Journal
MARINE ENVIRONMENTAL RESEARCH
Volume 162, Issue -, Pages -Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.marenvres.2020.105183
Keywords
Chelonia mydas; Ecosystem services; Grazer; Great Barrier Reef; Green turtle; Herbivory; Seagrass; Megaherbivore; Plant-herbivore interactions
Funding
- Australian Research Council [LP160100492]
- Holsworth Wildlife Research Endowment (Ecological Society of Australia)
- National Environment Science Programme Tropical Water Quality Hub
- Australian Government Research Training Program Scholarship
- Australian Research Council [LP160100492] Funding Source: Australian Research Council
Ask authors/readers for more resources
The Great Barrier Reef (GBR) contains extensive seagrass meadows with abundant and diverse herbivore populations. Typically, meadows in the region are multi-species and dominated by fast growing opportunistic seagrass species. However, we know little about how herbivores modify these types of seagrass meadows by grazing. We conducted the first megaherbivore exclusion study in the GBR at Green Island (Queensland) to understand how green turtle grazing structures these multi-species tropical seagrass meadows. After excluding green turtles for three months, we found that grazing only impacted seagrasses at one site, where green turtles created a grazing plot by actively feeding on both above and below ground seagrass structures, a rare observation for the species. Within this grazing plot at the end of the experiment, the un-caged control treatments open to grazing had a 60% reduction in both above and below ground biomass, and shoot height was reduced by 75%, but there was no impact of grazing on the seagrass species mix. Our study shows that grazing plot formation by green turtles occurs in GBR fast growing seagrass communities and reduces both above and below ground seagrass biomass, this behaviour may be targeting elevated leaf nutrients, or nutritional content of rhizomes. This study is the first documented case of grazing plot formation by green turtles in the GBR and suggests that grazing pressure has a major influence on seagrass meadow structure.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available