Fast-growing oysters show reduced capacity to provide a thermal refuge to intertidal biodiversity at high temperatures

1.Ecosystem engineers that modify the thermal environment experienced by associated organisms might assist in the climate change adaptation of species. This depends upon the ability of ecosystem engineers to persist and continue to ameliorate thermal stress under changing climatic conditions – traits that may display significant intraspecific variation.

2.In the physically stressful intertidal, the complex three-dimensional structure of oysters provides shading and traps moisture during aerial exposure at low tide. We assessed variation in the capacity of a faster- and slower-growing population of the Sydney Rock Oyster, Saccostrea glomerata, to persist, form three-dimensional structure and provide a cool microhabitat to invertebrates under warmer conditions.

3.The two populations of oysters were exposed to a temperature gradient in the field by attaching them to passively warmed white, grey and black stone pavers and their growth, survivorship and colonisation by invertebrates wa...