Role of crabs in nutrient cycling and productivity on tropical atolls

Slideshow

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Participants

  • Michael Burnett; PhD Candidate, University of California, Santa Barbara, USA
  • Charlie Braman; PhD Candidate, University of California, Santa Barbara, USA
  • Rayna Ruggeri; Conservation Technician, The Nature Conservancy, USA
  • Michael Bliss; PhD Student, Texas A&M University, USA
  • Hillary Young; Professor, University of California, Santa Barbara, USA
  • Leander Anderegg; Assistant Professor, University of California, Santa Barbara, USA

Methods

Land crabs on atolls remain vastly understudied. Very few studies have quantified how crabs influence nutrient cycling, productivity, or other key ecosystem processes, leaving a major gap in understanding their role. We are using automated “fluxbot” sensors to measure nutrient dynamics, such as carbon content, in soils within 3x3 meter exclosures that prevent crabs from entering. By comparing exclosure plots with open plots, we will evaluate the influence of crab activity on nutrient cycling and ecosystem productivity. This approach will allow us to quantify how crabs shape the flow of energy and nutrients across atoll systems.

Techniques

Soil flux sensors (“fluxbots”), nutrient sampling & stable isotope analyses, exclusion plots, biomass surveys.

Aim

Although the combined biomass of land crabs on this atoll is roughly equivalent to the weight of 20 adult elephants, their ecological role has received far less attention because they lack the charisma of larger megafauna. This project will directly test how critical crabs are to nutrient cycling and productivity in atoll ecosystems, in which our findings will highlight their fundamental importance and support conservation strategies that recognize crabs as key drivers of ecosystem function in island environments.