The deep reef refuge hypothesis (DRRH) postulates that mesophotic coral ecosystems (MCEs) may pro... more The deep reef refuge hypothesis (DRRH) postulates that mesophotic coral ecosystems (MCEs) may provide a refuge for shallow coral reefs (SCRs). Understanding this process is an important conservation tool given increasing threats to coral reefs. To establish a better framework to analyze the DRRH, we analyzed stony coral communities in American Sāmoa across MCEs and SCRs to describe the community similarity and species overlap to test the foundational assumption of the DRRH. We suggest a different approach to determine species as depth specialists or generalists that changes the conceptual role of MCEs and emphasizes their importance in conservation planning regardless of their role as a refuge or not. This further encourages a reconsideration of a broader framework for the DRRH. We found 12 species of corals exclusively on MCEs and 183 exclusively on SCRs with another 63 species overlapping between depth zones. Of these, 19 appear to have the greatest potential to serve as reseeding...
In 1917, Alfred Mayor surveyed a 270 m transect on a reef flat on American Samoa. Eleven surveys ... more In 1917, Alfred Mayor surveyed a 270 m transect on a reef flat on American Samoa. Eleven surveys were conducted on the transect from 1917 to 2019. The coral community on the reef crest was resilient over the century, occasionally being seriously damaged but always recovering rapidly. In contrast, the originally most dense coral community on the reef flat has been steadily deteriorating throughout the century. Resilience of coral communities in regions of high wave energy on the reef crests was associated with the important binding function of the crustose coralline alga (CCA) Porolithon onkodes. Successful coral recruits were found on CCA 94% of the time, yet living coral cover correlated negatively with CCA cover as they became alternative winners in competition. Mayor drilled a core from the transect on the surface to the basalt base of the reef 48 m below. Communities on Aua reef were dominated by scleractinians through the Holocene, while cores on another transect 2 km away show...
An annotated checklist of the stony corals (Scleractinia, Milleporidae, Stylasteridae, and Heliop... more An annotated checklist of the stony corals (Scleractinia, Milleporidae, Stylasteridae, and Helioporidae) of American Sāmoa is presented. A total of 377 valid species has been reported from American Sāmoa with 342 species considered either present (251) or possibly present (91). Of these 342 species, 66 have a recorded geographical range extension and 90 have been reported from mesophotic depths (30–150 m). Additionally, four new species records (AcanthastreasubechinataVeron, 2000,FavitesparaflexuosusVeron, 2000,EchinophylliaechinoporoidesVeron & Pichon, 1980,TurbinariairregularisBernard, 1896) are presented. Coral species of concern include species listed under the US Endangered Species Act (ESA) and the International Union for Conservation of Nature’s (IUCN) Red List of threatened species. Approximately 17.5% of the species present or possibly present are categorized as threatened by IUCN compared to 27% of the species globally. American Sāmoa has seven ESA-listed or ESA candidate ...
The deep reef refuge hypothesis (DRRH) postulates that mesophotic coral ecosystems (MCEs) may pro... more The deep reef refuge hypothesis (DRRH) postulates that mesophotic coral ecosystems (MCEs) may provide a refuge for shallow coral reefs (SCRs). Understanding this process is an important conservation tool given increasing threats to coral reefs. To establish a better framework to analyze the DRRH, we analyzed stony coral communities in American Sāmoa across MCEs and SCRs to describe the community similarity and species overlap to test the foundational assumption of the DRRH. We suggest a different approach to determine species as depth specialists or generalists that changes the conceptual role of MCEs and emphasizes their importance in conservation planning regardless of their role as a refuge or not. This further encourages a reconsideration of a broader framework for the DRRH. We found 12 species of corals exclusively on MCEs and 183 exclusively on SCRs with another 63 species overlapping between depth zones. Of these, 19 appear to have the greatest potential to serve as reseeding...
In 1917, Alfred Mayor surveyed a 270 m transect on a reef flat on American Samoa. Eleven surveys ... more In 1917, Alfred Mayor surveyed a 270 m transect on a reef flat on American Samoa. Eleven surveys were conducted on the transect from 1917 to 2019. The coral community on the reef crest was resilient over the century, occasionally being seriously damaged but always recovering rapidly. In contrast, the originally most dense coral community on the reef flat has been steadily deteriorating throughout the century. Resilience of coral communities in regions of high wave energy on the reef crests was associated with the important binding function of the crustose coralline alga (CCA) Porolithon onkodes. Successful coral recruits were found on CCA 94% of the time, yet living coral cover correlated negatively with CCA cover as they became alternative winners in competition. Mayor drilled a core from the transect on the surface to the basalt base of the reef 48 m below. Communities on Aua reef were dominated by scleractinians through the Holocene, while cores on another transect 2 km away show...
