Coral fragment growth across temperatures (EcoRRAP)

Coral fragment growth for five common species (Acropora hyacinthus, Acropora tenuis, Pocillopora verrucosa, Stylophora pistillata, and Platygyra daedelea) was measured after chronic exposure to temperatures ranging from 19 to 31ºC to quantify thermal-performance curves (TPCs). TPCs are an important tool to make predictions of how future changes in thermal regimes will affect organisms.

Coral colonies were collected in March 2021 in Kelso Reef (-18.44°, 146.99°) (Acropora hyacinthus, Acropora tenuis, Pocillopora verrucosa, and Stylophora pistillata) and No Name Reef (-14.64°, 145.64°) (Acropora hyacinthus and Pocillopora verrucosa) and in March 2022 in Heron Island (-23.44°, 151.91°) (Acropora hyacinthus, Acropora tenuis, Pocillopora verrucosa, Platygyra daedelea, and Stylophora pistillata) and Davies Reef (-18.82°, 147.64°) (Acropora hyacinthus and Pocillopora verrucosa). Colonies were transported to the National Sea Simulator (SeaSim) in the Australian Institute of Marine Science. Nine colonies per species were fragmented into ten small nubbins, each of which was randomnly assigned to a temperature (19, 21, 23, 25, 26, 27, 28, 29, 30, or 31ºC ) and a tank. Each tank had three fragments per species, each from a different colony. All tanks were initially held at 28ºC and temperatures were ramped up or down with a maximum daily change of 0.5ºC until all tanks had reach their target temperatures within 19 days. Fragments were buoyant weighted at the beginning of the experiment and then every second week for six weeks.

Buoyant weight was converted to dry weight using Archimedes' principle.