Coral reefs worldwide are under tremendous stress primarily due to human activities along the coasts. While climate change, over fishing, and coastal development have been implicated as a major cause of coral reef decline, diseases seem to play an increasing role.
Coral reefs are a constant struggle between slow growing corals and fast growing algae, and urchins play a critical role in maintaining that balance given their roles as important grazers. Unfortunately, we have little idea of what drives declines of urchins on reefs, and even fewer clues as to the causes of coral diseases.
Surveillance
We are applying methods used in investigation of animal diseases to corals and urchins. This begins with systematic descriptions of lesions at the gross and microscopic level. For instance, corals respond to insults in one of three basic ways:
1) Discoloration where there is a change in color from normal in the coral tissue. While this often applies to what is known as bleaching (loss of pigmentation and symbiotic algae in the tissues revealing the white skeleton underneath), it can apply to any coral manifesting areas of tissue discoloration (pallor, complete loss of pigment, or change in pigmentation).
2) Another response is tissue loss where there is absence of tissue revealing bare or algae covered skeleton.
The USGS National Wildlife Health Center in collaboration with NOAA and other partners is currently responding to the Florida Reef Tract coral disease outbreak, a disease event affecting the continental United States' only living barrier reef. Learn more about the Florida Reef Track Coral Disease Outbreak.
3) Finally, there are growth anomalies manifesting as abnormal growth of skeleton or tissue. Gross observations are complemented by microscopic examination of tissues.
As for urchins, we are trying to get a better idea of how to monitor their health from a biomedical perspective.
Research
Applying these tools to corals reveals that they, like other animals, are prone to a variety of infectious and non-infectious causes of mortality such as fungi, algae, cyanobacteria, parasitic corals, and ciliates. A significant challenge now is better characterization of host response at the light and electron microscope level along with development of cell markers to better understand pathogenesis of disease. For urchins, we are getting a handle on basic information such as gross and microscopic anatomy and how cells respond to insults.
Resources
Collecting corals for histopathology. A practical guide (English language edition) (Spanish language edition)
Histology Manual for Tripneustes gratilla (Collector Urchin)
Coral Disease Cards: In collaboration with various partners, we have made underwater cards that will help divers describe lesions in corals from Hawaii, American Samoa, and New Caledonia. The cards can be printed on underwater paper or laminated to help divers describe lesions in corals (cards designed to print front to back).
- Coral disease cards American Samoa
- Coral disease cards Hawaii
- Coral disease cards New Caledonia (English language edition)
- Coral Disease cards New Caledonia (French language edition)
Below are publications associated with this topic.
Wound repair in Pocillopora
Emerging coral diseases in Kāne'ohe Bay, O'ahu, Hawai'i (USA): two major disease outbreaks of acute Montipora white syndrome
Effects of Coralliophila violacea on tissue loss in the scleractinian corals Porites spp. depend on host response
Explained and unexplained tissue loss in corals from the Tropical Eastern Pacific
Assessing threats from coral and crustose coralline algae disease on the reefs of New Caledonia
First record of black band disease in the Hawaiian archipelago: response, outbreak, status, virulence, and a method of treatment
Gross and microscopic lesions in corals from Micronesia
Biocontainment practices for coral disease research
Skeletal growth anomalies in corals
Gross and microscopic pathology of hard and soft corals in New Caledonia
Gross and microscopic pathology of lesions in Pocillopora spp. from the subtropical eastern Pacific
- Overview
Coral reefs worldwide are under tremendous stress primarily due to human activities along the coasts. While climate change, over fishing, and coastal development have been implicated as a major cause of coral reef decline, diseases seem to play an increasing role.
Coral reefs are a constant struggle between slow growing corals and fast growing algae, and urchins play a critical role in maintaining that balance given their roles as important grazers. Unfortunately, we have little idea of what drives declines of urchins on reefs, and even fewer clues as to the causes of coral diseases.
Surveillance
We are applying methods used in investigation of animal diseases to corals and urchins. This begins with systematic descriptions of lesions at the gross and microscopic level. For instance, corals respond to insults in one of three basic ways:
1) Discoloration where there is a change in color from normal in the coral tissue. While this often applies to what is known as bleaching (loss of pigmentation and symbiotic algae in the tissues revealing the white skeleton underneath), it can apply to any coral manifesting areas of tissue discoloration (pallor, complete loss of pigment, or change in pigmentation).
2) Another response is tissue loss where there is absence of tissue revealing bare or algae covered skeleton.
The USGS National Wildlife Health Center in collaboration with NOAA and other partners is currently responding to the Florida Reef Tract coral disease outbreak, a disease event affecting the continental United States' only living barrier reef. Learn more about the Florida Reef Track Coral Disease Outbreak.
3) Finally, there are growth anomalies manifesting as abnormal growth of skeleton or tissue. Gross observations are complemented by microscopic examination of tissues.
As for urchins, we are trying to get a better idea of how to monitor their health from a biomedical perspective.
Research
Applying these tools to corals reveals that they, like other animals, are prone to a variety of infectious and non-infectious causes of mortality such as fungi, algae, cyanobacteria, parasitic corals, and ciliates. A significant challenge now is better characterization of host response at the light and electron microscope level along with development of cell markers to better understand pathogenesis of disease. For urchins, we are getting a handle on basic information such as gross and microscopic anatomy and how cells respond to insults.
Resources
Collecting corals for histopathology. A practical guide (English language edition) (Spanish language edition)
Histology Manual for Tripneustes gratilla (Collector Urchin)
Coral Disease Cards: In collaboration with various partners, we have made underwater cards that will help divers describe lesions in corals from Hawaii, American Samoa, and New Caledonia. The cards can be printed on underwater paper or laminated to help divers describe lesions in corals (cards designed to print front to back).
