropical habitats where fishes are the main herbivores.

To get started, use the links above to download the protocol, datasheet, and data entry template files.

Measured Parameters

Feeding intensity and selectivity by mobile herbivores (primarily fishes), measured as:

  • Rate of loss of macrophyte (seagrass and macroalgal) baits after 1 hour
  • Rate of loss of macrophyte baits after 24 Hours
  • Community feeding selectivity: relative loss rates of different macrophyte baits

Data submission

Use the data entry template to transfer data from the field datasheets into Excel and then submit data to marinegeo-data@si.edu.

Selected literature

Hay, M.E., 1981. Spatial patterns of grazing intensity on a Caribbean barrier reef: herbivory and algal distribution. Aquatic botany 11:97-109.

Rasher, D.B., Hoey, A.S. and Hay, M.E., 2013. Consumer diversity interacts with prey defenses to drive ecosystem function. Ecology 94:1347-1358.