An annotated checklist of the stony corals (Scleractinia, Milleporidae, Stylasteridae, and Heliop... more An annotated checklist of the stony corals (Scleractinia, Milleporidae, Stylasteridae, and Helioporidae) of American Sāmoa is presented. A total of 377 valid species has been reported from American Sāmoa with 342 species considered either present (251) or possibly present (91). Of these 342 species, 66 have a recorded geographical range extension and 90 have been reported from mesophotic depths (30–150 m). Additionally, four new species records (AcanthastreasubechinataVeron, 2000,FavitesparaflexuosusVeron, 2000,EchinophylliaechinoporoidesVeron & Pichon, 1980,TurbinariairregularisBernard, 1896) are presented. Coral species of concern include species listed under the US Endangered Species Act (ESA) and the International Union for Conservation of Nature’s (IUCN) Red List of threatened species. Approximately 17.5% of the species present or possibly present are categorized as threatened by IUCN compared to 27% of the species globally. American Sāmoa has seven ESA-listed or ESA candidate ...
A guide to the underwater identification of 79 species of corals in 27 genera that secrete hard s... more A guide to the underwater identification of 79 species of corals in 27 genera that secrete hard skeletons in Wake.
A guide to the underwater identification of 171 species of living stony reef corals in 56 genera ... more A guide to the underwater identification of 171 species of living stony reef corals in 56 genera in Tonga.
A guide to the underwater identification of 48 species of living reef corals in 19 genera that se... more A guide to the underwater identification of 48 species of living reef corals in 19 genera that secrete hard skeletons in Nauru.
Hawai‘I’s corals represent a dazzling array of colors and species and are home to a unique and wo... more Hawai‘I’s corals represent a dazzling array of colors and species and are home to a unique and wonderous underwater ecosystem. Presenting 87 hard coral species and 24 of their relatives, Corals of Hawaii is a comprehensive guide to virtually all currently known species of Hawaiian corals. From reef-building corals, such as hard or stony corals to black corals and soft corals, each is illustrated in glowing color, some for the first time. This field guidebook was designed with the novice and scientist in mind, with several aids to discovering and learning to identify the many species. This second edition presents additional species not presented in the first edition, and in addition has major new sections providing much more information. There are new sections for identifying corals diseases and explaining the formations and variations of Hawaiian reefs. The largest addition is a new section called “Introduction to Coral Reef Ecology.” This new section provides information about coral reefs and their formation, coral biology, and coral reef ecology. This large new section is essentially a coral reef textbook and introduces the reader to many fascinating aspects of coral reefs, both in Hawaii and worldwide. It introduces the reader to the many different groups of organisms on coral reefs, from algae to invertebrates to fish. The many different organisms on coral reefs live together in many different ways which are discussed here. Coral reefs in some parts of the world have declined sharply, but not in other parts, and some reefs have recovered from major damage and others not. The current state of the world’s reefs is reviewed, along with the many things humans do that damage reefs and a few natural events that damage reefs. Some major disturbances on reefs include hurricanes, crown-of-thorns starfish outbreaks, mass coral bleaching, coral diseases, overfishing, sedimentation, and nutrient runoff, all of which are reviewed along with more minor threats. And finally, the ultimate causes of reef decline are presented: overpopulation, overconsumption, and technology. Technology largely caused the problems, and technology can fix them, if we want it to. We CAN save coral reefs, but WILL we??
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This second edition presents additional species not presented in the first edition, and in addition has major new sections providing much more information. There are new sections for identifying corals diseases and explaining the formations and variations of Hawaiian reefs. The largest addition is a new section called “Introduction to Coral Reef Ecology.” This new section provides information about coral reefs and their formation, coral biology, and coral reef ecology. This large new section is essentially a coral reef textbook and introduces the reader to many fascinating aspects of coral reefs, both in Hawaii and worldwide. It introduces the reader to the many different groups of organisms on coral reefs, from algae to invertebrates to fish. The many different organisms on coral reefs live together in many different ways which are discussed here. Coral reefs in some parts of the world have declined sharply, but not in other parts, and some reefs have recovered from major damage and others not. The current state of the world’s reefs is reviewed, along with the many things humans do that damage reefs and a few natural events that damage reefs. Some major disturbances on reefs include hurricanes, crown-of-thorns starfish outbreaks, mass coral bleaching, coral diseases, overfishing, sedimentation, and nutrient runoff, all of which are reviewed along with more minor threats. And finally, the ultimate causes of reef decline are presented: overpopulation, overconsumption, and technology. Technology largely caused the problems, and technology can fix them, if we want it to. We CAN save coral reefs, but WILL we??