- Coral disease cards American Samoa
- Coral disease cards Hawaii
- Coral disease cards New Caledonia (English language edition)
- Coral Disease cards New Caledonia (French language edition)
- Publications
Below are publications associated with this topic.
Filter Total Items: 36Wound repair in Pocillopora
Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the grosAuthorsJenny Carolina Rodríguez-Villalobos, Thierry M. Work, Luis Eduardo Calderon-AguileraaEmerging coral diseases in Kāne'ohe Bay, O'ahu, Hawai'i (USA): two major disease outbreaks of acute Montipora white syndrome
In March 2010 and January 2012, we documented 2 widespread and severe coral disease outbreaks on reefs throughout Kāne‘ohe Bay, Hawai‘i (USA). The disease, acute Montipora white syndrome (aMWS), manifested as acute and progressive tissue loss on the common reef coral M. capitata. Rapid visual surveys in 2010 revealed 338 aMWS-affected M. capitata colonies with a disease abundance of (mean ± SE) 0.AuthorsGreta S. Aeby, Sean Callahan, Evelyn F. Cox, Christina M. Runyon, Ashley Smith, Frank G. Stanton, Blake Ushijima, Thierry M. WorkEffects of Coralliophila violacea on tissue loss in the scleractinian corals Porites spp. depend on host response
We investigated interactions between the corallivorous gastropod Coralliophila violacea and its preferred hosts Porites spp. Our objectives were to experimentally determine whether tissue loss could progress in Porites during or after Coralliophila predation on corals with and without tissue loss and to histologically document snail predation. In 64% of feeding scars, tissue regenerated within 3 wAuthorsL. Raymundo, Thierry M. Work, R. L. Miller, P.L. Lozada-MisaExplained and unexplained tissue loss in corals from the Tropical Eastern Pacific
Coral reefs rival rainforest in biodiversity, but are declining in part because of disease. Tissue loss lesions, a manifestation of disease, are present in dominant Pocillopora along the Pacific coast of Mexico. We characterized tissue loss in 7 species of Pocillopora from 9 locations (44 sites) spanning southern to northern Mexico. Corals were identified to species, and tissue loss lesions were pAuthorsJenny Carolina Rodriguez-Villalobos, Thierry M. Work, Luis Eduardo Calderon-Aguilera, Hector Reyes-Bonilla, Luis HernándezAssessing threats from coral and crustose coralline algae disease on the reefs of New Caledonia
The present study reports the results of the first quantitative survey of lesions on coral and crustose coralline algae (CCA) on reefs in the lagoon of New Caledonia. Surveys on inshore and offshore reefs were conducted at 13 sites in 2010, with 12 sites resurveyed in 2013. Thirty coral diseases affecting 15 coral genera were found, with low overall disease prevalence (<1%). This study extends theAuthorsGreta S. Aeby, Aline Tribollet, Gregory Lasne, Thierry M. WorkFirst record of black band disease in the Hawaiian archipelago: response, outbreak, status, virulence, and a method of treatment
A high number of coral colonies, Montipora spp., with progressive tissue loss were reported from the north shore of Kaua‘i by a member of the Eyes of the Reef volunteer reporting network. The disease has a distinct lesion (semi-circular pattern of tissue loss with an adjacent dark band) that was first observed in Hanalei Bay, Kaua‘i in 2004. The disease, initially termedMontipora banded tissue losAuthorsGreta S. Aeby, Thierry M. Work, Christina M. Runyon, Amanda Shore-Maggio, Blake Ushijima, Patrick Videau, Silvia Beurmann, Sean M. CallahanGross and microscopic lesions in corals from Micronesia
The authors documented gross and microscopic morphology of lesions in corals on 7 islands spanning western, southern, and eastern Micronesia, sampling 76 colonies comprising 30 species of corals among 18 genera, with Acropora, Porites, and Montipora dominating. Tissue loss comprised the majority of gross lesions sampled (41%), followed by discoloration (30%) and growth anomaly (29%). Of 31 cases oAuthorsThierry M. Work, Greta S. Aeby, Konrad A. HughenBiocontainment practices for coral disease research
No abstract available.AuthorsD. Palic, J. V. Warg, Thierry M. WorkSkeletal growth anomalies in corals
No abstract available.AuthorsThierry M. Work, L.T. Kaczmarsky, E. C. PetersGross and microscopic pathology of hard and soft corals in New Caledonia
We surveyed the reefs of Grande Terre, New Caledonia, for coral diseases in 2010 and 2013. Lesions encountered in hard and soft corals were systematically described at the gross and microscopic level. We sampled paired and normal tissues from 101 and 65 colonies in 2010 and 2013, respectively, comprising 51 species of corals from 27 genera. Tissue loss was the most common gross lesion sampled (40%AuthorsThierry M. Work, Greta S. Aeby, Gregory Lasne, Aline TribolletGross and microscopic pathology of lesions in Pocillopora spp. from the subtropical eastern Pacific
Coral reefs are threatened by a variety of factors including diseases that have caused significant damage in some regions such as in the Caribbean. At present, no data are available on coral diseases in the Mexican Pacific where Pocillopora spp. is a dominant component of coral communities. Here, we describe gross and microscopic morphology of lesions found in pocilloporids at four sites in the MeAuthorsJenny Carolina Rodríguez-Villalobos, Axayácatl Rocha-Olivares, Thierry M. Work, Luis Eduardo Calderon-Aguilera, Jorge Abelardo Cáceres-Martínez