An Abundant Mutualist Can Protect Corals From Multiple Stressors

Mutualisms can increase the ability of foundation species to resist individual stressors, but it remains unclear whether mutualisms can also ameliorate co-occurring stressors for habitat-forming species. To examine whether a suspected mutualist could improve foundation species’ resistance to multiple stressors, we tested how a common coral-dwelling crab affected corals exposed to macroalgal contact and physical wounding during a widespread heat stress event using flow-through tanks supplied with seawater from a nearby reef flat. High temperatures on the reef flat, which raised the temperature in our tanks, appeared to trigger rapid tissue loss in experimental corals, but the amount of tissue lost by corals was strongly determined by treatment. Macroalgal contact increased, while the presence of a crab decreased, the amount of tissue lost. Although the effect of wounding was not strong in isolation, when wounding occurred in the presence of a crab, coral survival unexpectedly increased a..., See associated manuscript for method information., , # An abundant mutualist can protect corals from multiple stressors

[https://doi.org/10.5061/dryad.hdr7sqvtd](https://doi.org/10.5061/dryad.hdr7sqvtd)

## Description of the data and file structure

These data were collected as part of a study on the Great Barrier Reef examining the effects of a coral-associated crab on coral health from 2020-2023.

### Files and variables

###### Lead & Corresponding Author Contact Information

```
Name: Julianna Renzi
Institution: University of California, Santa Barbara
Email: [e-mail]
```

## Dataset Overview

This dataset contains the data required to replicate analyses in Renzi et al. (2025), examining the effects of a common coral-dwelling crab on coral health.

### Permitting

All research was conducted on Heron Island, a small (0.29 km^2) coral cay in the Capricorn Bunker sector of the southern Great Barrier Reef (23°25.800'S 151°59.940'E) under Great Barrier Reef Marine Park Authority permit G19/43415.1. We collected all organisms an...