WAMSI 2 KMRP 1.1.2 Key Ecological Processes - Herbivory

Herbivory is a key ecological process that sustains food webs, and can regulate the biomass of primary producers in an ecosystem. It has long been hypothesized that rates of herbivory are greatest in the tropics, although strong evidence to support this is limited. The aim of this project was to identify the key species of herbivores, to identify the grazing rates of key herbivores, and in conjunction with project WAMSI 2 KMRP Project 2.2.4 (benthic primary productivity) provide estimates of the proportion of production that is consumed by herbivores. The research on herbivory was focused on the islands and coast of the Bardi Jawi Indigenous Protected Area in the Kimberley (Western Australia), encompassing Jalan (Tallon Island) and Iwany (Sunday Island). Focus of the herbivory study was on one type of habitat (seagrass meadows), and the diet of two species of herbivores (golden-lined rabbitfish and green turtle). Four surveys were conducted between October 2014 and April 2016. At these locations the following measurements or collections were made (not all measurements were made during each survey): (1) Rates of herbivory (three surveys). These data are presented in the report for WAMSI KMRP 2.2.4, here the focus is on assessing rates of herbivory as a proportion of primary production; (2) Collections of golden-lined rabbitfish (Siganus lineatus); and (3) Blood samples from green turtles (Chelonia mydas). Ten green turtles were tagged with satellite tags: 4 in April 2015, and 6 in April 2016. This data record only pertains to data held by CSIRO. For access to all other data generated by collaborative research partners of the KMRP 1.1.2 project refer to the additional metadata field.\nLineage: RUV deployments were completed at Jalan and Ngaloon (two of the sites included in measurements of rates of herbivory) to quantify variation in the composition and relative abundance of potential herbivores. These deployments were made during April 2015. On each of three days, ten remote underwater video cameras (GoPro Hero 4 Silver with a waterproof housing, GoPro Inc, San Mateo, California USA) were deployed in meadows of each of the two main species of seagrass, Thalassia hemprichii and Enhalus acoroides. Each camera filmed for 3 to 4 hours during each deployment. Cameras were placed on steel camera frames; each held two cameras facing in opposite directions. Individual frames were separated by at least 25 m. In the laboratory, 34 minutes from each camera during each