Coral Species Susceptibility
Not all coral species are equally susceptible to bleaching. In response to elevated sea temperatures, some corals may immediately show apparent signs of bleaching, while other coral species at the same location may not bleach at all. Furthermore, some corals have revealed the capacity to acclimatize to local temperature increases. Corals that have experienced (and survived) higher temperatures and light levels may be more resistant to bleaching stresses in the future.
From a colony perspective, species that are characterized by fine-structured, branching or tabular growth forms, and thin or well-connected tissue, tend to be less resistant to bleaching.
Coral species that are more susceptible to heat stress are characterized by branching or tabular growth forms, such as Seriatopora and Acropora. Photos left to right: © J. McManus; NOAA
Corals that are less resistant to bleaching tend to be those corals that are quick to colonize free space, are fast growing, and often short-lived. Those less resistant genera include:
- Acropora
- Millepora
- Stylophora
Coral species that are more resistant to bleaching can be characterized by massive growth forms, thick or less-integrated tissues and slow growth rates. Coral genera recognized as more resistant to thermal stress include:
Coral species that are more tolerant of thermal stress have massive growth forms, thick tissues and slow growth rates. Photos © S. Kilarski/TNC
- Acanthastrea
- Porites
- Hydnophora
- Merulina
- Favia
- Goniastrea
- Leptoria
- Montastrea
- Platygyra daedalea
- Cyphastrea
- Galaxae
A general hierarchy of resistance to bleaching provides a reasonable indication of susceptibility to heat stress1,2,3.
| Resistance | Growth type | Coral Family | Examples |
 |
Fine branching; thin or well-connected tissue | Pocilloporidae | Seriatopora |
| Stylophora | |||
| Pocillopora | |||
| Branching, tabulate, encrusting/foliose | Acroporidae | Acropora | |
| Montipora | |||
| Massive, brain | Faviidae | Favia | |
| Favities | |||
| Leptoria | |||
| Goniastrea | |||
| Platgyra | |||
| Massive, boulder; thick or less-integrated tissue | Poritidae | Porites | |
| Goniopora | |||
| Galaxea | |||
| Pavona |
A broad spatial resilience approach is recommended for MPA network site selections. Sites within the network should include corals that exhibit a range of resistant properties. Sites that contain corals exhibiting resistance properties serve as refuges and souces of seed, while sites with more vulnerable species may be vital to connectivty and other ecological dynamics at larger scales. The MPA network approach highights the management of sites with varied resistant properties as critical element within a connected network.