Train Your Eye

The following are training photo galleries to help you identify the type of outbreak or events that are to be reported to Eyes of the Reef Hawai‘i. To fully understand these threats to our reefs, attend a training workshop in your area and become an EOR member.

Each gallery contains many examples of the specific occurrence. Once in a gallery you can browse the thumbnails or click on any photo to be taken to a slideshow where you can see a larger version.

Coral Bleaching


Coral bleaching can be caused by a wide range of environmental stressors such as pollution, oil spills, increased sedimentation, changes in salinity, low oxygen, or disease, but most commonly by increased sea temperatures.  The corals are still alive after bleaching but begin to starve.  If the stressful conditions return to normal rather quickly, the corals may regain their zooxanthellae.  It is important to report bleaching incidents immediately.

Coral Disease

CD_Montipora band diseaseTissue Loss Diseases

Tissue loss diseases can be quite virulent, moving centimeters a day. These diseases are responsible for the decrease in coral cover on many reefs in Hawai‘i. Each disease may have specific pathogens and can spread to neighboring corals so it is important that suspected diseases are reported immediately.

DIS_endohypercropDiscoloration Diseases

Discolorations are often caused by other organisms such as flatworms or fungi. Please report any suspect cases.

GA_montiporatumor600Growth Anomalies

Growth anomalies are occurring more frequently on more species of corals than ever before. Acquaint your eye with these tumorous growths.

Crown-of-Thorn Sea Stars

COTS_caulcotpocciopora Crown-of-Thorn Sea Stars (COTS) are unusually large sea stars that can grow to almost a meter in diameter.  COTS are normally present in small numbers on coral reefs, but when outbreaks occur they can take over coral reefs quickly.

Fish and Other Diseases


Marine Invasives

Invasive species are introduced or native species that respond to changing environmental conditions and overgrow reefs and change natural reef structures and food webs.  Below are some of the most destructive invasive algae and invertebrates found on our local reefs.

  MI_KAP_kappwater2_jenAlien Algae

Alien invasive species are introduced species that have arrived accidentally or intentionally.  Though there are numerous introduced algae species in Hawai‘i, only a few have demonstrated exceptionally dangerous invasive tendencies. Early detection of these species are crucial to reef health.

 MI_INV_CarijoaInvasive2Invasive Invertebrates

Invasive invertebrate species displace other species, negatively changing the biodiversity, natural reef structures, and food webs. In the case of alien species, there often are no natural controls.  It is important to report occurrences of invasive invertebrates to enable possible remediation.

 MI_NS_HN Kara1Native Species Blooms

In stressed or disturbed environments, normally benign native algal and invertebrate species can bloom or grown out of control.  Signs of native blooms include changes in biodiversity, species composition and habitat.  Please report any changes on your local reef.